恒山黄芪内生真菌Aspergillus sp.中环二肽的分离和鉴定

目的:研究黄芪内生真菌AR-15-1的环二肽类次生代谢产物的成分。方法:内生真菌AR-15-1是采用组织学方法分离自恒山黄芪的根部,真菌的鉴定采用形态学法结合分子生物学法,内生真菌大量发酵采用固体培养的方法,环二肽成分的分离使用柱色谱法,HPLC法结合LH-20羟丙基葡聚糖凝胶色谱进行分离纯化,化合物结构鉴定采用波谱表征分析。结果:从黄芪根部分离到的内生真菌AR-15-1被鉴定为曲霉属Aspergillus sp.,从AR-15-1的固体发酵物中分离到8个环二肽化合物,分别为环(脯-甘)二肽(1),环(脯-亮)二肽(2),环(脯-异亮)二肽(3),环(脯-缬)二肽(4),环(苯丙-甘)二肽(5),环(苯丙-丙)二肽(6),环(苯丙-络)二肽(7)和环(苯丙-脯)二肽(8)。结论:环二肽类化合物1~8均为首次从黄芪内生真菌中分离得到,其中大部分环二肽化合物已被发现是具有很好的生物活性。

Isolation and Identification of Cyclic Dipeptides from Endophyic Aspergillus sp. in Astragali Radix

Objective: To study the cyclic dipeptides secondary metabolites from endophytic AR-15-1 in Astragali Radix. Method: AR-15-1 was isolated from the roots of Astragali Radix by the method of histology. The fungus was identified by morphological method combined with molecular biology method, and solid culture method was used for large-scale fermentation of endophytic fungi. Cyclic dipeptides were isolated by column chromatography, Sephadex LH-20, and HPLC, and their chemical structures were elucidated by the spectral analysis. Result: Endophytic fungi AR-15-1 isolated from roots of Astragali Radix were identified as Aspergillus sp. Eight cyclic dipeptides were obtained and elucidated as cyclo-(Pro-Gly) (1), cyclo-(Pro-Leu) (2), cyclo-(Pro-Ile) (3), cyclo-(Pro-Vla) (4), cyclo-(Phe-Gly) (5), cyclo-(Phe-Ala) (6), cyclo-(Phe-Tyr) (7) and cyclo-(Phe-Pro) (8). Conclusion: All cyclic dipeptides were isolated from the endophytic fungi of Astragali Radix for the first time, and most of the cyclic dipeptides of Aspergillus sp. showed good biological activity.