Studies On Secondary Metabolites And Bioactivities Of Three Microorganisms

Microbes can provide very rich secondary metabolites,some of which have been developed and applied by human.These metabolites play a major role in human production and life.In our study,the chemical components of three strains,including Stereum sp.ATCC64657,Irpex sp.FL289 and Streptomyces sp.294,have been studied.The nematicidal and antibacterial activities of compounds from the three strains have been further tested.The results are as follows;Nine compounds were isolated from the strain Stereum sp.ATCC64657.six compounds sterostrein S(1),sterostrein T(2),3-hydroxy-4,5-bis(hydroxymethyl)-2-(3-methylbut-2-en-1-yl)phenyl 2,4-dihydroxy-6-methylbenzoate(3),4-hydroxybenzoic acid(4),2-(4-hydroxyphenyl)acetic acid(5)and 3,3'-dihydroxy-5,5'-dimethyldiphenyl ether(6)were identified.Among these compounds,compound 1 and 2 are novel,and the others are known.Eleven compounds were isolated from the strain Irpex sp.FL289.Six compounds including benzoic acid(2),conocenolide A(3),conocenol C(5),conocenolide B(6),11,12-dihydroxy-1-tremulen-5-one(10)and stella sterol(11)were identified.They are isolated from this genus for the first time.Nine compounds were isolated from the strain Streptomyces sp.294.Six compounds indole-2-methylcarboxylate(1),fumitremorgin C(3),spirotryprostatin A(4),cyclouyprostatin B(5),1,2-benzene dicarboxylic acid bis(2a-methyl heptyl)ester(6)and cyclouyprostatin A(7)were identified.All the compounds obtained from the three strains had been assessed for the nematocidal and antimicrobial activities.The result showed that benzoic acid isolated from strain Irpex sp.FL289 had toxic activity against Meloidogyne incongnita at the concentration of 400 ?g/mL;also,the compound benzoic acid had an inhibitory activity against Escherichia coli at a concentration of 400 ?g/disc;the indole-2-methylcarboxylate isolated from the strain Streptomyces sp.294 had a weak inhibitory activity against Bacillus cereus at a concentration of 400 ?g/disc.Innovation points of this study,(1)two new sesquiterpenes were isolated from the fungus Stereum sp.ATCC64657 for the first time,(2)the nematocidal compound benzoic acid was identified from fungus Irpex sp.FL289,and compound indole-2-methylcarboxylate was identified from the strain Streptomyces sp.294 had a weak inhibitory activity against Bacillus cereus.