Preliminary Studies On The Secondary Metabolites And Biological Activities Of Two Actinomycety Strains

Mining novel active metabolites from actinobacteria habiting different niches has become a hotspot in microbial pharmaceutical research.Here we screened 80actinobacterial strains isolated from soil of Qinghai-Tibet Plateau by chemical diversity and bioactive assays of fermentation extracts.The isolates YIM PH20533and a potential novel species numbered as YIM PH21725 were selected for further investigated on their secondary metabolites.On the basis of morphological characteristics and the 16S rRNA gene sequence analysis,they were classified as Streptomyces albonige,Amycolatopsis sulphurea respectively.YIM PH20533 was fermented in the broth of 301#,and the extract crude was isolated by different chromatographic techniques.Thirty-three compounds were purified from the product of YIM PH20533.Among them,11 compounds were elucidated as new molecues(1-11)and 2 as new natural products(12-13)by analysis of MS and 1D and 2D NMR spectra.They were named streptalbonin A(1),streptalbonin B(2),streptalbonin C(3),streptalbonin D(4),streptalbonin E(5),streptalbonin F(6),streptalbonin G(7),streptalbonin H(8),streptalbonin I(9),strepalbin A(10),8a-hydroxy-streptazolin(11),4-(2-hydroxyphenyl)butyric acid(12),and pyrrolyl-2-carboxyl-N-acetylcysteamine thoester(13),respectively.YIM PH21725 was fermented in the broth of 400~#medium,and 8 known compunds were isolated and elucidated on the basis of MS and NMR spectra.Some compounds were selected to assay the bioactivities,such as antimicrobes,cell toxicity,anti-inflammatory,AchE inhibitory activity,anticoagulant APTT,and rabbit platelet aggregation activity induced by ADP and PAF.Compounds 9 and 41presented certain antimicrobial activities against target strains of Staphylococcus aureus,Escherichia coli,Fusarium flocciferum,Fusarium solani,Fusarium oxysporum.At the concentration of 50?M,1 and 18 showed antioxidant activities in the generation of nitric oxide(NO)experiments with the inhibitive rate of 55.04±2.80%and 37.79±1.11%,respectively.Compound 10 presented the inhibitive activity with a rate of 27.17%at the concentration of 50?M,and also showed APTT activity at 28.3±0.15 s(<0.05 vs Con).The anti PAF acitivity of compound 1 was26.0±9.1%(50?M).