Study On Secondary Metabolites Of Two Marine Actinomycetes

The ocean is a huge treasure trove of microbial diversity resources,and microorganism is an important source of active substances.Actinomycetes is the most important and the largest source of microbial population,which has been found in about 70% of the natural antibiotics,indicates that the rich marine actinomycete may produce large amounts of metabolites with novel structure and a special physiological activity,provides rich novel lead compounds for new drug research and development.Two strains of marine actinomycetes Streptomyces rutgersensis WP6(WP6)and Microbacterium amylolyticum TW43(TW43)were chosen to study the bioactive secondary metabolites.Isolation and purification were carried out using normal phase silica gel column chromatography,RP gel column chromatography,Sephadex LH-20 gel column chromatography,Preparative Thin-layer chromatography,Rapid preparative HPLC and medium pressure HPLC.After getting the compound monomers,13 C NMR,1H NMR,HSQC,1H-1H COSY,LC-MS were applied to determine the structures.1.Eight compounds were obtained from the marine actinomycetes Streptomyces rutgersensis WP6.By mainly detailed analysis of their NMR data,their structures were elucidated as cyclo-(Pro-Leu)(2),cyclo-(Pro-Phe)(3),phenylacetic acid(4),indol-3-carboxylic acid(5),N-acetyltryptamine(6),N-acetyltyramine(7),(4S)-4,10-Dihydroxy-10-methylundec-2-en-1,4-olide(8),di-(2-ethylhexyl)phthalate(9).2.Fifteen compounds were obtained from Microbacterium amylolyticum TW43.One is a novel compound,the structure was determined as 5-hydroxy-1,5,6,7-tetrahydro-4H-indol-4-one(1);Fourteen compounds were konwed as 5,7,9-Trihydroxyisoflavone(10),dibutyl phthalate(11),3-Hydroxy-(4’-hydroxyphenyl)butan-2-one(12),hydroxyphenylacetic acid(13),cylo-(Trp-Gly)(14),cycio-(Pro-Gly)(15),cyclo-(Val-Trp)(16),cyclo-(Val-Pro)(17),cyclo-(Ala-Leu)(18),cyclo-(4-hydroxy-Pro-Isoleu)(19),cyclo-(4-hydroxy-Pro-Leu)(20),cyclo-(Phe-Gly)(21),cyclo-(Tyr-Gly)(22),cyclo-(Tyr-Pro)(23).Twenty-three compounds were isolated and elucidated from two marine actinomycetes.Compound 1 is a novel compound,compounds 10~23 were isolated from the Microbacterium sp.for the frist time.