中文摘要：

为了解座壳孢次生代谢产物的抗菌活性，利用活性追踪从扁座壳孢（Aschersonia placenta Berk. et Br.）Jos009的发酵液中分离胞外代谢产物，进一步分离纯化获得纯物质，采用质谱和核磁共振方法进行结构解析，并以滤纸片法测定其最小抑菌浓度。将分离化合物鉴定为15α,22-二羟何帕烷；对6种病原细菌和10种病原真菌的抗菌活性测定显示，该化合物对供试真菌无活性，而对沙门氏杆菌（Salmonella）和粘质赛氏杆菌（Serratia marcescens）有一定抑制作用，MIC值为500 （g mL-1，是扁座壳孢前期胞外代谢产物对这两种菌MIC值的13倍。研究表明扁座壳孢胞外代谢产物除15α,22-二羟何帕烷外还含有其它抗菌物质（化合物或肽类等）。参22

英文摘要：

In order to identify the antibacterial compounds and their activities in the fermentation broth of Aschersonia placenta Berk. et Br. Jos009,, the extract of the fermentation broth of Jos009 was separated by activity guided isolation, and 15α,22-dihydroxyhopane was isolated and identified on the basis of MS and NMR spectroscopic data. The results of 15α,22-dihydroxyhopane against 6 pathogenic bacteria and 10 pathogenic fungi revealed that its minimum inhibitory concentrations （MICs） tested by filter paper method against Serratia marcescens and Salmonella typhimurium was 500 （g mL-1, 13 times of MICs of Jos009 fermentation broth to the two bacteria. Our findings suggested the existence of other antimicrobial substances （compounds or peptides） besides 15α,22-dihydroxyhopane in the extracellular metabolites of A. placenta Berk. et Br. Jos009. Ref 22