紫花玉簪内生真菌分离鉴定及其抗氧化活性研究

摘要

A total of 13 types of endophytic fungi,classified into six genera,were isolated from Hosta.ventricosa based on 18S rDNA sequencing of ITS region and microscopic examination.The antioxidant activities of the crude extracts were investigated by T-AOC,DPPH and ABTS+ methods.The results showed that the crude extracts from Fusarium oxysporum (HoV1) and Epicoccum (HoV4),which presented higher phenol levels (1.90±0.03 mg/g,and 2.41±0.01 mg/g,respectively),exhibited stronger comprehensive antioxidant activities,with higher T-AOC values (63.46±0.26 U/g,and 66.05±0.71 U/g,respectively),lower EC50 values against ABTS+ (30.25±0.05 μg/mL,and 24.66±0.65 μg/mL,respectively)and DPPH radicals (83.42±0.24 μg/mL,and 59.136 μg/mL,respectively).Moreover,Fusarium oxysporum (HoV8) showed excellent scavenging activity against DPPH radicals (EC5o=16.02 μg/mL),which was better than BHT.All of them could be useful in the developing of new natural antioxidant agents.%以紫花玉簪为研究对象,从其根部分离得到13株内生真菌,并通过IST序列扩增后18S rDNA进行鉴定.以总抗氧化能力,DPPH自由基清除能力,ABTS+在自由基清除能力为指标,研究13种内生真菌菌丝体醇提物抗氧化活性,并测定其总多酚含量.结果表明,HoV1(尖孢镰刀菌属)和HoV4(附球菌属)粗提物多酚含量较高(1.90±0.03 mg/g,2.41± 0.01 mg/g),且表现出较强的综合抗氧化能力.其总抗氧化能力分别为(63.46±0.26 U/g,66.05±0.71 U/g),ABTS+自由基清除IC50分别为(30.25±0.05 μg/mL,24.66±0.65 μg/mL),DPPH自由基清除IC50分别为(83.42± 0.24 μg/mL,59.136 μg/mL).另外,尖孢镰刀菌属的HoV8具有优于BHT的DPPH自由基清除活性(IC50=16.02 μg/mL).这些真菌都有望开发成为新型天然抗氧化制剂.