title: Antibacterial activities of flavonoids: structure-activity relationship and mechanism.
abstract: Flavonoids are well known as antibacterial agents against a wide range of pathogenic microorganism. With increasing prevalence of untreatable infections induced by antibiotic resistance bacteria, flavonoids have attracted much interest because of the potential to be substitutes for antibiotics. In this review, the structure-relationship of flavonoids as antibacterial agents is summarized, and the recent advancements on the antibacterial mechanisms of flavonoids are also discussed. It is concluded that hydroxyls at special sites on the aromatic rings of flavonoids improve the activity. However, the methylation of the active hydroxyl groups generally decreases the activity. Besides, the lipopholicity of the ring A is vital for the activity of chalcones. The hydrophobic substituents such as prenyl groups, alkylamino chains, alkyl chains, and nitrogen or oxygen containing heterocyclic moieties usually enhance the activity for all the flavonoids. The proposed antibacterial mechanisms of flavonoids are as follows: inhibition of nucleic acid synthesis, inhibition of cytoplasmic membrane function, inhibition of energy metabolism, inhibition of the attachment and biofilm formation, inhibition of the porin on the cell membrane, alteration of the membrane permeability, and attenuation of the pathogenicity.
authors.forename: Yixi
authors.initials: Y
authors.lastname: Xie
authors.forename: Weijie
authors.initials: W
authors.lastname: Yang
authors.forename: Fen
authors.initials: F
authors.lastname: Tang
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Chen
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P R China. xqchen@mail.csu.edu.cn.
authors.forename: Licheng
authors.initials: L
authors.lastname: Ren
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D001572:Benzofurans / Q000737:chemistry / Q000494:pharmacology; D047188:Chalcones / Q000737:chemistry / Q000494:pharmacology; D005419:Flavonoids / Q000737:chemistry* / Q000494:pharmacology; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D001572:Benzofurans; D047188:Chalcones; D005419:Flavonoids