title: Antimicrobial flavonoids from the twigs of Populus nigra x Populus deltoides.
abstract: A bioassay-guided fractionation of the ethyl acetate extract from the twigs of the hybrid poplar 'Neva', Populus nigra L. × Populus deltoides Marsh, led to the isolation of three flavonoids, which were identified by means of spectrometric and physicochemical analysis as 5-hydroxy-7-methoxy-flavone (1), 5,7-dihydoxy-flavone (2) and 5,7-dihydroxy-flavonol (3). These compounds were further screened for their antimicrobial activity against plant pathogens, including three bacteria (Pseudomonas lachrymans, Ralstonia solanacearum and Xanthomonas vesicatoria) and one fungus (Magnaporthe oryzae). Compounds 2 and 3 showed significant antibacterial activity, with minimum inhibitory concentrations (MICs) ranging from 15 to 25 µg mL(-1), and median inhibitory concentrations (IC(50) values) from 4 to 18 µg mL(-1). The results obtained provide promising baseline information for the potential use of the extract and flavonoids from this plant as antimicrobial agents to help control plant diseases.
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing, China.
authors.forename: Lingyun
authors.initials: L
authors.lastname: Zhong
authors.forename: Ligang
authors.initials: L
authors.lastname: Zhou
authors.forename: Yaming
authors.initials: Y
authors.lastname: Zhou
authors.forename: Yuanquan
authors.initials: Y
authors.lastname: Chen
authors.forename: Peng
authors.initials: P
authors.lastname: Sui
authors.forename: Jingguo
authors.initials: J
authors.lastname: Wang
authors.forename: Mingan
authors.initials: M
authors.lastname: Wang
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D020082:Magnaporthe / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D032107:Populus / Q000737:chemistry*; D011549:Pseudomonas / Q000187:drug effects; D043367:Ralstonia / Q000187:drug effects; D044184:Xanthomonas vesicatoria / Q000187:drug effects
chemical_list: C574172:5,7-dihydoxyflavone; C574173:5,7-dihydroxyflavonol; D000890:Anti-Infective Agents; D005419:Flavonoids