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The first example of C-3 alkoxylation in mitomycins has been achieved. 3 alpha-iso-Propoxy-10-O-decarbamoylmitomycin D (4) and 3 alpha-iso-propoxymitomycin D (5) were derived from mitomycin D (3) under decarbamoylation conditions with iso-propoxide. Under similar conditions 3 alpha-iso-propoxy-10-O-decarbamoylporfiromycin (8) and 3 alpha-methoxy-10-O-decarbamoylmitomycin B (11) were also derived from porfiromycin (6) and mitomycin B (9), respectively. The mechanism of generation of these novel analogs was based on the premise that the key intermediate of hydroquinone iminium salt (14) was led through the iminium salt (13), followed by alkoxide addition and oxidation.

The configuration of mitiromycin (2) was first determined by NMR experiments including the NOE technique. The absolute structure of 2 was related to mitomycin B (3) because 2 was derived from 3 under basic conditions. The ketonic form 4 was presumed to be involved in the generation of 2.

Mitomycin G (2) was derived from porfiromycin (10b) in 3 steps via the methanesulfonate (14b) in an overall yield of 39%. On the basis of the established method for the introduction of an exomethylene group in mitomycins with a 9a-methoxy group, the preparation of biologically more important 1a-demethylmitomycin G (5) from mitomycin C (1) was accomplished by the use of a protective acetyl group on the aziridine in an overall yield of 57%. 1a-Demethylmitomycin K (6) was obtained from 5 in a yield of 42%. In a preliminary evaluation of their antitumor activity, compound 5 showed superior activity against sarcoma 180 (sc-ip) to its 1a-methyl congener, i.e., mitomycin G (2).

The reaction between mitomycin A (1) and cysteamine afforded 7-N,7'-N'-bis(2-thioethyl)dimitomycin C (7), 7-N-[2-[(2-aminoethyl)dithio]ethyl]mitomycin C (8), and 7-methoxy mitosenes (10, 11). The structures of 7 and 8 were elucidated on the basis of spectroscopy and reactions between 1 and 8, and 1 and cystamine. The observation of the time course for the reaction revealed the mechanism of the formation of 7 and 8. The rapid oxidation of cysteamine by the quinone of 1 gave cystamine, which was trapped by 1 to give 8, and 8 was additionally reacted with 1 to give 7. Since 7 showed significant antitumor activities, related 7-N,7'-N'-bis(omega-thioalkyl)dimitomycins were synthesized. They also showed remarkable antitumor activities against HeLa-S3 in vitro, sarcoma 180 (sc-ip), leukemia P388 (ip-ip) in vivo. In these evaluations, compound 7 demonstrated unique potency.

An inosamine-idiotrophic mutant, KY11559, which produced no astromicin unless scyllo-inosamine was added to the fermentation medium, was isolated from Micromonospora olivasterospora. Biotransformation studies were performed with resting cells of this mutant and compounds assumed to be precursors of 1, 4-diaminocyclitol (fortamine). Scyllo-inosose, scyllo-inosamine and FU-10 were converted to astromicin. A number of mutants blocked in the biosynthesis of astromicin were developed from M. olivasterospora, and the intermediates accumulated by these mutants were isolated and identified. Twenty-five blocked mutants were classified into 10 groups, based on their complementation patterns by cosynthesis experiments. Further, utilizing these blocked mutants and the isolated compounds, biotransformation analyses were performed. The results showed that the amination at position 4 in fortamine occurred after formation of the pseudodisaccharide. Subsequently, the aminosugar and aminocyclitol moieties were aminated, methylated, dehydroxylated, epimerized and acylated to produce astromicin. Thus it was demonstrated that the astromicin biosynthetic pathway has a unique feature which is not found in the biosynthesis of other aminoglycoside antibiotics.

The structures of four new protein kinase C inhibitors of microbial origin, K-252a, b, c and d were determined by spectral studies and chemical conversion.

New components of tetrocarcins (E1, E2, F and F-1) were found in the culture broth of Micromonospora chalcea KY 11091 that was known to produce tetrocarcins A, B and C. Tetrocarcin F-1 consisted of tetronolide and nitro sugar (tetronitrose). Tetrocarcins E1 and E2 consisted of F-1 and deoxy sugar (L-digitoxose). Tetrocarcin F consisted of F-1 and two deoxy sugars (their structures were not yet determined). They all showed antibacterial activities against Gram-positive bacteria and the specific activity decreased with decrease in the numbers of deoxy sugars attached to the aglycone.

The new antibiotic, XK-90, produced by Streptomyces sp. is active against Gram-positive and Gram-negative bacteria. The structure has been determined as N-acetyl-N'-(3-formyl-4-hydroxyphenyl)hydrazine (1) and is the second example of a naturally occurring antibiotic having the phenylhydrazine skeleton.

The structure of K-13, a potent inhibitor of angiotensin I converting enzyme (ACE), was determined to be a cyclic dipeptide composed of tyrosine and an unusual diamino dicarboxylic acid, isodityrosine, by spectral and chemical studies of K-13 and its derivatives.

Novel antitumor antibiotics, trioxacarcin complex, were isolated from the fermentation broth of Streptomyces bottropensis DO-45 by the use of non-ionic porous resin and silica gel chromatography. The purified components (trioxacarcins A, B and C) were characterized as new antibiotics by their physico-chemical properties and chromatographic behaviors. The mode of action of trioxacarcin A against Bacillus subtilis was found to be through the of DNA synthesis.

Novel antitumor antibiotics, tetrocarcin complex composed of three components (A, B and C) were isolated from the culture broth of Micromonospora chalcea KY11091 through various procedures. Tetrocarcins showed marked activity against experimental tumors such as mouse sarcoma 180 and mouse leukemia P388. Multiple injections showed better therapeutic effect against tumors. Mode of action of tetrocarcin A against Bacillus subtilis was found to be through the inhibition of RNA synthesis.

2-Aminoethyl, glycyl, (S)-4-amino-2-hydroxybutyl and (S)-4-amino-2-hydroxybutyryl groups were introduced to the 2'-amino group of 4-N-[(S)-4-amino-2-hydroxybutyl]fortimicin B (2). All of the derivatives of this type prepared showed antibacterial activity almost as strong as fortimicin A (1) and were also active against fortimicin A resistant bacteria which can inactivate fortimicin A by producing an inactivating enzyme AAC(3)-I.

The 1, 2' or 6'-amino group of fortimicin A was alkylated or acylated and the antimicrobial activities of the derivatives were compared with each other. 2'-N-Substituted fortimicins A were active against the fortimicin A resistant strain which produced AAC(3)-I. AAC(3)-I is the only enzyme which can inactivate fortimicin A. Among the derivatives prepared in the present study, 2'-N-[(S)-4-amino-2-hydroxybutyl]fortimicin A showed stronger activity than fortimicin A.

A new component, nanaomycin E, has been isolated from the culture broth of Streptomyces rosa var. notoensis, which had been found to produce nanaomycins A, B, C and D. Nanaomycin E was an epoxy derivative of nanaomycin A and was converted into nanaomycin A and 4a-epi-nanaomycin B by treatment with sodium hydrosulfite in an acidic aqueous solution. 4a-epi-Nanaomycin B was quantitatively converted into nanaomycin A under alkaline conditions.

The structure of a new antibiotic, CV-1 was determined to be 1,2-diamino-1,2-N,N'-carbonyl-1,2-dideoxy-alpha-D-glucose hydrate by spectral and chemical studies. CV-1 possessed a unique open ring hemiaminal structure. CV-1 synthesized from N-carbamoyl-D-glucosamine was identical to material isolated from fermentation.

Pseudomonas methanica KY4634 was found to produce 5-lipoxygenase inhibitor designated KF8940, MY12-62a and MY12-62c. The inhibitors were purified by solvent extraction, silica gel column chromatography, reversed-phase low pressure liquid chromatography and crystallization. The chemical structures of KF8940, MY12-62a and MY12-62c were determined to be 2-n-heptyl-4-hydroxyquinoline-N-oxide, 2-n-heptyl-4-hydroxyquinoline and 3-n-heptyl-3-hydroxy-1,2,3,4-tetrahydroquinoline-2,4-dione, respectively, on the basis of their physico-chemical properties. Among them, KF8940 was the most potent inhibitor. The compound inhibited 5-lipoxygenase of rat basophilic leukemia cells in a dose-dependent manner and the half maximal inhibitory concentration (IC50) was 1.5 X 10(-7) M. At this concentration, KF8940 did not inhibit bovine platelet 12-lipoxygenase and cyclooxygenase, and the IC50 values for these enzyme were 3.5 X 10(-5) M and 1.7 X 10(-4) M, respectively. The results indicated that KF8940 is a potent and selective inhibitor of 5-lipoxygenase. The IC50 value of MY12-62c for 5-lipoxygenase was 1.9 X 10(-5) M and that of MY12-62a was 1.9 X 10(-5) M.

Two new antibiotics, fluopsins C and F, have been isolated from the culture broth of Pseudomonas fluorescens and characterized as bis(N-methyl-N-thioformylhydroxylaminato)copper(II) (I) and tris(N-methyl-N-thioformyl-hydroxylaminato) iron(III) (II) respectively.

The structure of KS-619-1, a potent inhibitor of Ca2+ and calmodulin-dependent cyclic nucleotide phosphodiesterase, was determined to be 8, 13-dioxo-3-(2-oxopropyl)-5, 6, 8, 13-tetrahydro-l, 7, 9, 11-tetrahydroxybenz[a]naphtacene-2-carboxylicacid by spectral studies of KS-619-1 and its methyl derivative.

Chemical-ionization (CI) mass spectra are described for methyl esters of eight clinically significant penicillins and their breakdown products. The substances give spectra with very few fragment ions and contain easily discernible protonated molecule ions. The main cleavage reaction is postulated to involve a retro 2+2 Diels-Alder-type fragmentation of the beta-lactam ring liberating one fragment (m/e=174) that is characteristic of the penicillin nucleus and a second fragment that is molecule specific, as it contains the elements of the side chain. The other fragment ions, though interesting, are of minor intensity. The free acids, on the other hand, fragment more extensively because of their relative instability and lack of volatility. These spectra resemble electron impact spectra more closely and, though they encode more structural information, are less reproducible from run to run. The ease with which the esters can be made and the relative simplicity of their CI mass spectra make this method significant for the identification and characterization of beta-lactam antibiotics.

Biosynthesis of astromicin, a unique pseudodisaccharide aminoglycoside antibiotic containing 1,4-diaminocyclitol component, was investigated by isolating a variety of possible precursor compounds from mutants of Micromonospora olivasterospora in which biosynthetic pathways for astromicin were blocked. Washed mycelia of M. olivasterospora mutants converted these compounds to astromicin, which was detected by thin-layer chromatography. Since astromicin possesses one glycyl and three methyl groups, [14C]glycine and [14C]methionine should be incorporated into precursors to form astromicin. To confirm the biosynthetic pathway, formation of labeled astromicin from the precursors was examined using [1-14C]-glycine or [methyl-14C]methionine. From above results, we propose the biosynthetic pathway for astromicin as shown in Fig. 2.

The structures of seldomycin factors 1 and 2 have been determined by consideration of chemical degradation and spectral properties. Factor 1, also known as XK-88-1, is shown to be 6-O-(2-amino-2-deoxy-alpha-D-xylopyranosyl) paromamine (1) and factor 2, also known as XK-88-2, is shown to be 4'-deoxy-neamine (2). Mass spectral evidence has been obtained that suggests the most probable structure for seldomycin factor 3, also known as XK-88-3, is 6'-amino-6'-deoxyseldomycin factor 1 (12).

Antibiotics containing a quinone group show characteristic reduced pseudo-molecular ions (M + 2)+ and (M + 3)+ during the measurements of secondary ion mass spectra using glycerol as a matrix. The ratios of peak intensities (M + 2)+ and (M + 3)+ over (M + 1)+ increase with time. As this phenomenon is not found using sulfolane as a matrix, the quinone group seems to be hydrogenated to a hydroquinone by active hydrogen which is produced from a free hydroxyl group of the glycerol by bombardment with the Xe+ beam. This hydrogenation reaction is specific for the quinone group.

Gilvocarcin V(1), C27H28O9, m.p. 264 approximately 267 degrees C (dec.), and gilvocarcin M(2), C26H26O9, m.p. 245 approximately 248 degrees C (dec.), are new antitumor antibiotics produced by Streptomyces gilvotanareus. The structure of gilvocarcins has been determined by chemical degradation, nmr and mass spectra. They have a benzonaphtopyran-one system, to which the furanose moiety is linked through a C-C glycosyl bond.

Fortimicins C, D, and KE are new aminocyclitol antibiotics produced by a mutant of fortimicin-producing organisms. Their structures have been determined by 1H and 13C NMR and mass spectra and chemical degradations. Fortimicin C is 4-N-hydantoylfortimicin B, fortimicin KE is 6'-demethylfortimicin B, and fortimicin D is 4-N-glycylfortimicin KE. The last two antibiotics have purpurosamine C instead of 6-epi-purpurosamine B.

Streptoverticillium hadanonense KY11449 was found to produce a 12-lipoxygenase inhibitor MY3-469. The compound was purified by chromatography on Diaion HP-10, charcoal, Sephadex LH-20 and crystallization. The chemical structure of MY3-469 was determined to be 3-methoxytropolone on the basis of its physico-chemical properties. The half maximal inhibitory concentration (IC50) of MY3-469 against bovine platelet 12-lipoxygenase was 1.8 X 10(-6)M. The compound did not inhibit bovine platelet cyclooxygenase at 10(-3)M and showed weak inhibition (IC50 2.8 X 10(-4)) against 5-lipoxygenase of rat basophilic leukemia cells. The results indicate that MY3-469 is a potent and selective inhibitor of 12-lipoxygenase.

The four amino groups of fortimicin B(4) could be differentiated from each other and 2'-N-benzyloxycarbonyl-, 2', 6'-di-N-benzyloxycarbonyl-, 2'-N-tert-butoxycarbonyl-, 6'-N-tert-butoxycarbonyl- and 2', 6'-di-N-tert-butoxycarbonyl-fortimicin B (7, 8, 16, 18, 17) were prepared from 4. From these fortimicin B derivatives, selectively protected fortimicin A derivatives 13, 15, 21, 22 and 25 were prepared by combination of procedures of benzyloxycarbonylation or tert-butoxycarbonylation, 4-N-glycylation.