广藿香内生真菌索氏平脐蠕孢中1个新旋孢腔菌醌类化合物及其生物活性

A new cochlioquinone from endophytic fungus Bipolaris sorokiniana derived from Pogostemon cablin and its bioactivity

目的研究分离自广藿香内生真菌索氏平脐蠕孢Bipolaris sorokiniana A606的活性次级代谢产物的化学结构及其活性。方法运用正相硅胶、C18反相硅胶、Sephadex LH-20凝胶和HPLC等色谱技术对菌株B.sorokiniana A606发酵液的醋酸乙酯萃取物进行分离纯化,并通过各种谱学分析方法进行结构鉴定;采用SRB染色法和滤纸片法分别测定化合物的细胞毒和抗菌活性。结果从B.sorokiniana A606发酵液的醋酸乙酯萃取物中分离得到2个化合物,分别鉴定为(3S*,4a S*,6a S*,12b S*)-3-(2-羟基-2-丙烷基)-6a,12b-二甲基-9-[(2R*,4R*)-2-(4-甲基-3-己酮基)]-1,2,3,4a,5,6-六氢吡喃并[3,2-a]氧杂蒽-8,11-二酮(1)和precochlioquinol D(2)。结论化合物1为新化合物,命名为11-羟基-12,13-去氢旋孢腔菌醌B。化合物2为首次从该属真菌中分离得到。其中化合物1具有细胞毒和抗菌活性。

Objective To study the chemical structure and activity of secondary metabolites of the endophytic fungus Bipolaris sorokiniana A606 isolated from Pogostemon cablin. Methods The compounds were isolated and purified from the ethyle acetate extract of the fungal fermentation broth by silica gel, reverse phase silica gel, Sephadex-LH20, HPLC, and so on. Their structures were identified by extensive spectroscopic analysis. The compounds were evaluated for their cytotoxic activities against human tumor cell lines by the SRB assay and their antibacterial activities against bacteria were evaluated by the filter paper method. Results Two compounds were isolated from the fermentation broth extract of the strain A606 and identified as （3S^＊,4aS^＊,6aS^＊,12bS^＊）-3-（2-hydroxypropan-2-yl）-6a, 12b-dimethyl-9-[（2R^＊,4R^＊）-4-methyl-3-oxohexan-2-yl]-l,2,3,4a,5,6-hexahydr opyrano [3,2-a]xanthene-8,11-dione （1） and precochlioquinol D （2）. Conclusion Compound 1 is a new compound, named l l-hydroxy-12,13-dehydrocochlioquinone B. Compound 2 is isolated from the species of genus Bipolaris for the first time. Compound 1 shows the cytotoxic and antibacterial activities.