Depsides and other polar constituents from Origanum dictamnus L. and their in vitro antimicrobial activity in clinical strains.

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.

Novel Secoiridoid glucosides in Olea europaea leaves suffering from boron deficiency.

From the methanol extract of boron deficient Olea europaea leaves, two secoiridoid glycosides, not detected in leaf extracts of untreated plants, 6'-E-p-coumaroyl-secologanoside and 6'-O-[(2E)-2,6-dimethyl-8-hydroxy-2-octenoyloxy]-secologanoside, were isolated together with three known secoiridoid glycosides, oleuropein, oleoside dimethyl ester, and secologanoside. The structures of the isolated compounds were established by means of NMR and MS spectral analyses. The above novel secoiridoids were synthesized by the plant as a physiological response to nutrient stress.