title: Macbecins I and II, new antitumor antibiotics. I. Producing organism, fermentation and antimicrobial activities.
abstract: New antibiotics, macbecins I and II, have been found in the culture fluid of an actinomycete, which has the following properties: delayed fragmentation of vegetative mycelia, formation of coremia on solid media, the occurrence of meso-diaminopimelic acid in the cell wall, lysozyme resistance, and guanine-cytosine content of 71 +/- 1 mol%. The organism has been designated Nocardia sp. No. C-14919 (N-2001). A marked enhancement of the production of macbecins I and II was observed in cultures containing L-tyrosine. The antibiotics are moderately active against several Gram-positive bacteria and fungi. The antibiotics also inhibit the growth of Tetrahymena pyriformis W at 2 microgram/ml but show no activity against the regeneration of cilia in partially deciliated Tetrahymena at 10 microgram/ml.
mesh_terms: D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000096:biosynthesis* / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D016227:Benzoquinones; D003470:Culture Media; D056890:Eukaryota / Q000187:drug effects; D005285:Fermentation; D005658:Fungi / Q000187:drug effects; D047029:Lactams, Macrocyclic; D009615:Nocardia / Q000187:drug effects / Q000378:metabolism*; D011809:Quinones / Q000096:biosynthesis / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D000903:Antibiotics, Antineoplastic; D016227:Benzoquinones; D003470:Culture Media; D047029:Lactams, Macrocyclic; D011809:Quinones; C025514:macbecin I; C025515:macbecin II