Phytochemical, antimicrobial and antiquorum-sensing studies of L.: a revision on the structure of 1β,2α,3β,19α,23-pentahydroxy-urs-12-en-28-oic acid.

Phytochemical study of the aerial part of L. led to the isolation of nine compounds. The structure of 1β,2α,3β,19α,23-pentahydroxy-urs-12-en-28-oic acid () was revised and confirmation of the stereochemical configuration of the hydroxyl groups was established using NOESY and selective decoupling experiments. The other compounds were identified as 1,2-dehydro-1,10α-dihydropseudoivalin (), axillarin (), grandifloric acid-15-β-glucoside (), myrianthic acid (), caffeic acid (), quercetin (), paniculoside IV () and caffeic anhydride (). The structures were characterized by 1 D, 2 D NMR spectroscopy and confirmed with HRMS. Antimicrobial and antiquorum-sensing activities of the different extracts and isolated compounds of the plant were investigated. Generally, the phenolic rather than the terpenoidal compounds exhibited remarkable antimicrobial and antiquorum-sensing activity.[Formula: see text].