Bioactive Quinic Acid Derivatives from Ageratina adenophora

摘要

A novel quinic acid derivative, 5-O-trans-o-coumaroylquinic acid methyl ester (>1), together with three known ones, chlorogenic acid methyl ester (>2), macranthoin F (>3) and macranthoin G (>4), were isolated from the aerial parts of the invasive plant Ageratina adenophora (Spreng.). The structure of new compound >1 was elucidated on the basis of extensive spectroscopic analysis, including 1D- and 2D-NMR techniques. Compounds >2–>4 were isolated from plant A. adenophora for the first time. All the compounds showed in vitro antibacterial activity toward five assayed bacterial strains, especially >3 and >4, which showed in vitro antibacterial activity against Salmonella enterica with MIC values of 7.4 and 14.7 μM, respectively. Compound >1 was further found to display in vitro anti-fungal activity against spore germination of Magnaporthe grisea with an IC50 value 542.3 µM. These four compounds were also tested for their antioxidant activity against DPPH (1,1-diphenyl-2-picrylhydrazyl) radical.