黄芩苷发酵转化成黄芩素和千层纸素A的黄芩内生真菌的筛选及鉴定

Screening and Identification of Endophytic Fungi in Scutellariae Radix Transformed Baicalin to Baicalein and Oroxylin A

目的:采用现代微生物发酵转化技术开发传统中药——黄芩,从黄芩植株体内筛选可发酵转化黄芩苷的内生真菌,以期替代传统化学方法获得天然药效成分,同时缓解该中药资源紧张的现状。方法:以新鲜黄芩植株为材料,采用马铃薯葡萄糖琼脂(PDA)平板培养消毒组织块,分离单菌落,黄芩药粉选择性培养法初筛,黄芩苷发酵转化实验复筛,HPLC分析转化产物。结果:从新鲜黄芩植株根部分离得到一株发酵转化黄芩苷的内生真菌R3,该菌在添加0.1%黄芩苷的马铃薯葡萄糖培养液(PDB)中能转化黄芩苷,同时产生黄芩素和千层纸素A共2种产物,于28℃,150 r·min^(-1)培养5 d转化率61.09%,其中黄芩素和千层纸素A的摩尔比3∶5。利用形态分析及显微鉴定并结合分子生物学技术手段,鉴定该菌为青霉菌,定名为Penicillium sp. R3。结论:筛选得到黄芩内生真菌Penicillium sp. R3,该菌能够转化黄芩苷得到活性更强、更易吸收的黄芩素,以及近年来因更多药效不断被发现而备受关注的千层纸素A,具有一定的研究价值与应用价值。

Objective: In order to explore natural active ingredients of Scutellariae Radix and alleviate the pressure of traditional medicinal resources, this research aimmed to screen endophytic fungus strains from Scutellariae Radix which could transform baicalin into some active ingredients. Method: Taking fresh plants of Scutellariae Radix as strain resource,endophytic fungus strains were isolated by potato dextrose agar( PDA) plate separation,Scutellariae Radix powder selective culture and HPLC detection. Result: An endophytic fungus strain R3 was isolated and it can transform baicalin to baicalein and oroxylin A simultaneously in potato dextrose broth( PDB) contained 0. 1% baicalin and the conversion rate reached 61. 09% in 5 d cultured at 28 ℃ and150 r·min^-1,molar ratio of baicalein and oroxylin A was 3 ∶ 5. With the method of morphological analysis,microscopic identification and 18 Sr DNA sequence analysis,the bacterium was identified as Penicillium sp. R3.Conclusion: Penicillium sp. R3 can transform baicalin to baicalein and oroxylin A with certain research value and application value.