Method of treating bacterial infection with phosphorus containing DHP enzyme inhibitors

Dipeptide mimics which contain phosphorus and their pharmaceutical use and preparation are disclosed. The compounds have dehydropeptidase (DHP) enzyme inhibitor activity.

BACKGROUND OF THE INVENTION 1. Field of the Invention 
This invention relates to new agents which inhibit renal dehydropeptidase 
(DHP) and, therefore, potentiate the antibiotic activity of carbapenem 
antibiotics. 2. Brief Description of the Art 
Renal dehydropeptidase (E.C. 3.4.13.11) is a mammalian enzyme which 
metabolizes carbapenem antibiotics such as thienamycin and imipenem. 
Inhibition of this enzyme enhances the urinary recovery of these 
antibiotics and reduces their renal toxicity. EPO Publication No. 0091594 
to Sanraku-Ocean Co., Ltd. describes aminocarboxylic acid derivatives 
possessing dipeptidase inhibiting activity EPO Publication No. 0210545 to 
Merck & Co., Inc. describes renin inhibitors which are phosphinic acids 
similar to the instant compounds where R.sub.l is cyclohexylmethyl. The 
development of cilastatin as a renal dehydropeptidase inhibitor for use in 
combination with imipenem has been reviewed by F. M. Kahan et al., J. 
Antimicrobial Chemotherapy, 12, Suppl. D, 1-35 (1983). 
U.S. Pat. No. 4,374,131 to Petrillo (assigned to E. R. Squibb & Sons, Inc.) 
discloses amino and substituted amino phosphinyl-alkanoyl compounds which 
are useful hypertensive agents due to their angiotensin-converting-enzyme 
(ACE) inhibition activity. 
E. D. Thorsett et al., (Merck & Co., Inc.) Proc. Natl. Acad. Sci. U.S.A. 
Vol. 79, pp 2176-2180 (April 1982) discloses phosphorus containing 
inhibitors of angiotensin-converting enzyme. 
Further, U.S. Pat. No. 4,715,994 by Parsons et al., (assigned to Merck & 
Co., Inc.) discloses 3-(1-aminoalkyl-propionic)-(2-substituted) phosphinic 
acids which display antibacterial activity and potentiate carbapenem 
antibiotics. 
With this background, the search for newer and more effective antibacterial 
agents is a continuing one. 
SUMMARY OF THE INVENTION 
It has been found that compounds of Formulae I and II, shown below, inhibit 
renal dehydropeptidase E.C. (3.4.13.11) and are useful in potentiating the 
in vivo effects of penem and carbapenem antibiotics such as imipenem. 
By this invention there is provided a method of treatment for bacterial 
infections which comprises administering to a host a therapeutically 
effective amount of a DHP-inhibiting compound of Formula I or II, in 
combination with a therapeutically effective amount of a carbapenem or 
penem antibiotic: 
##STR1## 
wherein: R.sub.1 is 
(a) C.sub.2 -C.sub.12 linear or branched unsubstituted alkyl; 
(b) C.sub.1 -C.sub.12 linear or branched substituted alkyl; 
(c) C.sub.2 -C.sub.12 linear or branched monoalkenyl; 
(d) C.sub.2 -C.sub.12 linear or branched alkynyl; 
(e) C.sub.7 -C.sub.20 aralkyl, wherein the alkyl chain is linear or 
branched C.sub.1 -C.sub.8 and the aryl moiety is C.sub.6 -C.sub.12 ; 
(f) C.sub.4 -C.sub.10 cycloalkylalkyl; 
(g) C.sub.3 -C.sub.7 cycloalkyl; 
wherein said above values for R.sub.1, excluding (a), can be substituted 
by one or more: C.sub.1 -C.sub.4 alkoxy, C.sub.3 -C.sub.6 cycloalkyloxy, 
C.sub.3 -C.sub.6 cycloalkylthio, C.sub.6 -C.sub.12 aryloxy, C.sub.1 
-C.sub.4 alkylthio, C.sub.6 -C.sub.12 arylthio, C.sub.7 -C.sub.10 
aralkyloxy, C.sub.7 -C.sub.16 aralkylthio; 
R.sub.2 is 
(a) H or C.sub.1 --C.sub.12 linear or branched alkyl; 
(b) C.sub.2 -C.sub.12 linear or branched monoalkenyl; 
(c) C.sub.7 -C.sub.20 aralkyl, wherein the alkyl chain is linear or 
branched C.sub.1 -C.sub.8 and the aryl moiety is C.sub.6 -C.sub.12 ; 
(d) heterocyclic alkyl, wherein the alkyl chain is linear or branched 
C.sub.1 -C.sub.8 and the heterocyclic ring is 5-6 membered, optionally 
fused with a benzene ring, fully aromatic, containing 1-2: O, N or S 
heteroatoms; 
(e) C.sub.4 -C.sub.10 cycloalkylalkyl; 
(f) C.sub.3 -C.sub.7 cycloalkyl; wherein said above values for R.sub.2 can 
be substituted by one or more: halo, hydroxy, carboxy, C.sub.1 -C.sub.4 
alkoxycarbonyl, C.sub.7 -C.sub.16 arylalkoxycarbonyl, C.sub.3 -C.sub.7 
cycloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.6 -C.sub.12 aryloxy, C.sub.3 
-C.sub.6 cycloalkyloxy, C.sub.3 -C.sub.6 cycloalkylthio, amino, mono- or 
di-C.sub.1 -C.sub.8 alkylamino, thio, C.sub.1 -C.sub.4 alkylthio, C.sub.6 
-C.sub.12 arylthio, C.sub.7 -C.sub.16 aralkylthio, or the radical 
--S--(CH.sub.2).sub.n --CH(NH.sub.2)COOH; 
R.sub.5 is 
(a) H or C.sub.1 -C.sub.12 linear or branched alkyl; 
(b) C.sub.2 -C.sub.12 linear or branched monoalkenyl; 
(c) C.sub.7 -C.sub.20 aralkyl, wherein the alkyl chain is linear or 
branched C.sub.1 -C.sub.8 and the aryl moiety is C.sub.6 -C.sub.12 ; 
(d) heterocyclic alkyl, wherein the alkyl chain is linear or branched 
C.sub.1 -C.sub.8 and the heterocyclic ring is 5-6 membered, optionally 
fused with a benzene ring, fully aromatic, containing 1-2: O, N or S 
heteroatoms; 
(e) C.sub.4 -C.sub.10 cycloalkylalkyl 
(f) C.sub.3 -C.sub.7 cycloalkyl; 
wherein said above values for R.sub.5 can be substituted by one or more: 
halo, hydroxy, carboxy, C.sub.1 -C.sub.4 alkoxycarbonyl, C.sub.7 -C.sub.16 
arylalkoxycarbonyl, C.sub.3 -C.sub.7 cycloalkyl, C.sub.1 -C.sub.4 alkoxy, 
C.sub.6 -C.sub.12 aryloxy, C.sub.3 -C.sub.6 cycloalkyloxy, C.sub.3 
-C.sub.6 cycloalkylthio, amino, mono- or di-C.sub.1 -C.sub.8 alkylamino, 
thio, C.sub.1 -C.sub.4 alkylthio, C.sub.6 -C.sub.12 arylthio, C.sub.7 
-C.sub.16 aralkylthio, or the radical --S--(CH.sub.2).sub.n 
--CH(NH.sub.2)COOH; and including DHP-inhibiting stereoisomers and 
racemates thereof Structures I and II. 
Further provided is a pharmaceutical composition useful in the treatment of 
antibacterial infections which comprises a pharmaceutically effective 
amount of a DHP-inhibiting compound of above-defined Formula I or II, or 
mixture thereof, in combination with a pharmaceutically effective amount 
of a carbapenem or penem antibiotic. 
Further provided is a DHP-inhibiting compound of Formula I or II: 
##STR2## 
wherein: R.sub.1 is 
(a) C.sub.2 -C.sub.12 linear or branched unsubstituted alkyl; 
(b) C.sub.2 -C.sub.12 linear or branched substituted alkyl; 
(c) C.sub.2 -C.sub.12 linear or branched monoalkenyl; 
(d) C.sub.2 -C.sub.12 linear or branched alkynyl; 
(e) C.sub.7 -C.sub.20 aralkyl, wherein the alkyl chain is linear or 
branched C.sub.1 -C.sub.8 and the aryl moiety is C.sub.6 -C.sub.12 ; 
(f) C.sub.3 -C.sub.7 cycloalkyl; 
(g) C.sub.4 -C.sub.10 cycloalkylalkyl, for structure II only; 
wherein said above values for R.sub.1, excluding (a), can be substituted 
by one or more: C.sub.1 -C.sub.4 alkoxy, C.sub.6 -C.sub.12 aryloxy, 
C.sub.1 -C.sub.4 alkylthio, C.sub.6 -C.sub.12 arylthio, C.sub.3 -C.sub.6 
cycloalkyloxy, C.sub.3 -C.sub.6 cycloalkylthio, C.sub.7 -C.sub.10 
aralkyloxy, C.sub.7 -C.sub.16 aralkylthio; 
R.sub.2 is 
(a) H or C.sub.1 -C.sub.12 linear or branched alkyl; 
(b) C.sub.2 -C.sub.12 linear or branched monoalkenyl; 
(c) C.sub.7 -C.sub.20 aralkyl, wherein the alkyl chain is linear or 
branched C.sub.1 -C.sub.8 and the aryl moiety is C.sub.6 -C.sub.12 ; 
(d) heterocyclic alkyl, wherein the alkyl chain is linear or branched 
C.sub.1 -C.sub.8 and the heterocyclic ring is 5-6 membered, optionally 
fused with a benzene ring, fully aromatic, containing 1-2: O, N or S 
heteroatoms; 
(e) C.sub.3 -C.sub.7 cycloalkyl; 
(f) C.sub.4 -C.sub.10 cycloalkylalkyl; wherein said above values for 
R.sub.2 can be substituted by one or more: halo, hydroxy, carboxy, C.sub.1 
-C.sub.4 alkoxycarbonyl, C.sub.7 -C.sub.16 arylalkoxycarbonyl, C.sub.3 
-C.sub.7 cycloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.6 -C.sub.12 aryloxy, 
C.sub.3 -C.sub.6 cycloalkyloxy, C.sub.3 -C.sub.6 cycloalkylthio, amino, 
mono- or di-C.sub.1 -C.sub.8 alkylamino, thio, C.sub.1 -C.sub.4 
alkylthio, C.sub.6 -C.sub.12 arylthio, C.sub.7 -C.sub.16 aralkylthio, or 
the radical --S--(CH.sub.2).sub.n --CH(NH.sub.2)COOH; 
R.sub.5 is 
(a) H or C.sub.1 -C.sub.12 linear or branched alkyl; 
(b) C.sub.2 -C.sub.12 linear or branched monoalkenyl; 
(c) C.sub.7 -C.sub.20 aralkyl, wherein the alkyl chain is linear or 
branched C.sub.1 -C.sub.8 and the aryl moiety is C.sub.6 -C.sub.12 ; 
(d) heterocyclic alkyl, wherein the alkyl chain is linear or branched 
C.sub.1 -C.sub.8 and the heterocyclic ring is 5-6 membered, optionally 
fused with a benzene ring, fully aromatic, containing 1-2: O, N or S 
heteroatoms; 
(e) C.sub.4 -C.sub.10 cycloalkylalkyl; 
(f) C.sub.3 -C.sub.7 cycloalkyl; 
wherein said above value for R.sub.5 can be substituted by one or more: 
halo, hydroxy, carboxy, C.sub.1 -C.sub.4 alkoxycarbonyl, C.sub.7 -C.sub.16 
arylalkoxycarbonyl, C.sub.3 -C.sub.7 cycloalkyl, C.sub.1 -C.sub.4 alkoxy, 
C.sub.6 -C.sub.12 aryloxy, C.sub.3 -C.sub.6 cycloalkyloxy, C.sub.3 
-C.sub.6 cycloalkylthio, amino, mono- or di-C.sub.1 -C.sub.8 alkylamino, 
thio, C.sub.1 --C.sub.4 alkylthio, C.sub.6 -C.sub.12 arylthio, C.sub.7 
-C.sub.16 aralkylthio, or the radical --S--(CH.sub.2).sub.n 
--CH(NH.sub.2)COOH; and including DHP-inhibiting stereoisomers and 
racemates thereof Structures I and II. 
DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS 
The novel claimed compounds of the above Structural Formulas I and II 
represent new and useful dehydropeptidase inhibitors. 
The values for R.sub.1 for (a) C.sub.2 -C.sub.12 linear or branched 
unsubstituted alkyl include ethyl, propyl, isopropyl, n-butyl, isobutyl, 
sec-butyl, t-butyl, n-pentyl, isopentyl, n-hexyl, n-heptyl, n-octyl, 
iso-octyl, n-decyl, n-undecyl, n-dodecyl and the like. Preferred in this 
series is n-butyl, isobutyl, n-pentyl and n-hexyl. 
Values for R.sub.1 for (b) C.sub.1 -C.sub.12 linear or branched alkyl, 
where substituted, include the values above for R.sub.1 (a), substituted 
by the above-defined substituents, including the following preferred 
substituents: methoxy, ethoxy, propoxy, butoxy, methylthio, ethylthio, 
propylthio, butylthio, cyclopentyloxy, cyclopentylthio, cyclopropylthio, 
benzylthio, 2-phenethylthio, 2-phenethylthio and the like. 
Values for R.sub.1 for (e) C.sub.2 -C.sub.2 linear or branched monoalkenyl 
include ethenyl, propenyl, 1-butenyl, 2-butenyl, 1-pentenyl, 2-pentenyl, 
2-methyl-2-butenyl and the like. 
Values for R.sub.1 for (d) C.sub.2 -C.sub.12 linear or branched alkynyl 
include: ethynyl, propynyl, 1-butynyl, 2-butynyl, 2-methyl-3-pentynyl and 
the like. 
Values for R.sub.1 for (e) C.sub.7 -C.sub.20 aralkyl include benzyl, 
2-phenylethyl, 1-phenylethyl, 4-methylphenyl-methyl and the like. 
Preferred in this series is benzyl. 
Values for R.sub.1 for (f) C.sub.4 -C.sub.10 cycloalkylalkyl include: 
cyclohexylmethyl, cyclopentylmethyl, 2-cyclohexylethyl, 2-cyclooctylethyl, 
and the like. Preferred in this series is cyclopentylmethyl and 
cyclohexylmethyl. 
The method of use and pharmaceutical composition claims include the 
compounds of Formulas I and II where R.sub.1 is cyclohexylmethyl whereas 
the new compound claims of Structure I do not. 
Values for R.sub.1 for (g) C.sub.3 -C.sub.7 cycloalkyl include: 
cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like. Preferred 
in this series is cyclopentyl and cyclohexyl. 
Preferred substituent values for R.sub.1 include: methoxy, ethoxy, phenoxy, 
methylthio, ethylthio, phenylthio, benzyloxy, 2-phenylethyloxy, 
benzylthio, 2-phenylethylthio, and the like. 
The values of the alkyl, alkenyl groups for R.sub.2 and R.sub.5, except 
where noted otherwise, represented by any of the variables include linear 
or branched, alkyl and monoalkenyl and chain hydrocarbon radicals from two 
to twelve carbon atoms, for example, ethyl, n-propyl, isopropyl, n-butyl, 
isobutyl, sec-butyl, t-butyl, n-pentyl, isopentyl, n-heptyl, n-nonyl, 
4,4-dimethylpentyl, or vinyl, allyl, 1-butenyl, 2-butenyl, 5-hexenyl and 
the like. Preferred are isopropyl, n-butyl, n-pentyl, n-heptyl or 
1-butenyl. 
Values of C.sub.3 -C.sub.7 cycloalkyl and C.sub.4 -C.sub.10 cycloalkylalkyl 
include: cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, 
cyclohexylmethyl, cyclohexylethyl, cyclopropyl, and the like. 
The aralkyl group represented by the above variables has from one to eight 
carbon atoms in the alkyl portion and "aryl" where noted, represents 
phenyl, naphthyl, or biphenyl. Representative examples include benzyl, 
phenethyl, 4-phenyl-n-butyl, 1-phenyl-n-octyl, and the like. 
The aromatic heterocyclic, i.e. "heteroaryl" substituent, are synonymous, 
and recited above represents a 5- or 6-membered aromatic ring containing 
from one to three O, N or S heteroatoms, preferably one O or S and/or 1-3 
N heteroatoms, such as, for example, pyridyl, thienyl, furyl, imidazolyl, 
and thiazolyl as well as any bicyclic group derivable therefrom in which 
any of the above heterocyclic rings is fused to a benzene ring such as, 
for example, indolyl, quinolinyl, isoquinolinyl, benzimidazolyl, 
benzothiazolyl, benzofuryl, and benzothienyl. 
The named substituents on the R.sub.2 and R.sub.5 alkyl and alkenyl chains 
can be present on the aromatic rings in the aralkyl, heterocyclic alkyl 
and heteroaryl groupings as well. Site of substitution includes all 
available sites and substitution can involve one or more of the same or 
different groups. 
The substituents are: halo, meaning fluoro, chloro, bromo or iodo; hydroxy; 
carboxy; C.sub.1 -C.sub.4 linear or branched alkoxycarboxy, e.g. 
methoxycarbonyl and ethoxycarbonyl; C.sub.7 -C.sub.16 arylalkoxy carbonyl, 
e.g. benzyloxycarbonyl, n-butyloxycarbonyl; C.sub.3 -C.sub.7 cycloalkyl, 
e.g. cyclopentyl and cyclohexyl; C.sub.1 -C.sub.4 alkoxy, e.g. t-butoxy 
and ethoxy; C.sub.6 -C.sub.12 aryloxy, e.g. biphenyloxy, benzyloxy; amino; 
mono- or di-C.sub.1 -C.sub.8 dialkylamino, e.g. methylamino, 
isopropylamino, n-butylamino, isohexylamino, N,N-diethylamino, 
methylethylamino, methyl-t-butylamino, di-n-octylamino; thio; C.sub.1 
-C.sub.4 alkylthio, e.g. methylthio, ethylthio; C.sub.6 -C.sub.12 
arylthio, e.g. phenylthio; C.sub.7 -C.sub.16 aralkylthio, e.g. benzylthio, 
naphthylmethylthio; the radicals --S--CH.sub.2 --CH(NH.sub.2)COOH and 
--S--(CH.sub.2).sub.2 --CH(NH.sub.2)--COOH, both preferably in the 
L-configuration; and, where a thio substituent is present, R.sub.2 
/R.sub.5 must be at least a C.sub.2 alkyl grouping. Where an aryl or 
heteroaryl group is present in the substituent, the ring carbons can 
additionally be substituted by one or more of linear or branched C.sub.1 
-C.sub.4 alkyl, e.g. methyl, ethyl, isopropyl, t-butyl; trihalomethyl, 
"halo" having the same meaning as described above, e.g. trichloromethyl, 
trifluoromethyl; nitro, cyano or sulfonamide. 
Preferred are the compounds wherein: 
R.sub.1 is cyclohexylmethyl, cyclopentylmethyl, n-pentyl, n-butyl, n-hexyl, 
isobutyl, 
R.sub.2 and R.sub.5 are: 
C.sub.3 -C.sub.7 cycloalkyl; 
C.sub.1 -C.sub.10 linear or branched alkyl, substituted or unsubstituted; 
C.sub.7 -C.sub.14 aralkyl, substituted or unsubstituted; 
wherein these groups can be substituted with halo, amino, mono- or 
di-C.sub.1 -C.sub.4 linear or branched alkylamino, carboxyl, C.sub.1 
-C.sub.4 alkoxycarbonyl, hydroxy, C.sub.1 -C.sub.4 alkoxy, C.sub.5 
-C.sub.6 cycloalkyl, C.sub.6 -C.sub.10 aryloxy, thio, C.sub.1 -C.sub.4 
linear or branched alkylthio, C.sub.6 -C.sub.10 arylthio, C.sub.7 
-C.sub.14 aralkylthio, --S--(CH.sub.2).sub.n --CH(NH.sub.2)CO.sub.2 H; 
wherein the aryl group ring carbons can further be substituted by linear 
or branched C.sub.1 -C.sub.4 alkyl; R.sub.3 and R.sub.4 are hydrogen, 
C.sub.1 -C.sub.4 linear or branched alkyl e.g. methyl, ethyl, or C.sub.7 
-C.sub.14 aralkyl e.g. benzyl. 
The preferred compounds of Structures I or II, for use as DHP inhibiting 
agents include those having the carbon attached to R.sub.1 in the (R) or 
(RS) configuration preferably (R), and the carbon attached to R.sub.2 in 
the (R) (RS) or (S) configuration, preferably (RS) or (S) and if R.sub.5 
is present, the double bond is preferred in the Z configuration. 
The Formulas I and II compounds can be used in the form of salts derived 
from inorganic or organic acids and bases. Included among such acid 
addition salts are the following: acetate, adipate, alginate, aspartate, 
benzoate, benzenesulfonate, bisulfate, butyrate, citrate, camphorate, 
camphorsulfonate, cyclopentanepropionate, digluconate, dodecylsulfate, 
ethanesulfonate, fumarate, glucoheptanoate, glycerophosphate, hemisulfate, 
heptanoate, hexanoate, hydrochloride, hydrobromide, hydroiodide, 
2-hydroxyethanesulfonate, lactate, maleate, methanesulfonate, 
2-naphthalenesulfonate, nicotinate, oxalate, pamoate, pectinate, 
persulfate, 3-phenylpropionate, picrate, pivalate, propionate, succinate, 
tartrate, thiocyanate, tosylate, and undecanoate. Base salts include 
ammonium salts, alkali metal salts such as sodium and potassium salts, 
alkaline earth metal salts such as calcium and magnesium salts, salts with 
organic bases such as dicyclohexylamine and N-methyl-D-glucamine, and 
salts with amino acids such as arginine, lysine, and so forth. Water or 
oil-soluble or dispersible products are thereby obtained. 
The pharmaceutical compositions herein useful in the treatment of 
antibacterial infections comprise a pharmaceutically effective amount of a 
compound of Formula I or II, or mixture thereof, in combination with a 
pharmaceutically effective amount of a carbapenem or penem antibiotic. 
By the term "carbapenem" or "penem" antibiotic as used herein is meant 
those carbapenems and penems which are known in the art as possessing 
antibacterial activity. Inclusive therein are those carbapenems and penems 
described in U.S. Pat. No. 4,539,208 to F. M. Kahan and H. Kropp, and EPO 
Publication No. 0,161,546, both assigned to Merck & Co., Inc., hereby 
incorporated by reference, those specifically listed in the Merck Index, 
Tenth Edition, i.e., imipenem and 3-[2-dimethylaminocarbonyl 
tetrahydro-pyrrolidin-4-yl]thio-6-(1-hydroxyethyl)-7-oxo-1-azabicyclo-[3.2 
.0]hept-2-ene-2-carboxylic acid (Sumitomo). 
Specifically preferred DHP-inhibiting compounds useful in the composition 
include: 
1. 1-Amino-3-methylbutyl-[2-carboxy-l-hexyl]phosphinic acid 
2. 1-Aminopropyl-[2-carboxy-4-phenyl-l-butyl]phosphinic acid 
3. 1-Aminopropyl-[2-carboxy-l-butyl]phosphinic acid 
4. 1-Aminopropyl-[2-carboxy-l-hexyl]phosphinic acid 
5. 1-Aminopropyl-2-phenylethyl-[2-carboxy-l-hexyl]phosphinic acid 
6. (1-Amino-2-cyclohexylethyl)-2-carboxy-5-(4- pyridyl)-pentyl phosphinic 
acid 
7. 1-Amino-2-cyclohexylethyl-[2-carboxy-5-(4-methyl)-1- pentyl phosphinic 
acid 
8;9 (1-Amino-2-cyclohexylethyl)-2-carboxy-4-methyl(E & Z)-2-butenyl 
phosphinic acids 
10. (1-Amino-2-cyclohexylethyl)-2-carboxy-3(Z)-cyclohexyl-2-butenyl 
phosphinic acid 
11. (1-Amino-2-cyclohexylethyl)-2-carboxy-3-cyclohexyl-1-propyl phosphinic 
acid 
12. (1-Aminohexyl)-2-carboxy-2(Z)-octenyl phosphinic acid 
13. (1-Amino-l-hexyl)-2-carboxy-l-octyl phosphinic acid 
14. (1-Aminohexyl)-2-carboxy-4-cyclopentyl-2(Z)-butenyl phosphinic acid 
15. (1-Amino-l-hexyl)-2-carboxy-4-cyclopentyl-1-butyl phosphinic acid 
16. (1-Amino-2-cyclohexylethyl)-2-carboxy-2-(Z)-octenyl phosphinic acid 
17. (1-Amino-2-cyclohexylethyl)-2-carboxy-1-octenyl phosphinic acid 
18. (1-Amino-2-cyclohexylethyl)-2-carboxy-4-cyclopentyl-2(Z)-butenyl 
phosphinic acid 
19. (1-Amino-2-cyclohexylethyl)-2-carboxy-4-cyclopentyl-1-butylphosphinic 
acid 
20. (1-Aminohexyl)-2-carboxy-3-cyclohexyl-2(Z)-butenyl phosphinic acid 
21. (1-Amino-l-hexyl)-2-carboxy-3-cyclohexyl-1-propyl phosphinic acid 
22. [1(R)-Amino-2-cyclohexylethyl]-2-carboxy-4-methyl-2-(Z)-butylphosphinic 
acid 
23. [1-(R)-Amino-2-cyclohexylethyl]-2-carboxy-3(Z)-cyclohexyl-2-propenyl 
phosphinic acid 
24. 
[1-(R)-Amino-2-cyclohexylethyl]-2-carboxy-4-cyclopentyl-2(Z)-butenylphosph 
inic acid. 
Also provided is a method for treating a bacterial infection in a mammalism 
host comprising administering to said host a therapeutically effective 
amount of the above-described composition containing a compound of Formula 
I or II or mixture thereof. 
Compounds of this invention inhibit dehydropeptidase-I (renal dipeptidase, 
EC 3.4.13.11) and, therefore, potentiate the antibiotic activity of 
carbapenem antibiotics. Renal dehydropeptidase activity was first 
described by M. Bergmann and H. Schleich, Z. Physiol. Chem., 205, 65 
(1932); see also B. J. Campbell et al., Biochem. Biophys. Acta, 118, 371 
(1966) and references therein. 
In order to demonstrate the ability of the compounds of Formula I to 
suppress the action of the renal dipeptidase enzyme, an in vitro screen 
procedure was followed. This measured the ability of compounds to inhibit 
hydrolysis of glycyldehydrophenylalanine (GDP) by a solubilized 
preparation of dipeptides isolated from hog kidneys. The procedure is as 
follows: to a 1 ml system containing 50 mM "MOPS" 
(3-(N-morpholino)-propanesulfonic acid) buffer, pH 7.1 is added 5 mg of 
lyophilized enzyme, and the test compound at a final concentration of 0.1 
mM. After a five minute incubation at 37.degree. C., GDP is added to a 
final concentration of 0.05 mM. Incubation is continued for 10 minutes, at 
37.degree. C. and hydroylsis of GDP is measured by the change in optical 
density with time at 275 nm. Inhibition of the enzyme is gauged by 
comparison to a standard run containing no inhibitor and is expressed as 
the inhibitor binding constant K. This is the concentration of the 
inhibitor which achieves 50% inhibition of the enzyme. 
The tables below summarize some representative data with compounds of this 
invention. 
TABLE I 
______________________________________ 
RENAL DEHYDROPEPTIDASE I INHIBITION 
##STR3## II 
Con- Olefin 
figuration 
Geo- K.sub.i 
R.sub.1 R.sub.5 at R.sub.1 
metry (nM) 
______________________________________ 
(CH.sub.3).sub.2 CHCH.sub.2 
CH.sub.3 (CH.sub.2).sub.3 
RS Z 1.6 
CH.sub.3 (CH.sub.2).sub.4 
cyclo-C.sub.6 H.sub.11 
RS Z 0.5 
CH.sub.3 (CH.sub.2).sub.4 
CH.sub.3 (CH.sub.2).sub.4 
RS Z 1.4 
PhCH.sub.2 CH.sub.3 (CH.sub.2).sub.4 
RS Z 68 
(cyclo-C.sub.6 H.sub.11)CH.sub.2 
(CH.sub.3).sub.2 CH 
RS Z 2.1 
(cyclo-C.sub.6 H.sub.11)CH.sub.2 
(CH.sub.3).sub.2 CH 
RS Z 21 
(cyclo-C.sub.6 H.sub.11)CH.sub.2 
(CH.sub.3).sub.2 CH 
R Z 0.54 
(cyclo-C.sub.6 H.sub.11)CH.sub.2 
CH.sub.3 (CH.sub.2).sub.4 
RS Z 3.1 
(cyclo-C.sub.6 H.sub.11)CH.sub.2 
cyclo-C.sub.6 H.sub.11 
RS Z 0.9 
(cyclo-C.sub.6 H.sub.11 )CH.sub.2 
(cyclo-C.sub.5 H.sub.9)CH.sub.2 
R Z 0.86 
(cyclo-C.sub.6 H.sub.11)CH.sub.2 
cyclo-C.sub.6 H.sub.11 
R Z 0.52 
______________________________________ 
TABLE II 
__________________________________________________________________________ 
##STR4## I 
Configuration 
Configuration 
R.sub.1 R.sub.2 at R.sub.1 
at R.sub.2 
K.sub.i (nM) 
__________________________________________________________________________ 
CH.sub.3 CH.sub.2 
Ph(CH.sub.2).sub.2 
RS RS 6.8 
CH.sub.3 CH.sub.2 
CH.sub.3 CH.sub.2 
RS RS 1.3 
CH.sub.3 CH.sub.2 
CH.sub.3 (CH.sub.2).sub.3 
RS RS 2.3 
(CH.sub.3).sub.2 CHCH.sub.2 
CH.sub.3 (CH.sub.2).sub.3 
RS RS 2.4 
PhCH.sub.2 
CH.sub.3 (CH.sub.2).sub.3 
RS RS 84 
CH.sub.3 (CH.sub.2).sub.4 
CH.sub.3 (CH.sub.2).sub.5 
RS RS 8.0 
CH.sub.3 (CH.sub.2).sub.4 
(cyclo-C.sub.5 H.sub.9)CH.sub.2 CH.sub.2 
RS RS 7.0 
CH.sub.3 (CH.sub.2).sub.4 
(cyclo-C.sub.6 H.sub.11)CH.sub.2 
RS RS 9.7 
(cyclo-C.sub.6 H.sub.11)CH.sub.2 
CH.sub.3 (CH.sub.2).sub.5 
RS RS 1.6 
(cyclo-C.sub.6 H.sub.11)CH.sub.2 
(cyclo-C.sub.5 H.sub.9)CH.sub.2 CH.sub.2 
R RS 2.7 
(cyclo-C.sub.6 H.sub.11)CH.sub.2 
(cyclo-C.sub.6 H.sub.11)CH.sub.2 
R RS 0.5 
(cyclo-C.sub.6 H.sub.11)CH.sub.2 
(CH.sub.2).sub.3 -pyridin-4-yl 
R RS 4.0 
__________________________________________________________________________ 
The in vivo effectiveness of DMP inhibitors to increase the metabolic 
stability if carbapenem antibiotics can be demonstrated by measuring the 
urinary recovery of such antibiotics in the presence and absence of 
coadministered dehydropeptidase inhibitor. For example, see F. M. Kahan et 
al., J. Antimicrobial Chemotherapy, 12, Suppl. D, 1-35 (1983). It is also 
possible to observe this potentiation by measuring the dosage required to 
treat infections in animals with a dehydropeptidase susceptible antibiotic 
alone or in combination with a dehydropeptidase inhibitor. 
For administration, the compositions of the invention can also contain 
other conventional pharmaceutically acceptable compounding ingredients, as 
necessary or desired. Such ingredients are generally referred to as 
carriers or diluents. Conventional procedures for preparing such 
compositions in appropriate dosage forms can be utilized. Whatever the 
dosage form, it will contain a pharmaceutically effective amount of the 
compounds of the invention. 
The present compositions can be administered parenterally and this is 
preferred when they are used in combination with a carbapenem antibiotic 
such as imipenem. They may also be administered orally. The compounds of 
this invention may also be used to treat topical antibacterial infection. 
Therefore, these compounds may be presented in a number of appropriate 
dosage forms; e.g., tablets, capsules, suspensions, solutions, and the 
like, for oral administration; solutions, suspensions, emulsions, and the 
like, for parenteral administration; solutions for intravenous 
administration; and ointments, transdermal patches, and the like, for 
topical administration. 
Compositions intended for oral use may be prepared according to any method 
known to the art for the manufacture of pharmaceutical compositions and 
such compositions may contain one or more agents selected from the group 
consisting of sweetening agents, flavoring agents, coloring agents and 
preserving agents in order to provide pharmaceutically elegant and 
palatable preparation. Tablets containing the active ingredient in 
admixture with non-toxic pharmaceutically acceptable excipients may also 
be manufactured by known methods. The excipients used may be for example, 
(1) inert diluents such as calcium carbonate, sodium carbonate, lactose, 
calcium phosphate or sodium phosphate; (2) granulating and disintegrating 
agents such as corn starch, or alginic acid; (3) binding agents such as 
starch, gelatin or acacia, and (4) lubricating agents such as magnesium 
stearate, stearic acid or talc. The tablets may be uncoated or they may be 
coated by known techniques to delay disintegration and absorption in the 
gastrointestinal tract and thereby provide a sustained action over a 
longer period. For example, a time delay material such as glyceryl 
monostearate or glyceryl distearate may be employed. They may also be 
coated by the techniques described in U.S. Pat. Nos. 4,256,108; 4,160,452; 
and 4,265,874 to form osmotic therapeutic tablets for controlled release. 
In some cases, formulations for oral use may be in the form of hard gelatin 
capsules wherein the active ingredient is mixed with an inert solid 
diluent, for example, calcium carbonate, calcium phosphate or kaolin. They 
may also be in the form of soft gelatin capsules wherein the active 
ingredient is mixed with water or an oil medium, for example peanut oil, 
liquid paraffin, or olive oil. 
Aqueous suspensions normally contain the active materials in admixture with 
excipients suitable for the manufacture of aqueous suspensions. Such 
excipients may be 
(1) suspending agents such as sodium carboxymethylcellulose, 
methylcellulose, hydroxypropylmethylcellulose, sodium alginate, 
polyvinylpyrrolidone, gum tragacanth and gum acacia; 
(2) dispersing or wetting agents which may be 
(a) a naturally-occurring phosphatide such as lecithin, 
(b) a condensation product of an alkylene oxide with a fatty acid, for 
example, polyoxyethylene stearate, 
(c) a condensation product of ethylene oxide with a long chain aliphatic 
alcohol, for example, heptadecaethyleneoxycetanol, 
(d) a condensation product of ethylene oxide with a partial ester derived 
from a fatty acid and a hexitol such as polyoxyethylene sorbitol 
monooleate, or 
(e) a condensation product of ethylene oxide with a partial ester derived 
from a fatty acid and a hexitol anhydride, for example polyoxyethylene 
sorbitan monooleate. 
The aqueous suspensions may also contain one or more preservatives, for 
example, ethyl or n-propyl P-hydroxybenzoate; one or more coloring agents; 
one or more flavoring agents; and one or more sweetening agents such as 
sucrose or saccharin. 
Oily suspension may be formulated by suspending the active ingredient in a 
vegetable oil, for example arachis oil, olive oil, sesame oil or coconut 
oil, or in a mineral oil such as liquid paraffin. The oily suspensions may 
contain a thickening agent, for example beeswax, hard paraffin or cetyl 
alcohol. Sweetening agents and flavoring agents may be added to provide a 
palatable oral preparation. These compositions may be preserved by the 
addition of an antioxidant such as ascorbic acid. 
Dispersible powders and granules are suitable for the preparation of an 
aqueous suspension. They provide the active ingredient in admixture with a 
dispersing or wetting agent, a suspending agent and one or more 
preservatives. Suitable dispersing or wetting agents and suspending agents 
are exemplified by those already mentioned above. Additional excipients, 
for example, those sweetening, flavoring and coloring agents described 
above may also be present. 
The pharmaceutical compositions of the invention may also be in the form of 
oil-in-water emulsions. The oily phase may be a vegetable oil such as 
olive oil or arachis oils, or a mineral oil such as liquid paraffin or a 
mixture thereof. Suitable emulsifying agents may be (1) 
naturally-occurring gums such as gum acacia and gum tragacanth, (2) 
naturally-occurring phosphatides such as soy bean and lecithin, (3)esters 
or partial esters derived from fatty acids and hexitol anhydrides, for 
example, sorbitan monooleate, (4) condensation products of said partial 
esters with ethylene oxide, for example, polyoxyethylene sorbitan 
monooleate. The emulsions may also contain sweetening and flavoring 
agents. 
Syrups and elixirs may be formulated with sweetening agents, for example, 
glycerol, propylene glycol, sorbitol or sucrose. Such formulations may 
also contain a demulcent, a preservative and flavoring and coloring 
agents. 
The pharmaceutical compositions may be in the form of a sterile injectable 
aqueous or oleagenous suspension. This suspension may be formulated 
according to known methods using those suitable dispersing or wetting 
agents and suspending agents which have been mentioned above. The sterile 
injectable preparation may also be a sterile injectable solution or 
suspension in a non-toxic parenterally-acceptable diluent or solvent, for 
example as a solution in 1,3-butane diol. Among the acceptable vehicles 
and solvents that may be employed are water, Ringer's solution and 
isotonic sodium chloride solution. In addition, sterile, fixed oils are 
conventionally employed as a solvent or suspending medium. For this 
purpose any bland fixed oil may be employed including synthetic mono- or 
diglycerides. In addition, fatty acids such as oleic acid find use in the 
preparation of injectibles. 
For topical use, creams, ointments, jellies, solutions or suspensions, 
etc., containing the compositions of the invention are employed. 
Treatment dosage for human beings can be varied as necessary. Generally, 
oral dosages of the antibacterial compounds of this invention when given 
orally are in the range 250 mg to 4 g per patient given 3-4 times daily. 
The intravenous or intramuscular dosages are 100 mg to 1 g given 3-4 times 
daily. When the compounds of the invention are given intravenously or 
intramuscularly to potentiate carbapenem antibiotics such as imipenem they 
are given in combination with the antibiotic in amounts of 0.1-10 
mg/kg/day. 
The amount of active ingredient that may be combined with the carrier 
materials to produce a single dosage form will vary depending upon the 
host treated and the particular mode of administration. For example, a 
formulation intended for oral administration may contain, for example, 
from 100 mg to 2000 mg of active agent compounded with an appropriate and 
convenient amount of carrier material which may vary from about 5 to about 
95 percent of the total composition. 
The amount of active ingredient that may be combined with the carrier 
materials to produce a single dosage form will vary depending upon the 
host treated and the particular mode of administration. 
It will be understood, however, that the specific dose level for any 
particular patient will depend upon a variety of factors including the 
activity of the specific compound employed, the age, body weight, general 
health, sex, diet, time of administration, route of administration, rate 
of excretion, drug combination and the severity of the particular disease 
undergoing therapy. 
The compounds of Formula I can be prepared by the methods shown in the 
following Reaction Schemes wherein R.sup.1 and R.sup.2 are as defined 
above unless otherwise indicated. 
As will be evident to those skilled in the art and as demonstrated in the 
Examples hereinafter, reactive groups not involved in the reactions, such 
as amino, carboxy, mercapto, etc., may be protected by methods standard in 
peptide chemistry prior to the coupling reactions and subsequently 
deprotected to obtain the desired products. Cbz refers to carbobenzyloxy, 
and BOC refers to t-butoxycarbonyl. 
##STR5## 
The Cbz aminoalkylphosphonous acids (1) in Reaction Scheme A can be 
prepared according to procedures described by P. A. Bartlett et al. (J. 
Amer. Chem. Soc. 106, 4282-4283 (1984)) and E. K. Baylis et al. (J. Chem. 
Soc. Perkin Trans. 1, 2845-2853 (1984)) and can be resolved to give 
optically active materials by the method of Baylis (reference above) both 
methods hereby incorporated by reference. Compounds derived from both the 
optically active and racemic materials are claimed in the present 
invention. 
The protected aminoalkylphosphonous acid (1) is esterified with either 
diazomethane or triethylorthoformate to give the methyl or ethyl ester (2) 
which is deprotonated with either sodium methoxide or ethoxide in the 
corresponding alcohol and treated with the appropriately substituted 
acrylate to give (4), the protected form of Formula I. The acrylates can 
be prepared by procedures outlined by J. Harley-Mason in tetrahedron 36, 
1036-1070 (1980), hereby incorporated by reference. 
Compound 4 can be alternatively synthesized by alkylation of the protected 
aminoalkylphosphonous acid (1) with appropriately substituted 
3-halopropionates or acrylates in the presence of a trialkylsilylchloride 
such as trimethylsilylchloride and a tertiary amine such as triethylamine 
according to the general methods of J. K. Thottathil et al. (Tetrahedron 
Lett. 25, 4737-40, 4741-44 (1984), hereby incorporated by reference. 
The phosphinic acid 3 may be esterified by diazomethane to give compound 4. 
##STR6## 
As illustrated in Reaction Scheme B, Compound 4 is converted to formula I 
by two standard routes. The carbobenzyloxy group can be removed by either 
bydrogenation in an alcohol such as ethanol with a catalyst such as Pd/C, 
or by cleavage with HBr in acetic acid. Subsequent ester hydrolysis in 
concentrated HCl provides, after treating with propylene oxide, for 
example, compounds of formula I. 
##STR7## 
Reaction Scheme C illustrates an alternative route involving a conjugate 
addition of the phosphonous ester under the conditions previously outlined 
to trimethyl-2-phosphonoacrylate. The subsequent anion is then trapped 
with an aldehyde yielding the dehydro compound 9, as a mixture of E and Z 
isomers. A similar intermediate 8 can be prepared by alkylation of the 
protected aminoalkylphosphonous acid with substituted 
2-bromomethylacrylates under conditions reported by J. K. Thottathil, et 
al. Tetrahedron Lett. 25, 4737-40, 4741-44 (1984), hereby incorporated by 
reference. Treatment of either 8 or 9 under acidic conditions then yields 
compounds of Formula II. Alternatively, olefin 9 may be selectively 
reduced using homogenous catalysis. For instance, one may use a 
[(COD)RhCl].sub.2 complex with an organophosphine ligand in methanol to 
give compound I which can be further elaborated by procedures already 
outlined. 
Chiral organophosphine ligands such as 
(-)2,3-0-isopropylidene-2,3-dihydroxy-1,4-bis (diphenylphosphino)butane, 
((-) DIOP), may be used in order to produce the S or R stereoisomers at 
R.sub.2 in high enantiomeric excess. 
Preferred diastereomers for dehydropeptidase inhibition correspond to 
L-amino acids (R stereochemistry) at the carbon bearing R.sub.1. 
Stereochemistry at R.sub.2 may correspond to either D- or L-amino acids 
for good activity (R or S). The stereochemistry at R.sub.5 in dehydro 
analogs can be either E or Z and preferably is Z. 
Melting points were recorded on a Thomas-Hoover melting point apparatus and 
are uncorrected as are all boiling points. .sup.1 H NMR spectra were taken 
on a Varian XL-300 FT spectrometer. Chemical shifts are reported in ppm 
downfield from tetramethylsilane as internal standard. IR spectra were 
recorded on a Perkin-Elmer Model 297 spectrometer. Optical rotations were 
measured with a Perkin Elmer 141 automatic polarimeter in the solvents 
indicated. Mass spectra (MS) were taken on a Varian 731 spectrometer at 70 
eV. Those marked FAB were taken by using the fast atom bombardment method.