title: Depsides and other polar constituents from Origanum dictamnus L. and their in vitro antimicrobial activity in clinical strains.
abstract: Phytochemical investigation of the polar extracts of the aerial parts of Origanum dictamnus afforded 15 secondary metabolites. One new depside was isolated, to which the trivial name salvianolic acid P (1) was given, in addition to the known depsides rosmarinic acid (2) and rosmarinic acid methyl ester (3), as well as two monoterpenes, thymoquinone (4) and thymoquinol 2-O-beta-glucopyranoside (5); two simple phenolic acids, oresbiusin A (6) and E-caffeic acid (7); six flavonoids, namely, apigenin (8), kaempferol (9), quercetin (10), eriodictyol (11), taxifolin (12), naringenin (13); and two alicyclic derivatives, that is, 12-hydroxyjasmonic acid (14) and its 12-O-beta-d-glucoside (15). The structures of all isolated compounds were established by spectroscopic methods, mainly 1D and 2D NMR, as well as HPLC-DAD-MS and HR-MS spectrometric analyses. The absolute configuration of compound 1 was determined by CD measurements as 7'R, 7''S, 8''S. Compound 1 is interesting as it contains a benzodioxane ring, which is unusual in natural products. Moreover, it has been proved to be active against the Gram-negative clinical strains Acinetobacter hemolyticus , Empedobacter brevis , Pseudomonas aeruginosa , and Klebsiella pneumoniae .
authors.affiliation: Department of Pharmacognosy and Chemistry of Natural Products, School of Pharmacy, University of Athens, Panepistimiopolis, Zografou, 157 71 Athens, Greece.
authors.forename: Aliki
authors.initials: A
authors.lastname: Chatzopoulou
authors.forename: Anastasia
authors.initials: A
authors.lastname: Karioti
authors.forename: Chrysoula
authors.initials: C
authors.lastname: Gousiadou
authors.forename: Vanesa
authors.initials: V
authors.lastname: Lax Vivancos
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Kyriazopoulos
authors.forename: Stamatina
authors.initials: S
authors.lastname: Golegou
authors.forename: Helen
authors.initials: H
authors.lastname: Skaltsa
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D002934:Cinnamates / Q000494:pharmacology; D053630:Depsides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D005419:Flavonoids / Q000494:pharmacology; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D062385:Hydroxybenzoates / Q000494:pharmacology; D039821:Monoterpenes / Q000494:pharmacology; D031341:Origanum / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D000097123:Rosmarinic Acid
chemical_list: D000890:Anti-Infective Agents; D002934:Cinnamates; D053630:Depsides; D005419:Flavonoids; D062385:Hydroxybenzoates; D039821:Monoterpenes; D010936:Plant Extracts; D000097123:Rosmarinic Acid