Taxonomy Characteristics And Its Secondary Metabolites Of Anti-Candida Albicans Actinomyce Strain H41-51

This thesis has studied on the taxonomy characteristics and active chemical constituents of fermentation broth of an antifungal actinomycete strain No.H41-51,which was isolated from sea sediment at mangrove site in South China Sea,Zhapo,Yangjiang,Guangdong province.The strain H41-51 was identified as Streptomyces antibioticus according to 16 S rDNA sequence and phylogentic tree analysis in combination with morphological,cultural,and physiological and biochemical characteristics of the strain,and its 16 S rDNA accession number in Genbank was KU756253.Eighteen compounds were isolated from the active fractions by column chromatography on silica gel and Sephadex LH-20,and semi-preparative reverse phase HPLC.The isolation progress was monitored by paper disc diffusion assays in an agar plate.Structure identifications of the isolates were performed by spectroscopic methods including NMR and MS as well as comparison with the data of literatures.They were identified to be 3,3-diindole-2-hydroxye-propanol(1),cyclo(Phe-Ala)(2),cyclo(R-Pro-S-Phe)(3),cyclo(S-Pro-S-Phe)(4),cyclo(D-Phe-L-Ile)(5),dankasterone(6),4-hydroxy-17R-methylincisterol(7),calvasterol B(8),calvasterol A(9),antimycin A1a(10),antimycin A1b(11),3?-N-deformyl antimycins A1a(12)and A1b(13),antimycin A21(14),(2S,3R,6R,8S)-3-(4-benzoxazolinone-amido)-7-hexyl-4,9-dimethyl-2,6-dioxo-1,5-dixonan-8-yl isobutynoate(15),(9Z)-glycerin-1-monooleate(16),dibutyl phthalate(17),bis(2-ethylhexyl)-benzene-1,2-dicarboxylate(18).Among them,compounds 12-15 were new natural products.In vitro bioassay showed that compounds 6-9 exhibited various cytotoxic activities against MCF-7,SF-268 and NCI-H460 cell lines.Additionally,compounds 10,11 and 14 exhibited antifungal activity against Candida albicans.