一株海洋来源真菌Aspergillus flavipes次生代谢产物研究

The research of secondary metabolites of a marine-derived fungus Aspergillus flavipes

目的:探究海洋来源真菌Aspergillus flavipes次生代谢产物的化学成分。方法:综合运用硅胶色谱、凝胶色谱(sephadex LH-20)、ODS柱色谱(octadecyl silan)、半制备型高效液相色谱(high performance liquid chromatography,HPLC)等分离技术对该菌株的大米发酵产物进行分离纯化;通过核磁共振氢谱(1H nuclear magnetic resonance,1H NMR)、核磁共振碳谱(13C nuclear magnetic resonance,13C NMR)、电喷雾电离质谱(electrospray ionization-mass spectrum,ESI-MS)和X-ray单晶衍射等方法鉴定了6个化合物的化学结构;并采用cell counting Kit-8(CCK-8)法,用宫颈癌细胞株HELA、人肺癌细胞株PC9和黑色素瘤细胞株A375评价了化合物的细胞毒活性。结果:从Aspergillus flavipes中分离得到6个化合物:Cyclo(glycyl-L-tryptophyl-Lprolylglycyl-L-valylglycyl-β-hydroxy-L-tyrosyl)(1),aspersymmetide A (2),geodin hydrate (3),methyl chloroasterrate (4),2,4-dichloroasterric acid (5)以及questin (6)。结论:其中首次从黄炳曲霉属Aspergillus flavipes中分离得到具有中心对称结构的环肽类化合物(2),并首次通过X-ray单晶衍射实验确定化合物2的平面结构和绝对构型。细胞毒活性显示化合物1~6在20μmol·L-1浓度下对宫颈癌细胞株HELA、人肺癌细胞株PC9和黑色素瘤细胞株A375无明显细胞毒活性,化合物2对顺铂耐药胃癌细胞株SGC7901有细胞毒活性,其半抑制浓度(half maximal inhibitory concentration,IC50)为15. 31μmol·L-1。

Objective: To investigate the chemical consitituents of secondary metabolites in the marinederived fungus Aspergillus flavipes. Methods: The rice fermentation products of the strain were isolated and purified by multidimensional chromatography of silica gel column, Sephadex LH-20, octadecyl silan (ODS), and semi-preparative high performance liquid chromatography (HPLC). The chemical structures of six compounds were identified by 1H nuclear magnetic resonance(1H NMR),13C nuclear magnetic resonance(13C NMR),electrospray ionization-mass spectrum (ESI-MS) and X-ray crystal diffraction. Cytotoxicity of the compounds were evaluated on cervical cancer cell line (HELA),human lung cancer PC9 and Melanoma cell line A375 by CCK8 method. Results: Six compounds were obtained and identified as cyclo (glycyl-L-tryptophyl-L-prolylglycyl-Lvalylglycyl-β-hydroxy-L-tyrosyl) (1),aspersymme-tide A (2),geodin hydrate (3),methyl chloroasterrate (4),2,4-dichloroasterric acid (5) and questin (6). Conclusion: Cyclic peptide type compound (2) with a central symmetrical structure was first isolated from the fungus Aspergillus flavipes,and its planar and absolute structure was determined by X-ray crystal diffraction. Compounds 1 ~ 6 showed no significant cytotoxicity against cervical cancer cell line (HELA),human lung cancer PC9 and melanoma cell line A375 at the concentration of 20 μmol·L-1,but compound 2 showed the cytotoxicity against cisplatin-resistant human gastric cancer cell line SGC7901 with an IC50 of 15. 31 μmol·L-1.