Summary:
In the present study, the essential oil of Phlomis herba-venti, P. pichleri, P.
lycia and P. lunariifolia (Labiatae), members of the genus Phlomis, were
analysed. The plant P. lycia D.Don. was also studied for the chemical
composition of its secondary metabolites.
Concerning the essential oil analysis, the essential oils were obtained by
hydrodistillation and analysed by GC-FID and GC-MS. All the samples analyzed
were characterized by the presence of the sesquiterpenes germacrene D and (E)-β-
farnesene and the monoterpene α-pinene. The essential oil composition of P.
pichleri differentiates from the rest analyzed samples, while the main
constituents were the sesquiterpenes sesquithuriferol and ar-curcumene and the
monoterpene a-pinene.
From the aerial parts of P. lycia, dried stems and leaves were thoroughly
extracted with organic solvents and the crude extract was subjected to a series
of chromatographic separations to afford nine metabolites, two flavanones
(naringenin, eriodictyol), two dihydroflavonols (taxifolin,
6-hydroxy-dihydroisorhamnetin), three flavones (apigenin, luteolin,
chrysoeriol), one flavonol (quercetin) and a phenolic acid (vanillic acid). The
metabolite 6-hydroxy-dihydroisorhamnetin is a new natural product.
Keywords:
Phlomis lycia, Essential oil composition, Flavonoids, 6-hydroxy-dihydroisorhamnetin
