Secondary Metabolites Of Two Streptomyces

With the continuous development of natural product chemistry research,it has become more difficult to find new drug source molecules from animals and plants traditionally.The microorganisms from animal and plant symbionts and marine sources in special environment have become research hotspots.We have screened these microorganisms derived from plants,animals and the sea in large quantities,with the consideration of strain type,colony morphology,feature absorption,product molecular weight and formula and so on.In this way,the strain which is of great value will be fermented and its metabolites will be purified and identified in order to find the potential drug value of secondary metabolites.In this paper,two representative actinomycetes were selected from a large number of strains.One of them is the insect-derived actinomycete Streptomyces sp.NA4075,and the other is the marine-derived actinomycete Streptomyces sp.HN-6H5a4.The two strains were subjected to liquid fermentation,and the metabolites were separated,purified and identified by column chromatography,HPLC,LC-MS and NMR and so on.From NA4075,12 angucycline-like compounds(compounds 1-12)were isolated,of which 6 were new compounds isolated for the first time,and there were few reports about the glycosyl groups in compounds 1-3.All isolated compounds were screened for cytotoxic activity,with compounds 4 and 12 exsiting some activity against human breast cancer cell MCF-7.From HN-6H5a4,totally of 9 compounds(compounds 13-21)were isolated which were belong to the geldanamycin group.And 6 of them were new compounds reported for the first time.The incorpaoration of glycolic acid in compound 14-19 caught our attention.This phenomenon is relatively novel among such compounds.All the compounds were screened for cytotoxic activity,with compound 13 having weak activity against human breast cancer cell MCF-7.In addition,the research on angucyclines is reviewed.