title: New antibiotic napyradiomycins A2 and B4 and stereochemistry of napyradiomycins.
abstract: Napyradiomycins A2 and B4, new members of the napyradiomycins, have been isolated from the culture broth of Chainia rubra MG802-AF1. The structure of napyradiomycin A2 was elucidated as 16-hydroxy-17-methylenenapyradiomycin A1 by NMR studies. The absolute structure of napyradiomycin B4 was determined as 13-hydroxy-13-methylnapyradiomycin B1 by X-ray crystallography and therefore the configuration of C(4a) in other napyradiomycins is assumed as the R configuration. The geometrical isomerism of napyradiomycin C1 was estimated as 12E and 16E by nuclear Overhauser effect experiments.
authors: Institute of Microbial Chemistry, Tokyo, Japan.
authors: K
authors: K
authors: Shiomi
authors: H
authors: H
authors: Nakamura
authors: H
authors: H
authors: Iinuma
authors: H
authors: H
authors: Naganawa
authors: T
authors: T
authors: Takeuchi
authors: H
authors: H
authors: Umezawa
authors: Y
authors: Y
authors: Iitaka
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification; D003461:Crystallography; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009285:Naphthoquinones / Q000302:isolation & purification; D013237:Stereoisomerism; D013302:Streptomyces / Q000032:analysis; D013329:Structure-Activity Relationship; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D009285:Naphthoquinones; C054262:napyradiomycin A2; C054263:napyradiomycin B4