A strain of Streptoverticillium dnnamoneum produced a peptide antibiotic named lanthiopeptin, which contained four unusual amino acids, erythro-β-hydroxyaspartic acid, meso-lanthionine, threo-β-methyllanthionine and lysinoalanine. Lanthiopeptin showed antiviral activity against herpes simplex virus type 1 KOS strain infection in Vero cells by cytopathic effect reduction assay. The structure of lanthiopeptin is similar to that of ancovenin.

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A new antibacterial antibiotic, designated LL-E19085α, was isolated from the fermentation broth of an actinomycete strain. Based on cultural, physiological, morphological and chemical characteristics, culture LL-E19085 was identified as a new subspecies of Micromonospora citrea. Antibiotic LL-E19085α demonstrated potent activity against a spectrum of Gram-positive aerobic and anaerobic bacteria.

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A complex of new antifungal antibiotics designated karnamicin was isolated from the cultured broth of Saccharothrix aerocolonigenes No. N806-4. Fifteen components have so far been isolated from the complex; the major component karnamicin B₂ was identified by X-ray crystallography to be a novel molecule unrelated to known antibiotics.
All components of karnamicin exhibited a rather broad spectrum of activity against fungi and yeasts with MICs ranging from 3.1 to 50 μg/ml.

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A new antifungal antibiotic, CB-25-I, was isolated from the culture broth of a strain of Senatia plymuthica. The antibiotic, a water-soluble dipeptide, is structurally related to Sch 37137 and A 19009, both produced by strains of Actinomycetales. The antibiotic exhibits inhibitory activity against Candida albicans in YNB medium (a synthetic medium), but the activity is significantly reduced in Sabouroud dextrose medium.

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Aleurodiscal, an antifungal antibiotic has been isolated from mycelial cultures of Aleurodiscus mirabilis (Berk. & Curt.) Höhn. It causes abnormal apical branchings of Mucor miehei hyphae at very low concentrations. The structure and absolute configuration of the antibiotic has been determined by a single crystal X-ray analysis and hydrolysis to D-(+)-xylose. Aleurodiscal is a hydroxysesterterpene aldehyde β-D-xyloside with a novel carbon skeleton.

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Mannostatins have been isolated as part of a program designed to find microorganismproduced inhibitors of α-D-mannosidase from Streptoverticillium verticillus var. quintum. They were purified by sequential use of active carbon and Dowex resins and then isolated as colorless powders. Mannostatins A and B have the molecular formula, C₆H₁₃NO₃S and C₆H₁₃NO₄S, respectively. They were competitive with the substrate, and the inhibition constants (Ki) of mannostatins A and B were 4.8 × 10^-8 M.

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A new thiolactone containing antibiotic 834-B1 was isolated from the culture broth of Streptomyces sp. Y-0834H which has also produced thiolactomycin and thiotetromycin at the same time. The structure of 834-B1 was determined as I by the decoupling experiment in NMR.

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A number of derivatives of mutalomycin (1), a naturally occurring polyether antibiotic, have been synthesized. In the desulfurization reaction of the ethylthio derivative (5) of mutalomycin (1) with Raney-nickel we observed an unusual course of the reaction, namely the introduction of a hydroxy group instead of the usual exchange against hydrogen, leading to two reaction products, mutalomycin (1) and 28-epimutalomycin (3). The structure of 3 and 2-epimutalomycin (2), both minor metabolites from the mutalomycin fermentation, were elucidated by X-ray analysis.

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19-Deformyl-4'-deoxydesmycosin was synthesized by the following synthetic route: 19-Deformylation of desmycosin, 3, 2', 4''-tri-O-trimethylsilylation, 4'-O-sulfonylation, 4'-iodination, reductive deiodination and 3, 2', 4''-tri-O-detrimethylsilylation.
Deformylation of the aldehyde group at the C-19 position was achieved by two different methods: A) A simple one-step deformylation using Wilkinson's catalyst ((Ph₃P)₃RhCl). B) Reductive decarboxylation of the 19-carboxyl derivative following NaClO₂ oxidation of the aldehyde.
19-Deformyl-4'-deoxydesmycosin showed very strong antimicrobial activity in vitro and in vivo.

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To isolate Streptomyces tendae mutants blocked in the biosynthesis of the nikkomycin nucleoside base 4-formyl-4-imidazoline-2-one, an assay was developed to detect the formation of nikkomycins containing this base during growth on solid medium. The assay is based on the reaction of the 4-formylimidazolone structure of nikkomycins with the aldehyde reagent barbituric acid leading to red-colored products. Among 18, 000 N-methyl-N'-nitro-N-nitrosoguanidine treated clones tested in the barbituric acid assay, we isolated one mutant which was incapable of forming any nikkomycins containing the 4-formylimidazolone base (nikkomycins C_x, X and I) but instead produced nikkomycins containing uracil (nikkomycins C, Z and J). In addition, we isolated strains with mutations affecting the biosynthesis of 2-amino-4-hydroxy-4-(5-hydroxy-2-pyridyl)-3-methylbutyric acid, the unusual amino acid of nikkomycins Z, X, J and I. By analyzing colonies derived from single spores or protoplasts of S. tendae Tü901/395, a mutant producing besides nikkomycins Z, X, J and I, also nikkomycins K_z/K_x and O_z/O_x, we obtained strains which only formed nikkomycins K_z/K_x and O_z/O_x with 2-amino-4-hydroxy-4-(2-pyridyl)butyric acid and 2-amino-4-hydroxy-4-(5-hydroxy-2-pyridyl)-butyric acid as amino acids. Mutation of such a strain (Tü901/395-11) by UV_365nm in the presence of 8-methoxypsoralen and selection of S-2-aminoethyl-L-cysteine-resistant clones led to the isolation of Tü901/AECl and AEC2 which produced exclusively nikkomycins K_z and K_x. According to their nikkomycin spectrum, these strains were blocked at the hydroxylation step occuring at the pyridyl residue during biosynthesis of the nikkomycin amino acid.

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¹³C NMR analysis of ¹³C-labeled cytovaricin which was obtained by feeding sodium [1-¹³C]-, [2-¹³C]-, and [1, 2-¹³C]acetates, [1-¹³C]- and [3-¹³C]propionates, [1-¹³C]isobutyrate and [methyl-¹³C]mQthiomnQ to cultures of Streptomyces diastatochromogenes showed that the aglycone of cytovaricin is derived from nine acetate units, six propionate units and one isobutyrate unit and the methoxy group at C-3' of cymarose moiety is derived from the methionine-S-methyl group. The ¹³C NMR spectra of ¹³C-labeled cytovaricins which were obtained from feeding experiments allowed the complete assignment of the ¹³C NMR spectrum of cytovaricin.

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Feeding experiments with D-[6, 6-²H₂] D-(6R)-(6-²H₁]- and D-(6S)-[6-²H₁]glucose in the fermentation of Streptomyces ribosidificus, followed by field desorption MS and ²H NMR analyses of the resulting labeled ribostamycin samples, clearly demonstrated that 1) both hydrogens of the C-6 hydroxymethyl group of D-glucose are stereospecifically incorporated into the C-2 position of 2-deoxystreptamine and 2) the pro S hydrogen of the C-6 position of D-glucose is stereospecifically removed during the elaboration of neosamine C in the biosynthesis of ribostamycin. A plausible mechanism of formation of the deoxy-scyllo-inosose, an early precursor to 2-deoxystreptamine, is suggested to be analogous to the dehydroquinate synthesis in the shikimate pathway and the conversion of the C-6 hydroxymethyl group of D-glucose into the aminomethyl group of neosamine C is likely to involve a dehydrogenation step to a formyl group.

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The fortimicin (FTM) group antibiotics are produced by actinomycetes belonging to various genera. FTM's and sannamycins are the products of Micromonospora olivasterospora and Streptomyces sannanensis, respectively. The possible presence of common features of the biosynthesis of these structurally related antibiotics in the two producers was examined. Enzymatic studies were done by the bioconversion experiments using FTM precursors and the washed cells of S. sannanensis. Ion pair/reverse-phase HPLC was employed as the analytical tool. S. sannanensis could convert almost all FTM precursors to the expected structures in the down stream of the pathway except one step. Thus the sets of the biosynthetic enzymes of the two bacteria share the common substrate specificity and react alternatively.

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Efrotomycin, a modified polyketide antibiotic with utility as a growth permittant in the animal industry, is produced by Nocardia lactamdurans. A resting cell system has been developed to facilitate biosynthetic studies. Washed cells harvested from oil-based medium at 64 hours and resuspended in buffer produce up to 700 mg/ml efrotomycin in 60 hours when supplemented with a carbon source, optimally glucose. No evidence of carbon or nitrogen repression was observed. Productivity declines progressively with cell age but becomes less dependent on ongoing protein synthesis. The protein synthesis dependent and independent systems were used to study carbon utilization, incorporation of labeled precursors and to examine inhibitors of efrotomycin biosynthesis. A system derived from an efrotomycin non-producer was used to examine the glycosylation of the aglycone, aurodox, to efrotomycin through a monosaccharide form, 6'-deoxyallosyl aurodox.

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IC201 was found in cultured broth of Streptomyces cirratus as an antitumor antibiotic which was effective in retarding growth of the established solid tumor of Ehrlich carcinoma by treatment starting 8 days after tumor inoculation. It retarded growth of the established solid tumor of IMC carcinoma but had no cytotoxicity at 100 μg/ml. IC201 treatment kept NK cell activity of tumor-bearing mice at normal level and stimulated cytostatic activity of peritoneal macrophages. It stimulated phagocytosis of yeast and phorbol myristate acetateelicited superoxide production by peritoneal macrophages. The addition of IC201 to P388D₁ cell cultures enhanced release of interleukin 1 (IL-1) into cultured supernatant but it affected lipopolysaccharide-induced IL-1 production. Although the addition to macrophage-depleted cultures did not show any stimulatory effect, mixed lymphocyte culture reaction was augmented in cultures using spleen cells as stimulator cells taken from mice given IC201. Results indicate that IC201 primarily activates macrophages and the activation may cause modulation of immune responses.

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Three of 29 clinical isolates of Bacteroidcs distasonis strains, GAI2095, GAI2361 and GAI6270 were found to produce high levels of β-lactarnase relative to the remaining 26 strains. The enzymes from these strains showed a broad substrate profile, hydrolyzing cephaloridine, cephalothin, cefazolin, oxyimino-cephalosporins such as cefuroxime, cefotaxime and cefmenoxime, and piperacillin at high rates. Examination of the substrate profiles indicated that the enzymes were mainly oxyimino-cephalosporinases. Inactivation of latamoxef over a long time by crude enzyme extracts of GAI2095 and GAI2361 was detected by a microbiological assay. The enzyme activities were inhibited by imipenem, cefoxitin, clavulanic acid and sulbactam but not by EDTA. The majority of β-lactamase activity was found in the cell extract prepared by ultrasonic treatment, especially in the precipitate by ultracentrifugation including membrane fraction. When the cells of B. distasonis were subjected to osmotic shock, negligible levels of β-lactamase activity were found in the supernatant fluid. The enzymes appeared to be tightly associated with the cell envelope since detergents were required to elute these activities.

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Antitumor antibiotic streptonigrin (STN-COOH) is a potent inhibitor of avian myeloblastosis virus (AMV) and human immunodeficiency virus reverse transcriptases. The carboxyl group at 2'-position of STN-COOH was modified to give esters, hydrazide, amides and amino acid derivatives for biological studies.
Against AMV reverse transcriptase, the hydrazide, amides and amino acid derivatives showed inhibitory activity, which compared favorably to that of STN-COOH, with the ID₅₀ values ranging 2-8 μg/ml. In contrast, the esters lacked this activity except for those having a dimethylamino group in the substituent. Splenomegaly caused by Friend leukemia virus infection was significantly inhibited by STN-COOH and STN-COO(CH₂)₃N(CH₃)₂, but not STN-CONH(CH2)₃N(CH₃)₂. Doxorubicin-resistant murine lymphoblastoma L5178Y cells showed collateral sensitivity to both STN-COOH and STN-COO(CH₂)₃N(CH₃)₂ not only in vitro but also in vivo.

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The new oral penem antibiotic SUN5555 shows broad antibacterial activity against both aerobic and anaerobic Gram-positive and Gram-negative bacteria. SUN5555 is highly stable against various β-lactamases. It binds preferentially to the penicillin-binding proteins 2 and 1A of Escherichia coli.

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We evaluated the ingestion of anti-sheep erythrocyte (anti-E) IgG- and IgM-coated sheep erythiocytes by murine peritoneal macrophages exposed to cefodizime, a new semisynthetic cephalosporin, and other antibiotics. Cefodizime enhanced the ingestion of anti-E IgG-coated erythrocytes by peritoneal macrophages from CD-1 and BALB/c mice in a dosedependent manner, but had no effect on uncoated or IgM-coated erythrocytes. Similar enhancement was observed only in the case of cefpimizole (AC-1370), among the other antibiotics examined. These results suggest that the favorable in vivo activity of cefodizime and cefpimizole may result from their phagocytosis-enhancing as well as antimicrobial properties.

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The synthesis and biological evaluation of D-forphenicinol-cephalosporins are described. 7-Amino-3-(substituted)-3-cephem-4-carboxylic acid esters were coupled with N-tert-butoxycarbonyl-D-forphenicinol derivatives. Most of cephalosporin analogs in this series had good antibacterial activities and were well absorbed from the gastrointestinal tract in mice. Among them, 7-(mono-O-methyl-D-forphenicinol)-3-propenyl analog showed the most significant result in biological evaluations.

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