title: New antibiotics miyakamides produced by a fungus.
abstract: New antibiotics, miyakamides A1, A2, B1, and B2, were isolated from the cultured broth of Aspergillus flavus Link var. columnaris FKI-0739 together with known compounds, parasiticolide A, hydroxyaspergillic acid, and kojic acid. The structure of miyakamide A1 is N-acetyl-L-phenylalanyl-N-methyl-L-phenylalanyl-(alphaZ)-alpha,beta-didehydrotryptamine, and miyakamide A2 is E isomer of A1 at didehydrotryptamine. The structure of miyakamide B1 is N-acetyl-L-tyrosyl-N-methyl-L-phenylalanyl-(alphaZ)-alpha,beta-didehydrotryptamine, and B2 is E isomer of B1. Both miyakamides A1 and B1 existed as equilibrium isomers in solvents, and this isomerism was associated with cis-trans rotation of the amide bond between two amino acids. Conformational isomerism between two amino acids of miyakamides A2 and B2 is cis-form. Miyakamides showed growth inhibitory activity against brine shrimp, Artemia salina.
authors.affiliation: Kitasato Institute for Life Sciences, Kitasato University, and The Kitasato Institute, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan. shiomik@pharm.kitasato-u.ac.jp
authors.forename: Kazuro
authors.initials: K
authors.lastname: Shiomi
authors.forename: Kenji
authors.initials: K
authors.lastname: Hatae
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Rokuro
authors.initials: R
authors.lastname: Masuma
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tomoda
authors.forename: Susumu
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Omura
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000737:chemistry / Q000494:pharmacology; D001156:Artemia / Q000187:drug effects; D001231:Aspergillus flavus / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D017173:Caenorhabditis elegans / Q000187:drug effects; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004354:Drug Screening Assays, Antitumor; D005285:Fermentation; D007941:Leukemia P388 / Q000473:pathology; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D010455:Peptides
chemical_list: D000900:Anti-Bacterial Agents; D010455:Peptides; C471245:miyakamide A1; C471246:miyakamide A2; C471247:miyakamide B1; C471248:miyakamide B2