1a-7-SUBSTITUTED DERIVATIVES OF MITOMYCIN AND USES THEREOF

Abstract: 1a- and 7-substituted derivatives of mitosanes containing thiocarbamoyl and glycosyl residues. The compounds possess antibacterial and antitumor activity, with a concomitant reduction in bone marrow toxicity as compared to the parent compounds.

Description: TITLE OF THE INVENTION: la-7-SOBSTITUTED DERIVATIVES OF MITOMYCIN AMD USES THEREOF Technical Field; This invention is directed to new mitomycin deriv¬ atives having good anti-tumor activity while at the same time demonstrating reduced bone marrow toxicity as compared to the parent compounds. The mitomycin derivatives of the present invention •are characterized by thiourea substitution at position la and, additionally, glycosyl substitution at either the la or 7 position. Background Art; The mitomycins are compounds corresponding to the general formula (I): - Z Mitomycins A, B and C are related to one another as set forth in Table 1 below, the designations X., Y and Z being those of formula (I). TABLE I Mitomycin: A -OCH, -OCH, -H B -OCH -OH J -CE C - H 2 J -OCH, -H Mitomycins are derived from mitosane compounds which, generically have the following skeleton II: The mitosanes are formed during the cultivation, under artificially controlled conditions, of the microorgan¬ ism Streptomyces caespitosus in a liquid nutrient medium. After separating the resulting mycellium, for example, by filtration, from the obtained culture broth, the various mitomycins may be isolated from the latter by active carbon or preferably non-ion exchange resin adsorption, organic solvent extraction, or chromatography on alumina, as disclosed by U.S. Patent No. 3,660,578 to Hata et al. The mitosanes are acknowledged as excellent anti¬ biotics but are disadvantageous in that they are toxic to human blood (see U.S. Patent 3,450,705 to Matsui et al. ) . The relatively highly toxic nature of the compounds has prompted.prior art synthesis of numerous mitomycin derivatives and analogues in an attempt to secure compounds having equal or enhanced antibiotic activity but lesser toxicity than the naturally occur¬ ring mitomycins. In the above noted U.S. Patent 3,450,705 to Matsui et al. , there are disclosed mitomycin compounds substituted at the 7 position with amino, lower alkyl amino, phenyl amino, or pyridyl, and substituted at the la position with haloalkanoyl, halobenzoyl, nitrobenzoyl, . alkenoyl, acetyl glycyl, sorbyl or acetyl methionyl. U.S. Patent 3,558,651 to Matsui e_t . al. discloses mitosane derivatives which are la-acyl-7-acyloxy- 9a-methoxy compounds. Certain mitomycins and mitomycin derivatives pos¬ sess a degree of i_n vivo anti-tumor activity as well, as reported by Oboshi et al. , GANN, 5J3: 315-321 (1967); Usubuchi et al^, GANN, ^8: 307-313 (1967); Matsui et al. , J. Antibiotics, XXI, No. 3; 189-198 (1968); Japanese Patent 68 06 627 to Mastui et -al. (as reported in Chem. Abstracts, Vol. 69, 86986K (1968)); and Cheng et al. , J. Med. Chem. , 20, No. 6; 767-770 (1977). As disclosed in Mitomycin C: Current Status and New Developments, Carter et al., Eds., Academic Press, New York (1979), while mitomycin C is active against a relatively broad spectrum of experimental tumors, clinical practice restricts its use to certain carcinomas owing to its toxicity and particularly its yelosuppressive effects. Recent pre-clinical and clinical studies of mito¬ mycin C have confirmed its activity in a variety of murine and human neoplasms, but its clinical use has been limited by the severe, delayed bone marrow toxicity of the compound, and its narrow therapeutic index (Goldin, A. et al. , NCI-EORTC Symposium on Mitomycin C, Brussels, Belgium, 1981). In that same reference, Goldin e_t al. reported preclinical studies which indicated that animal studies are predictive for the clinical toxicities of mitomycin C. In mice, rats, cats, dogs, and rhesus monkeys, the toxicities caused severe bone marrow depression and gastrointes¬ tinal damage, and were delayed in onset. Trials initiated at the Lombardi Cancer Research Center of Georgetown University (Schein, P. S. et al. , "Mitomycin C: Current Status and New Developments, pp. 133-143, Carter e_t al. , Eds., Academic Press, New York (1979)) demonstrated that a combination of three drugs, 5-fluorouracil, adriamycin, and mitomycin C, was effective in the treatment of patients with advanced gastric and colorectal cancer. The regimen incorporated mitomycin C administration in a single dose schedule every two months, to decrease the treatment-limiting delayed myelosuppressive effects of the compound. As disclosed by Remers, U.S. 4,268,676, numerous semi-synthetic analogues of mitomycin C have been pre¬ pared in the hope of obtaining compounds with improved therapeutic properties, especially anti-tumor proper¬ ties. These analogues have involved substitution on the aziridine ring, carbamoyl, or acyl group substitu¬ tion on the hydroxymethyl side chain, and replacement of the 7-substituent in the quinone ring with other functional groups, especially substituted amines. However, as disclosed by Remers, none of these ana¬ logues has emerged as a clinical agent, with the pos¬ sible exception of the 7-hydroxy analogue of mitomycin C, which has been involved in a recent study in Japan. This analogue is asserted to be less leukopenic than mitomycin C, although it is also much less potent. Further mentioned by Remers are totally synthetic mitomycin analogues of the mitosane type (Mott et al. , J. Med. Chem., 21; 493 (1978)), prepared mainly for their antibacterial activity. Kinoshita, S. et al. , J. Med. Chem. , 14, No. 2: 103-112 (1971), reported the results of studies of several derivatives of mitomycin substituted in the la, 7, and 9a positions. Included in this study were compounds substituted at the la position with sulfonyl, ortho-substituted benzoyl, and acyl deriva¬ tives. Iyengar, B. et al. , J. Med. Chem., 26; 16-20 (1983), describe a study wherein a series of 7-substi- tuted mitomycin C's and porfiromycins were prepared and screened in standard anti-tumor systems. Certain of the analogues showed better activity than mitomycin C against various tumors, with some less leukopenic and some more leukopenic than the mitomycin C. The authors describe the selection of the 7 position for substitution with the 2-substituted-ethyl analogues because position 7 controls the reduction of the quinone ring, thereby offering an opportunity to gain selectivity between normal cells and certain cancer cells. Suami, S. et al. , J. Med. Chem., 27: 701-708 (1984), prepared a series of 30 different phenyl-sub- stituted mitomycin C analogues, the phenyl substitu¬ tion being at the 7 position. Seven of the compounds prepared were disclosed as clearly superior to mito¬ mycin C in activity against P-388 murine leukemia. It is also known from Suami, T. et al. , J. Med. Chem. , 22, No. 3: 247-250 (1979), that N-(2-chloro- ethyl)-N-nitrosocarbamoyl derivatives of glycosyla- ines, including three disaccharide derivatives, exhibited strong anti-tumor activity against Leukemia 1210 in mice. • Further, it has been demonstrated that glucopyranose derivatives of N-nitrosoureas possess immunogenic and marrow sparing properties (Anderson et al. , Cancer Research 35, 761-765 (March 1975); Panasci, e_t al. , J. Clin. Invest., Vol. 64, 1103-1111 (October 1979)). Thus, as may be seen from the above disclosures, research has continued in an effort to synthesize and isolate analogues of the mitomycins which have com¬ parable anti-neoplastic capability, but, at the same time, are less toxic to the animal system than the parent compound. DESCRIPTION OF THE INVENTION. Recognizing the long-standing need in the medical and scientific community for compounds demonstrating the anti-neoplastic capability of the mitomycins which would, at the same time, be substantially less toxic to the animal system, the inventors have synthesized mitomycin analogues, said analogues combining glycosidic residues and thiourea moieties. This effort has resulted in the synthesis of compounds having the following general formula (III): where R, is selected from the group consisting of NH-, C- j -C. alkoxy, and a glycosyl residue; and R- is selected from hydrogen, C-,-C. alkyl, and a glycosyl residue, with the proviso that either R, or R 2 but not both, contains a glycosyl group. The com¬ pounds represented by formula (III) demonstrate the excellent anti-neoplastic capability of the mitomycins and, at the same time, possess reduced bone marrow toxicity and lower overall toxicity. BRIEF DESCRIPTION OF THE FIGURES Figure 1 presents the results of the peripheral leukocyte ( BC) study of Example 10 below. Figure 2 is a schematic of the synthetic proced¬ ures for production of the mitosane compounds of the present invention. Figure 3 is a schematic of the synthetic procedure for preparation of isothiocyanate intermediates useful in the preparation of the mitosane derivatives of this invention. Figure 4 is a graph comparing induction of phage formation by M-TAG and mitomycin C at various concentrations as a measure of genotoxicity. BEST MODE OF CARRYING OUT THE INVENTION The la- and 7-substituted derivatives of mitomycin of this invention have the general formula (III): In this formula, R, is selected from the group consisting of NH-, c τ_~ C 4 alkoxy, and a glycosyl resi- due, and R 2 is selected from the group consisting of hydrogen, C,-C 4 alkyl, and a glycosyl residue. How¬ ever, the compounds are characterized in that at least one, but not both of R, and R- simultaneously is said glycosyl residue. By the term "glycosyl residue" is meant monosac- charides and disaccharides and the glycosides and aminated derivatives thereof. Typical monosaccharides include glucose, galac- tose, mannose, arabinose, xylose, fructose, ribose, and apiose. Typical disaccharides include sucrose, cellobiose, maltose, lactose, trehalose, gentiobiose, and melibiose. The glycosides of the mono- and disaccharides may be acylated, partially or completely, with a group R-.-C0- where R 3 is C,-C 4 alkyl. Preferably, the glycosides are acylated with acetyl or propionyl groups. The glycosyl residues may be in ring configuration as well. Typical six-membered ring compounds, the pyranosyl derivatives, include, but are not limited to, glucopyranose, galactopyranose, mannopyranose, and xylopyranose, as well as the fully or partially acylated derivatives thereof, and further including aminated derivatives thereof. Typical five-membered ring compounds, furanosyl derivatives, include fructofuranose, arabinofuranose, and xylofuranose, including as well the fully or par¬ tially acylated derivatives thereof, and further including aminated derivatives thereof. Preferred aminated glycosyl residues include those pyranosyl and furanosyl residues which include a 2-acetamido group. Typical of these preferred gly¬ cosyl residues are 2-acetamido-3,4,6-tri-0-acetyl-2- deoxy-D-galactopyranosyl; 2-acetamido-3,4,6-tri-0- acetyl-2-deoxy-glucopyranosyl; and 2-acetamido-3,4,5- tri-0-acetyl-2-deoxy-D-xylopyranosyl. Other preferred glycosyl residues include xylopy- ranosyl, cellobiosyl, maltosyl, lactosyl, galactopy- ranosyl, glucopyranosyl and glucofuranosyl. Among the more preferred compounds corresponding to the general formula III above are those set forth in Table II below, where R. and R-, are as designated therein. T5_ELE 2 Coπpound R l *2 1 NR, 2-acetamido-3,4,6-tri-0- acetyl-2-deαxy-D-gluco- pyranosyl MeO 2-acetamido-3,4,6-tri-0- acetyl-2-decκy-D-gluco- pyranosyl 2-acetamido-3,4,6-tri-0- Ethyl acetyl-2-deoxy-D-gluco- pyranosyl-amine NH- 2-acetamido-3,4,6-tri-0- acetyl-2-deαxy-E>-galacto- pyranosyl 5 NH_ 2-acetamido-2-decκy-D-glu- copyranosyl 6 NH- 2-acetamido-2-cieαxy-_>-gal- actopyrcinosyl 7 NH- xylopyranosyl- 8 NH 2 3,4,5-tri-0-acetyl-D- xylσpyranosyl 9 NH 2 cellobiosyl 10 NH 2 maltosyl 11 NH2 lactosyl 12 NH- galactopyranosyl 13 NB- glucopyranosyl 14 NH2 gluσofuranosyl 15 xxyylliopyranosylamine-3,4,5- ( NH) tri-0-acetyl The synthetic preparation of the mitomycin deriva¬ tives of the invention have, as their starting point, mitomycin C. Mitomycin C may be prepared according to the methods generally disclosed in Cheng et al. , J. Med. Chem. , 20, No. 6: 767-770 (1977). Alternatively, mitomycin C may be obtained from mitomycin A by treat¬ ment of mitomycin A with a methanolic-ammonia solution as described by Matsui, M. et al. , J. Antibiotics, XXI, No. 3: 189 (1968). To obtain amination of the 7 position, mitomycin C is reacted with a basic methanol solution to produce the sodium salt thereof. Extraction with methanol and precipitation with ether yields the 7-hydroxy-9a- methoxy-mitosane. Reaction with diazomethane in ether produces, as an intermediate, mitomycin A. Mitomycin A may then be reacted with an excess of the corresponding amiήe in anhydrous methanol to produce 7-amino-mitomycin C, compound C in Figure 2. The preparation of mitomycin A from mitomycin C is described more fully in Example 1 below. The preparation of the 7-amino-mitomycin C is described more fully in Example 2 below. Preparation of derivatives of the mitosanes (mito¬ mycin A and mitomycin C) substituted at the la posi¬ tion with the thiocarbamyl glycose proceeds through the formation of glyσosamine-1-isothiocyanate inter¬ mediates. These intermediates are prepared by react¬ ing the glycosyl halide, under appropriate conditions, with a metal isothiocyanate. A typical reaction is described more fully in Example 3 below. The isothiocyanate intermediate is then reacted with the desired mitosane, a typical reaction des¬ cribed more fully in Example 4 below. Therapeutic methods of the invention comprise the administration of effective amounts of one or more of the compounds of formula (III), as an active ingredient, together with desired pharmaceutically acceptable diluents, adjuvants and carriers, to an animal for antibiotic and/or anti-neoplastic purposes. As an antibiotic, the compounds of the present invention are useful against all microorganisms susceptible to the anti-bacterial action of the parent compounds, these microorganisms including, but not limited to, Pseudomonas, Staphylococcus, Sarcinia, Diplococcus, Streptococcus, Corynebacterium, Hemophilus, Escherichia, Klebsiella, Proteus, Salmonella, Shigella, Brucella, Mycobacterium, Nocardia, Saccharomyces, Candida, Penicillium, and Aspergillus. Specific microorganism treatable with the compounds of the present invention include Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus albus, Staphylococcus citreus, Sarcina lutea, Diplococcus pneumoniae. Streptococcus hemolyticus. Streptococcus lactis, Corynebacterium diphtheriae, Hemophilus pertussis, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris. Salmonella typhosa, Salmonella paratyphi, Shigella dysenteriae, Brucella abortus, Brucella megatherium, Brucella mycoides, Brucella anthracius, Mycobacterium ATCC 607, Mycobacterium avium, Mycobacterium phlei, Nocardia asteroides, Saccharomyces cervisiae, Candida albicans, Penicillium glacum, and Aspergillus niger. The mitosane derivatives of the present invention are useful vitro as antiseptics, i.e. for disinfecting. The compounds are also useful topically and internally as a therapeutic agents in combating pathogenic bacteria, e.g. in cases of staphyloderma- titis, bacterial pneumoniae, leptopserosis, rickettsi- osis, salmonellosis, and the like. Typically, as a topographical application, the mitosanes of this invention are applied in compositions which deliver the active ingredient in concentrations in the range of .004 to 4,000 ug/ml. As antineoplastic ' agents, the compounds of the present invention are useful in treating a variety of cancers, including, but not limited to, those cancers susceptible to cell growth suppression by the parent compounds. Treatment of cancers with the parent compounds are described in the following references: Driscoll, J.S., Hazard, G.F., Wood, H.B. Jr., et al.. Cancer Chemotherapy Rep., ^, 1, (1974). Kojima, R. , Goldin, A. .& Mantel, N.-, Cancer Chemotherapy Rep., 3_, 111 (1972). Sugiura, K. , Cancer Res., 19. (#VIII) 438 (1959). Oboshi, S. , Matsui, M. , Ishii, S. , et al. , GANN, 5_8, 315 (1967). Sugiura, K. , Cancer Chemotherapy Rep., ^ , 51 (1961). Venditti, J.M. , Goldin, A., Miller, I., et al.. Advances in Cancer Chemotherapy, pp. 201-209 (1978) Editors: ' H. Umezawa et al. , Japan Soc. Press, Tokyo/Univ. Park Press, Baltimore. Usubuchi, I., Sobajima, Y. , Hongo, T. , ' et al. , GANN, , 307 (1967). Typical cancers treated by the ^ mitosane derivatives of this invention include, but are not limited to, gastric and pancreatic neoplasms (Schein, P.S. et al., "Mitomycin C: Current Status and New Developments, pp. 133-143, & Carter et al. , Eds., Academic Press, New York (1979)). Other cancers that may be treated by the invention thereof include lung, breast, anal, colorectal, head & neck & melanoma. These analogs may also be active against the following tumor systems: Leukemia L 1210, Leukemia P388, P1534 leukemia, Friend Virus Leukemia, Leukemia L4946, Mecca lymphosarcoma, Gardner lymphosarcoma, Ridgway Osteogenic sarcoma. Sarcoma 180 (ascites), Wagner osteogenic sarcoma. Sarcoma T241, Lewis lung carcinoma. Carcinoma 755, CD8F, Mammary carcinoma. Colon 38, Carcinoma 1025, Ehrlich carcinoma (ascites & solid), Krubs 2 carcinoma (ascites), Bashford carcinoma 63, Adenocarcinoma E 0771, B16 Melanoma, Harding-Passey melanoma, Giloma 26, Miyona adenocarcinoma. Walker carcinosarcoma 256, Flexner-Jobling carcinoma, Jensen sarcoma, Iglesias sarcoma, Iglesias ovarian tumor, Murphy-Sturn lymphosarcoma, Yoshida sarcoma. Dunning leukemia, Rous chicken sarcoma, and Crabb hamster sarcoma. The compounds of this invention may be adminis¬ tered by any means that effects palliating conditions in warm-blooded animals. For example, administration may be parenterally, i.e., subcutaneously, intrave¬ nously, intramuscularly, or intraperitoneally. Paren- teral compositions suitable for the practice of the present invention include the active mitosane deriva¬ tives as described above, in combination with a pharmacologically acceptable carrier, solvent, or diluent. Typical vehicles for parenteral administra¬ tion of the active ingredient include aqueous vehi¬ cles, water-miscible vehicles such as ethyl alcohol, polyethylene glycol, and polypropylene glycol, and nonaqueous vehicles such as corn oil, cotton seed oil, peanut oil, sesame oil, ethyl oleate, isopropyl myristate and benzyl benzoate. Typical parenteral preparations are described by Remington's Pharmaceu¬ tical Sciences, Mack Publishing Company, Easton, Pennsylvania, 16th Edition, Chapter 84 (1980). Alternatively, or concurrently, administration can be by the oral route with the active mitosane deriva¬ tives being compounded with pharmacologically accept¬ able carriers and extenders known to the art. The dosage administered will be dependent upon the age, health and weight of the recipient, kind of con¬ current treatment, if any, frequency of treatment, and the nature of the effect desired. Therapeutic methods of the present invention com¬ prehend the administration of effective amounts of one or more of the compounds of Formula III as an active ingredient together with desired pharmaceutically acceptable diluents, adjuvants, and carriers, to an animal suffering from a neoplastic disease state. Unit dosage forms of compounds administered according to the methods of the invention may range from about 0.001 to about 5.0 g and preferably from about 0.004 to about 1.0 mg, of the compounds. Such unit dosage quantities may be given to provide a daily dosage of from about 0.1 to about 100 mg per kg, and preferably from about 0.2 to about 60 mg per kg, of body weight of the animal treated. Parenteral administration, and especially intraperitoneal administration, is the pre¬ ferred route for antineoplastic therapy. The compounds can be employed in unit dosage form such as tablets, capsules, powder packets, or liquid solutions, suspensions, or elixirs, for oral adminis¬ tration, or sterile liquid for formulations such as solutions or suspensions for parenteral use. In such compositions, the active ingredient will ordinarily always be present in an amount of at least 0.5% by weight based on the total weight of the composition and not more than 90% by weight. Having generally described the invention, a more complete understanding may be obtained by reference to certain examples, which are included for purposes of illustration only and are not intended to be limiting unless otherwise specified. EXAMPLE 1 Preparation of Mitomycin A (Compound A of Figure 2) 1600 mg of mitomycin C were dissolved in 12 ml of 0.1N NaOH solution of 50% methanol with stirring at room temperature for 48 hours. The reaction mixture was quenched with excess dry ice to neutralize the NaOH. This mixture was freeze-dried m vacuo to give the sodium salt plus NaHCO.-,. A small amount of methanol was added to extract the mitosane compound. The methanol solution was concentrated jLn vacuo to dryness and the extraction and filtration in methanol was repeated. This methanol extract was precipitated with ether to yield approximately 1400 mg of a blue- purplish powder. This powder was dissolved in methan¬ ol and added to a silica gel column (pretreated with acid) and eluted with methanol. The methanol was evaporated jj vacuo to dryness to give 1200 mg of a reddish-purple compound, 7-hydroxy-9a-methoxy- mitosane. 1000 mg of this precipitate were dissolved in 200 ml of ethyl acetate and cooled to 5 C; and diazomethane in ether was added in excess. The mix¬ ture was allowed to stand at room temperature for 30-45 minutes. This .mixture was then evaporated in vacuo to dryness to give a purplish residue which was then dissolved in ethyl acetate and added to a silica gel column and eluted with ethyl acetate. The reddish-purple band was collected and evaported to dryness i_n vacuo and recrystallized from ether to give 650 mg of purple needles of mitomycin A with a melting point of 159-160 ' °C (160°C lit.). TLC (ETOAC:Acetone) one spot R f = 0.91; UV (MeOH) 216 and 358 u NMR(CDC1 3 ); appearance of singlet at 4.04 corresponding to the 7-methoxy group which is not present in the parent compound mitomycin C. EXAMPLE 2 Preparation of 7-Amino-Mitomycin (Compound C of Figure 2) Mitomycin A, 500 mg, was dissolved in 10 ml of MeOH (anhydrous) and an excess of the corresponding amine was added with stirring under a nitrogen atmos¬ phere at room atmosphere for 24 hours. The course of reaction was followed with TLC (ETOAc:Me-CO, 1:1). The reaction mixture was evaporated to dryness _in vacuo at room temperature and the crude residue redissolved in a minimal amount of MeOH; a purplish powder was precipitated with addition of petroleum ether. The powder was filtered, collected, and dried ^n vacuo over powder was recrystallized from ethyl acetate. NMR analysis showed no singlet at 4.04 . See Matsui, M. et al. , J. Antibiotics, XXI, No. 3: 189 (1968). EXAMPLE 3 Preparation of the Glycosyl Isothiocyanate Intermediate 2-acetamido-2-deoxy-D-glucopyranose (Compound X of Figure 3), 10 grams, was mixed with 22 ml of acetyl bromide with cooling and allowed to react at room temperature under nitrogen atmosphere for 16 hours and worked up as follows: 100 ml of methylene chloride was added to the reaction mixture and the mixture poured onto 100 grams of crushed ice with 20 ml of water. The organic layer was separated and dried over anhydrous magnesium sulfate. The CH^Cl- was evaporated i_n vacuo to 10-15 ml, glacial acetic acid added, and the mixture chilled to give 8-8.5 g (47%) mp 180-190°C, [«_5- D +148 (C1,CHC1 3 ). The migrated product had a mp of 180-200°C decomp. O 20 +118,(Cl, HOAc) (Compound Y of Figure 3). D 1000 mg of this bromo compound, Y intermediate, was dissolved in 25 ml of freshly distilled ace- tonitrile (from 2 0 ζ ) along with 1000 mg of silver isothiocyanate (protected from light) and heated to 50-60°C for approximately 1/2 hour. This mixture was cooled and evaporated ij vacuo (§ 40°C water bath). Recrystalliztion of the residue from EtOAc gave 915-920 mg (94-98%) [P4] 20 +9(C1, CHC1,). D J This was compound Z_. NMR(CDC1 3 ): 5.7 £ J=8.5-9 Hz doublet (^anomer H-l); 2.0-2.116^ (NAc,3, 4,6 tri-O- acetyl protons). This compound showed one spot on TLC (EtOAc:MeOH; 5:1) R- 0.94) developed with r _ι H 4 S0 4 H 2 SO. spray and charring: IR (EtOAc); 2020 cm (N=C=S). This compound was 2-acetamido-3,4,6,-tri-0- acetyl-2-deoxy-B-D-glucosaminer-l-isothiocyanate (Compound Z of Figure 3). EXAMPLE 4 Preparation of la(N-2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-D- glucopyranosylthlocarbamoyl)-mitomycin C (M-TAG) Now compound Z ^ was coupled with mitomycin C in freshly distilled tetrahydrofuran (THF) (distilled from P~0- under N- ): 200 mg of mitomycin C and 240 mg of compound _ in 200 ml of dry THF were stirred at room temperature under N_ atmosphere for 24 hours. The reaction was followed with TLC (silica gel; EtOAc:Me-C0; 1:1); R f =0.80, one spot. NMR(DMSO-d )&: disappearance of aziridine NH moiety at 2.7 ; addition of multiplet (1.988-2.02<T corresponding to compound Z s OAc's to the mitomycin C basic NMR chemical shift. Also a doublet . at . l£, J=8-9Hz (& anomer of compound _Z). IR(EOTAc); no band for N=C=S at 2020 cm " . The¬ oretical analysis for C 3 Q H 38 6 0 1_ S? C==49 « 85 ' H=5.31; N-11.63 S=4.44: Found; C=49.43; H=5.57; N=11.06; S=4.49, confirming M-TAG. ANTIBIOTIC STUDIES EXAMPLE 5 The antibiotic characteristics of la-(N-2-aceta- mido-3,4,6-tri-0-acetyl-2-deoxy-D-glucopyranosylthio- carbamoyl)-mitomycin C were evaluated against seven microorganisms and compared with mitomycin C as well. Bacteria were grown in a standard growth culture at pH 7.2. After the cultures were incubated at 37°C overnight and diluted into fresh medium, controls and the test antibiotics dissolved in 0.3% hydroxy propylcellulose (HPC), were added at various concentrations and then reincubated overnight. The measure of antibiotic activity was determined by the amount of bacterial growth inhibition as shown by measurement of the optical density at 660 n . The results are shown in Table 3 below. As may be seen from Table 3, the mitomycin C derivative demonstrates excellent antibiotic activity, possessing anti-bacterial activity against gram positive and -gram negative microorganisms in a fashion similar to that of the naturally occurring mitomycins. Further, the mitomycin-C derivatives are less toxic on a log dose-response scale when compared to the parent mitomycin-C. TABLE 3 CONCENTRATION (m_q ml ) la-(N-2 ace_amido-3,4,6-tri-0-acetyl-2-deoxy-D-glucopyranosyl thio car bamoyl ) -mitomycin C Name of Microorganism 400 40 4.0 0.4 0.04 W3100 (E. coli) 92(0.04)* 86(0.07) 50(0.30) 31(0.51) 33(0.48) Pseudomonas Sp. 78(0.11 75(0.11) 75(0.13) 45(0.35) 30(0.52) TA100 (Salmonella Sp. ) 95(0.02) 80(0.97) 80(0.97) 78(0.11) 46(0.34) Staphylococcus Sp. 100 (0.00) 94(0.03) 96(0.018) 95(0.02) 30(0.52) Klebsiella Pneumonia 92(0.04) 40(0.40) 26(0.59) 24(0.62) 22(0.66) Lis eria Sp. 100(0.00) 92(0.036) 26(0.59) 26(0.59) 26(0.59) WP 2s (E. coli) 98 (0.009) 76(0.12) 50(0.30) 51 (0.29) 39(0.41) *% Transmittance at 660 mu (optical density) COMPOUND B: MITOMYCIN C: W3100 (E. coli) 80(0.097) 80(0.097) 88(0.06) 89(0.051) 74(0.13) Pseudomonas Sp. 71(0.15) 72(0.14) 78(0.11) 78(0.11) 78(0.11) TA100 80(0.97) 81(0.092) 85(0.07) 84(0.076) 84(0.076 S-aphylococcus Sp. 90(0.046) 91(0.041 93(0.03) 93(0.03) 30(0.52) Klebsiella Pneumonia 75(0.13) 85(0.07) 87(0.06) 82(0.086) 30(0.52) Listeria Sp. 96(0.018) 96(0.018) 93(0.03) 95(0.13) 85(0.07) WP 2s 85(0.07) 85(0.07) 84(0.076) 86(0.07) 70(0.16) TABLE 3 CONTINUED CONTROLS: Name of Microorganism W3100 (E. coli) 45 37 36 36 36 Pseudomonas Sp. 35 31 33 35 35 TA100 31 36 36 36 46 Staphylococcus Sp. 37 38 32 39 24 Klebsiella Pneumonia 39 30 31 30 30 Listeria Sp. 38 27 36 36 — 48 47 32 35 32 ^23 ANIMAL STUDIES EXAMPLE 6 Determination of Toxic Doses of the Compound in Normal Mice Normal CD2F, male mice, 6-10 weeks old, were used for initial studies to determine toxic single doses of the thiocarbamyl N-Ac glucopyranosyl derivative of mitomycin C, designated M-TAG, in mice (Table 4 be¬ low) . Doses of the compound in the range of the LD, n dose (single intraperitoneal dose that produces toxic deaths in 10% of the normal mice) " were then tested for antitumor activity against several murine tumor sys¬ tems (Examples 7, 8 and 9 below).. The LD, Q dose was then evaluated in normal CD2F, mice for effects on the hematopoietic system (Example 10 below). Normal CD2F, male mice were used to determine the LD, Q dose (single intraperitoneal dose toxic to 10% of normal mice) for the compound. Various concentrations of the compound were prepared immediately prior to use by dissolving the drug in absolute ethanol, and then adding the resultant solution to either sterile water or hydroxypropyl cellulose (HPC, 0.3% in saline) at a final concentration of 8% ethanol and 92% water or HPC vehicle. Drug was administered intraperitoneally (i.p.) in a volume of 0.1 ml per 10 grams body weight. The normal mice were then observed for up to 45 days post-drug administration to determine deaths due to acute and chronic (up to 45 days) drug toxicity. Results are summarized in the following Table 4: TABLE 4 Dose (mg/kg) Deaths due to drug toxicity 250 0/10 275 1/10 LD 1Q 300 3/10 The approximate IO 1Q dose of the compound (single i.p. dose toxic to 10% of normal mice) was 250-275 mg/kg; single doses in this range were used to evalu¬ ate antitumor activity in three murine tumor systems. EXAMPLE 7 Determination of Murine P338 Leukemia Antitumor Activity The murine P388 leukemia system, maintained intra- peritoneally in female DBA/2 mice, was used to eval¬ uate antitumor activity. This tumor was selected be¬ cause of its known sensitivity to the parent compound, mitomycin C (Driscoll et al. , Cancer Chemotheraphy Reports, 4_: 1 (1974)). The compound (M-TAG) and the parent mitomycin C were both dissolved in absolute ethanol, and the resultant solution was added to either sterile water or HPC vehicle to result in a final concentration of 8% ethanol-92% sterile water or HPC vehicle. The compound (M-TAG) and mitomycin C were adminis¬ tered to groups of 10 CD2F, male mice on day one after implantation of 1 x 10 6 P388 leukemia cells i.p. (in a volume of 0.10 ml). The P388 antileukemic activity of the test compound (M-TAG) was assessed by mean surviv¬ al days, percentage increased life span or %ILS, and number of survivors after 45 days. The %ILS was calculated as follows: %ILS = (T-O/C x 100 where T is the mean survival days of the treated mice and C is the mean survival days of the untreated mice P388 antileukemic activity of M-TAG was compared to that achieved with the clinically used mitomycin C, and the results are summarized in the following Table 5: TABLE 5 Antitumor Activity against P388 Leukemia Mean Survival Drug Dose (mg/kg) %ILS (Days) M-TAG 250 mg/kg a (346 umol/kg) 85% 22 Mitomycin C 4 mg/kg a (12 umol/kg) 84% 21 a approximate LD- Q dose There was no statistical difference in the overall survivals when an LD. Q dose of M-TAG was compared to an LD,,. dose of mitomycin C. EXAMPLE 8 Determination of Murine Ehrlich Ascites Antitumor Activity The antitumor activity of M-TAG for the murine Ehrlich ascites tumor was also determined. Ehrlich ascites was maintained i.p. in female BALB/C mice. For antitumor studies, 1 x 10 7 Ehrlich ascites cells (in 0.10 ml) were implanted i.p. in male BD2F 1 mice. Drug was administered i.p. (single LD, Q dose) one day after tumor implantation. The %ILS was calculated as pre¬ viously described, and the results are presented in the following Table 6: TABLE 6 Antitumor Activity against Ehrlich Ascites Mean Survival Drug Dose (mg/kg) %ILS (Days) M-TAG 250 mg/kg a 66% 22.8 Mitomycin C 4 mg/kg a 82% b a approximate LD, n dose 50% of the mice were alive on Day 30 EXAMPLE 9 Determination of Murine B16 Melanoma Antitumor Activity Activity against the murine B16 melanoma is cur¬ rently being determined. The tumor is maintained sub- cutaneously in female C57 mice, and antitumor activity is determined in male BD2F, mice that have received 0.5 ml of a 10% tumor brei i.p., with drug adminis¬ tered i.p. on day 1 following tumor implantation. All mice which received M-TAG (250 mg/kg) or mitomycin C (4 mg/kg) were alive on day 10, after all vehicle-control mice died. On day 20, 6 out of 10 mice receiving M-TAG and 5 out of 10 mice receiving mitomycin C were alive. In summary, the new analogue (M-TAG) has antitumor activity against the murine P388 leukemia equivalent to that achieved with the parent mitomycin C. M-TAG also demonstrated significant antitumor activity against the murine Ehrlich ascites and B16 melanoma tumors. EXAMPLE 10 Determination of the Effects of the Compound on the Hematopoietic System in Mice Effects on Peripheral Leukocyte Count Measurement of peripheral leukocyte (WBC) count was performed using a 20-ul sample of retro-orbital sinus blood obtained from normal CD2F. male mice on days 3, 4, 5, 6 and 10 following i.p. administration of doses in the range of the LD..; groups of 10 mice were treated with drug as described previously. Comparative studies were performed with M-TAG and mitomycin C. Drug was dissolved in absolute ethanol, and then adjusted to a final concentration of 8% ethanol-92% sterile water. Blood samples obtained were diluted in 9.98 ml of Isoton (a neutral isotonic buffer solution) and counted in a Coulter counter after lysis with Zapoglobin (an enzyme solution which lyses red blood cells but not white blood cells). WBC counts are expressed as a percentage of values from control mice receiving drug vehicle only. Results of the peripheral leukocyte (WBC) study are presented in Figure 1. The nadir for mitomycin C (4 mg/kg) occurred on day 3 or 4 after drug administration, and was 76% of the control. In contrast, the compound (M-TAG, 250 mg/kg) produced no significant depression in WBC counts at all days tested (days 3, 4, 5, 6 and 10). These data demonstrate M-TAG to have no significant myelotoxicity as measured by WBC depression, in contrast to the 24% decrease in WBC counts produced by an equivalent LD, Q dose of mitomycin C. The WBC nadir depression produced by mitomycin C was significantly greater than that produced by an equitoxic dose of M-TAG (P<0.01). Exanple 11 Human CFU-C assay The human bone marrow CFU-C assay measures human bone marrow cells committed to granulocyte-macrophage differentiation. This in vitro assay serves as a model for predicting the relative toxicity of an experimental drug on the granulocytic series of the bone marrow. The derivative, M-TAG, was tested at an approximate 30-40-fold increased molar concentration relative to the parent mitomycin C. This concentra¬ tion was increased to correspond to the demonstrated 30-40-fold difference in LD.. dose in mice (see Table 5). Both drugs were dissolved in o.5% DMSO, and nucleated human bone marrow cells were exposed in vitro (for 90 minutes at 37°C) to varying concentra¬ tions of each drug. The cells were then plated in triplicate in 3% agar for the CFU-C assay, using GCT, (Giant Cell Tumor) extract (Gibco, Grand Island, New York) as colony-stimulating factor. (Lohrmann and Schreml "Cytotoxic Drugs and the Granulopoietic System", Springer-Verlag Press, (1982)). The following results were obtained: Drug Concentration CFU- -C: % Control Mitomycin C- .01 mM <10% .005 mM 21% .001 mM 30% M-TAG 1.0 mM <20% 0.5 mM 43% 0.1 mM 66% These data further demonstrate the reduced bone marrow toxicity of M-TAG compared to the parent mitomycin-C. Example 12 The toxicity of the mitosanes (including the derivatives of this invention) can be evaluated by their induction of lambda prophage development in E. coli WP2s ( λ) . This short-term bacterial assay for genotoxic effects is used to predict the carcinogeni- city of the drugs tested. (T.G. Rossman, et al.. Environmental Mutagenesis 6_, 59-69 (1984)). In a micro suspension assy for prophage induction in E. coli WP2s ( ) , using a 24 hour exposure time and MNNG (N-methyl-N-nitrosoguanidine) as a positive control, the analog of mitomycin C, M-TAG, produced maximum induction of ^-phage at 2 mg/ml, while maximum induction with mitomycin C occurred at 0.02 mg/ml. Each compound produced a maximum 50-100% increase of phage titer over control. Both compounds were geno- toxic, but the toxicity of M-TAG was about 50 fold less than the parent compound. (See Table 8 and Figure 4). Hence M-TAG also demonstrates in this set of experiments that it is as active as the parent compound but much less genotoxic. Microsuspension Assay: All strains used were derivatives of E. coli B/r. WP2s (A) is a lysogen or WP2s (trp E, UVrA. SR714 was used as indicator. Cultures were developed in Minimal Broth Davis (Difco) which contains 0.2% glucose and 20 ug/ml of tryptophan (MST). Mid-exponential phase cultures were used for every experiment (O.D. 0.3 at 550 nm). Two fold dilutions of the test drug in 150 ml MST were -made in tissue , culture- ultiwell plate. After scoring for growth, an aliquot of 25 ml from each well was diTuted in 5 ml MST. Diluted samples were added to tubes containing 2.5 ml of soft agar (0.65% Bacto agar, lOmM MgS0 4 ) and held at 47°C. A mid-exponential culture of indicator strain was 'added and tubes mixed and poured onto nutrient broth agar plates (Difco). After overnight incubation at 37 C, the plates were scored for plaques. All assays were run in duplicate. TABLE 8 Induction of Propage in Microtiter Assay *PFU/DISH [Cone] ug/ml Control MMC MTAG MNNG -1 200.000 156.0 - 14.5 473, .5 50.000 - 169.0 2366. ,0 12.500 - 461.5 - 3.125 14.0 3516.5 - 2.000 34.0 5395.0 - 0.500 182.0 260.0 2535.0 - 0.125 1449.5 799.5 416. .0 0.03125 >6000.0 1 591.5 1813. ,.5 0.020 >6000.0 1 152.5 - 0.005 >6000.0 1 148.5 - 0.00125 1228.5 - - 0.0003125 56.5.5 — — *PFU (plaque forming units) SSttrraaiinn WWPP22ss ,, SSRRI714 indicator used above. l"T r oo many to count 2 MNNG (N-methyl-N 1 -mtrosoguani.di.ne. Note: Exposure time to all above chemicals was 24 hours. In summary, i_n vivo murine studies demonstrate the compounds of this invention to have significant antibacterial activity against Escherichia, Pseudomonas, Salmonella, Staphylococcus, klebsiella, an< ^ Listeria and antitumor activity against the murine P388, Ehrlich ascites and melanoma tumor systems at doses producing no significant bone marrow toxicity, as determined by depression of peripheral leukocyte (WBC) count. Human CFU-C assay results (Example II) further demonstrate the reduced bone marrow toxicity of the compounds of this invention as compared to the parent compounds. Further, studies of prophage induction in E. coli demonstrate that M-TAG is about 50-fold less genotoxic than mitomycin C (Example 12). Having now fully described this invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without changing the scope or meaning thereof.

Claims: CLAIMS : 1. A compound having the formula: where R, is selected from the group consisting of NH 2 , C- j -C 4 , alkoxy and a glycosyl residue; and R 2 is selected from the group consisting of hydro¬ gen, C,-C 4 alkyl, and a glycosyl residue; with the proviso that at least one but not both R, and R- contains a glycosyl residue. 2. A pharmaceutical composition comprising a compound having the formula: CS - NHR. where R, is selected from the group consisting of NH 2 ' c 1 -c 4 . alkoxy and a glycosyl residue; and R 2 is selected from the group consisting of hydro¬ gen, C,-C 4 alkyl, and a glycosyl residue; with the proviso that at least one but not both R, and R 2 contains a glycosyl residue, together with a pharmaceutically acceptable carrier. 3. The compound of claim 1 or composition of claim 2 wherein R, is selected from the group consist¬ ing of NH 2 , methoxy, and 3,4,5-tri-O-acetyl-xylopyran- osylamine and R 2 is selected from the group consisting of 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-D-glucopy- ranosyl; 2-acetamido-2-deoxy-D-glucopyranosyl; 2-acetamido-2-deoxy-D-galactopyranosyl; xylopyranosyl; 3,4,5-tri-O-acetyl-D-xylopyranosyl; cellobiosyl; maltosyl; lactosyl; galactopyranosyl; glucopyranosyl; glucofuransoyl; ethyl; and hydrogen. 4. The compound of claim 1 or composition of claim 2 wherein R, is NH- and R„ is N-2-acetamido- 3,4,6-tri-O-acetyl-2-deoxy-D-glucopyranosy1. 5. A method of suppressing bacterial growth comprising contacting said bacteria, in an antibac¬ terial amount, with a compound having the formula: CS - NHR 2 where R, is selected from the group consisting of NH,, c ι~ C 4' alkoxy and a glycosyl residue; and R 2 is selected from the group consisting of hydro¬ gen, C,-C 4 alkyl, and a glycosyl residue; with the proviso that at least one but not both R- and R« contains a glycosyl residue. 6. The method of claim 5 wherein R, is selected from the group consisting of NH,, methoxy, and 3,4,5- tri-O-acetyl-xylopyranosylamine and R 2 is selected from the group consisting of 2-acetamido-3,4,6-tri-0- acetyl-2-deoxy-D-glucopyranosyl; 2-acetamido-2-deoxy- D-glucopyranosyl; 2-acetamido-2-deoxy-D-galactopyran- osyl; xylopyranosyl; 3,4,5-tri-O-acetyl-D-xylopyrano- syl; cellobiosyl; maltosyl; lactosyl; galactopyrano- syl; glucopyranosyl; glucofuranosyl; ethyl; and hydrogen. 7. The method of claim 5 wherein R, is NH 2 and R 2 is N-2-acetamido-3,4,6-tri-0-acetyl-2-deoxy-D- glucopyranosyl. 8. A method for suppressing growth of cancer cells susceptible to growth suppression in an animal which comprises administering to said animal, in a growth suppressing amount, a compound having the formula: CS - NHR. where R, is selected from the group consisting of NH,, C,-C 4 , alkoxy and a glycosyl residue; and R 2 is selected from the group consisting of hydro¬ gen, C,-C 4 alkyl, and a glycosyl residue; with the proviso that at least one but not both R, and R 2 contains a glycosyl residue. 9. The method of claim 8 wherein R, is selected from the group consisting of NH,, methoxy, and 3,4,5- tri-O-acetyl-xylopyranosylamine and R 2 is selected from the group consisting of 2-acetamido-2-deoxy- 3,4,6-tri-O-acetyl-D-glucopyranosyl; 2-acetamido-2- deoxy-D-glucopyranosyl; 2-acetamido-2-deoxy-D-galacto- pyranosyl; xylopyranosyl; 3,4,5-tri-O-acetyl-D-xylo- pyranosyl; cellobiosyl; maltosyl; lactosyl; galacto- pyranosyl; glucopyranosyl; glucofuranosyl; ethyl; and hydrogen. 10. The method of claim 8 wherein R, is NH 2 and R 2 is N-2-acetamido-3,4,6-tri-0-acetyl-2-deoxy-D- glucopyranosyl. 11. The method of claim 5 wherein said bacterial growth comprises bacteria selected from the group con¬ sisting of Escherichia, Pseudomonas, Salmonella, Staphylococcus, Klebsiella, and Listeria. 12. The method of claim 8 wherein said cancer is selected from the group consisting of leukemia, melanoma, sarcoma, and carcinoma.

Inventors: MCPHERSON EUGENE, SCHEIN PHILIP S, MCPHERSON, EUGENE, SCHEIN, PHILIP, S.
Applicants: UNIV GEORGETOWN, GEORGETOWN UNIVERSITY
Application year: 1986
Main classification: A61K31
IPC codes: C07H15