Study On Secondary Metabolites Of Three Strains Lived In Special Niche

This dissertation reports the isolation and characterization of the secondary metabolities from a marine actinomycete,an insect endophytic actinomycete and an endophytic fungus.The crude extracts produced by three strains were preliminarily treated by a variety of chromatographic separation methods.At last,high performance liquid chromatography was used to obtain pure compounds.According to the spectral data(HR-ESI-MS,1HNMR?13CNMR?HMQC?1H-1HCOSY?HMBC?NOESY and CD)of the compounds and single-crystal X-ray diffraction,the structure of compounds were determind.Finally,bioactivity screening was tested.The details as follows:Streptomyces chartreusis NA02069 was isolated from the marine soil samples collected from Hainan Island.Twelve alkaloid compounds were obtained from its fermentation broth,including ten new compounds and two known compounds.The activity of these compounds was screened and the results showed that compound 1 had weak antibacterial activity and inhibitory activity of acetylcholinesterase.Its MIC was 64.0 ?M and IC50 was 50.6 ?M respectively.Nocardiopsisflavescens sp.NA01583 was isolated from Forficula auricularia Three new indolacarbazole compounds were islated from the fermentation broth.Compound 13 was selected for bioactivities assay and the results showed that compound 13 had strong cytotoxic effect on cancer cells,the IC50 of SUM 1315 was about 2 ?M and the IC50 of M468 was about 0.2 ?M.Alternaria sp.NF02128 was isolated from the leaf of Maianthemum bifolium collected from Mount Emei.Two alkaloids and seven polyketides were isolated from its fermentation products.The activity of these compounds was screened.The results showed that compounds(+)-18 and 19 had acetylcholinesterase inhibitory activity,and their IC50 were 15.5 and 68.3 ?M respectively.In summery,the strains lived in special niche could produce novel and active secondary metabolites.Therefore,the study on metabolites of strains lived in special niche had great significance to the expansion of natural products.