A new monoterpene glucoside and complete assignments of dihydroflavonols of <i>Pulicaria jaubertii</i>: potential cytotoxic and blood pressure lowering activity
<p>One new monoterpene glucoside and five dihydroflavonols were isolated for the first time from the aerial parts of <i>Pulicaria jaubertii</i> and identified as <i>p</i>-menthane-2-<i>O</i>-<i>β</i>-D-glucopyranoside [<b>1</b>], dihydroquercetin (taxifolin) [<b>2</b>], 7,3′-di-<i>O</i>-methyltaxifolin [<b>3</b>], 3′-<i>O</i>-methyltaxifolin [<b>4</b>], 7-<i>O</i>-methyltaxifolin (padmatin) [<b>5</b>] and 7-<i>O</i>-methyl-dihydrokampferol (7-<i>O</i>-methylaromadenderin) [<b>6</b>]. The structures of these compounds were unambiguously assigned on the basis of NMR spectroscopic data (<sup>1</sup>H, <sup>13</sup>C, DEPT, HSQC, HMBC) and MS analysis. 2D-NMR methods required revision of assignments of H-6 and H-8 for dihydroflavonol compounds. Possible cytotoxic activity as well as blood pressure (BP) lowering activity were tested. The alcoholic extract showed cytotoxic activity against prostate carcinoma (PC-3), breast carcinoma (MCF-7) and hepatocellular carcinoma (HepG-2) human cell lines with IC<sub>50</sub> 19.1, 20.0 and 24.1 μg, respectively. The higher dose levels of the alcoholic extract significantly reduced normal BP of rats in a dose-dependent manner.</p
