title: Antifungal activities of triterpenoids from the roots of Astilbe myriantha Diels.
abstract: During a search for plant extracts that possess activity against the fungi that cause diseases in plants, a 95% ethanol extract from the roots of Astilbe myriantha Diels showed inhibitory activity against Colletotrichum gloeosporioides. Bioassay-guided fractionation of the 95% ethanol extract led to the isolation of seven triterpenoids (1-7). Their structures were elucidated by spectroscopy and by a comparison with literature data. Among these compounds, 3β,6β,24-trihydroxyurs-12-en-27-oic acid (7) was the most active inhibitor of C. gloeosporioides, with >68.0% inhibition at 100mg/ml after 72h. Moreover, compound 7 displayed broad-spectrum inhibitory activity against Rhizoctonia solani, Fusarium oxysporum f. sp. Niveum, Fusarium oxysporum f. sp. Cubens, C. gloeosporioides, Penicillium citrinum, Colletotrichum lagenarium, and Penicillium digitatum, with EC50 values ranging from 13.9 to 34.0μg/ml. The potential of compound 7 as a fungicide is therefore promising. In addition, compound 1 was found to be a new triterpenoid, 3β,6β-dihydroxyurs-12-en-7α,27α-olide, which possesses six rings.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, People's Republic of China.
authors.forename: Qiu-Yan
authors.initials: QY
authors.lastname: Song
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, People's Republic of China.
authors.forename: Wei-Yan
authors.initials: WY
authors.lastname: Qi
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, People's Republic of China.
authors.forename: Zheng-Ming
authors.initials: ZM
authors.lastname: Li
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, People's Republic of China. Electronic address: chenjj@lzu.edu.cn.
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, People's Republic of China. Electronic address: npchem@lzu.edu.cn.
authors.forename: Kun
authors.initials: K
authors.lastname: Gao
keywords: Antifungal activity; Astilbe myriantha Diels; Triterpenoids