关键词: 白花前胡, 内生真菌, 抑菌活性, 细胞毒性, 次级代谢产物

Abstract: This study aims to isolate endophytes with good bioactivity from Peucedanum praeruptorum to provide a basis for the research and development of new drugs. The endophytic fungi were isolated by tissue block method and fermented in ME medium. The fermented liquids were extracted by ethyl acetate and concentrated to obtain the crude extracts. The antimicrobial activities of the crude extracts against four bacteria, Staphylococcus aureus, Salmonella enteritidis, Pseudomonas aeruginosa and Escherichia coli, and four fungi, Fusarium graminearum, Verticillium dahliae, Botrytis cinerea and Candida albicans, were determined by cup-plate method. The cytotoxicity against human lung cancer cell line A549 and human breast cancer cell line MDA-MB-231 was determined by MTT method. Finally, morphological observation combined with ribosomal internal transcription spacer sequence (rDNA-ITS) was used to identify one strain with potent activity, and the secondary metabolites of the strain were isolated, purified and identified. A total of 7 strains of endophytic fungi were isolated. Among them, 4 strains, bhqh-2, 3, 5 and 7 showed good biological activities, and their crude extracts had inhibitory effects on all of the test bacteria and fungi, and the inhibitory rates on the two kinds of cancer cells were more than 95%. Strain bhqh-2 was identified as Aspergillus aspergillus, and 6 known compounds were isolated and purified from its crude extract. In conclusion, some P. praeruptorum associated fungi showed good biological activity, which provided a basis for the study of endophytic metabolites and their biological activities.

Key words: Peucedanum praeruptorum, endophytic fungi, antimicrobial activity, cytotoxicity, secondary metabolites