| Actinomycetes are the main producers of antibiotics.In this paper,three strains of active actinomycetes were obtained from more than 500 strains of actinomycetes isolated from soil samples of Gaoligong Mountain.16 S r RNA gene sequence and morphological analysis were used to identify them as Streptomyces niveus YNNP00059,Streptomyces scopuliridis YNNP 00076 and Streptomyces lincolnensis YNNP00164.A total of 24 compounds were isolated from the fermentation products of the three strains,of which compound 4 was a new compound and temporarily identified as 2-hydroxy-2-(4-methoxy-3-(3-methyl-2-en-1-yl)phenyl)acetic acid.Among these compounds,compounds 1,4,16 and 21 showed inhibitory activity against Candida albicans,with MIC values(minimum inhibitory concentration)of 32μg/m L,64 μg/m L,64 μg/ml and 64 μg/m L,respectively.Compounds 1,5 and 19 showed inhibitory activity against Listeria monocytogenes,with MIC values of 128μg /m L,32 μg /m L and 128 μg /m L,respectively.Compounds 1,10,14 and 18 showed inhibitory activity against Pseudomonas aeruginosa,with MIC values of 128μg /m L,128 μg/m L,128 μg/m L and 64 μg/m L,respectively.Compounds 4,10,20 and 21 showed inhibitory activity against Staphylococcus aureus with MIC values of32 μg /m L,128 μg /m L,16 μg /m L and 32 μg /m L;Compounds 14 and 20 showed inhibitory activity against Bacillus subtilis with MIC value of 64 μg /m L.Compounds14 and 18 showed inhibitory activity against Escherichia coli with MIC value of 64μg/m L.Compounds 5,20 and 21 showed inhibitory activity against methicillin-resistant Staphylococcus aureus,with MIC values of 128 μg/m L,256μg/m L and 256 μg/m L,respectively.Compounds 1,5 and 19 showed inhibitory activity against kanamycin-resistant Pseudomonas aeruginosa with MIC values of128 μg /m L,128 μg /m L and 256 μg /m L,respectively.Compounds 1,4,5 and 6showed inhibitory activity against fluconazole-resistant Candida albicans,with MIC values of 128 μg/m L,128 μg /m L,128 μg/m L and 256 μg/m L,respectively.In other bioactivity experiments,the scavenging rates of DPPH radical were 40%,48% and43% for compounds 8,10 and 22 at the concentration of 80 μg/ml,respectively.The inhibition rates of acetylcholinesterase were 23.40% and 26.76% for compounds 2and 5 at the concentration of 50 μM.These results show that actinomycetes from Gaoligong Mountain soil can produce metabolites with antibacterial activities. |
