Chemical Constituents Of Antibiotic Actinomycete Strains From The Mangrove Zone Of South China Sea

This thesis has studied on the isolation and structural determination of active constituents in fermented mycelium and broth from two strains of marine actinomycetes No. H74-18 and No. H41-26, which were isolated from the bottom soil of mangrove zone in south China sea and showed antibiotic activity. Twenty-one pure samples, one crystal sample and one mixed crystal sample were isolated from the active fractions by silica gel column, ODS open column chromatography, preparative HPLC, Sephadex LH-20 permeation chromatography, and other chromatographic techniques. Twelve compounds were identified by MS, 1D and 2D NMR spectroscopic analysis, or X-ray diffraction analysis, they were determined to be 7 antimycins as antimycin A1a(1), antimycin A1b(2), antimycin A2a(3), antimycin A3a(4), antimycin A3b(5), (2S,3R,6R,8S)-3-(3-formamido-2-hydroxybenzamido)-8-hexyl-2,6-dimethyl-4,9-dioxo-1,5-diox onan-7-yl acetate (antimycin A1g,6),(2S,3R,6R,8S)-3-(3-formamido-2-hydroxybenzamido)-2,6-dimethyl-4,9-dioxo-8-pentyl-1,5-dio xonan-7-yl 2,3-dimethylbutanoate (antimycin A19,7).4 actinomycins as actinomycin D (8), actinomycin X2 (9), actinomycin X0p (10), actinomycin X0s(11), and imidacloprid (12). Compounds 6 and 7 were two new natural products..