Abbeymycin, a new anthramycin-type antibiotic produced by a streptomycete

A new antibiotic, abbeymycin, has been isolated from Streptomyces sp. AB-999F-52. The structure of abbeymycin was assigned on the basis of NMR, mass spectrometric and UV spectral data. Abbeymycin has weak activity against a limited number of anaerobic bacteria.     

A new antitumor substance BE-13793C, produced by a streptomycete. Taxonomy, fermentation, isolation, structure determination and biological activity.

A new antitumor substance, BE-13793C, which has topoisomerase inhibitory activity was isolated from the culture broth of a strain of actinomycetes. The producing strain, BA13793, isolated from a soil sample collected in Seto, Aichi Prefecture, Japan, has a resemblance to Streptoverticillium mobaraense. The active principle was extracted from the mycelium of strain BA13793 with methanol and purified by Sephadex LH-20 column chromatography. BE-13793C showed strong inhibitory activity against topoisomerases I and II and inhibited the growth of doxorubicin-resistant or vincristine-resistant P388 murine leukemia cell lines, as well as their parent P388 cell line.     

Karabemycin, a new antimetabolite of glutamine produced by a strain of streptomycete

Karabemycin, a new peptide antibiotic, was isolated from the culture filtrate of Streptomyces sp. AM-6424, a soil isolate. The molecular formula of the antibiotic was determined as C15H24N4O6 on the basis of elemental analysis, FD-mass spectrum and 1H and 13C NMR. Acid hydrolysate of karabemycin contains one mol each of valine, alanine and an unknown amino acid. The antibiotic is active against Gram-positive and -negative bacteria on a synthetic medium. The inhibitory activity is reversed by L-glutamine and L-glutamic acid.     

New cytotoxic agents, BE-52440A and B, produced by a streptomycete

New cytotoxic substances, designated BE-52440A and B, were isolated from the mycelium of Streptomyces sp. A52440. The active principles were extracted from the mycelium by methanol and purified by silica gel column chromatography. BE-52440A and B exhibited cytotoxic activity against murine and human tumor cell lines.     

New cytotoxic agents, BE-54238A and B, produced by a streptomycete

New cytotoxic substances, designated BE-54238A and B, were isolated from the culture broth of Streptomyces sp. A54238. The active principles were extracted from the mycelium by methanol and purified by Diaion HP-20 and Sephadex LH-20 column chromatographies. BE-54238A and B exhibited cytotoxic activity against murine and human tumor cell lines.     

A new polyene with antimycotic activity produced by a streptomycete from the rhizosphere of an indoor plant

From the rhizosphere of a potted Sanseviera trifasciata, a Streptomyces griseus strain with a broad antifungal activity was isolated; in the soil of this plant, a sole hyphomycete, Aspergillus niger, was found in pure culture at 37 degrees C. This streptomycete produced a polyene, belonging to the pentaene group. It was found to inhibit, in vitro, the growth of all the 123 strains tested; the strains belonging to the genera Aspergillus, Cryptococcus, Candida, Trichophyton, Epidermophyton, Microsporum, Penicillium and Mucor. An antimycotic activity of this substance was also found to be present after i.v. administration to white mice infected with Cr. neoformans. Toxicological tests will have to show if this polyene could be considered as a candidate antimycotic drug. The soil of potted indoor plants is discussed as a possible habitat for streptomycetes with defined antifungal activities.     

A new topoisomerase-II inhibitor, BE-10988, produced by a streptomycete. I. Taxonomy, fermentation, isolation and characterization.

A new topoisomerase inhibitor, BE-10988, was isolated from the culture broth of a strain of actinomycetes. The producing strain had a close resemblance to Streptomyces fimicarius and Streptomyces xanthocidicus. The active principle was extracted from the whole broth of strain BA10988 with ethyl acetate and purified by silica gel chromatography and by HPLC. BE-10988 increased DNA-topoisomerase complex formation and inhibited the growth of both doxorubicin-resistant and vincristine-resistant P388 murine leukemia cell lines, as well as sensitive P388 cell lines.     

Quadrone, a new antitumor substance produced by Aspergillus terreus. Production, isolation and properties

A new antitumor compound named quadrone was isolated from the culture broth of Aspergillus terreus NRRL 11,156. Quadrone was active against KB cells in vitro, but died not possess antimicrobial activity.     

A new streptomycete producing diphenyl sulfone antibiotic--S. sulfonensis

About 359 actinomycetes were isolated from 8 different natural substrates collected from different parts of Andhra Pradesh. The isolates were screened on the basis of their inhibitory effect against test organisms. Finally one potent antibiotic producer was chosen having broad-spectrum activity against Gram-positive and Gram-negative bacteria and it was found to produce a diphenyl sulfone antibiotic. On the basis of morphological, cultural, physiological and biochemical characters, the diphenyl sulfone antibiotic producer was identified as a new species and was designated as S. sulfonensis.     

New antitumor substances, BE-12406A and BE-12406B, produced by a streptomycete. II. Structure determination

The structure of BE-12406A and BE-12406B, which were isolated from the culture broth of a streptomycete as antitumor substances, were determined by means of spectral analyses and chemical studies. The structure of BE-12406A is 1-hydroxy-10-methoxy-8-methyl-12-alpha- L-rhamnopyranosyloxy-6H-benzo[d]naphtho[1,2-b]pyran-6-one, and that of BE-12406B is 1,10-dihydroxy-8-methyl-12-alpha-L-rhamnopyranosyloxy-6H- benzo[d]naphtho[1,2-b]pyran-6-one.