Specialized metabolites from Ageratina adenophora and their inhibitory activities against pathogenic fungi. (April 2018)

• Record Type: Journal Article
• Authors: Zheng, Guowei; Luo, Shihong; Li, Shifei; Hua, Juan; Li, Weiqi; Li, Shenghong
• Is Part Of: Phytochemistry. Volume 148(2018)
• Page Start: 57
• Page End: 62
• Publication Date: 2018-04
• Subjects: Ageratina adenophora -- Asteraceae -- Roots -- Specialized metabolites -- Antifungal activity; Botanical chemistry -- Periodicals; Biochemistry -- Periodicals; Botany -- Periodicals; Chimie végétale -- Périodiques; 572.2
• DOI: 10.1016/j.phytochem.2018.01.013
• Languages: English
• ISSNs: 0031-9422

Abstract

Abstract: The Asteraceae plant Ageratina adenophora (also called Eupatorium adenophorum ) has became the most destructive invasive species in China, especially the southwestern region, and is gravely threatening the native biodiversity. Its high reproductive capacity is partly due to the developed root system. From the roots of A. adenophora, ten compounds including three previously undescribed benzofuran derivatives (7-hydroxy-dehydrotremetone, 7, 10, 11-trihydroxy dehydrotremetone, 10- oxo -7-hydroxy-nordehydrotremetone), a previously undescribed chromene derivative (5- β -glucosyl-7-demethoxy-encecalin) and a previously undescribed monoterpene glucoside (8-hydroxy-8- β -glucosyl-2-carene) were isolated and identified. The previously undescribed structures were established by spectroscopic studies including 1D and 2D-NMR and HR-MS analyses. Antifungal activity of six compounds against one strain of pathogenic fungus of A. adenophora, Alternaria alternata, and other four strains of agricultural pathogenic fungi, Colletotrichum gloeosporioides, C. musae, Rhizoctonia solani and Fusarium oxysporum f. sp. niveum were investigated. The most abundant compound we isolated from A. adenophora roots was 7-hydroxy-dehydrotremetone, which showed significant broad-spectral inhibitory activity against the growth of all tested fungal strains, with diameter of inhibitory zones ranging from 13.90 ± 1.05 mm to 17.28 ± 0.46 mm at 50 μg/disk (nystatin: 24.76 ± 1.19 mm to 36.64 ± 0.85 mm). Encecalin also showed weak inhibitory activity against F. oxysporum f. sp. niveum, while other compounds were not active. Our results suggested that 7-hydroxy-dehydrotremetone might function as a constitutive defense compound in the roots of A. adenophora against pathogenic fungi. Graphical abstract: Ageratina adenophora is a notorious invasive plant worldwide and has caused great economically loss in southwest China. The specialized metabolites synthesized by this plant may play a role during its invasion. Ten compounds including five previously undescribed ones were isolated and identified from roots of invasive plants A. adenophora . The most abundant compound we isolated in A. adenophora roots was 7-hydroxy-dehydrotremetone, which showed significant broad-spectral inhibitory activity against the growth of all tested fungal strains. 7-hydroxy-dehydrotremetone may act as antifungal metabolite during the invasion of A. adenophora, which may influence the dominance of A. adenophora . Highlights: Five previously undescribed compounds were isolated from Ageratina adenophora root. 7-hydroxy-dehydrotremetone showed strong activity against pathogenic fungi. 7-hydroxy-dehydrotremetone can also inhibit pathogenic fungi of A. adenophora.