Secondary metabolites from Teucrium polium L. collected in Southern Iran

In this paper a comprehensive phytochemical analysis of the ethanolic extract obtained from a sample of Teucrum polium collected in Southern Iran is reported. Several phenolic components were identified such as flavonoids and phenylethanoid glycosides which together resulted to be the principal components of the extract. In particular, these compounds were cirsilineol (1), apigenin 7-O-rutinoside (isorhoifolin) (2), cirsimaritin (4), diosmetin (5), apigenin (6), cirsiliol (7) and, lastly, poliumoside (3). Their presence may justify, from the phytochemical point of view, the ancient ethnomedicinal uses of this species as antispasmodic, anti-inflammatory, anti-diabetic, hypolipidemic and antirheumatic. Besides these health-promoting compounds, it was yet evidenced a minor presence of neo-clerodane diterpenoids which are, actually, known to possess hepatotoxic properties. In detail, these compounds were 10-β-hydroxy-teucjaponin B (8), picropolin (9) and teupolin I (10). Indeed, their presence underlines the necessity of a more accurate screening for this class of compounds on the raw materials devoted to botanicals and ethno-medicinal uses. Iridoids, considered to be marker compounds for the genus and for the Lamiaceae family, were completely absent in the studied sample, instead. This fact reveals the presence of an intraspecific variability for these metabolites in the studied species.