Dactylocyclines, novel tetracycline derivatives produced by a Dactylosporangium sp. II. Structure elucidation.

Fermentation of Dactylosporangium sp. (ATCC 53693) produces a mixture of tetracycline derivatives from which several related tetracycline glycosides, the dactylocyclines, were isolated and their structures determined. The most abundant glycoside in initial fermentations was found to be dactylocycline A. Each glycoside proved to be acid sensitive and readily hydrolyzed to a common aglycone, dactylocyclinone. While the aglycone was cross resistant with tetracycline, the dactylocyclines proved active against certain tetracycline-resistant organisms.     

Dactylocyclines, novel tetracycline derivatives produced by a Dactylosporangium sp. III. Absolute stereochemistry of the dactylocyclines.

The dactylocycline antibiotics were found through circular dichroism measurements, NMR spectroscopy and chemical transformations to possess the usual tetracycline family absolute configuration at carbons 4, 4a, 5a and 12a. The absolute stereochemistry about the C-6 carbon, however, was the reverse of that found with previously investigated tetracyclines.     

Tripropeptins, novel antimicrobial agents produced by Lysobacter sp. I. Taxonomy, isolation and biological activities

Peptide antibiotics tripropeptins A, B, C, D and Z were isolated from cultured cells and broth of Lysobacter sp. The differences among these components are in the lengths of the alkyl side chain. Tripropeptins are active against Gram-positive bacteria including MRSA in vitro. Bactericidal activity of tripropeptin C disappeared in the simultaneous presence of chloramphenicol, a bacteriostatic agent.     

Pyloricidins, novel anti-helicobacterpylori antibiotics produced by Bacillus sp. I. Taxonomy, fermentation and biological activity

Novel anti-Helicobacter pylori antibiotics, pyloricidins A, A1, A2, B, C and D, were discovered in the culture broth of two bacilli strains. Pyloricidins selectively inhibited the growth of H. pylori. Pyloricidin B was efficacious in the treatment of gastric infection caused by H. pylori in Mongolian gerbils and may be promising for cure of H. pylori infection as a single agent.     

Radamycin,a novel thiopeptide produced by streptomyces sp. RSP9. I. Taxonomy,fermentation, isolation and biological activities

The newly isolated strain Streptomyces sp. RSP9 produces two thiopeptides; one of them is methylsulfomycin I, which shows potent antibiotic activity against several gram-positive bacteria such as Micrococcus luteus and Staphylococcus aureus. The other is a new thiopeptide named radamycin. In the present work, this compound was purified and tested against several microorganisms and no antibiotic activity was detected in the assays. However, it does have a very strong capacity as an inducer of the tipA promoter, and indeed is the first reported molecule with tipA promoter induction capacity without detectable antibiotic activity. Induction of the tipA promoter also occurs with methylsulfomycin I.     

A new antibiotic SF-2185 produced by Dactylosporangium. I. Taxonomy, fermentation and biological properties

A new antibiotic SF-2185 was found active against plant pathogen, particularly the causal organisms of cucumber downy mildew and rice blast. The producing organism, strain SF-2185, is a novel actinomycete and has been identified as Dactylosporangium aurantiacum subsp. gifuense.     

SF2809 compounds, novel chymase inhibitors from Dactylosporangium sp. 1. Taxonomy, fermentation, isolation and biological properties

Six novel chymase inhibitors, SF2809-I, SF2809-II, SF2809-III, SF2809-IV, SF2809-V and SF2809-VI, were isolated from the fermentation broth of an actinomycete strain SF2809. The strain was identified as Dactylosporangium sp. by morphological, chemotaxonomical and phylogenetic studies. These six novel compounds inhibited recombinant human chymase in the range between IC50 of 0.014 and 7.3 microM. However, they showed little or no inhibitory activity against chymotrypsin or cathepsin G, even though these two and chymase belong to the chymotryptic serine protease family. This result indicates that these compounds work as specific chymase inhibitors.     

Lysobactin, a novel antibacterial agent produced by Lysobacter sp. I. Taxonomy, isolation and partial characterization

A new antibacterial agent, lysobactin, has been isolated from a species of Lysobacter (ATCC 53042). The antibiotic was recovered from the Lysobacter cell mass by extraction and reversed phase chromatography. Lysobactin is a dibasic peptide with marked activity against Gram-positive aerobic and anaerobic bacteria.     

Lactoquinomycin, a novel anticancer antibiotic. I. Taxonomy, isolation and biological activity

Lactoquinomycin, a novel basic antibiotic, was isolated from the culture broth of a soil streptomyces by repeated solvent extraction and adsorption column chromatography. Morphological, cultural and physiological studies revealed that the organism belongs to the species Streptomyces tanashiensis. The antibiotic was active against bacteria, particularly Gram-positive organisms, and neoplastic cells in vitro. Antibiotic-resistant cell sublines of L5178Y lymphoblastoma were more significantly inhibited by lactoquinomycin than the parental cell line. Lactoquinomycin was effective against Ehrlich carcinoma in mice.     

Resorthiomycin, a novel antitumor antibiotic. I. Taxonomy, isolation and biological activity

Resorthiomycin, a novel antitumor antibiotic, was isolated from the fermentation broth of a strain of Streptomyces collinus by ethyl acetate extraction, silica gel chromatography and HPLC. Resorthiomycin exhibited an in vitro cytotoxic activity against mouse leukemia L5178Y cells (IC50, 15.5 micrograms/ml) and also inhibited the clonogenic activity of a multidrug-resistant mutant of human hepatoma PLC/PRF/5 cells to a greater extent than that of the parental cells. On the other hand, this antibiotic does not possess any antibacterial or antifungal activity.     

Two new monobactam antibiotics produced by a Flexibacter sp. I. Taxonomy, fermentation, isolation and biological properties

Two new beta-lactam antibiotics, namely SQ 28,502 and SQ 28,503, have been isolated from fermentations of a Flexibacter sp. They are demethoxy monobactams with oligopeptide side chains and have molecular weights of 1,462 and 1,446, respectively. These beta-lactams show a high degree of stability to a variety of beta-lactamases and act as potent irreversible inactivators of P99 beta-lactamase from Enterobacter cloacae. They exhibit weak antibacterial activity.     

Yaequinolones, new insecticidal antibiotics produced by Penicillium sp. FKI-2140. I. Taxonomy, fermentation, isolation and biological activity

New nine insecticidal antibiotics designated yaequinolones were isolated from the culture broth of the fungal strain Penicillium sp. FKI-2140 by solvent extraction, centrifugal partition chromatography and HPLC. Yaequinolones showed growth inhibitory activity against brine shrimp (Artemia salina). Among them, yaequinolone F has the most potent activity with MIC value of 0.19 microg/ml.     

SW-163C and E, novel antitumor depsipeptides produced by Streptomyces sp. I. Taxonomy, fermentation, isolation and biological activities

Novel depsipeptides, SW-163C and E were isolated from the culture broth of an actinomycete strain. The producing organism, designated as SNA15896, was identified as a member of Streptomyces from its morphological and cultural characteristics. SW-163C and E exhibited potent antitumor activities against various tumor cell lines in vitro and against murine leukemia P388 in vivo. The compounds also showed antimicrobial activities.     

小单孢菌FIM99468产生的弹性蛋白酶抑制剂Ⅰ.菌种分类、发酵、提取和生物学活性

在筛选弹性蛋白酶抑制剂过程中,从福建省永泰青云山土壤中分离到放线菌FIM99468,经分类鉴定为佛罗里达小单孢菌,定名为Micromonospora floridensis FIM99468.经发酵、提取,产生的次级代谢产物Fw99468能够抑制弹性蛋白酶,半数抑制浓度IC50为3.4×10-6mol/L.     

GEX1 compounds,novel antitumor antibiotics related to herboxidiene,produced by Streptomyces sp. I. Taxonomy,production, isolation,physicochemical properties and biological activities

Six structurally related antitumor antibiotics named GEX1 compounds were isolated from a culture broth of Streptomyces sp. GEX1A was identified as a known herbicide, herboxidiene, structurally interested by the tetrahydropyran moiety and the side chain including a conjugated diene. GEX1Q1 to approximately Q5 were determined as novel compounds related to herboxidiene. All GEX1 compounds showed cytotoxicity with IC50 values of 0.0037 to approximately 0.99 microM against human tumor cell lines in vitro, but were not active against both gram-positive and -negative bacteria. Though GEX1A/herboxidiene exhibited antitumor activity in murine tumor-planted mouse models, both GEX1Q3 and GEX1Q5 did not.     

Takanawaenes,novel antifungal antibiotics produced by Streptomyces sp. K99-5278. I. Taxonomy,fermentation, isolation and biological properties

Three new pentaene macrolides having a 28-membered ring, designated takanawaenes A, B and C, were isolated from the fermentation broth of Streptomyces sp. K99-5278 by solvent extraction, silica-gel column chromatography and HPLC. Takanawaenes showed antifungal activity against Aspergillus niger, Mucor racemosus, Candida albicans and Saccharomyces cerevisiae.     

Sch 37137, a novel antifungal compound produced by a Micromonospora sp. Taxonomy, fermentation, isolation, structure and biological properties

A new antifungal compound, Sch 37137, was isolated from the cultured broth of a Micromonospora sp., SCC 1792. Sch 37137 is structurally related to A 19009, a dipeptide previously discovered from a Streptomyces sp. The compound was weakly active against species of Candida and dermatophytes (mean MICs greater than or equal to 128 micrograms/ml) in Sabouraud dextrose, yeast-nitrogen and modified Eagles minimum essential media; however activity against Candida sp. (mean MICs greater than or equal to 12 micrograms/ml) and dermatophytes (mean MICs greater than or equal to 0.8 microgram/ml) significantly improved in MA medium.     

IC202A, a new siderophore with immunosuppressive activity produced by Streptoalloteichus sp. 1454-19. I. Taxonomy, fermentation, isolation and biological activity

IC202A, a new immunosuppressive compound, was isolated from the culture filtrate of Streptoalloteichus sp. 1454-19. It showed a suppressive effect on mixed lymphocyte culture reaction with an IC50 value of 3.6 microg/ml and mitogen induced lymphocyte blastogenesis in vitro.     

Aridicins, novel glycopeptide antibiotics. I. Taxonomy, production and biological activity

A new species of a new genus of the Actinomycetales was discovered, Kibdelosporangium aridum. This strain produces a new family of glycopeptide antibiotics designated aridicins, that contain an unusual glycolipid constituent. They inhibit Gram-positive bacteria, including staphylococci, enterococci and Clostridium sp.     

Tubelactomicin A, a novel 16-membered lactone antibiotic, from Nocardia sp. I. Taxonomy, production, isolation and biological properties

A novel 16-membered lactone antibiotic named tubelactomicin A was isolated from the culture broth of an actinomycete strain. The producing organism, designated MK703-102F1, was identified as a member of Nocardia. Tubelactomicin A was isolated from the culture broth by Diaion HP20 absorption, ethyl acetate extraction, silica gel and Sephadex LH-20 column chromatographies and centrifugal liquid-liquid partition chromatography (CPC). Tubelactomicin A showed strong activity against acid-fast bacteria including the drug-resistant strains.