Abstract:
Administration of an N-acylated amino acid in association with a penem or carbapenem antibiotic relieves or eliminates the renal problems associated with administration of the antibiotic alone. The amino acid derivative and antibiotic may be formulated together as a composition or administered separately, either simultaneously or sequentially.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This is a continuation-in-part of U.S. patent application Ser. No. 787,609 filed Oct. 15, 1985, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a novel composition comprising a penem or carbapenem antibiotic in association with an amino acid derivative. The invention also provides a method of treating bacterial infections by administering to the patient, simultaneously or sequentially, a penem or carbapenem antibiotic and at least one amino acid derivative selected from a class of acylated amino acids. 
     The class of compounds known as &#34;penem and carbapenem antibiotics&#34; is, of course, very well known and is potentially of great value for the treatment of bacterial infections. Although, as a group, these penem and carbapenem antibiotics exhibit excellent anti-bacterial activity and a variety of other properties which render them highly suitable for pharmaceutical use, they do have a number of disadvantages. One of the problems of these antibiotics is that, in general, they exhibit a degree of renal toxicity, and some degree of kidney damage is a frequent side effect of their use; accordingly, such penem and carbapenem antibiotics should not be used for the treatment of patients with actual or suspected impaired renal function. As a result, the penem and carbapenem antibiotics cannot be used for many patients for whom otherwise they would be the antibiotic of choice. The problem of renal toxicity is particularly acute when the antibiotics are administered by intravenous or intrasmuscular injection in a high dose. 
     We have now surprisingly discovered that the concurrent, or effectively concurrent, administration, with the penem or carbapenem antibiotic, of one or more of a certain class of acylated amino acid derivatives significanty reduces this renal toxicity. 
     EP Publication No. 7614 discloses the use of a dipeptidase inhibitor in association with antibiotics similar to those to which the present invention relates. However, the dipeptidase inhibitors employed are structurally different from the amino acid derivatives of the present invention and are employed for a totally different purpose. The amino acid derivatives employed in the present invention possess little or no dipeptidase inhibitory activity. 
     BRIEF SUMMARY OF INVENTION 
     It is, therefore, an object of the present invention to provide a composition comprising a penem or carbapenem antibiotic having lower renal toxicity than does the antibiotic on its own. 
     It is a further object of the invention to provide a method of treating a bacterial infection in a mammal by administering to said mammal, simultaneously or sequentially, a penem or carbapenem antibiotic and an acylated amino acid derivative. 
     Accordingly, in one aspect, the present invention provides a composition comprising: 
     (a) an antibiotic selected from the group consisting of penem antibiotics and carbapenem antibiotics; and 
     (b) a pharmaceutically acceptable N-acylated derivative of an amino acid wherein the amino group and the carboxylic acid group are attached to a saturated aliphatic carbon chain or carbon atom, or a salt thereof. 
     In another aspect, the invention provides a method of treating a mammal suffering from a bacterial infection by administering to said mammal: 
     (a) an antibiotic selected from the group consisting of penem antibiotics and carbapenem antibiotics; and 
     (b) a pharmaceutically acceptable N-acylated derivative as defined above. 
     DETAILED DESCRIPTION OF INVENTION 
     There is no particular limitation on the nature of the penem or carbapenem antibiotic to which the present invention can be applied and it is believed that the beneficial effects of the concurrent administration of an N-acylated amino acid derivative will be achieved regardless of the particular antibiotic chosen. However, the penem and carbapenem antibiotics which are currently of most actual or potential interest may be represented by the general formula (I): ##STR1## in which: Y represents a sulfur atom, a methylene group or a methylene group having 1 or 2 substituents selected from the group consisting of methyl and methoxy groups; and 
     R 1  represents a C 1  -C 6  alkyl group, a C 1  -C 6  alkyl group having at least one substituent selected from the group consisting of substituents (i) or a heterocyclic group having from 4 to 14 ring atoms of which from 1 to 5 are hetero-atoms selected from the group consisting of nitrogen, oxygen and sulfur atoms where said heterocyclic group is unsubstituted or has at least one substituent selected from the group consisting of substituents (ii): 
     substituents (i): 
     halogen atoms, amino groups, amino groups having at least one substituent selected from the group consisting of substituents (iii), C 1  -C 4  alkylideneamino groups, C 1  -C 4  aminoalkylideneamino groups, amidino groups, amidino groups having from 1 to 3 substituents selected from the group consisting of substituents (iii), heterocyclic groups having from 4 to 14 ring atoms of which from 1 to 5 are hetero-atoms selected from the group consisting of nitrogen, oxygen and sulfur hetero-atoms wherein said heterocyclic group is unsubstituted or has at least one substituent selected from the group consisting of substituents (ii), imino groups, cyano groups, carbamoyl groups and carbamoyl groups having at least one substituent selected from the group consisting of C 1  -C 4  alkyl groups and C 1  -C 4  alkoxy groups; 
     substituents (ii): 
     C 1  -C 6  alkanimidoyl groups, C 1  -C 6  alkyl groups, alkoxyalkyl groups where the alkoxy and alkyl parts are each C 1  -C 4 , carbamoyl groups, carbamoyl groups having at least one substituent selected from the group consisting of C 1  -C 4  alkyl groups and C 1  -C 4  alkoxy groups. C 1  -C 4  haloalkyl groups, heterocyclic acylimidoyl groups where the heterocyclic part has from 5 to 9 ring atoms of which from 1 to 3 are hetero-atoms selected from the group consisting of nitrogen, oxygen and sulfur hetero-atoms, amidino groups, amidino groups having from 1 to 3 substituents selected from the group consisting of substituents (iii), imino groups, oxygen atoms, C 1  -C 6  alkanoyl groups, C 1  -C 6  alkanesulfonyl groups, C 1  -C 6  alkanesulfinyl groups, hydroximino groups, C 1  -C 4  alkoximino groups, carbamoyloxy groups, carbamoyloxy groups having at least one substituent selected from the group consisting of C 1  -C 4  alkyl groups and C.sub. 1 -C 4  alkoxy groups, carbamoyloxyalkyl groups where the alkyl part is C 1  -C 4  and the carbamoyl part is unsubstituted or has at least one substituent selected from the group consisting of C 1  -C 4  alkyl groups and C 1  -C 4  alkoxy groups and C 1  -C 4  iminoalkyl groups; 
     substituents (iii): 
     C 1  -C 6  alkyl groups, C 2  -C 6  alkenyl groups, C 2  -C 6  alkynyl groups, oxygen atoms and said alkyl, alkenyl and alkynyl groups having at least one substituent selected from the group consisting of halogen atoms, carbamoyloxy groups and carbamoyloxy groups having at least one substituent selected from the group consisting of C 1  -C 4  alkyl groups and C 1  -C 4  alkoxy groups. 
     Preferably Y represents a sulfur atom, a methylene group, or the group CH 3  --CH&lt;, CH 3  O--CH&lt; or (CH 3 ) 2  C&lt;. 
     Preferred examples of groups which may be represented by R 1  include the ethyl, 2-fluoroethyl, 2-(aminomethyleneamino)ethyl, N 1 ,N 1  -dimethylamidinomethyl, N 1 ,N 1 ,N 2  -trimethylamidinomethyl, 3-pyrrolidinyl, 1-formimidoyl-3-pyrrolidinyl, 1-acetimidoyl-3-pyrrolidinyl, 1-propionimidoyl-3-pyrrolidinyl, 2-methyl-1,4,5,6-tetrahydro-5-pyrimidinyl, 2-methoxymethyl-1,4,5,6-tetrahydro-5-pyrimidinyl, 3-azetidinyl, 1-acetimidoyl-3-azetidinyl, N 1  -methyl-N 1  -(2-propynyl)amidinomethyl, N 1  -(2-fluoroethyl)-N 1  -methylamidinomethyl, N 1  -(3-fluoropropyl)-N 1  -methylamidinomethyl, N 1  -methyl-N 1  -(2,2,2-trifluoroethyl)amidinomethyl, 1-(3-azetidinyl)ethyl, 1-(1-acetimidoyl-3-azetidinyl)ethyl, 1,4,5,6-tetrahydro-2-pyrimidinylmethyl, 1-(4,5-dihydro-2-thiazolyl)ethyl, 5-carbamoyl-3-pyrrolidinyl, 1-acetimidoyl-5-carbamoyl-3-pyrrolidinyl, 2-chloromethyl-1,4,5,6-tetrahydro-5-pyrimidinyl, 1-butyrimidoyl-3-pyrrolidinyl, 1-nicotinimidoyl-3-pyrrolidinyl, N 1 ,N 1  -diallylamidinomethyl, N 1  -methyl-N 1  -(2-propynyl)amidino, N 1  -(2-fluoroethyl)-N 1  -methylamidino, N 1  -(3-fluoropropyl)-N 1  -methylamidino, N 1  -methyl-N 1  -(2,2,2-trifluoroethyl)amidino, N 1  -allyl-N 1  -methylamidinomethyl, cyanomethyl, 2-cyanoethyl, 1-cyanoethyl, 2-cyano-1-methylethyl, 2-aminoethyl, 1-carbamoylethyl, 2-(1-aminoethylideneamino)ethyl, 1-amidino-3-pyrrolidinyl, 2-methyl-1,3-diazabicyclo[3.3.0]oct-2-en-7-yl, 2-methoxymethyl-1,3-diazabicyclo[3.3.0]oct-2-en-7-yl, 5-imino-2-pyrrolidinyl, 2-imino-5-piperidinyl, 1-acetimidoyl-5-methylcarbamoyl-3-pyrrolidinyl, 1-acetimidoyl-5-methoxycarbamoyl-3-pyrrolidinyl, 2-imino-2-(S-oxothiomorpholino)ethyl, 2-imino-2-(1,1-dioxo-1,3-thiazolidin-3-yl)ethyl, 2-imino-2-(S,S-dioxothiomorpholino)ethyl, 2-imino-2-(3,5-dioxo-1-piperazinyl)ethyl, 2-imino-2-(4-methyl-3,5-dioxo-1-piperazinyl)ethyl, 2-imino-2-(3-oxo-1-piperazinyl)ethyl, 2-imino-2-(4-methyl-3-oxo-1-piperazinyl)ethyl, 2-imino-2-(4-acetyl-3-oxo-1-piperazinyl)ethyl, 2-imino-2-(4-methanesulfonyl-3-oxo-1-piperazinyl)ethyl, N 1  -(2-carbamoyloxyethyl)-N 1  -methylamidinomethyl, 2-(3-hydroximino-1-pyrrolidinyl)-2-iminoethyl, 2-imino-2-(3-methoximino-1-pyrrolidinyl)ethyl, 2-(4-hydroximinopiperidino)-2-iminoethyl, 2-imino-2-(4-methoximinopiperidino)ethyl, 2-(3-carbamoyloxy-1-pyrrolidinyl)-2-iminoethyl, 2-imino-2-(3-oxo-1-piperazinyl)ethyl, 2-(3-carbamoylpiperidino)-2-iminoethyl, 2-(3-carbamoyloxypiperidino)-2-iminoethyl, 2-(2-carbamoyloxy-1-pyrrolidinyl)-2-iminoethyl, 2-(2-carbamoyloxymethyl-1-pyrrolidinyl)-2-iminoethyl, 2-(4-carbamoyloxypiperidino)-2-iminoethyl, 2-(4-formyl-1-piperazinyl)-2-iminoethyl, 2-(4-acetyl-1-piperazinyl)-2-iminoethyl, 1-formyl-3-azetidinyl, 1 -iminomethyl-3-azetidinyl, 1-methyl-4-piperidyl, 1-acetimidoyl-4-piperidyl and 1-acetyl-3-pyrrolidinyl groups. 
     The invention may also be applied to pharmaceutically acceptable salts and esters of such antibiotics, such as are well known in the art. 
     Specific examples of compounds of formula (I) which may be employed in the present invention are those in which R 1  and Y are as defined below: 
     
         ______________________________________Comp. No.   R.sup.1               Y______________________________________ 1.    ##STR2##             CH.sub.2 2.    ##STR3##             CH.sub.2 3.    ##STR4##                          ##STR5## 4.    ##STR6##             CH.sub.2 5.    ##STR7##             S 6.    ##STR8##             CH.sub.2 7.    ##STR9##             CH.sub.2 8.    ##STR10##            CH.sub.2 9.    ##STR11##            CH.sub.210.    ##STR12##            CH.sub.2    ##STR13##            CH.sub.2    ##STR14##            CH.sub.2    ##STR15##            CH.sub.2    ##STR16##            CH.sub.2    ##STR17##            CH.sub.2    ##STR18##            CH.sub.2    ##STR19##            CH.sub.2    ##STR20##            CH.sub.2    ##STR21##            CH.sub.220.    ##STR22##                          ##STR23##    ##STR24##                          ##STR25##    ##STR26##                          ##STR27##    ##STR28##                          ##STR29##    ##STR30##                          ##STR31##    ##STR32##                          ##STR33##    ##STR34##            CH.sub.2    ##STR35##                          ##STR36##    ##STR37##            CH.sub.2    ##STR38##            CH.sub.230.    ##STR39##            CH.sub.2    ##STR40##            CH.sub.2    ##STR41##                          ##STR42##    ##STR43##                          ##STR44##    ##STR45##                          ##STR46##    ##STR47##                          ##STR48##36.     CH.sub.2 CH.sub.3     S37.     CH.sub.2 CH.sub.2 F   S    ##STR49##            S39.     CH.sub.2 CN           S40.    ##STR50##            S    ##STR51##            S42.     CH.sub.2 CH.sub.2 NH.sub.2                         S    ##STR52##            CH.sub.2    ##STR53##            S45.     CH.sub.2 CH.sub.2 CN  CH.sub.2    ##STR54##            CH.sub.2    ##STR55##            CH.sub.2    ##STR56##                          ##STR57##    ##STR58##                          ##STR59##50.    ##STR60##                          ##STR61##    ##STR62##            CH.sub.2    ##STR63##            CH.sub.2    ##STR64##                          ##STR65##    ##STR66##            CH.sub.2    ##STR67##                          ##STR68##    ##STR69##            CH.sub.2    ##STR70##                          ##STR71##    ##STR72##            CH.sub.2    ##STR73##                          ##STR74##60.    ##STR75##            CH.sub.2    ##STR76##                          ##STR77##    ##STR78##            CH.sub.2    ##STR79##                          ##STR80##    ##STR81##            CH.sub.2    ##STR82##                          ##STR83##    ##STR84##            CH.sub.2    ##STR85##                          ##STR86##    ##STR87##                          ##STR88##    ##STR89##            CH.sub.270.    ##STR90##            CH.sub.2    ##STR91##            CH.sub.2    ##STR92##                          ##STR93##    ##STR94##            CH.sub.2    ##STR95##                          ##STR96##    ##STR97##            CH.sub.2    ##STR98##            CH.sub.2    ##STR99##            CH.sub.2    ##STR100##           CH.sub.2    ##STR101##           CH.sub.2______________________________________ 
    
     Of the compounds listed above, we particularly prefer those which have the same configuration as thienamycin, i.e. (5R,6S)-6-[1(R)-hydroxyethyl]. In particular, the following compounds are preferred: 
     (5R,6S)-2-{2-[(aminomethylene)amino]ethylthio}-6-[1(R)-hydroxyethyl]-2-carbapenem-3-carboxylic acid (isomer of Compound No. 1) 
     (5R,6S)-2-[(3S)-1-acetimidoylpyrrolidin-3-ylthio]-6-[1(R)-hydroxyethyl]-2-carbapenem-3-carboxylic acid (isomer of Compound No. 6) 
     (5R,6S)-2-[(3R)-1-acetimidoylpyrrolidin-3-ylthio]-6-[1(R)-hydroxyethyl]-2-carbapenem-3-carboxylic acid (isomer of Compound No. 7) 
     (5R,6S)-2-[(3R)-1-acetimidoylpyrrolidin-3-ylthio]-6-[1(R)-hydroxyethyl]-1(S)-methyl-2-carbapenem-3-carboxylic acid (isomer of Compound No. 23) 
     (5R,6S)-2-[(3S)-1-acetimidoylpyrrolidin-3-ylthio]-6-[1(R)-hydroxyethyl]-1(R)-methyl-2-carbapenem-3-carboxylic acid (isomer of Compound No. 24) 
     (5R,6S)-2-[(3S)-1-acetimidoylpyrrolidin-3-ylthio]-6-[1(R)-hydroxyethyl]-1(S)-methyl-2-carbapenem-3-carboxylic acid (isomer of Compound No. 27) 
     (5R,6S)-2-[(3S)-1-acetimidoyl-5(S)-carbamoylpyrrolidin-3-ylthio]-6-[1(R)-hydroxyethyl]-2-carbapenem-3-carboxylic acid (isomer of Compound No. 28) 
     The above compounds may likewise be employed in the form of their pharmaceutically acceptable salts or esters, examples of which are well-known to those skilled in the art and which are given, for example, in U.S. Pat. No. 4,552,873, the disclosure of which is incorporated herein by reference. 
     The protective effect against renal toxicity appears to be exhibited by the whole range of amino acids wherein the amino and carboxylic acid groups are attached to a saturated aliphatic carbon chain or carbon atom. However, we have found that best results are achieved when employing N-acylated derivatives of those amino acids which may be represented by the formula (II): 
     
         H.sub.2 N--X--COOH                                         (II) 
    
     wherein X represents a C 1  -C 10  alkylene group or a C 1  -C 10  alkylene group having at least one substituent selected from the group consisting of hydroxy groups, C 1  -C 4  alkoxy groups, C 6  -C 14  aryloxy groups, substituted C 6  -C 14  aryloxy groups, C 7  -C 9  aralkyloxy groups, substituted C 7  -C 9  aralkyloxy groups, mercapto groups, C 1  -C 4  alkylthio groups, C 6  -C 14  arylthio groups, substituted C 6  -C 14  arylthio groups, C 7  -C 9  aralkylthio groups, substituted C 7  -C 9  aralkylthio groups, C 2  -C 5  carboxyalkylthio groups, amino groups, amino groups having one or two substituents selected from the group consisting of 
     C 1  -C 4  alkyl groups, C 6  -C 14  aryl groups, substituted C 6  -C 14  aryl groups, C 7  -C 9  aralkyl groups, substituted C 7  -C 9  aralkyl groups and carboxylic acyl groups, 
     C 6  -C 14  aryl groups, substituted C 6  -C 14  aryl groups, carboxy groups, amidino groups, sulfo groups, C 1  -C 4  alkylsulfinyl groups, C 1  -C 4  alkylsulfonyl groups and heterocyclic groups having from 5 to 14 ring atoms of which from 1 to 5 are hetero-atoms selected from the group consisting of nitrogen, oxygen and sulfur atoms, said substituted aryloxy, aralkyloxy, arylthio, aralkylthio, aryl and aralkyl groups having at least one substituent selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups and C 1  -C 4  alkoxy groups. 
     In general terms, the N-acylated derivatives of these amino acids may be represented by the formula (III): 
     
         R.sup.2 HN--X--COOH                                        (III) 
    
     wherein R 2  represents a carboxylic acyl group and X is as defined above. 
     N-acylated derivatives of ornithine and lysine may be represented by the general formula (IV): 
     
         R.sup.4 --NH--(CH.sub.2).sub.n --CH(COOH)NH--R.sup.3       (IV) 
    
     and phenylalanine and phenylglycine derivatives may be represented by the general formula (V): 
     
         Ph--(CH.sub.2).sub.m --CH(COOH)--NHR.sup.2                 (V) 
    
     In the above formulae, n represents the integer 3 or 4, whilst m represents the cypher 0 or the integer 1. 
     Ph represents the phenyl group. 
     R 3  and R 4  are independently selected from the group consisting of hydrogen atoms and carboxylic acyl groups, provided that R 3  and R 4  are not simultaneously hydrogen atoms. 
     Examples of carboxylic acyl groups which may be represented by R 2 , R 3  and R 4  include: 
     alkanoyl groups, and preferably alkanoyl groups having from 1 to 18, more preferably from 1 to 10 and still more preferably from 1 to 8, e.g. from 2 to 5 or from 5 to 8, carbon atoms, for example the acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl, hexanoyl, heptanoyl, octanoyl, nonanoyl and decanoyl groups; in the case of those amino acids (e.g. ornithine, lysine, phenylglycine and phenylalanine) which have relatively bulky and lipophilic groups, lower (e.g. C 2  -C 5 ) alkanoyl groups are preferred; for others (e.g. glycine), higher (e.g. C 5  -C 8 ) groups are preferred; 
     alkenoyl and alkynoyl groups, and more preferably such groups having from 3 to 8, more preferably 3 or 4, carbon atoms, for example the acryloyl, methacryloyl, crotonoyl or propioloyl groups; 
     aromatic acyl groups in which the aryl ring is a carbocyclic ring having from 6 to 14, preferably 6 to 10, carbon atoms and optionally having from 1 to 5, more preferably from 1 to 3, substituents preferably selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, C 1  -C 4  alkoxy groups, amino groups, sulfo groups and halogen atoms, for example the benzoyl and naphthoyl (1- or 2-naphthoyl) groups and the benzoyl and naphthoyl (1- or 2-naphthoyl) groups having one or more of the above substituents, for example the p-toluoyl, m-toluoyl, o-toluoyl, 4-butylbenzoyl, 4-hydroxybenzoyl, 3-hydroxybenzoyl, 2-hydroxybenzoyl, 4-methoxybenzoyl, 3-methoxybenzoyl, 2-methoxybenzoyl, 4-butoxybenzoyl, 4-aminobenzoyl, 3-aminobenzoyl, 2-aminobenzoyl, 3-sulfobenzoyl, 4-chlorobenzoyl, 3-fluorobenzoyl, 2-bromobenzoyl, 3-hydroxy-2-naphthoyl and 1-hydroxy-2-naphthoyl groups; 
     alicyclic acyl groups in which the carbocyclic ring has from 3 to 8 carbon atoms, more preferably from 3 to 6 carbon atoms, and in which the cycloalkane ring is unsubstituted or has at least one substituent selected from the group consisting of C 1  -C 4  alkyl groups and phenyl groups, for example the cyclopropanecarbonyl, cyclobutanecarbonyl, cyclopentanecarbonyl, cyclohexanecarbonyl, 1-phenyl-1-cyclopropanecarbonyl, 1-phenyl-1-cyclopentanecarbonyl, 1-methyl-1-cyclohexanecarbonyl and 1-phenyl-1-cyclohexanecarbonyl groups; 
     araliphatic acyl groups in which the aryl ring is a carbocyclic ring having from 6 to 14, preferably 6 to 10, carbon atoms and optionally having from 1 to 5, more preferably from 1 to 3, substituents preferably selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, C 1  -C 4  alkoxy groups, amino groups, sulfo groups and halogen atoms, and in which the alkyl moiety has from 1 to 4 carbon atoms, such as the phenylacetyl, α-phenyl-α-methylacetyl, α-phenyl-α-ethylacetyl, α,α-diphenylacetyl, α-phenyl-α-cyclopentylacetyl, 3-phenylpropionyl, 4-phenylbutyryl, 4-tolylacetyl, 4-hydroxyphenylacetyl, 4-aminophenylacetyl, 4-methoxyphenylacetyl, 3-sulfophenylacetyl and 4-chlorophenylacetyl groups; 
     heterocyclic acyl groups which may have saturated or unsaturated ring systems, the rings having 5 to 6 ring atoms, of which from 1 to 3 are hetero-atoms independently selected fronm the group consisting of nitrogen, sulfur and oxygen atoms and the ring being unsubstituted or having from 1 to 3 substituents selected from the group consisting of C 1  -C 4  alkyl groups and hydroxy groups, for example the nicotinoyl, 2-thiophenecarbonyl, 2-furoyl, 2-pyrazinecarbonyl, 2-piperidinecarbonyl, N-methylnicotinoyl and 6-hydroxynicotinoyl groups; 
     alkoxycarbonyl groups having a total of from 2 to 7 carbon atoms, for example the methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, t-butoxycarbonyl and pentyloxycarbonyl groups; and 
     aralkyloxycarbonyl groups in which the aralkyl moiety has from 7 to 9 carbon atoms and is unsubstituted or has from 1 to 5, more preferably from 1 to 3, substituents selected from the group consisting of amino groups, C 1  -C 4  alkyl groups, C 1  -C 4  alkoxy groups and hydroxy groups, for example the benzyloxycarbonyl, α-methylbenzyloxycarbonyl, phenethyloxycarbonyl, 3-phenylpropoxycarbonyl, 4-methoxybenzyloxycarbonyl, 4-hydroxybenzyloxycarbonyl, p-tolyloxycarbonyl and 4-aminobenzyloxycarbonyl groups. 
     In addition to the acyl groups listed above, R 2 , R 3  or R 4  can also represent an acyl group derived from an amino acid by removal of OH from the carboxylic acid group and N-acylation of the amino group with at least one of the above-mentioned acyl groups. Hence, R 2 , R 3  and R 4  can also represent such an acyl group connected to the parent amino acid via one or more amino acid residues, preferably from 0 to 5, more preferably from 0 to 3 and most preferably from 0 to 2, such residues. Hence, R 2 , R 3  or R 4  could represent a group derived from an N-acylated amino acid, for example the N-benzoylglycyl or N-benzoylglycylglycyl group. Hence, compounds of formula (I) also include such oligopeptide compounds as N-benzoylglycylglycine, N-benzoylglycylglycylglycine and similar compounds. 
     Preferred examples of groups which may be represented by R 2 , R 3  and R 4  include: saturated aliphatic acyl groups having from 1 to 8 carbon atoms; aromatic acyl groups in which the aryl moiety has from 6 to 10 ring carbon atoms and is unsubstituted or has from 1 to 3 substituents independently selected from the group consisting of C 1  -C 4  alkyl groups and C 1  -C 4  alkoxy groups; alicyclic acyl groups in which the cycloalkane ring has from 3 to 6 carbon atoms; araliphatic acyl groups in which the aryl ring has from 6 to 10 ring carbon atoms and the alkyl group has from 1 to 4 carbon atoms, the aryl ring being unsubstituted or having from 1 to 3 substituents independently selected from the group consisting of C 1  -C 4  alkyl groups and C 1  -C 4  alkoxy groups; heterocyclic acyl groups in which the heterocyclic ring is saturated or unsaturated and has 5 or  6 ring atoms of which one is a nitrogen, sulfur or oxygen hetero-atom; alkoxycarbonyl groups having a total of from 2 to 7 carbon atoms; and aralkyloxycarbonyl groups in which the aralkyl moiety has from 7 to 9 carbon atoms and the aryl ring is unsubstituted or has from 1 to 3 substituents independently selected from the group consisting of C 1  -C 4  alkyl groups and C 1  -C 4  alkoxy groups. 
     Particularly preferred groups which may be represented by R 2 , R 3  and R 4  include: aromatic acyl groups in which the aryl ring has from 6 to 10 ring atoms and which is unsubstituted or has a single substituent selected from the group consisting of C 1  -C 4  alkyl groups, C 1  -C 4  alkoxy groups, hydroxy groups and amino groups; alicyclic acyl groups in which the cycloalkane moiety has from 3 to 6 carbon atoms; phenylaliphatic acyl groups in which the phenyl groups is unsubstituted or has a single C 1  -C 4  alkyl substituent, and in which the alkyl part has from 1 to 4 carbon atoms; alkoxycarbonyl groups having a total of from 4 to 6 carbon atoms; and aralkyloxycarbonyl groups in which the aralkyl part has from 7 to 9 carbon atoms and has 0 or 1 substituent selected from the group consisting of C 1  -C 4  alkyl groups and C 1  -C 4  alkoxy groups. 
     In addition, such acyl groups linked to the amino acid via at least one further amino acid residue are preferred. 
     Of the groups exemplified above, the following are most preferred: acetyl, benzoyl, cyclohexanecarbonyl, cyclopropanecarbonyl, hexanoyl, isobutyryl, crotonoyl, ethoxycarbonyl, 4-hydroxybenzoyl, anisoyl, 4-aminobenzoyl, naphthoxyl, toluoyl, benzyloxycarbonyl and 4-methoxybenzyloxycarbonyl groups, of which the acetyl and benzoyl, particularly benzoyl, groups are most preferred. 
     As explained previously, the lower alkanoyl groups, notably the acetyl group, are only most preferred in relation to their use with those amino acids which have relatively bulky and lipophilic groups. 
     In the compounds of formula (II), X represents an alkylene group having from 1 to 10, preferably from 1 to 8 and more preferably from 1 to 5, carbon atoms. Such groups may have the &#34;free&#34; valencies attached to different carbon atoms or to the same carbon atom. In the latter case, the groups are sometimes referred to as &#34;alkylidene&#34; groups. Examples include the methylene, ethylidene, ethylene, propylidene, 1-methylethylidene, 1-methylethylene, trimethylene, butylidene, 2-methylpropylidene, 1-methylpropylidene, 1,2-dimethylethylene, 1-ethylethylene, 1-methyltrimethylene, 2-methyltrimethylene, tetramethylene, pentylidene, 3-methylbutylidene, 2-methylbutylidene, 2,2-dimethylpropylidene, 1-ethylpropylidene, 1,2-dimethylpropylidene, 1-propylethylene, 1-(1-methylethyl)ethylene, 1-ethyl-2-methylene, 1-ethyltrimethylene, 2-ethyltrimethylene, 1,3-dimethyltrimethylene, 1-methyltetramethylene, 2-methyltetramethylene, pentamethylene, hexylidene, 4-methylpentylidene, 3-methylpentylidene, 2-methylpentylidene, 1-methylpentylidene, 2-ethylbutylidene, 1-ethylbutylidene, 1,3-dimethylbutylidene, 1,2-dimethylbutylidene, 3,3-dimethylbutylidene, 2,3-dimethylbutylidene, 1-butylethylene, 1-methyl-2-propylethylene, 1,2-diethylethylene, 1-methyl-1-propylethylene, 2-propyltrimethylene, 1-ethyl-3-methyltrimethylene, 1-ethyltetramethylene, 2-ethyltetramethylene, 1,3-dimethyltetramethylene, 1-methylpentamethylene, 2-methylpentamethylene, 3-methylpentamethylene, hexamethylene, heptylidene, 5-methylhexylidene, 4-methylhexylidene, 3-methylhexylidene, 1-methylhexylidene, 3-ethylpentylidene, 1-ethylpentylidene, 4,4-dimethylpentylidene, 2,4-dimethylpentylidene, 1,2-dimethylpentylidene, 1-propylbutylidene, 2-ethyl-1-methylbutylidene, 1-ethyl-2-methylbutylidene, 1,2,2-trimethylbutylidene, 1,2,3-trimethylbutylidene, 1-pentylethylene, 1-butyl-2-methylethylene, 1-ethyl-2-propylethylene, 1-butyl-1-methylethylene, 1-ethyl-1-propylethylene, 1-butyltrimethylene, 2-butyltrimethylene, 1,3-diethyltrimethylene, 1-methyl-3-propyltrimethylene, 1-propyltetramethylene, 2-propyltetramethylene, 1-ethyl-4-methyltetramethylene, 3-ethyl-1-methyltetramethylene, 1-ethylpentamethylene, 3-ethylpentamethylene, 1,3-dimethylpentamethylene, 1-methylhexamethylene, 3-methylhexamethylene, heptamethylene, octylidene, 6-methylheptylidene, 4-methylheptylidene, 2-methylheptylidene, 1-methylheptylidene, 4-ethylhexylidene, 3-ethylhexylidene, 2-ethylhexylidene, 1-ethylhexylidene, 3,5-dimethylhexylidene, 4,5-dimethylhexylidene, 2,4-dimethylhexylidene, 1,5-dimethylhexylidene, 1,4-dimethylhexylidene, 2-propylpentylidene, 1-propylpentylidene, 2-ethyl-4-methylpentylidene, 3-ethyl-2-methylpentylidene, 3-ethyl-1-methylpentylidene, 1-ethyl-3-methylpentylidene, 3-methyl-1-propylbutylidene, 2-methyl-1-propylbutylidene, 1-ethyl-2,3-dimethylbutylidene, 1,2-diethylbutylidene, 1-hexylethylene, 1-methyl-2-pentylethylene, 1-butyl-2-ethylethylene, 1,2-dipropylethylene, 1-pentyltrimethylene, 2-pentyltrimethylene, 1-butyl-3-methyltrimethylene, 1-butyl-2-methyltrimethylene, 1-ethyl-3-propyltrimethylene, 1,2-dimethyl-3-propyltrimethylene, 1-butyltetramethylene, 1-methyl-4-propyltetramethylene, 1-propylpentamethylene, 3-propylpentamethylene, 2-ethyl-4-methylpentamethylene, 1-ethylhexamethylene, 3-ethylhexamethylene, 1,3-dimethylhexamethylene, 1-methylheptamethylene, 4-methylheptamethylene and octamethylene groups. 
     The alkylene group represented by X, including those alkylene groups exemplified above, may be unsubstituted or may have at least 1, preferably from 1 to 4 and more preferably 1 or 2, substituents selected from the following groups: 
     hydroxy groups; 
     C 1  -C 4  alkoxy groups, for example the methoxy or ethoxy groups; 
     aryloxy groups in which the aryl ring has from 6 to 14, more preferably from 6 to 10, ring carbon atoms and which is unsubstituted or has from 1 to 5, more preferably from 1 to 3, substituents selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups and C 1  -C 4  alkoxy groups, for example the phenoxy, p-tolyloxy, 4-hydroxyphenoxy, 4-aminophenoxy and 4-methoxyphenoxy groups; 
     C 7  -C 9  aralkyloxy groups in which the aryl ring is unsubstituted or has from 1 to 5, more preferably from 1 to 3, substituents selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups and C 1  -C 4  alkoxy groups, for example the benzyloxy, 4-methylbenzyloxy, 4-hydroxybenzyloxy, 4-aminobenzyloxy and 4-methoxybenzyloxy groups; 
     mercapto groups; 
     C 1  -C 4  alkylthio groups, for example the methylthio or ethylthio groups; 
     arylthio groups in which the aryl ring has from 6 to 14, more preferably from 6 to 10, ring carbon atoms and which is unsubstituted or has from 1 to 5, more preferably from 1 to 3, substituents selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups and C 1  -C 4  alkoxy groups, for example the phenylthio, p-tolylthio, 4-hydroxyphenylthio, 4-aminophenylthio and 4-methoxyphenylthio groups; 
     C 7  -C 9  aralkylthio groups in which the aryl ring is unsubstituted or has from 1 to 5, more preferably from 1 to 3, substituents selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups and C 1  -C 4  alkoxy groups, for example the benzylthio, 4-methylbenzylthio, 4-hydroxybenzylthio, 4-aminobenzylthio and 4-methoxybenzylthio groups; 
     carboxyalkylthio groups having from 1 to 4 carbon atoms in the alkyl moiety, for example the carboxymethylthio and carboxyethylthio groups; 
     amino groups; 
     amino groups having one or two C 1  -C 4  alkyl substituents, for example the methylamino, ethylamino and dimethylamino groups; 
     amino groups having one or two aryl substituents, wherein the aryl ring has from 6 to 14 ring carbon atoms and is unsubstituted or has from 1 to 5, preferbly from 1 to 3, substituents selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups, and C 1  -C 4  alkoxy groups, such as the phenylamino, p-tolylamino, 4-hydroxyphenylamino, 4-aminophenylamino and 4-methoxyphenylamino groups; 
     amino groups having one or two C 7  -C 9  aralkyl substituents wherein the aryl moiety is unsubstituted or has from 1 to 5, preferably from 1 to 3, substituents selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups and C 1  -C 4  alkyl groups, such as the benzylamino, 4-methylbenzylamino, 4-hydroxybenzylamino, 4-aminobenzylamino and 4-methoxybenzylamino groups; 
     amino groups substituted by one or two carboxylic acyl groups as defined in relation to R 2 , R 3  and R 4  ; 
     aryl groups having from 6 to 14 ring carbon atoms, and being unsubstituted or having from 1 to 5, preferably from 1 to 3, substituents selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups and C 1  -C 4  alkoxy groups; 
     carboxy groups; 
     amidino groups; 
     sulfo groups; 
     C 1  -C 4  alkylsulfinyl groups, such as the methanesulfinyl or ethanesulfinyl groups; 
      C 1  -C 4  alkylsulfonyl groups, such as the methanesulfonyl or ethanesulfonyl groups; and 
     heterocyclic groups, such as the pyrrolyl, imidazolyl, pyrazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolazinyl, indolyl and indazolyl groups. 
     Preferred groups which may be represented by X include C 1  -C 5  alkylene groups which are unsubstituted or have one or two substituents independently selected from the group consisting of: hydroxy groups; C 1  -C 4  alkoxy groups; aryloxy groups wherein the aryl ring has from 6 to 14 ring carbon atoms and which is unsubstituted or has from 1 to 3 substituents independently selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups and C 1  -C 4  alkoxy groups; C 7  -C 9  aralkyloxy groups, wherein the aryl moiety is unsubstituted or has from 1 to 3 substituents independently selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups and C 1  -C 4  alkoxy groups; mercapto groups; C 1  -C 4  alkylthio groups; arylthio groups wherein the aryl ring has from 6 to 14 ring carbon atoms and which is unsubstituted or has from 1 to  3 substituents independently selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups and C 1  -C 4  alkoxy groups; C 7  -C 9  aralkylthio groups wherein the aryl ring is unsubstituted or has from 1 to 3 substituents independently selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups and C 1  -C 4  alkoxy groups; carboxyalkylthio groups in which the alkyl part has from 1 to 4 carbon atoms; amino groups; amino groups having one or two C 1  -C 4  alkyl substituents; amino groups having one or two aryl substituents in which the aryl ring has from 6 to 14 ring carbon atoms and is unsubstituted or has from 1 to 3 substituents independently selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups and C 1  -C 4  alkoxy groups; amino groups having one or two C 7  -C 9  aralkyl substituents in which the aryl part is unsubstituted or has from 1 to 3 substituents selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups and C 1  -C 4  alkoxy groups; amino groups having one or two carboxylic acyl substituents as defined in relation to R 2 , R 3  and R 4  ; aryl groups having from 6 to 14 ring carbon atoms and being unsubstituted or having from 1 to 3 substituents selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups and C 1  -C 4  alkoxy groups; carboxy groups; and heterocyclic groups having from 5 to 9 ring atoms, of which from 1 to 3 are hetero-atoms selected from the group consisting of nitrogen, oxygen and sulfur hetero-atoms. 
     More preferred groups which may be represented by X are C 1  -C 5  alkylene groups which are unsubstituted or have 1 or 2 substituents independently selected from the group consisting of: hydroxy groups; C 1  -C 4  alkoxy groups; mercapto groups; C 1  -C 4  alkylthio groups; amino groups; amino groups having one or two C 1  -C 4  alkyl substituents; amino groups having one or two carboxylic acyl substituents as defined for R 2 , R 3  and R 4  ; aryl groups having from 6 to 14 carbon atoms wherein the aryl ring is unsubstituted or has from 1 to 3 substituents selected from the group consisting of C 1  -C 4  alkyl groups, hydroxy groups, amino groups and C 1  -C 4  alkoxy groups; carboxy groups; and heterocyclic groups having from 5 to 9 ring atoms, of which from 1 to 3 are hetero-atoms selected from the group consisting of nitrogen and oxygen hetero-atoms. 
     Preferred amino acids which may be represented by formula (II) include glycine, β-alanine, 4-aminobutyric acid, 5-aminovaleric acid, 6-aminohexanoic acid, 8-aminooctanoic acid, alanine, 2-aminobutyric acid, norvaline, valine, leucine, isoleucine, norleucine, phenylglycine, phenylalanine, tyrosine, O-methyltyrosine, aspartic acid, glutamic acid, 4-carboxyglutamic acid, 3-methylaspartic acid, 2-aminoadipic acid, 2-aminopimelic acid, 2-aminosuberic acid, 3-hydroxyaspartic acid, 3-hydroxyglutamic acid, 2,3-diaminopropionic acid, 2,4-diaminobutyric acid, ornithine, lysine, 5-hydroxylysine, arginine, N.sup.δ,N.sup.δ -dimethylornithine, N.sup.ε -methyllysine, cysteine, methionine, ethionine, S-carboxymethylcysteine, S-benzylcysteine, methionine S-oxide, ethionine S-oxide, methionine S,S-dioxide, cysteic acid, serine, O-methylserine, threonine, O-methylthreonine, homothreonine, ethoxinine (=2-amino-4-ethoxybutyric acid), 3-methoxyvaline, 3-phenylserine, 3-methyl-3-phenylalanine, histidine, tryptophan, 2-methylalanine, 2-methylserine, 2-hydroxyisoleucine, 2-methylmethionine, 2-ethyl-2-phenylglycine, 3-aminobutyric acid, 3-amino-4-methylvaleric acid, 3-amino-3-phenylpropionic acid, 3-amino-2-hydroxypropionic acid and 4-amino-3-hydroxybutyric acid. 
     More preferred amino acids are glycine, β-alanine, 4-aminobutyric acid, 5-aminovaleric acid, 6-aminohexanoic acid, 8-aminooctanoic acid, alanine, norvaline, valine, leucine, isoleucine, norleucine, N.sup.δ,N.sup.δ -dimethylornithine, methionine, ethionine, O-methylserine, O-methylthreonine, ethoxinine, 3-methoxyvaline, 3-phenylserine, 3-methyl-3-phenylalanine, histidine, 2-methylalanine, 2-methylserine, 2-hydroxyisoleucine, 2-ethylphenylglycine, 3-aminobutyric acid, 3-amino-4-methylvaleric acid, 3-amino-3-phenylpropionic acid, ornithine, lysine, phenylalanine and phenylglycine. 
     The most preferred amino acids are β-alanine, 4-aminobutyric acid, 5-aminovaleric acid, 6-aminohexanoic acid, alanine, valine, leucine, norleucine, methionine, histidine, ornithine, glycine, phenylalanine and phenylglycine. 
     When the amino acid derivative is an oligopeptide compound, such as a dipeptide or tripeptide, this type of compound is preferably formed by suitable combination of such amino acids as glycine, β-alanine, 4-aminobutyric acid, 5-aminovaleric acid, 6-aminohexanoic acid, alanine, valine, leucine, norleucine, phenylglycine, phenylalanine, methionine and histidine. Examples include leucylglycine, glycyl-β-alanine, glycylalanine, valylalanine, leucylalanine, glycylvaline, alanylvaline, leucylvaline, valylleucine, phenylalanylleucine, histidylleucine, glycylphenylalanine, alanylphenylalanine, leucylphenylalanine, glycylmethionine, valylmethionine, glycylhistidine, alanylvalylglycine, glycylalanylvaline, glycylphenylalanylleucine and glycylglycylhistidine. 
     Specific examples of the amino acid compounds which may be employed in the present invention are given in the following list. It should, of course, be appreciated that these compounds can exist in the D-, L- and DL-forms and any of these forms can be employed. The compounds are hereinafter referred to by the numbers appended to them in this list. In the case of the mono-acylated derivatives of ornithine or substituted ornithine compounds, the acyl group can be present on either the N.sup.α - or the N.sup.δ -position, whilst, in the case of mono-acylated derivatives of lysine or substituted lysine compounds, the acyl group can be present on either the N.sup.α - or N.sup.ε -position. Of course, the respective individual mono-acylated derivatives or a mixture of the N.sup.α and N.sup.δ or N.sup.α and N.sup.ε derivatives may be used. When the compounds of the invention are hereinafter referred to by the numbers appended to them in the following list, the N.sup.α isomer is identified by the appropriate number followed by the character &#34;α&#34; , the N.sup.δ  isomer is identified by the number followed by &#34;δ&#34; and the N.sup.ε isomer is identified by the number followed by &#34;ε&#34;. Where the number alone is given, a mixture is meant. Where the compound is identified by the number followed by &#34;α/δ&#34; or &#34;α/ε&#34;, this defines specifically the three options: the isolated N.sup.α isomer; the isolated N.sup.δ isomer or N.sup.ε isomer; or a mixture of these two isomers. Other derivatives of amino acids having 2 or more amino groups (e.g. 2,3-diaminopropionic acid, 2,4-diaminobutyric acid and arginine) are identified similarly. 
     1. Glycine derivatives 
     1-1. N-hexanoylglycine 
     1-2. N-heptanoylglycine 
     1-3. N-octanoylglycine 
     1-4. N-nonanoylglycine 
     1-5. N-decanoylglycine 
     1-6. N-(p-toluoyl)glycine 
     1-7. N-(4-methoxybenzoyl)glycine 
     1-8. N-(1-naphthoyl)glycine 
     1-9. N-(1-phenyl-1-cyclohexanecarbonyl)glycine 
     1-10. N-(α,α-diphenylacetyl)glycine 
     1-11. N-(α-phenyl-α-cyclopentylacetyl)glycine 
     1-12. N-butoxycarbonylglycine 
     1-13. N-octanoylleucylglycine 
     1-14. N-benzoylleucylglycine 
     1-15. N-butoxycarbonylleucylglycine 
     1-16. N-octanylalanylvalylglycine 
     1-17. N-benzoylalanylvalylglycine 
     1-18. N-cyclohexanecarbonylalanylvalylglycine 
     1-19. N-butoxycarbonylalanylvalylglycine 
     2. β-Alanine derivatives 
     2-1. N-hexanoyl-β-alanine 
     2-2. N-heptanoyl-β-alanine 
     2-3. N-octanoyl-β-alanine 
     2-4. N-nonanoyl-β-alanine 
     2-5. N-(p-toluoyl)-β-alanine 
     2-6. N-(4-methoxybenzoyl)-β-alanine 
     2-7. N-(3-hydroxy-2-naphthoyl)-β-alanine 
     2-8. N-(1-phenyl-1-cyclopentanecarbonyl)-β-alanine 
     2-9. N-(α,α-diphenylacetyl)-β-alanine 
     2-10. N-(3-phenylpropionyl)-β-alanine 
     2-11. N-(4-phenylbutyryl)-β-alanine 
     2-12. N-(4-methoxyphenylacetyl)-β-alanine 
     2-13. N-t-butoxycarbonyl-β-alanine 
     2-14. N-benzyloxycarbonyl-β-alanine 
     2-15. N-(4-methoxybenzyloxycarbonyl)-β-alanine 
     2-16. N-(4-methylbenzyloxycarbonyl)-β-alanine 
     2-17. N-(α-methylbenzyloxycarbonyl)-β-alanine 
     2-18. N-benzoylglycyl-β-alanine 
     2-19. N-(1-naphthoyl)glycyl-β-alanine 
     2-20. N-cyclohexanecarbonylglycyl-β-alanine 
     2-21. N-benzyloxycarbonylglycyl-β-alanine 
     2-22. N-benzoyl-β-alanine 
     3. 4-Aminobutyric acid derivatives. 
     3-1. N-hexanoyl-4-aminobutyric acid 
     3-2. N-heptanoyl-4-aminobutyric acid 
     3-3. N-benzoyl-4-aminobutyric acid 
     3-4. N-(p-toluoyl)-4-aminobutyric acid 
     3-5. N-(3-methoxybenzoyl)-4-aminobutyric acid 
     3-6. N-cyclopentanecarbonyl-4-aminobutyric acid 
     3-7. N-cyclohexanecarbonyl-4-aminobutyric acid 
     3-8. N-(1-phenyl-1-cyclopropanecarbonyl)-4-aminobutyric acid 
     3-9. N-(1-phenyl-1-cyclopentanecarbonyl)-4-aminobutyric acid 
     3-10. N-phenylacetyl-4-aminobutyric acid 
     3-11. N-(3-phenylpropionyl)-4-aminobutyric acid 
     3-12. N-(p-tolylacetyl)-4-aminobutyric acid 
     3-13. N-nicotinoyl-4-aminobutyric acid 
     3-14. N-butoxycarbonyl-4-aminobutyric acid 
     3-15. N-benzyloxycarbonyl-4-aminobutyric acid 
     3-16. N-(3-phenylpropoxycarbonyl)-4-aminobutyric acid 
     3-17. N-(α-methylbenzyloxycarbonyl)-4-aminobutyric acid 
     3-18. N-(1-naphthoyl)-4-aminobutyric acid 
     4. 5-Aminovaleric acid derivatives 
     4-1. N-butyryl-5-aminovaleric acid 
     4-2. N-isobutyryl-5-aminovaleric acid 
     4-3. N-valeryl-5-aminovaleric acid 
     4-4. N-isovaleryl-5-aminovaleric acid 
     4-5. N-hexanoyl-5-aminovaleric acid 
     4-6. N-benzoyl-5-aminovaleric acid 
     4-7. N-(m-toluoyl)-5-aminovaleric acid 
     4-8. N-(2-methoxybenzoyl)-5-aminovaleric acid 
     4-9. N-cyclopentanecarbonyl-5-aminovaleric acid 
     4-10. N-cyclohexanecarbonyl-5-aminovaleric acid 
     4-11. N-(1-phenyl-1-cyclopropanecarbonyl)-5-aminovaleric acid 
     4-12. N-(1-phenyl-1-cyclohexanecarbonyl)-5-aminovaleric acid 
     4-13. N-phenylacetyl-5-aminovaleric acid 
     4-14. N-(α-phenyl-α-methylacetyl)-5-aminovaleric acid 
     4-15. N-nicotinoyl-5-aminovaleric acid 
     4-16. N-(2-thiophenecarbonyl)-5-aminovaleric acid 
     4-17. N-(2-furoyl)-5-aminovaleric acid 
     4-18. N-isopropoxycarbonyl-5-aminovaleric acid 
     4-19. N-pentyloxycarbonyl-5-aminovaleric acid 
     4-20. N-benzyloxycarbonyl-5-aminovaleric acid 
     4-21. N-(4-methoxybenzyloxycarbonyl)-5-aminovaleric acid 
     4-22. N-(4-methylbenzyloxycarbonyl)-5-aminovaleric acid 
     4-23. N-(4-hydroxyphenylacetyl)-5-aminovaleric acid 
     4-24. N-(N-methylnicotinoyl)-5-aminovaleric acid 
     5. 6-Aminohexanoic acid derivatives. 
     5-1. N-acetyl-6-aminohexanoic acid 
     5-2. N-propionyl-6-aminohexanoic acid 
     5-3. N-butyryl-6-aminohexanoic acid 
     5-4. N-isobutyryl-6-aminohexanoic acid 
     5-5. N-isovaleryl-6-aminohexanoic acid 
     5-6. N-hexanoyl-6-aminohexanoic acid 
     5-7. N-acryloyl-6-aminohexanoic acid 
     5-8. N-methacryloyl-6-aminohexanoic acid 
     5-9. N-crotonoyl-6-aminohexanoic acid 
     5-10. N-propioloyl-6-aminohexanoic acid 
     5-11. N-benzoyl-6-aminohexanoic acid 
     5-12. N-(o-toluoyl)-6-aminohexanoic acid 
     5-13. N-(4-methoxybenzoyl)-6-aminohexanoic acid 
     5-14. N-(4-aminobenzoyl)-6-aminohexanoic acid 
     5-15. N-(1-naphthoyl)-6-aminohexanoic acid 
     5-16. N-cyclobutanecarbonyl-6-aminohexanoic acid 
     5-17. N-cyclopentanecarbonyl-6-aminohexanoic acid 
     5-18. N-cyclohexanecarbonyl-6-aminohexanoic acid 
     5-19. N-phenylacetyl-6-aminohexanoic acid 
     5-20. N-(3-phenylpropionyl)-6-aminohexanoic acid 
     5-21. N-nicotinoyl-6-aminohexanoic acid 
     5-22. N-(2-thiophenecarbonyl)-6-aminohexanoic acid 
     5-23. N-methoxycarbonyl-6-aminohexanoic acid 
     5-24. N-ethoxycarbonyl-6-aminohexanoic acid 
     5-25. N-butoxycarbonyl-6-aminohexanoic acid 
     5-26. N-pentyloxycarbonyl-6-aminohexanoic acid 
     5-27. N-benzyloxycarbonyl-6-aminohexanoic acid 
     5-28. N-phenethyloxycarbonyl-6-aminohexanoic acid 
     5-29. N-(3-phenylpropoxycarbonyl)-6-aminohexanoic acid 
     5-30. N-(4-methoxybenzyloxycarbonyl)-6-aminohexanoic acid 
     5-31. N-(4-methylbenzyloxycarbonyl)-6-aminohexanoic acid 
     5-32. N-(α-methylbenzyloxycarbonyl)-6-aminohexanoic acid 
     5-33. N-(N-methylnicotinoyl)-6-aminohexanoic acid 
     5-34. N-(4-chlorophenylacetyl)-6-aminohexanoic acid 
     6. 8-Aminooctanoic acid derivatives. 
     6-1. N-acetyl-8-aminooctanoic acid 
     6-2. N-valeryl-8-aminooctanoic acid 
     6-3. N-benzoyl-8-aminooctanoic acid 
     6-4. N-(3-hydroxybenzoyl)-8-aminooctanoic acid 
     6-5. N-(3-sulfobenzoyl)-8-aminooctanoic acid 
     6-6. N-cyclopropanecarbonyl-8-aminooctanoic acid 
     6-7. N-(4-aminophenylacetyl)-8-aminooctanoic acid 
     6-8. N-methoxycarbonyl-8-aminooctanoic acid 
     6-9. N-propoxycarbonyl-8-aminooctanoic acid 
     6-10. N-isopropoxycarbonyl-8-aminooctanoic acid 
     6-11. N-benzyloxycarbonyl-8-aminooctanoic acid 
     6-12. N-(4-hydroxybenzyloxycarbonyl)-8-aminooctanoic acid 
     6-13. N-(N-methylnicotinoyl)-8-aminooctanoic acid 
     6-14. N-(6-hydroxynicotinoyl)-8-aminooctanoic acid 
     7. Alanine derivatives. 
     7-1. N-valerylalanine 
     7-2. N-hexanoylalanine 
     7-3. N-benzoylalanine 
     7-4. N-(4-methoxybenzoyl)alanine 
     7-5. N-(1-naphthoyl)alanine 
     7-6. N-(1-phenyl-1-cyclopropanecarbonyl)alanine 
     7-7. N-phenylacetylalanine 
     7-8. N-butoxycarbonylalanine 
     7-9. N-benzyloxycarbonylalanine 
     7-10. N-(α-methylbenzyloxycarbonyl)alanine 
     7-11. N-octanoylglycylalanine 
     7-12. N-benzoylglycylalanine 
     7-13. N-butoxycarbonylglycylalanine 
     7-14. N-benzoylvalylalanine 
     7-15. N-(p-toluoyl)valylalanine 
     7-16. N-cyclopentanecarbonylvalylalanine 
     7-17. N-cyclohexanecarbonylvalylalanine 
     7-18. N-benzyloxycarbonylvalylalanine 
     7-19. N-benzoylleucylalanine 
     7-20. N-(4-methoxybenzoyl)leucylalanine 
     7-21. N-butoxycarbonylleucylalanine 
     7-22. N-benzyloxycarbonylleucylalanine 
     7-23. N-(2-bromobenzoyl)alanine 
     8. 2-Aminobutyric acid derivatives. 
     8-1. N-pivaloyl-2-aminobutyric acid 
     8-2. N-hexanoyl-2-aminobutyric acid 
     8-3. N-heptanoyl-2-aminobutyric acid 
     8-4. N-benzoyl-2-aminobutyric acid 
     8-5. N-(p-toluoyl)-2-aminobutyric acid 
     8-6. N-(1-phenyl-1-cyclopentanecarbonyl)-2-aminobutyric acid 
     8-7. N-(α,α-diphenylacetyl)-2-aminobutyric acid 
     8-8. N-ethoxycarbonyl-2-aminobutyric acid 
     8-9. N-benzyloxycarbonyl-2-aminobutyric acid 
     8-10. N-(4-methoxybenzyloxycarbonyl)-2-aminobutyric acid 
     9. Norvaline derivatives. 
     9-1. N-valerylnorvaline 
     9-2. N-decanoylnorvaline 
     9-3. N-benzoylnorvaline 
     9-4. N-(m-toluoyl)norvaline 
     9-5. N-(3-sulfobenzoyl)norvaline 
     9-6. N-cyclohexanecarbonylnorvaline 
     9-7. N-(1-phenyl-1-cyclohexanecarbonyl)norvaline 
     9-8. N-(α-phenyl-α-ethylacetyl)norvaline 
     9-9. N-(4-methoxyphenylacetyl)norvaline 
     9-10. N-(2-pyrazinecarbonyl)norvaline 
     9-11. N-benzyloxycarbonylnorvaline 
     9-12. N-(4-methylbenzyloxycarbonyl)norvaline 
     10. Valine derivatives. 
     10-1. N-propionylvaline 
     10-2. N-butyrylvaline 
     10-3. N-isobutyrylvaline 
     10-4. N-valerylvaline 
     10-5. N-acryloylvaline 
     10-6. N-methacryloylvaline 
     10-7. N-crotonoylvaline 
     10-8. N-propioloylvaline 
     10-9. N-(2-methoxybenzoyl)valine 
     10-10. N-(4-butoxybenzoyl)valine 
     10-11. N-cyclopentanecarbonylvaline 
     10-12. N-cyclohexanecarbonylvaline 
     10-13. N-(1-phenyl-1-cyclopentanecarbonyl)valine 
     10-14. N-phenylacetylvaline 
     10-15. N-nicotinoylvaline 
     10-16. N-(2-piperidinecarbonyl)valine 
     10-17. N-ethoxycarbonylvaline 
     10-18. N-isopropoxycarbonylvaline 
     10-19. N-t-butoxycarbonylvaline 
     10-20. N-pentyloxycarbonylvaline 
     10-21. N-benzyloxycarbonylvaline 
     10-22. N-(p-tolylacetyl)valine 
     10-23. N-benzoylglycylvaline 
     10-24. N-(p-toluoyl)glycylvaline 
     10-25. N-(1-naphthoyl)glycylvaline 
     10-26. N-cyclopentanecarbonylglycylvaline 
     10-27. N-butoxycarbonylglycylvaline 
     10-28. N-octanoylalanylvaline 
     10-29. N-benzylalanylvaline 
     10-30. N-(p-toluoyl)alanylvaline 
     10-31. N-(4-aminobenzoyl)alanylvaline 
     10-32. N-(1-naphthoyl)alanylvaline 
     10-33. N-cyclohexanecarbonylalanylvaline 
     10-34. N-phenylacetylalanylvaline 
     10-35. N-benzyloxycarbonylalanylvaline 
     10-36. N-benzoylleucylvaline 
     10-37. N-benzoylglycylalanylvaline 
     10-38. N-(p-toluoyl)glycylalanylvaline 
     10-39. N-(1-naphthoyl)glycylalanylvaline 
     10-40. N-cyclopentanecarbonylglycylalanylvaline 
     10-41. N-butoxycarbonylglycylalanylvaline 
     10-42. N-benzyloxycarbonylglycylalanylvaline 
     10-43. N-(N-methylnicotinoyl)valine 
     10-44. N-(3-fluorobenzoyl)valine 
     10-45. N-benzoylvaline 
     11. Leucine derivatives. 
     11-1. N-butyrylleucine 
     11-2. N-isovalerylleucine 
     11-3. N-benzoylleucine 
     11-4. N-(4-butylbenzoyl)leucine 
     11-5. N-(2-hydroxybenzoyl)leucine 
     11-6. N-(3-sulfobenzoyl)leucine 
     11-7. N-cyclopentanecarbonylleucine 
     11-8. N-cyclohexanecarbonylleucine 
     11-9. N-(1-phenyl-1-cyclopropanecarbonyl)leucine 
     11-10. N-phenylacetylleucine 
     11-11. N-nicotinoylleucine 
     11-12. N-ethoxycarbonylleucine 
     11-13. N-benzyloxycarbonylleucine 
     11-14. N-(4-hydroxyphenylacetyl)leucine 
     11-15. N-benzoylvalylleucine 
     11-16. N-ethoxycarbonylvalylleucine 
     11-17. N-benzoylphenylalanylleucine 
     11-18. N-phenylacetylphenylalanylleucine 
     11-19. N-benzyloxycarbonylphenylalanylleucine 
     11-20. N-benzoylhistidylleucine 
     11-21. N-(p-toluoyl)histidylleucine 
     11-22. N-(4-hydroxybenzoyl)histidylleucine 
     11-23. N-(1-naphthoyl)histidylleucine 
     11-24. N-benzoylglycylphenylalanylleucine 
     11-25. N-(4-methoxybenzoyl)glycylphenylalanylleucine 
     11-26. N-phenylacetylglycylphenylalanylleucine 
     11-27. N-t-butoxycarbonylleucine 
     12. Isoleucine derivatives. 
     12-1. N-valerylisoleucine 
     12-2. N-pivaloylisoleucine 
     12-3. N-octanoylisoleucine 
     12-4. N-benzoylisoleucine 
     12-5. N-(3-hydroxybenzoyl)isoleucine 
     12-6. N-cyclopentanecarbonylisoleucine 
     12-7. N-cyclohexanecarbonylisoleucine 
     12-8. N-(1-phenyl-1-cyclopentanecarbonyl)isoleucine 
     12-9. N-phenylacetylisoleucine 
     12-10. N-methoxycarbonylisoleucine 
     12-11. N-propoxycarbonylisoleucine 
     12-12. N-isopropoxycarbonylisoleucine 
     12-13. N-benzyloxycarbonylisoleucine 
     13. Norleucine derivatives. 
     13-1. N-propionylnorleucine 
     13-2. N-valerylnorleucine 
     13-3. N-pivaloylnorleucine 
     13-4. N-nonanoylnorleucine 
     13-5. N-benzoylnorleucine 
     13-6. N-(4-hydroxybenzoyl)norleucine 
     13-7. N-cyclohexanecarbonylnorleucine 
     13-8. N-(1-phenyl-1-cyclopropanecarbonyl)norleucine 
     13-9. N-(α-phenyl-α-ethylacetyl)norleucine 
     13-10. N-ethoxycarbonylnorleucine 
     13-11. N-propoxycarbonylnorleucine 
     13-12. N-t-butoxycarbonylnorleucine 
     13-13. N-benzyloxycarbonylnorleucine 
     14. Ornithine derivatives. 
     14-1α/δ. N-Acetylornithine 
     14-2α/δ. N-Propionylornithine 
     14-3α/δ. N-Butyrylornithine 
     14-4α/δ. N-Isobutyrylornithine 
     14-5α/δ. N-Valerylornithine 
     14-6α/δ. N-Hexanoylornithine 
     14-7α/δ. N-Heptanoylornithine 
     14-8α/δ. N-Octanoylornithine 
     14-9α/δ. N-Nonanoylornithine 
     14-10α/δ. N-Decanoylornithine 
     14-11α/δ. N-Crotonoylornithine 
     14-12α/δ. N-Benzoylornithine 
     14-13α/δ. N-Cyclopropanecarbonylornithine 
     14-14α/δ. N-Cyclohexanecarbonylornithine 
     14-15. N.sup.α,N.sup.δ -Diacetylornithine 
     14-16. N.sup.α,N.sup.δ -Dipropionylornithine 
     14-17. N.sup.α,N.sup.δ -Dibutyrylornithine 
     14-18. N.sup.α,N.sup.δ -Diisobutyrylornithine 
     14-19. N.sup.α,N.sup.δ -Divalerylornithine 
     14-20. N.sup.α,N.sup.δ -Diisovalerylornithine 
     14-21. N.sup.α,N.sup.δ -Dihexanoylornithine 
     14-22. N.sup.α,N.sup.δ -Diheptanoylornithine 
     14-23. N.sup.α,N.sup.δ -Dioctanoylornithine 
     14-24. N.sup.α,N.sup.δ -Dinonanoylornithine 
     14-25. N.sup.α,N.sup.δ -Didecanoylornithine 
     14-26. N.sup.α,N.sup.δ -Dicrotonoylornithine 
     14-27. N.sup.α,N.sup.δ -Dibenzoylornithine 
     14-28. N.sup.α,N.sup.δ -Dicyclopropanecarbonylornithine 
     14-29. N.sup.α,N.sup.δ -Dicyclohexanecarbonylornithine 
     14-30. N.sup.α -Isobutyryl-N.sup.δ -benzoylornithine 
     14-31. N.sup.α -Crotonoyl-N.sup.δ -benzoylornithine 
     14-32. N.sup.α -Cyclopropanecarbonyl-N.sup.δ -isobutyrylornithine 
     14-33. N.sup.α -Cyclohexanecarbonyl-N.sup.δ -crotonoylornithine 
     14-34. N.sup.α -Benzoyl-N.sup.δ -isobutyrylornithine 
     14-35. N.sup.α -Benzoyl-N.sup.δ -crotonoylornithine 
     14-36. N.sup.α -Benzoyl-N.sup.δ -cyclopropanecarbonylornithine 
     14-37. N.sup.α -Benzoyl-N.sup.δ -cyclohexanecarbonylornithine 
     14-38. N.sup.α -Benzoyl-N.sup.δ -acetylornithine 
     14-39. N.sup.α -Benzoyl-N.sup.δ -propionylornithine 
     14-40α/δ. N-Methoxycarbonylornithine 
     14-41α/δ. N-Ethoxycarbonylornithine 
     14-42α/δ. N-Butoxycarbonylornithine 
     14-43. N.sup.α,N.sup.δ -Dimethoxycarbonylornithine 
     14-44. N.sup.α,N.sup.δ -Diethoxycarbonylornithine 
     14-45. N.sup.α,N.sup.δ -Dibutoxycarbonylornithine 
     14-46. N.sup.α -Methoxycarbonyl-N.sup.δ -ethoxycarbonylornithine 
     14-47. N.sup.α -Methoxycarbonyl-N.sup.δ -butoxycarbonylornithine 
     14-48. N.sup.α -Ethoxycarbonyl-N.sup.δ -methoxycarbonylornithine 
     14-49. N.sup.α -Butoxycarbonyl-N.sup.δ -ethoxycarbonylornithine 
     14-50. N.sup.α -Ethoxycarbonyl-N.sup.δ -butyrylornithine 
     14-51. N.sup.α -Ethoxycarbonyl-N.sup.δ -crotonoylornithine 
     14-52. N.sup.α -Ethoxycarbonyl-N.sup.δ -cyclopropanecarbonylornithine 
     14-53. N.sup.α -Ethoxycarbonyl-N.sup.δ -benzoylornithine 
     14-54. N.sup.α -Propionyl-N.sup.δ -ethoxycarbonylornithine 
     14-55. N.sup.α -Benzoyl-N.sup.δ -ethoxycarbonylornithine 
     14-56α/δ. N-(4-Hydroxybenzoyl)ornithine 
     14-57α/δ. N-Anisoylornithine 
     14-58α/δ. N-(4-Aminobenzoyl)ornithine 
     14-59α/δ. N-Naphthoylornithine 
     14-60α/δ. N-(4-Sulfonylbenzoyl)ornithine 
     14-61α/δ. N-Toluoylornithine 
     14-62α/δ. N-Benzyloxycarbonylornithine 
     14-63α/δ. N-(4-Methoxybenzyloxycarbonyl)ornithine 
     14-64. N.sup.α,N.sup.δ -Di(4-hydroxybenzoyl)ornithine 
     14-65. N.sup.α,N.sup.δ -Dianisoylornithine 
     14-66. N.sup.α,N.sup.δ -Di(4-aminobenzoyl)ornithine 
     14-67. N.sup.α,N.sup.δ -Dinaphthoylornithine 
     14-68. N.sup.α -Cyclohexanecarbonyl-N.sup.δ -acetylornithine 
     14-69. N.sup.α,N.sup.δ -Ditoluoylornithine 
     14-70. N.sup.α,N.sup.δ -Dibenzyloxycarbonylornithine 
     24-71. N.sup.α,N.sup.δ -Di(4-methoxybenzyloxycarbonyl)ornithine 
     15. Lysine derivatives. 
     15-1α/ε. N-Acetyllysine 
     15-2α/ε. N-Propionyllysine 
     15-3α/ε. N-Butyryllysine 
     15-4α/ε. N-Isobutyryllysine 
     15-5α/ε. N-Valeryllysine 
     15-6α/ε. N-Hexanoyllysine 
     15-7α/ε. N-Heptanoyllysine 
     15-8α/ε. N-Octanoyllysine 
     15-9α/ε. N-Nonanoyllysine 
     15-10α/ε. N-Decanoyllysine 
     15-11α/ε. N-Crotonoyllysine 
     15-12α/ε. N-Benzoyllysine 
     15-13α/ε. N-Cyclopropanecarbonyllysine 
     15-14α/ε. N-Cyclohexanecarbonyllysine 
     15-15. N.sup.α,N.sup.ε -Diacetyllysine 
     15-16. N.sup.α,N.sup.ε -Dipropionyllysine 
     15-17. N.sup.α,N.sup.ε -Dibutyryllysine 
     15-18. N.sup.α,N.sup.ε -Diisobutyryllysine 
     15-19. N.sup.α,N.sup.ε -Divaleryllysine 
     15-20. N.sup.α,N.sup.ε -Diisovaleryllysine 
     15-21. N.sup.α,N.sup.ε -Dihexanoyllysine 
     15-22. N.sup.α,N.sup.ε -Diheptanoyllysine 
     15-23. N.sup.α,N.sup.ε -Dioctanoyllysine 
     15-24. N.sup.α,N.sup.ε -Dinonanoyllysine 
     15-25. N.sup.α,N.sup.ε -Didecanoyllysine 
     15-26. N.sup.α,N.sup.ε -Dicrotonoyllysine 
     15-27. N.sup.α,N.sup.ε -Dibenzoyllysine 
     15-28. N.sup.α,N.sup.ε -Dicyclopropanecarbonyllysine 
     15-29. N.sup.α,N.sup.ε -Dicyclohexanecarbonyllysine 
     15-30. N.sup.α -Isobutyryl-N.sup.ε -crotonoyllysine 
     15-31. N.sup.α -Isobutyryl-N.sup.ε -benzoyllysine 
     15-32. N.sup.α -Crotonoyl-N.sup.ε -benzoyllysine 
     15-33. N.sup.α -Cyclopropanecarbonyl-N.sup.ε -isobutyryllysine 
     15-34. N.sup.α -Cyclohexanecarbonyl-N.sup.ε -crotonoyllysine 
     15-35. N.sup.α -Cyclopropanecarbonyl-N.sup.ε -cyclohexanecarbonyllysine 
     15-36. N.sup.α -Cyclohexanecarbonyl-N.sup.ε -benzoyllysine 
     15-37. N.sup.α -Benzoyl-N.sup.ε -isobutyryllysine 
     15-38. N.sup.α -Benzoyl-N.sup.ε -crotonoyllysine 
     15-39. N.sup.α -Benzoyl-N.sup.ε -cyclopropanecarbonyllysine 
     15-40. N.sup.α -Benzoyl-N.sup.ε -cyclohexanecarbonyllysine 
     15-41. N.sup.α -Benzoyl-N.sup.ε -acetyllysine 
     15-42. N.sup.α -Benzoyl-N.sup.ε -propionyllysine 
     15-43. N-Methoxycarbonyllysine 
     15-44. N-Ethoxycarbonyllysine 
     15-45. N-Butoxycarbonyllysine 
     15-46. N.sup.α,N.sup.ε -Dimethoxycarbonyllysine 
     15-47. N.sup.α,N.sup.ε -Diethoxycarbonyllysine 
     15-48. N.sup.α,N.sup.ε -Dibutoxycarbonyllysine 
     15-49. N.sup.α -Methoxycarbonyl-N.sup.ε -ethoxycarbonyllysine 
     15-50. N.sup.α -Methoxycarbonyl-N.sup.ε -butoxycarbonyllysine 
     15-51. N.sup.α -Ethoxycarbonyl-N.sup.ε -methoxycarbonyllysine 
     15-52. N.sup.α -Butoxycarbonyl-N.sup.ε -ethoxycarbonyllysine 
     15-53. N.sup.α -Ethoxycarbonyl-N.sup.ε -propionyllysine 
     15-54. N.sup.α -Ethoxycarbonyl-N.sup.ε -crotonoyllysine 
     15-55. N.sup.α -Ethoxycarbonyl-N.sup.ε -cyclohexanecarbonyllysine 
     15-56. N.sup.α -Ethoxycarbonyl-N.sup.ε -benzoyllysine 
     15-57. N.sup.α -Isobutyryl-N.sup.ε -ethoxycarbonyllysine 
     15-58. N.sup.α -Benzoyl-N.sup.ε -ethoxycarbonyllysine 
     15-59α/ε. N-(4-Hydroxybenzoyl)lysine 
     15-60α/ε. N-Anisoyllysine 
     15-61α/ε. N-(4-Aminobenzoyl)lysine 
     15-62α/ε. N-Naphthoyllysine 
     15-63α/ε. N-(4-Sulfonylbenzoyl)lysine 
     15-64α/ε. N-Toluoyllysine 
     15-65α/ε. N-Benzyloxycarbonyllysine 
     15-66α/ε. N-(4-Methoxybenzyloxycarbonyl)lysine 
     15-67. N.sup.α,N.sup.ε -Di(4-hydroxybenzoyl)lysine 
     15-68. N.sup.α,N.sup.ε -Dianisoyllysine 
     15-69. N.sup.α,N.sup.ε -Di(4-aminobenzoyl)lysine 
     15-70. N.sup.α,N.sup.ε -Dinaphthoyllysine 
     15-71. N.sup.α -Cyclohexanecarbonyl-N.sup.ε -acetyllysine 
     15-72. N.sup.α,N.sup.ε -Ditoluoyllysine 
     15-73. N.sup.α,N.sup.ε -Dibenzyloxycarbonyllysine 
     15-74. N.sup.α,N.sup.ε -Di(4-methoxybenzyloxycarbonyl)lysine 
     16. Phenylalanine derivatives. 
     16-1. N-Acetylphenylalanine 
     16-2. N-Benzoylphenylalanine 
     16-3. N-(4-methoxybenzoyl)phenylalanine 
     16-4. N-cyclopropanecarbonylphenylalanine 
     16-5. N-Propionylphenylalanine 
     16-6. N-Butyrylphenylalanine 
     16-7. N-Isobutyrylphenylalanine 
     16-8. N-Valerylphenylalanine 
     16-9. N-Hexanoylphenylalanine 
     16-10. N-Heptanoylphenylalanine 
     16-11. N-Octanoylphenylalanine 
     16-12. N-Nonanoylphenylalanine 
     16-13. N-Decanoylphenylalanine 
     16-14. N-Crotonoylphenylalanine 
     16-15. N-Cyclopropanecarbonylphenylalanine 
     16-16. N-Cyclohexanecarbonylphenylalanine 
     16-17. N-Methoxycarbonylphenylalanine 
     16-18. N-Ethoxycarbonylphenylalanine 
     16-19. N-Butoxycarbonylphenylalanine 
     16-20. N-(4-Hydroxybenzoyl)phenylalanine 
     16-21. N-(4-Sulfobenzoyl)phenylalanine 
     16-22. N-(4-Aminobenzoyl)phenylalanine 
     16-23. N-(1-Naphthoyl)phenylalanine 
     16-24. N-Anisoylphenylalanine 
     16-25. N-(p-Toluoyl)phenylalanine 
     16-26. N-Benzyloxycarbonylphenylalanine 
     16-27. N-(4-Methoxybenzyloxycarbonyl)phenylalanine 
     16-28. N-nicotinoylphenylalanine 
     16-29. N-(2-thiophenecarbonyl)phenylalanine 
     16-30. N-(2-furoyl)phenylalanine 
     16-31. N-benzoylglycylphenylalanine 
     16-32. N-(4-hydroxybenzoyl)glycylphenylalanine 
     16-33. N-(1-naphthoyl)glycylphenylalanine 
     16-34. N-ethoxycarbonylglycylphenylalanine 
     16-35. N-benzyloxycarbonylglycylphenylalanine 
     16-36. N-benzoylalanylphenylalanine 
     16-37. N-(p-toluoyl)alanylphenylalanine 
     16-38. N-(4-hydroxybenzoyl)alanylphenylalanine 
     16-39. N-(4-aminobenzoyl)alanylphenylalanine 
     16-40. N-(1-naphthoyl)alanylphenylalanine 
     16-41. N-benzyloxycarbonylalanylphenylalanine 
     16-42. N-benzoylleucylphenylalanine 
     16-43. N-(4-hydroxybenzoyl)leucylphenylalanine 
     16-44. N-cyclohexanecarbonylleucylphenylalanine 
     16-45. N-benzyloxycarbonylleucylphenylalanine 
     17. Phenylglycine derivatives. 
     17-1. N-Acetylphenylglycine 
     17-2. N-Benzoylphenylglycine 
     17-3. N-Propionylphenylglycine 
     17-4. N-Butyrylphenylglycine 
     17-5. N-Isobutyrylphenylglycine 
     17-6. N-Valerylphenylglycine 
     17-7. N-Hexanoylphenylglycine 
     17-8. N-Heptanoylphenylglycine 
     17-9. N-Octanoylphenylglycine 
     17-10. N-Nonanoylphenylglycine 
     17-11. N-Decanoylphenylglycine 
     17-12. N-Crotonoylphenylglycine 
     17-13. N-Cyclopropanecarbonylphenylglycine 
     17-14. N-Cyclohexanecarbonylphenylglycine 
     17-15. N-Methyoxycarbonylphenylglycine 
     17-16. N-Ethoxycarbonylphenylglycine 
     17-17. N-Butoxycarbonylphenylglycine 
     17-18. N-(4-Hydroxybenzoyl)phenylglycine 
     17-19. N-Anisoylphenylglycine 
     17-20. N-(4-Aminobenzoyl)phenylglycine 
     17-21. N-(1-Naphthoyl)phenylglycine 
     17-22. N-(4-Sulfobenzoyl)phenylglycine 
     17-23. N-(p-Toluoyl)phenylglycine 
     17-24. N-Benzyloxycarbonylphenylglycine 
     17-25. N-(4-Methoxybenzyloxycarbonyl)phenylglycine 
     17-26. N-(4-methoxybenzoyl)phenylglycine 
     17-27. N-nicotinoylphenylglycine 
     17-28. N-(2-thiophenecarbonyl)phenylglycine 
     17-29. N-(2-furoyl)phenylglycine 
     17-30. N-(4-chlorobenzoyl)phenylglycine 
     18. Tyrosine derivatives. 
     18-1. N-benzoyltyrosine 
     18-2. N-(3-methoxybenzoyl)tyrosine 
     18-3. N-cyclohexanecarbonyltyrosine 
     18-4. N-benzyloxycarbonyltyrosine 
     18-5. N-phenethyloxycarbonyltyrosine 
     19. O-Methyltyrosine derivatives. 
     19-1. N-acetyl-O-methyltyrosine 
     19-2. N-propioloyl-O-methyltyrosine 
     19-3. N-benzoyl-O-methyltyrosine 
     19-4. N-(4-aminobenzoyl)-O-methyltyrosine 
     19-5. N-(1-phenyl-1-cyclopentanecarbonyl)-O-methyltyrosine 
     19-6. N-(1-phenyl-1-cyclohexanecarbonyl)-O-methyltyrosine 
     19-7. N-methoxycarbonyl-O-methyltyrosine 
     19-8. N-benzyloxycarbonyl-O-methyltyrosine 
     19-9. N-phenethyloxycarbonyl-O-methyltyrosine 
     20. Aspartic acid derivatives. 
     20-1. N-heptanoylaspartic acid 
     20-2. N-decanoylaspartic acid 
     20-3. N-(4-hydroxybenzoyl)aspartic acid 
     20-4. N-(3-hydroxy-2-napthoyl)aspartic acid 
     20-5. N-(1-phenyl-1-cyclopentanecarbonyl)aspartic acid 
     20-6. N-(1-phenyl-1-cyclohexanecarbonyl)aspartic acid 
     20-7. N-benzyloxycarbonylaspartic acid 
     20-8. N-(4-methoxybenzyloxycarbonyl)aspartic acid 
     21. Glutamic acid derivatives. 
     21-1. N-nonanoylglutamic acid 
     21-2. N-(4-methoxybenzoy)glutamic acid 
     21-3. N-(1-naphthoyl)glutamic acid 
     21-4. N-(1-phenyl-1-cyclopentanecarbonyl)glutamic acid 
     21-5. N-benzyloxycarbonylglutamic acid 
     21-6. N-benzoylglutamic acid 
     22. 4-Carboxyglutamic acid derivatives. 
     22-1. N-heptanoyl-4-carboxyglutamic acid 
     22-2. N-(4-methoxybenzoyl)-4-carboxyglutamic acid 
     22-3. N-(1-naphthoyl)-4-carboxyglutamic acid 
     22-4. N-(1-hydroxy-2-naphthoyl)-4-carboxyglutamic acid 
     22-5. N-phenylacetyl-4-carboxyglutamic acid 
     23. 3-Methylaspartic acid derivatives. 
     23-1. N-octanoyl-3-methylaspartic acid 
     23-2. N-(4-methoxybenzoyl)-3-methylaspartic acid 
     23-3. N-(α-phenyl-α-cyclopentylacetyl)-3-methylaspartic acid 
     24. 2-Aminoadipic acid derivatives. 
     24-1. N-hexanoyl-2-aminoadipic acid 
     24-2. N-benzoyl-2-aminoadipic acid 
     24-3. N-(p-toluoyl)-2-aminoadipic acid 
     24-4. N-(1-naphthoyl)-2-aminoadipic acid 
     24-5. N-(4-phenylbutyryl)-2-aminoadipic acid 
     24-6. N-phenylacetyl-2-aminoadipic acid 
     24-7. N-ethoxycarbonyl-2-aminoadipic acid 
     25. 2-Aminopimelic acid derivatives. 
     25-1. N-valeryl-2-aminopimelic acid 
     25-2. N-benzoyl-2-aminopimelic acid 
     25-3. N-(3-phenylpropionyl)-2-aminopimelic acid 
     25-4. N-methoxycarbonyl-2-aminopimelic acid 
     25-5. N-ethoxycarbonyl-2-aminopimelic acid 
     25-6. N-benzyloxycarbonyl-2-aminopimelic acid 
     26. 2-Aminosuberic acid derivatives. 
     26-1. N-butyryl-2-aminosuberic acid 
     26-2. N-benzoyl-2-aminosuberic acid 
     26-3. N-(1-naphthoyl)-2-aminosuberic acid 
     26-4. N-(α-phenyl-α-cyclopentylacetyl)-2-aminosuberic acid 
     26-5. N-methoxycarbonyl-2-aminosuberic acid 
     26-6. N-propoxycarbonyl-2-aminosuberic acid 
     27. 3-Hydroxyaspartic acid derivatives. 
     27-1. N-(1-naphthoyl)-3-hydroxyaspartic acid 
     27-2. N-(1-phenyl-1-cyclohexanecarbonyl)-3-hydroxyaspartic acid 
     27-3. N-(α-phenyl-α-ethylacetyl)-3-hydroxyaspartic acid 
     28. 3-Hydroxyglutamic acid derivatives. 
     28-1. N-(1-naphthoyl)-3-hydroxyglutamic acid 
     28-2. N-(1-phenyl-1-cyclohexanecarbonyl)-3-hydroxyglutamic acid 
     28-3. N-(α,α-diphenylacetyl)-3-hydroxyglutamic acid 
     29. 2,3-Diaminopropionic acid derivatives. 
     29-1. N.sup.α -hexanoyl-2,3-diaminopropionic acid 
     29-2. N.sup.α -(4-butylbenzoy)-2,3-diaminopropionic acid 
     29-3. N.sup.α,N.sup.β -dibenzoyl-2,3-diaminopropionic acid 
     29-4. N.sup.α -(1-phenyl-1-cyclopentanecarbonyl)-2,3-diaminopropionic acid 
     29-5. N.sup.α -(α-phenyl-α-ethylacetyl)-2,3-diaminopropionic acid 
     30. 2,4-Diaminobutyric acid derivatives. 
     30-1. N.sup.α -(1-naphthoyl)-2,4-diaminobutyric acid 
     30-2. N.sup.α,N.sup.γ -dibenzoyl-2,4-diaminobutyric acid 
     30-3. N.sup.α -(1-phenyl-1-cyclopentanecarbonyl)-2,4-diaminobutyric acid 
     30-4. N.sup.α -(α-phenyl-α-ethylacetyl)-2,4-diaminobutyric acid 
     31. 5-Hydroxylysine derivatives. 
     31-1. N.sup.α -(p-toluoyl)-5-hydroxylysine 
     31-2. N.sup.α,N.sup.δ -dibenzoyl-5-hydroxylysine 
     31-3. N.sup.α -(1-phenyl-1-cyclopentanecarbonyl)-5-hydroxylysine 
     31-4. N.sup.α -(α-phenyl-α-cyclopentylacetyl)-5-hydroxylysine 
     31-5. N.sup.α -(1-phenyl-1-cyclopentanecarbonyl)-5-hydroxylysine 
     32. Arginine derivatives. 
     32-1. N.sup.α -heptanoylarginine 
     32-2. N.sup.α -(2-methoxybenzoyl)arginine 
     33. N.sup.δ,N.sup.δ -Dimethylornithine derivatives. 
     33-1. N.sup.α -pivaloyl-N.sup.δ,N.sup.δ -dimethylornithine 
     33-2. N.sup.α -octanoyl-N.sup.δ,N.sup.δ -dimethylornithine 
     33-3. N.sup.α -acryloyl-N.sup.δ,N.sup.δ -dimethylornithine 
     33-4. N.sup.α -benzoyl-N.sup.δ,N.sup.δ -dimethylornithine 
     33-5. N.sup.α -(4-hydroxybenzoyl)-N.sup.δ,N.sup.δ -dimethylornithine 
     33-6. N.sup.α -cyclohexanecarbonyl-N.sup.δ,N.sup.δ -dimethylornithine 
     33-7. N.sup.α -(α-phenyl-α-methylacetyl)-N.sup.δ,N.sup.δ -dimethylornithine 
     33-8. N.sup.α -ethoxycarbonyl-N.sup.δ,N.sup.δ -dimethylornithine 
     33-9. N.sup.α -butoxycarbonyl-N.sup.δ,N.sup.δ -dimethylornithine 
     33-10. N.sup.α -benzyloxycarbonyl-N.sup.δ,N.sup.δ -dimethylornithine 
     34. N.sup.ε -Methyllysine derivatives. 
     34-1. N.sup.α -hexanoyl-N.sup.ε -methyllysine 
     34-2. N.sup.α -nonanoyl-N.sup.ε -methyllysine 
     34-3. N.sup.α -acryloyl-N.sup.ε -methyllysine 
     34-4. N.sup.α -benzoyl-N.sup.ε -methyllysine 
     34-5. N.sup.α -(4-butoxybenzoyl)-N.sup.ε -methyllysine 
     34-6. N.sup.α -(3-sulfobenzoyl)-N.sup.ε -methyllysine 
     34-7. N.sup.α -cyclobutanecarbonyl-N.sup.ε -methyllysine 
     34-8. N.sup.α -cyclohexanecarbonyl-N.sup.ε -methyllysine 
     34-9. N.sup.α -phenylacetyl-N.sup.ε -methyllysine 
     34-10. N.sup.α -propoxycarbonyl-N.sup.ε -methyllysine 
     34-11. N.sup.α -isopropoxycarbonyl-N.sup.ε -methyllysine 
     34-12. N.sup.α -benzyloxycarbonyl-N.sup.ε -methyllysine 
     35. Cysteine derivatives. 
     35-1. N-phenylacetylcysteine 
     36. Methionine derivatives. 
     36-1. N-valerylmethionine 
     36-2. N-acryloylmethionine 
     36-3. N-methacryloylmethionine 
     36-4. N-benzoylmethionine 
     36-5. N-(p-toluoyl)methionine 
     36-6. N-(4-methoxybenzoyl)methionine 
     36-7. N-(4-aminobenzoyl)methionine 
     36-8. N-cyclopentanecarbonylmethionine 
     36-9. N-cyclohexanecarbonylmethionine 
     36-10. N-(1-phenyl-1-cyclohexanecarbonyl)methionine 
     36-11. N-phenylacetylmethionine 
     36-12. N-(α-phenyl-α-methylacetyl)methionine 
     36-13. N-methoxycarbonylmethionine 
     36-14. N-ethoxycarbonylmethionine 
     36-15. N-butoxycarbonylmethionine 
     36-16. N-benzyloxycarbonylmethionine 
     36-17. N-(4-methylbenzyloxycarbonyl)methionine 
     36-18. N-benzoylglycylmethionine 
     36-19. N-(4-methoxybenzoyl)glycylmethionine 
     36-20. N-benzyloxycarbonylglycylmethionine 
     36-21. N-benzoylvalylmethionine 
     36-22. N-cyclopentanecarbonylvalylmethionine 
     36-23. N-ethoxycarbonylvalylmethionine 
     37. Ethionine derivatives. 
     37-1. N-butyrylethionine 
     37-2. N-benzoylethionine 
     37-3. N-(p-toluoyl)ethionine 
     37-4. N-(m-toluoyl)ethionine 
     37-5. N-(4-butylbenzoyl)ethionine 
     37-6. N-(4-hydroxybenzoyl)ethionine 
     37-7. N-(4-aminobenzoyl)ethionine 
     37-8. N-(3-sulfobenzoyl)ethionine 
     37-9. N-(1-phenyl-1-cyclopropanecarbonyl)ethionine 
     37-10. N-phenylacetylethionine 
     37-11. N-methoxycarbonylethionine 
     37-12. N-ethoxycarbonylethionine 
     37-13. N-benzyloxycarbonylethionine 
     37-14. N-(4-methoxybenzyloxycarbonyl)ethionine 
     37-15. N-cyclohexanecarbonylethionine 
     38. S-Carboxymethylcysteine derivatives. 
     38-1. N-propionyl-S-carboxymethylcysteine 
     38-2. N-acryloyl-S-carboxymethylcysteine 
     38-3. N-benzoyl-S-carboxymethylcysteine 
     38-4. N-(p-toluoyl)-S-carboxymethylcysteine 
     38-5. N-(4-methoxybenzoyl)-S-carboxymethylcysteine 
     38-6. N-(4-butoxybenzoy)-S-carboxymethylcysteine 
     38-7. N-cyclohexanecarbonyl-S-carboxymethylcysteine 
     38-8. N-(1-phenyl-1-cyclopentanecarbonyl)-S-carboxymethylcysteine 
     38-9. N-(α-methylbenzyloxycarbonyl)-S-carboxymethylcysteine 
     39. S-Benzylcysteine derivatives. 
     39-1. N-benzoyl-S-benzylcysteine 
     39-2. N-(4-hydroxybenzoy)-S-benzylcysteine 
     39-3. N-(3-sulfobenzoyl)-S-benzylcysteine 
     39-4. N-cyclopropanecarbonyl-S-benzylcysteine 
     39-5. N-methoxycarbonyl-S-benzylcysteine 
     39-6. N-ethoxycarbonyl-S-benzylcysteine 
     39-7. N-propoxycarbonyl-S-benzylcysteine 
     39-8. N-(4-hydroxybenzyloxycarbonyl)-S-benzylcysteine 
     40. Methionine S-oxide derivatives. 
     40-1. N-(p-toluoyl)methionine S-oxide 
     40-2. N-pentyloxycarbonylmethionine S-oxide 
     40-3. N-benzyloxycarbonylmethionine S-oxide 
     41. Ethionine S-oxide derivatives. 
     41-1. N-benzoylethionine S-oxide 
     41-2. N-benzyloxycarbonylethionine S-oxide 
     42. Methionine S,S-dioxide derivatives. 
     42-1. N-(1-naphthoyl)methione S,S-dioxide 
     42-2. N-cyclohexanecarbonylmethionine S,S-dioxide 
     42-3. N-pentyloxycarbonylmethionine S,S-dioxide 
     43. Cysteic acid derivatives. 
     43-1. N-(p-toluoyl)cysteic acid 
     43-2. N-(1-naphthoyl)cysteic acid 
     43-3. N-(3-hydroxy-2-naphthoyl)cysteic acid 
     43-4. N-(1-phenyl-1-cyclohexanecarbonyl)cysteic acid 
     44. Serine derivatives. 
     44-1. N-octanoylserine 
     44-2. N-benzoylserine 
     44-3. N-(m-toluoyl)serine 
     44-4. N-(4-methoxybenzoyl)serine 
     44-5. N-(1-naphthoyl)serine 
     44-6. N-(1-phenyl-1-cyclopentanecarbonyl)serine 
     44-7. N-benzyloxycarbonylserine 
     44-8. N-(α-methylbenzyloxycarbonyl)serine 
     45. O-methylserine derivatives. 
     45-1. N-valeryl-O-methylserine 
     45-2. N-benzoyl-O-methylserine 
     45-3. N-cyclohexanecarbonyl-O-methylserine 
     45-4. N-phenylacetyl-O-methylserine 
     45-5. N-(α-phenyl-α-methylacetyl)-O-methylserine 
     45-6. N-(3-phenylpropionyl)-O-methylserine 
     45-7. N-phenethyloxycarbonyl-O-methylserine 
     46. Threonine derivatives. 
     46-1. N-hexanoylthreonine 
     46-2. N-nonanoylthreonine 
     46-3. N-benzoylthreonine 
     46-4. N-(3-hydroxy-2-naphthoyl)threonine 
     46-5. N-cyclohexanecarbonylthreonine 
     46-6. N-(α,α-diphenylacetyl)threonine 
     46-7. N-butoxycarbonylthreonine 
     46-8. N-benzyloxycarbonylthreonine 
     46-9. N-(4-methoxybenzyloxycarbonyl)threonine 
     47. O-Methylthreonine derivatives. 
     47-1. N-butyryl-O-methylthreonine 
     47-2. N-(4-methoxybenzoyl)-O-methylthreonine 
     47-3. N-(1-naphthoyl)-O-methylthreonine 
     47-4. N-(1-phenyl-1-cyclopentanecarbonyl)-O-methylthreonine 
     47-5. N-ethoxycarbonyl-O-methylthreonine 
     47-6. N-(3-phenylpropoxycarbonyl)-O-methylthreonine 
     48. Homoserine derivatives. 
     48-1. N-heptanoylhomoserine 
     48-2. N-benzoylhomoserine 
     48-3. N-(3-methoxybenzoyl)homoserine 
     48-4. N-(α-phenyl-α-cyclopentylacetyl)homoserine 
     48-5. N-(4-hydroxybenzyloxycarbonyl)homoserine 
     48-6. N-(4-methylbenzyloxycarbonyl)homoserine 
     49. Ethoxinine derivatives. 
     49-1. N-benzoylethoxinine 
     49-2. N-(4-butoxybenzoyl)ethoxinine 
     49-3. N-cyclohexanecarbonylethoxinine 
     49-4. N-methoxycarbonylethoxinine 
     50. 3-Methoxyvaline derivatives. 
     50-1 N-isovaleryl-3-methoxyvaline 
     50-2. N-(p-toluoyl)-3-methoxyvaline 
     50-3. N-(1-naphthoyl)-3-methoxyvaline 
     50-4. N-cyclopentanecarbonyl-3-methoxyvaline 
     50-5. N-cyclohexanecarbonyl-3-methoxyvaline 
     50-6. N-methoxycarbonyl-3-methoxyvaline 
     50-7. N-ethoxycarbonyl-3-methoxyvaline 
     51. 3-Phenylserine derivatives. 
     51-1. N-propionyl-3-phenylserine 
     51-2. N-(4-aminobenzoyl)-3-phenylserine 
     51-3. N-(1-naphthoyl)-3-phenylserine 
     51-4. N-benzoyl-3-phenylserine 
     51-5. N-cyclohexanecarbonyl-3-phenylserine 
     51-6. N-phenylacetyl-3-phenylserine 
     51-7. N-methoxycarbonyl-3-phenylserine 
     51-8. N-butoxycarbonyl-3-phenylserine 
     51-9. N-benzyloxycarbonyl-3-phenylserine 
     51-10. N-(α-methylbenzyloxycarbonyl)-3-phenylserine 
     52. 3-Methyl-3-phenylalanine derivatives. 
     52-1. N-acetyl-3-methyl-3-phenylalanine 
     52-2. N-hexanoyl-3-methyl-3-phenylalanine 
     52-3. N-benzoyl-3-methyl-3-phenylalanine 
     52-4. N-(4-aminobenzoyl)-3-methyl-3-phenylalanine 
     52-5. N-(3-sulfobenzoyl)-3-methyl-3-phenylalanine 
     52-6. N-cyclobutanecarbonyl-3-methyl-3-phenylalanine 
     52-7. N-cyclopentanecarbonyl-3-methyl-3-phenylalanine 
     52-8. N-phenylacetyl-3-methyl-3-phenylalanine 
     52-9. N-isopropoxycarbonyl-3-methyl-3-phenylalanine 
     52-10. N-butoxycarbonyl-3-methyl-3-phenylalanine 
     52-11. N-(4-aminobenzyloxycarbonyl)-3-methyl-3-phenylalanine 
     53. Histidine derivatives. 
     53-1. N-acetylhistidine 
     53-2. N-hexanoylhistidine 
     53-3. N-acryloylhistidine 
     53-4. N-methacryloylhistidine 
     53-5. N-benzoylhistidine 
     53-6. N-(p-toluoyl)histidine 
     53-7. N-(4-methoxybenzoyl)histidine 
     53-8. N-(4-butoxybenzoyl)histidine 
     53-9. N-cyclopentanecarbonylhistidine 
     53-10. N-cyclohexanecarbonylhistidine 
     53-11. N-(1-phenyl-1-cyclopentanecarbonyl)histidine 
     53-12. N-phenylacetylhistidine 
     53-13. N-(α-phenyl-α-cyclopentylacetyl)histidine 
     53-14. N-(4-methoxybenzyloxycarbonyl)histidine 
     53-15. N-benzoylglycylhistidine 
     53-16. N-(4-butylbenzoyl)glycylhistidine 
     53-17. N-phenylacetylglycylhistidine 
     53-18. N-ethoxycarbonylglycylhistidine 
     53-19. N-benzyloxycarbonylglycylhistidine 
     53-20. N-benzoylglycylglycylhistidine 
     53-21. N-ethoxycarbonylglycylglycylhistidine 
     53-22. N-benzyloxycarbonylglycylglycylhistidine 
     53-23. N-t-butoxycarbonylhistidine 
     54. Tryptophan derivatives. 
     54-1. N-(4-hydroxybenzoyl)tryptophan 
     54-2. N-benzyloxycarbonyltryptophen 
     55. 2-Methylalanine derivatives. 
     55-1. N-propionyl-2-methylalanine 
     55-2. N-benzoyl-2-methylalanine 
     55-3. N-(m-toluoyl)-2-methylalanine 
     55-4. N-(3-methoxybenzoyl)-2-methylalanine 
     55-5. N-cyclobutanecarbonyl-2-methylalanine 
     55-6. N-phenylacetyl-2-methylalanine 
     55-7. N-phenethyloxycarbonyl-2-methylalanine 
     56. 2-Methylserine derivatives. 
     56-1. N-valeryl-2-methylserine 
     56-2. N-octanoyl-2-methylserine 
     56-3. N-benzoyl-2-methylserine 
     56-4. N-(o-toluoyl)-2-methylserine 
     56-5. N-(4-methoxybenzoyl)-2-methylserine 
     56-6. N-(1-naphthoyl)-2-methylserine 
     56-7. N-cyclopentanecarbonyl-2-methylserine 
     56-8. N-(α,α-diphenylacetyl)-2-methylserine 
     56-9. N-pentyloxycarbonyl-2-methylserine 
     57. 2-Hydroxyisoleucine derivatives. 
     57-1. N-valeryl-2-hydroxyisoleucine 
     57-2. N-heptanoyl-2-hydroxyisoleucine 
     57-3. N-benzoyl-2-hydroxyisoleucine 
     57-4. N-(4-butoxybenzoyl)-2-hydroxyisoleucine 
     57-5. N-(3-hydroxy-2-naphthoyl)-2-hydroxyisoleucine 
     57-6. N-cyclohexanecarbonyl-2-hydroxyisoleucine 
     57-7. N-phenylacetyl-2-hydroxyisoleucine 
     58. 2-Methylmethionine derivatives. 
     58-1 N-hexanoyl-2-methylmethionine 
     58-2. N-benzoyl-2-methylmethionine 
     58-3. N-(4-hydroxybenzoyl)-2-methylmethionine 
     58-4. N-propoxycarbonyl-2-methylmethionine 
     58-5. N-isopropoxycarbonyl-2-methylmethionine 
     59. 2-Ethyl-2-phenylglycine derivatives. 
     59-1. N-acetyl-2-ethyl-2-phenylglycine 
     59-2. N-butyryl-2-ethyl-2-phenylglycine 
     59-3. N-(3-sulfobenzoyl)-2-ethyl-2-phenylglycine 
     59-4. N-ethoxycarbonyl-2-ethyl-2-phenylglycine 
     59-5. N-propoxycarbonyl-2-ethyl-2-phenylglycine 
     60. 3-Aminobutyric acid derivatives. 
     60-1. N-hexanoyl-3-aminobutyric acid 
     60-2. N-benzoyl-3-aminobutyric acid 
     60-3. N-(4-methoxybenzoyl)-3-aminobutyric acid 
     60-4. N-(3-sulfobenzoyl)-3-aminobutyric acid 
     60-5. N-(1-naphthoyl)-3-aminobutyric acid 
     60-6. N-cyclopropanecarbonyl-3-aminobutyric acid 
     60-7. N-(α,α-diphenylacetyl)-3-aminobutyric acid 
     60-8. N-(4-phenylbutyl)-3-aminobutyric acid 
     60-9. N-(α-methylbenzyloxycarbonyl)-3-aminobutyric acid 
     61. 3-Amino-4-methylvaleric acid derivatives. 
     61-1. N-valeryl-3-amino-4-methylvaleric acid 
     61-2. N-isovaleryl-3-amino-4-methylvaleric acid 
     61-3. N-heptanoyl-3-amino-4-methylvaleric acid 
     61-4. N-benzoyl-3-amino-4-methylvaleric acid 
     61-5. N-(m-toluoyl)-3-amino-4-methylvaleric acid 
     61-6. N-(3-sulfobenzyl)-3-amino-4-methylvaleric acid 
     61-7. N-(1-naphthoyl)-3-amino-4-methylvaleric acid 
     61-8. N-phenylacetyl-3-amino-4-methylvaleric acid 
     61-9. N-(3-phenylpropionyl)-3-amino-4-methylvaleric acid 
     61-10. N-butoxycarbonyl-3-amino-4-methylvaleric acid 
     61-11. N-(4-methylbenzyloxycarbonyl)-3-amino-4-methylvaleric acid 
     62. 3-Amino-3-phenylpropionic acid derivatives. 
     62-1. N-butyryl-3-amino-3-phenylpropionic acid 
     62-2. N-valeryl-3-amino-3-phenylpropionic acid 
     62-3. N-benzoyl-3-amino-3-phenylpropionic acid 
     62-4. N-(4-aminobenzoyl)-3-amino-3-phenylpropionic acid 
     62-5. N-cyclopropanecarbonyl-3-amino-3-phenylpropionic acid 
     62-6. N-cyclobutanecarbonyl-3-amino-3-phenylpropionic acid 
     62-7. N-cyclopentanecarbonyl-3-amino-3-phenylpropionic acid 
     62-8. N-methoxycarbonyl-3-amino-3-phenylpropionic acid 
     62-9. N-propoxycarbonyl-3-amino-3-phenylpropionic acid 
     62-10. N-butoxycarbonyl-3-amino-3-phenylpropionic acid 
     62-11. N-(4-aminobenzyloxycarbonyl)-3-amino-3-phenylpropionic acid 
     63. 3-Amino-2-hydroxypropionic acid derivatives. 
     63-1. N-valeryl-3-amino-2-hydroxypropionic acid 
     63-2. N-heptanoyl-3-amino-2-hydroxypropionic acid 
     63-3. N-benzoyl-3-amino-2-hydroxypropionic acid 
     63-4. N-(3-methoxybenzoyl)-3-amino-2-hydroxypropionic acid 
     63-5. N-cyclohexanecarbonyl-3-amino-2-hydroxypropionic acid 
     63-6. N-benzyloxycarbonyl-3-amino-2-hydroxypropionic acid 
     63-7. N-(3-phenylpropoxycarbonyl)-3-amino-2-hydroxypropionic acid 
     64. 4-Amino-3-hydroxybutyric acid 
     64-1. N-isobutyryl-4-amino-3-hydroxybutyric acid 
     64-2. N-decanol-4-amino-3-hydroxybutyric acid 
     64-3. N-benzoyl-4-amino-3-hydroxybutyric acid 
     64-4. N-(o-toluoyl)-4-amino-3-hydroxybutyric acid 
     64-5. N-(3-aminobenzoyl)-4-amino-3-hydroxybutyric acid 
     64-6. N-(1-phenyl-1-cyclohexanecarbonyl)-4-amino-3-hydroxybutyric acid 
     64-7. N-(α-phenyl-α-methylacetyl)-4-amino-3-hydroxybutyric acid 
     64-8. N-(4-methoxybenzyloxycarbonyl)-4-amino-3-hydroxybutyric acid 
     Of the amino acid derivatives listed above, the following are particularly preferred: Compounds No. 2-5, 2-6, 2-7, 2-18, 2-22, 4-6, 5-11, 5-18, 5-33, 6-3, 7-3, 7-5, 7-14, 8-4, 9-3, 10-4, 10-29, 10-45, 11-3, 11-24, 13-5, 14-27, 14-28, 14-29, 14-37, 14-38, 14-68, 15-27, 15-28, 15-29, 15-40, 15-41, 15-68, 15-71, 16-2, 16-3, 16-9, 16-15, 16-16, 16-24, 16-31, 16-36, 16 -44, 17-2, 17-13, 17-14, 17-19, 17-26, 19-3, 36-4, 36-11, 36-21, 37-2, 37-14, 46-3, 53-5, 53-6, 53-7, 60-3 and 62- 1. Of these, Compounds No. 2-22 and 10-45, especially No. 2-22, are most preferred. 
     The amino acid derivatives employed in the present invention are acids and, as such, are capable of forming salts; any pharmaceutically acceptable salt of these amino acids may be employed. Examples of such salts include: alkali metal salts such as the sodium or potassium salts; alkaline earth metal salts, such as the calcium salt; other metal salts, such as the magnesium, aluminum, iron, zinc, copper, nickel and cobalt salts; the ammonium salt; and salts with amino sugars, such as glucosamine and galactosamine. 
     The compositions of the invention may be prepared by any suitable method which involves mixing the antibiotic with the amino acid derivative and the invention is not intended to be limited by any particular method of preparation. Since the amino acid derivatives employed in this invention have, in general, very limited solubility in water, it is preferred that they should first be dispersed in water and then converted to a suitable salt by adding an aqueous solution of an appropriate base, for example: a metal compound, such as sodium hydroxide or potassium hydroxide, ammonia; or an amino sugar, such as glucosamine or galactosamine. Sufficient of the base is preferably added to adjust the pH of the mixture to a value within the range from 5.5 to 9, more preferably from 6 to 9. 
     The penem or carbapenem antibiotic is then added to the resulting solution. The mixed solution thus obtained may be employed as such or it may first be lyophilized to give a powdery mixture, which may be subsequently formulated into an appropriate dosage form suitable for the chosen route of administration, either by the manufacturer or prior to use. 
     The above mixing and preparation steps may take place at any temperature at which the components are fluid (especially the media) and are not decomposed, e.g. from 0° to 100° C., more conveniently from 0° to 50° C. and most conveniently at about ambient temperature. 
     Although it is convenient to administer the antibiotic and the amino acid derivative simultaneously in a single composition, it is, of course, clear that the two compounds may be administered separately, provided that they are administered sufficiently closely in time to each other that the amino acid derivative has a suitable concentration in the blood for all or most of the time that the antibiotic is present. Normally, it is anticipated that this will be achieved if the two compounds are administered within about one hour of each other, the amino acid preferably being administered before the antibiotic. 
     The composition of the invention is particularly suitable for use by intravenous administration. 
     There is no particular restriction on the relative proportions of the amino acid derivative and the penem or carbapenem antibiotic; in general, we have found that weight proportions of amino acid derivative to antibiotic of from 0.1:1 to 4:1 give good results, but equally proportions outside this range may successfully be employed. Approximately equal weights are generally most convenient. 
     The invention includes a method of treating a mammal suffering from a bacterial infection by administering to said mammal an antibiotic selected from the group consisting of penem antibiotics and carbapenem antibiotics capable of causing renal damage; and an effective amount of a pharmaceutically acceptable N-acylated derivative of an amino acid wherein the amino group and the carboxylic acid group are attached to a saturated aliphatic carbon chain or carbon atom, or a salt thereof wherein said effective amount is at least sufficient to reduce, alleviate or eliminate said renal damage. A preferred composition comprises (5R,6S)-2-[(3S)-1-acetimidoylpyrrolidin-3-ylthio]-6-[1(R)-hydroxyethyl]-2-carbapenem-3-carboxylic acid; and N-benzoyl-β-alanine. The weight ratio of said carbapenem to said alanine is from about 1:0.1 to 1:4 and preferably about 1:1. 
     The invention is further illustrated by the following Examples and Activity Tests. In the following, the penem or carbapenem antibiotics are referred to by the numbers appended to them in the foregoing list and are identified as &#34;(Carba)-Penem Cpd No&#34; whilst the amino acid derivatives are also identified by the numbers appended to them in the foregoing list and are referred to as &#34;Amino Acid Cpd No. 
    
    
     EXAMPLE 1 
     5 g of N.sup.α,N.sup.ε -dibenzoyllysine (Amino Acid Compound No. 15-27) were weighed out and dispersed in 80 ml of water. A 1N aqueous solution of sodium hydroxide was slowly added to this dispersion, and dissolved the N.sup.α,N.sup.ε -dibenzoyllysine when the pH of the solution reached a value of 7-8. Then, 5 g of (5R,6S)-2-[(3S)-1-acetimidoylpyrrolidin-3-ylthio]-6-[1(R)-hydroxyethyl]-2-carbapenem-3-carboxylic acid (Carbapenem Compound No. 6) were dissolved in this solution, to give a total volume of 100 ml. 
     EXAMPLE 2 
     5 g of N-benzoyl-β-alanine (Amino Acid Compound No. 2-22) were weighed out and dispersed in 40 ml of water. A 1N aqueous solution of sodium hydroxide was slowly added to this dispersion, and dissolved the N-benzoyl-β-alanine when the pH of the solution reached a value of 7-8. Then, 5 g of (5R,6S)-2-[(3S)-1-acetimidoylpyrrolidin-3-ylthio]-6-[1(R)-hydroxyethyl]-2-carbapenem-3-carboxylic acid (Carbapenem Compound No. 6) were dissolved in this solution, to give a total volume of 50 ml. 
     EXAMPLE 3 
     Similar procedures to those described in Examples 1 and 2 were carried out, using the other penem or carbapenem antibiotic substances and the other acylated amino acid derivatives shown in the following Table, in the amounts shown in that Table. 
     In this Table, where the amino acid derivatives are not specified as being D- or L-, then they are the DL-form. 
     ACTIVITY TESTS 
     The preparation obtained by the procedure described in Example 1 was injected into the ear vein of a rabbit (about 3 kg body weight) in an amount of 3 ml/kg [that is 150 mg/kg of the carba penem Compound No. 6+150 mg/kg of N.sup.α,N.sup.ε -dibenzoyllysine (amino acid Compound No. 15-27)]. A preparation which had been obtained by the same procedure as that described in Example 1 but not including the N.sup.α,N.sup.ε -dibenzoyllysine was injected into another rabbit, as a control, in a similar manner to the above. 
     After one week, the kidneys of both rabbits were excised and examined. A change was observed in the renal tissue of the rabbits to which had been administered the preparation without the N.sup.α,N.sup.ε -dibenzoyllysine, but no such change at all was observed in the renal tissue of rabbits to which had been administered the preparation containing the N.sup.α,N.sup.ε -dibenzoyllysine. 
     Similar experiments were carried out on other preparations which were prepared from other penem or carbapenem antibiotic substances and other amino acid derivatives. The Table also shows the results of these experiments. 
     The observed change in the renal tissue of the control rabbits was a degenerative necrosis of the proximal renal tubules in the region of the renal cortex. In the following Table, where the proportion of the total area of this region which exhibited such necrosis was from 0 to 25%, this is shown as +++. Where the area is less than 50% this is shown as ++ and where it is less than 75% this is shown as +. Where different animals within each test group exhibited different responses, this is shown as e.g. +++--++ or ++--+. 
     It should be noted that, whenever penem or carbapenem antibiotic substances which were not combined with amino acid derivatives were administered, a change in the renal tissue was observed. Hence, all of the experiments carried out (even where the effect is only &#34;+&#34;) demonstrated a significant protective effect of the amino acid derivative. 
     
                       TABLE______________________________________              Amino(Carba)-Penem     Amount   Acid      AmountCpd. No.  mg/kg    Cpd. No.  mg/kg  Effect______________________________________6         150      1-5       150    +6         150      1-8       150    ++6         150       1-10     150    +6         150       1-11     150    ++6         150       1-12     150    +6         150      2-3       150    ++6         150      2-4       150    ++6         150      2-5       150    +++6         250      2-6       250    +++6         150      2-7       150    +++6         150       2-10     150    ++6         150       2-11     150    ++6         150       2-13     150    ++6         150       2-14     150    ++6         150       2-15     150    ++6         250       2-18     250    +++6         150       2-22     150    +++6         200       2-22     200    +++6         300       2-22     300    +++6         300       2-22     150    ++6         400      3-3       400    +++6         150      3-6       150    +6         150      3-8       150    +6         150       3-15     150    +6         150      4-1       150    +6         150      4-4       150    +6         150      4-5       150    ++5         150      4-6       150    +++6         150      5-3       150    ++6         150       5-11     150    ++6         150       5-14     150    +6         250       5-18     250    ++6         150       5-33     150    +++6         150      6-2       150    ++6         50       6-3       150    +++6         150       6-11     150    ++6         150      7-2       150    +6         150      7-3       150    +++6         150      7-5       150    +++6         150       7-12     150    ++6         150       7-18     150    ++6         150      8-2       150    +6         150      8-4       150    +++6         150      8-8       150    ++6         150       8-10     150    +6         150      9-3       150    +++6         150      9-5       150    +6         150      10-4      150    +++6         250      10-19     250    ++6         150      10-24     150    +6         150      10-30     150    +6         150      10-32     150    +6         150      10-33     150    +6         150      10-34     150    ++6         150      10-35     150    ++6         150      10-45     150    +++6         400      10-45     400    +++6         400      10-45     200    ++6         150      11-3      150    +++6         150      11-6      150    +6         150      11-7      150    +6         150      11-8      150    +6         150      11-24     150    +++6         150      12-1      150    ++6         150      12-4      150    ++6         150      13-1      150    ++6         150      13-2      150    ++6         150      13-5      150    +++6         150      13-12     150    +6         150      14-18     150    +++-++6         150      14-21     150    +++-++6         150      14-26     150    +++-++6         150      14-27     150    +++6         150      14-28     150    +++6         150      14-29     150    +++6         150      14-44     150    +++-++6         150      14-65     150    ++6         150      14-71     150    +6         150      15-18     150    +++-++6         150      15-21     150    +++-++6         150      15-26     150    +++-++6         150      15-27     300    +++6         150      15-27     150    +++6         150      15-27      75    +++6         150      15-27       37.5 +++-++6         150        .sub.--L-15-27                        150    +++-++6         150       .sub.--D-15-27                        150    +++6         150      15-28     150    +++-++6         150      15-29     150    +++6         150       .sub.--D-15-29                        150    +++6         150      15-30     150    +++-++6         150      15-35     150    +++-++6         150      15-36     150    +++-++6         150      15-42     150    +++-++6         150      15-47     150    +++-++6         150      .sup.  15-55α                        150    +++-++6         150      15-67     150    ++6         150      15-68     150    +++6         150      15-69     150    ++6         150      15-70     150    +6         150      15-72     150    ++6         150      15-73     150    +6         150      16-1      150    ++6         150       .sub.--D-16-1                        150    ++6         150       .sub.--L-16-1                        150    ++6         150      16-2      300    +++6         150      16-2      150    ++-+++6         150      16-2       75    ++6         150      16-2        37.5 +-++6         150       .sub.--D-16-2                        150    ++-+++6         150       .sub.--L-16-2                        150    ++-+++6         150      16-3      150    +++6         150      16-9      150    +++6         150      16-15     150    +++6         150      16-16     150    +++6         150      16-18     150    +6         150      16-20     150    ++6         150      16-22     150    +6         150      16-23     150    +6         150      16-24     150    +++6         150      16-25     150    ++6         150      16-27     150    +6         150      16-36     150    +++6         150      16-37     150    +6         150      16-38     150    ++6         150      16-39     150    +6         150      16-41     150    +6         150      16-44     150    +++6         150      17-1      150    ++6         150       .sub.--D-17-1                        150    ++6         150       .sub.--L-17-1                        150    ++6         150      17-2      300    +++6         150      17-2      150    +++6         150      17-2       75    ++-+++6         150      17-2        37.5 ++6         150       .sub.--L-17-2                        150    +++6         150      17-4      150    +6         150      17-5      150    +6         150      17-7      150    ++6         150      17-12     150    ++6         150      17-13     150    +++6         150      17-14     150    +++6         150      17-16     150    ++6         150      17-18     150    ++6         150      17-19     150    +++6         150      17-24     150    +6         150      17-26     150    +++6         150      17-30     150    ++6         150      18-1      150    +6         150      19-3      150    +++6         150      20-1      150    ++6         150      20-3      150    +6         150      20-8      150    +6         150      21-2      150    +6         150      22-2      150    +6         150      22-3      150    +6         150      24-4      150    +6         150      25-6      150    +6         150      26-3      150    ++6         150      27-2      150    ++6         150      28-2      150    +6         150      29-1      150    +6         150      30-3      150    +6         150      33-9      150    +6         150      34-5      150    +6         400      36-4      400    +++6         150      36-5      150    ++6         150      36-7      150    +6         150      36-11     150    +++6         150      36-14     150    ++6         150      36-15     150    +6         150      36-16     150    +6         150      36-20     150    ++6         150      37-2      150    +++6         150      37-3      150    ++6         150      37-6      150    +6         150      37-8      150    +6         150      37-12     150    ++6         150      37-13     150    ++6         150      37-14     150    +++6         150      38-3      150    +6         150      39-3      150    ++6         150      40-3      150    ++6         150      42-2      150    ++6         150      44-2      150    +6         150      44-4      150    ++6         150      44-7      150    +6         150      45-2      150    ++6         150      46-1      150    +6         150      46-3      150    +++6         150      46-5      150    +6         150      46-7      150    ++6         150      46-8      150    ++6         150      47-3      150    ++6         150      48-5      150    +6         150      49-1      150    ++6         150      50-3      150    ++6         150      51-2      150    +6         150      51-5      150    ++6         150      51-9      150    +6         150      52-2      150    +6         150      52-7      150    +6         400      53-5      400    +++6         150      53-6      150    +++6         150      53-7      150    +++6         150      53-10     150    ++6         150      53-12     150    ++6         150      54-1      150    ++6         150      55-6      150    ++6         150      56-1      150    ++6         150      57-1      150    ++6         150      58-3      150    ++6         150      59-3      150    ++6         150      60-3      150    +++6         150      60-4      150    ++6         150      60-6      150    +6         150      60-7      150    +6         150      61-1      150    +6         150      61-3      150    ++6         150      61-6      150    +6         150      61-9      150    +6         150      62-1      150    +++6         150      62-4      150    ++6         150      62-7      150    ++6         150      63-2      150    +6         150      63-6      150    +6         150      64-2      150    ++1         150       2-22     150    ++1         150      3-3       150    ++1         250       5-11     250    +++1         150       5-18     150    +++1         150      10-45     150    ++1         150      16-36     150    +++1         150      36-4      150    +++1         150      37-10     150    ++1         150      53-5      150    ++2         150      4-6       150    +++2         150       5-11     150    +++2         150       7-14     150    +++2         250      9-3       250    +++2         150      10-23     150    ++2         150      36-15     150    ++2         250      53-5      250    ++2         150      53-23     150    ++3         150       5-11     150    +++3         250      10-29     250    +++3         250      13-5      250    ++3         150      13-13     150    ++3         150      36-20     150    ++3         250      37-2      250    ++3         150      53-12     150    ++7         150       2-22     150    +++7         250       5-11     250    ++7         150      10-45     150    +++7         150      .sup.  14-14α                        150    ++7         150      14-27     150    +++-++7         150      14-28     150    +++-++7         150      15-4ε                        150    ++-+7         150      .sup.  15-12α                        150    ++7         150      15-27     150    +++-++7         150      15-29     150    +++-++7         150      15-44     150    ++-+7         150      16-1      150    ++7         150      16-2      150    ++7         150      16-31     150    ++ +7         150      17-1      150    ++7         150      17-2      150    ++-+++7         150      53-6      150    +++8         150       2-22     150    ++8         150       6-11     150    +-++8         150      14-29     150    +++-++8         150      15-27     150    +++8         150      16-1      150    ++8         150      16-2      150    ++-+++8         150      17-1      150    ++8         150      17-2      150    +++8         250      53-5      250    ++-+++9         150      36-6      150    +9         250      53-5      250    ++10        150      13-5      150    ++10        150      21-6      150    +11        150       2-22     150    ++11        150      15-28     150    +++11        150      16-2      150    ++-+++11        150      17-2      150    +++15        150      10-45     150    +++15        150      15-26     150    +++-++15        150      17-2      150    ++19        150        .sub.--L-10-45                        150    ++19        150      15-27     150    +++19        150      17-2      150    ++22        250      36-4      250    ++22        150      37-15     150    +-++23        150       2-22     150    +++23        150      15-27     150    +++23        150      15-29     150    +++23        150      16-2      150    ++23        150      17-2      150    +++24        150       2-22     150    +++24        150      10-45     150    +++24        150       .sub.--D-10-45                        150    +++24        150        .sub.--L-10-45                        150    +++24        150      14-27     150    +++24        150      14-28     150    +++-++24        150      14-29     150    +++-++24        150      15-18     150    ++24        150      15-26     150    ++24        150      15-27     150    +++- ++24        150      15-28     150    +++-++24        150      15-29     150    +++24        150      15-47     150    ++24        150      16-1      150    ++24        150      16-2      150    ++-+++24        150      17-1      150    ++24        150      17-2      150    +++24        150      21-5      150    +25        150      9-3       150    ++28        150       3-18     150    +28        150      36-21     150    +++32        150       2-22     150    ++32        150      14-27     150    +++32        150      15-27     150    +++32        150      16-2      150    ++32        150      17-2      150    ++38        150       2-22     150    +++38        300      14-27     150    ++38        300      15-27     150    ++38        300      16-2      150    ++38        300      17-2      150    ++39        150      10-45     150    ++39        300      14-27     150    ++39        300      15-27     150    ++39        300      16-2      150    ++39        300      17-2      150    ++40        150       2-22     150    +++40        300      14-27     150    +++40        300      15-27     150    +++40        300      16-2      150    ++40        300      17-2      150    ++66        250      3-3       250    ++67        150       5-19     150    ++67        150      12-4      150    +-++71        250       2-18     250    +++71        250       5-21     250    ++73        150      11-27     150    +73        150      37-10     150    ++75        150      16-36     150    ++75        150      36-9      150    ++______________________________________