Studies On Bioactive Components From The Secondary Metabolites Of Three Actinomycetes

Actinomycetes are important producers for medicine and agricultural antibiotics,their secondary metabolites are novel in structure and unique in bioactivity,and it is of great significance to find novel bioactive leading compounds from actinomycetes.In this thesis,through TLC and antimicrobial activity screening methods,3 strains were selected for further studies from 20 actinomycete strains by their riches in secondary metabolites and good performances in antagonistic activities against Panax notoginseng root rot pathogenic fungi.By 16S rRNA gene sequence analysis,they were classified as Streptomyces diastaticus subsp.Ardesiacus,Streptomyces yatensis and Streptomyces ardus respectively.With the practice of silica gel column chromatography,gel chromatography on Sephadex LH-20,and high-performance liquid chromatographic technology,12 compounds were isolated and purified from the broth of strain YIM PH20095,and their chemical structures were elucidated by spectrum data.They respectively are:izumiphenazine B(CX-1),phenacein(CX-2),strepphenazine A(CX-3),strepphenazine B(CX-4),strepphenazine C(CX-5),1-hydroxyphenazine(CX-6),9-hydroxy-1-phenazinecarboxylic acid(CX-7),phena ecarboxylic acid(CX-8),strepphenazine D(CX-9),6-(methoxycarbonyl)phenazine-2-carboxylic acid(CX-10),6-hydroxy-1-phenazinecarboxylic acid(CX-11)and strepphenazine E(CX-12).Among them,strepphenazine A-E are five new compounds never been reported in literature,we preliminary named them as strepphenazine A-E considering their microbiological origin Streptomyces sp..10 compounds were isolated and purified from the broth of strain YIM PH20103,and their chemical structures were elucidated by spectrum data.They respectively are:4-tetralol-l-one(CX-13),coumarin(CX-14),cyclo-(glycyl-try)(CX-15),cyclo-(trp-tyr)(CX-16),cyclo-(L-phe-L-pro)(CX-17),cyclo-(D-phe-L-pro)(CX-18),3-benzyl-6-ethylpiperazine-2,5-dione(CX-19),cyclo-(phe-val)(CX-20),indole-3-acetic acid(CX-21)and cyclo-(pro-trp)(CX-22).7 compounds were isolated and purified from the broth of strain YIM 121489,and their chemical structures were elucidated by spectrum data.They respectively are:isomigrastatin(CX-23),4-((E)-7-((6E,10E)-4-hydroxy-3-methyl-12-oxooxacyclododeca-6,10-dien-2-yl)-5-methyl-4-oxooct-6-en-1-yl)-piperidine-2,6-dione(CX-24),9(E)-18-((E)-1-hydroxy-3-phenylallyl)-10-methyl-12-methylene-2,8-dioxo-1-oxa-7-azacyclooctadec-15-en-14-yl acetate(CX-25),4-(7-((3Z,8E,12E)-6,7-dihydroxy-3-methyl-14-oxooxacyclotetradeca-3,8,12-trien-2-yl)-4-oxoheptyl)-piperidine-2,6-dione(CX-26),adenosine(CX-27),cinnamic acid(CX-28)and 1H-pyrrole-2-carboxamide(CX-29).Antimicrobial bioactivity assay were performed on isolated compounds by 4 Panax notoginseng root rot pathogenic fungi and 3 common pathogenic bacterial,test results indicate that new compound strepphenazine A showed obvious inhibition activity against Staphylococcus aureus,Bacillus subtilis and Alternaria panax with the MIC values of 16,32 and 32 ?g/mL respectively;strepphenazine B showed inhibition activity against,Fusarium oxysporum,Plectosphaerella cucumerina and A.panax etc with the same MIC values of 64 ?mL;strepphenazine C showed strong inhibition activity against B.subtilis and S.aureus with the MIC values of 8 and 16?g/mL respectively,and it also showed obvious inhibition activity against F.oxysporum,P.cucumerina,and A.panax with the same MIC values of 32 ?g/mL respectively;strepphenazine D showed obvious inhibition activity against A.panax,P.cucumerina and S.aureus ect with the MIC values of 16,32 and 32 ?g/mL respectively;strepphenazine E showed obvious inhibition activity against A.panax and S.aureus with the same MIC values of 32 ?g/mL respectively.Besides,24 known compounds were also found to have antimicrobial activity against tested pathogenic microbe with the MIC values in the range of 8-512 ?g/mL.