Studies On Characterization And Chemical Constituents Of Actinomycete Strain H41-59

As is known to al, antifungal antibiotics are produced mainly by actinomycete. In our studies, an antifungal actinomycete strain H41-59, isolated from sea sediment sample collected at mangrove district in South China Sea, was investigated on species characterization, optimation of fermentation and its chemical constituents. The result of the study were listed below:(1) Strain H41-59 was identified as Streptomyces anandii by investigating its morphological characteristics, cultural characteristics and 16 S rDNA sequence analysis. It is 99.9% similar to the sequence of S. anandii deposited in Genbank under accession number GU350497.1. Strain H41-59 displayed a broad-spectrum activity against Candida albicans, Staphylococcus aureus, Magnaporthe oryzae, Alter aria alternata(Fries) Keissler, P. capsici.(2) Using agar diffusion method with Candida albicans as an indicator, four culture media were screened for a better culture medium to imulate strain H41-59 to secrete more antifungal components, and a modified Guserium synthetic No. 1 medium was choosed for fermentation under 30 ℃ and 5 d.(3) By using multiple chromatographic and spectroscopic methods, twenty compounds were isolated from a fraction of ethyl acetate of 95% ethanol extract, and identified as ananstrep D(1), ananstrep E(2), ergosta-7,22-diene-3β,5α,6β-triol(3), ergosta-7,22-diene-3β,5α,6α-triol(4), ergosta-7,22-diene-3β,5α,6β,27-tetraol(ananstrep A, 5), ergosta-7,22-diene-3β,5α,6β,25-tetraol(6), ergosta-7,22-diene-3β,5α,6β,9α-tetraol(7), ergosta-7,22-diene-3β,5α,6β,9α,25-pentol(ananstrep B, 8), 5α,6α-epoxy-ergosta-8(9),22-diene-3β,7α-diol(9), 5β,6β-epoxy-ergosta-8(9),22-diene-3β,7β-diol(ananstrep C, 10), 5α,6α-epoxy-ergosta-8(14),22-diene-3β,7β-diol(11), 5α,6α-epoxy-ergosta-8(14),22-diene-3β,7α-diol(12), ergosta-8(9),22-diene-3β,5α,6β,7α-triol(13), ergosta-8(14),22-diene-3β,5α,6β,7α-triol(14), ergosta-5,7,22–triene-3β-ol(15), 3,3-bis(3-indol) propane-1,2-diol(16), ubiquinone Q9(17), hexadecanoic acid, 2,3-dihydroxypropyl ester(18), methyl Linoleate(19), 9Z-octadecenoic acid(20). Among them, compound 1, 2, 5, 8 and 10 were new compounds.(4) Their antibacterial activity and cytotoxicities were evaluated, compounds 1 ~ 15 displayed cytotoxicities at different degrees. Among them, compound 1 showed potent inhibitory activity against three cancer cell lines with IC50 values of 7.8 μg/mL.