内生真菌对姜黄素的微生物转化

Transformation of Curcumin by Endophytic Fungus Diaporthe sp.Isolated from Curcuma Longa

目的:调查姜黄根茎内生真菌对姜黄素的微生物转化,以期获得一些姜黄素的结构类似物或衍生物。方法:利用表面消毒法分离内生真菌;采用薄层层析和高效液相色谱(HPLC)技术筛选生物转化姜黄素的内生真菌;利用硅胶柱层析和制备型HPLC分离纯化生物转化产物;应用波谱技术解析转化产物的化学结构;通过形态学特征和内转录间隔区(ITS)序列分析对内生真菌进行初步鉴定。结果:从姜黄根茎中分离出18株内生真菌,经筛选发现其中1株丝状真菌能转化姜黄素,其产物分别为去甲基姜黄素和二去甲基姜黄素。初步鉴定该内生真菌属于Diaporthe sp.。结论:内生真菌Diaporthe sp.能对姜黄素进行去甲基化修饰,推测它可能具有O-去甲基化酶系。

Objective：The microbial transformation of curcumin by endophytic fungi isolated from the rhizoma of Curcuma longa was investigated to obtain some curcuminoids or its derivatives.Methods：Endophytic fungi were isolated from the rhizoma of C.longa by surface-sterilization method,and screening test for the microbial transformation of curcumin was carried out using thin layer chromatography and high performance liquid chromatography （HPLC）.Bio-transformed products of curcumin were isolated and purified by silica column chromatography and preparative HPLC,and chemical structures of transformed products were elucidated on the basis of chemical spectral data.The endophytic fungus was identified by morphological characteristics and the analysis of internal transcribed spacer（ITS） fragment of rDNA.Results：Among totally 18 endophytic fungi,one filamentous fungus was found to transform curcumin into demethylcurcumin and bisdemethylcurcumin,which was identified preliminarily as Diaporthe sp.by morphological characteristics and the analysis of ITS1-5.8S-ITS2 rDNA region.Conclusion：Endophytic fungus Diaporthe sp.was able to modify the chemical structure of curcumin by demethylation reaction,and it was deduced that this fungus possessed O-demethylation enzyme system.