Coumaroyl flavone glycosides and cinammic acid derivatives from the aerial parts of Phlomis bruguieri Desf

Background and objectives: Phlomis bruguieri Desf. (Lamiaceae) is a perennial herbaceous plant distributed in Iran, Turkey and Iraq. Despite medicinal potentials of this species, the current knowledge on its phytochemical constituents is limited. The aim of the present study was to investigate the phytochemical constituents of the essential oil and various extracts of this species. Methods: Essential oils of the plant aerial parts were extracted by hydrodistillation and steam distillation methods and analysed using GC and GC/MS. Column chromatography with silica gel (normal and reversed phases) and Sephadex LH-20 were also used for the isolation of compounds from various extracts obtained from P. bruguieri aerial parts. The structures of isolated compounds were established by 1D and 2D NMR techniques. Results: By GC and GC/MS analysis, germacrene D (29.8%), apiole (20.7%) and myristicin (16.63%) were identified as the main compounds of hydrodistilled oil. Apiole (53.20%) and myristicin (34.87%) were also detected as the main compounds of the oil extracted by steam distillation method. Phytochemical analysis of the plant extracts resulted in the isolation and structural elucidation of β-sitosterol (1), p-coumaric acid methyl ester (2), chrysoeriol 7-O-(3''-(E)-p-coumaroyl)-β-D-glucopyranoside (3), chrysoeriol 7-O-(3'',6''-diO-(E)-p-coumaroyl)-β-D glucopyranoside (4), chrysoeriol 7-O-β-D-glucopyranoside (5), chlorogenic acid (6) and verbascoside (7). Conclusion: the results of the present study introduce steam distilled oil of P. bruguieri as a new source of apiole and myristicin. Moreover, identification of coumaroyl flavone glycosides and cinammic acid derivatives from the aerial parts of this species highlighted the species as a good candidate for further biological and pharmacological studies.