BIOACTIVITY OF ANTIDESMA BUNIUS LEAVES (EUPHORBIACEAE) AND THEIR MAJOR PHENOLIC CONSTITUENTS

Chromatographic fractionation of the methanol extract of Antidesma bunius leaves afforded six polyphenols, namely, corilagin (1), gallic (2), ferrulic (3) and ellagic (4) acids in addition to the flavone vicinin II (5) and the dimmer amentoflavone (6). Their structures were elucidated by NMR and HRESI analysis. This is the first reported occurrence of the biflavone (amentoflavone) and vicinin in this species. The total phenolic content was estimated at 90 mg/ml of gallic acid equivalent (GAE) per 100 g plant extract using the Folin-Ciocalteu method. Antioxidant biochemical assay of the plant methanol extract was carried out using culture medium of hepatocyte cell lines. An increase in glutathione reductase enzyme and a reduction of the nitric oxide level in the cell culture revealed that A. bunius leaf extract possesses significant antioxidant activity in comparing with quercetine as a reference. The hepatotoxicity and hepatoprotective activities of A.bunius leaf extract and the pure isolated compounds: 1 , 2 and 5 were evaluated by adopting the MTT colorimetric assay. Compounds 1 and 2 revealed a margin of safety on the monolayer hepatocyte with an IC50 > 1000 μg/ml while for 5, IC50 was at 125 μg/ml. The hepatoprotective activities for A.bunius leaf extract, 1 and 2 in comparison to Silymarin (50 μg/ml) were at 6.5, <12.5 and 12.5 μg/ml respectively while 5 did not show hepatoprotective activity at the tested concentrations

Phytochemical constituents and chemosystematic significance of <i>Chrozophora tinctoria</i> (L.) Raf

<p>Twelve compounds were isolated from <i>Chrozophora tinctoria</i> (L.) Raf. They were identified as kaempferol, kaempferol 3-<i>O</i>-β-glucopyranoside, kaempferol 3-<i>O</i>-(6″-α-rhamnopyranosyl)-β-glucopyranoside, quercetin, quercetin 3-<i>O</i>-β-glucopyranoside, quercetin 3-<i>O</i>-(6″-α-rhamnopyranosyl)-β-glucopyranoside, apigenin, apigenin 7-<i>O</i>-β-glucopyranoside, acacetin, gallic acid, methyl gallate and β-sitosterol-3-<i>O</i>-β-glucopyranoside. Their structures were elucidated by chemical and spectral methods. Furthermore, chemosystematics of the isolated compounds is briefly discussed. It was indicated that <i>C. tinctoria</i> is the only species of <i>Chrozophora</i> that has the capability to synthesis kaempferol aglycone and their glycosides, and the finding is supported by its distinct morphological and anatomical aspects.</p

Chemosystematic significance of flavonoids isolated from <i>Diplotaxis acris</i> (Brassicaceae) and related taxa

<p>The chemosystematic relationship of four <i>Diplotaxis</i> species; <i>Diplotaxis acris</i>, <i>Diplotaxis erucoides</i>, <i>Diplotaxis harra</i> and <i>Diplotaxis muralis</i> were surveyed from the flavonoids point of view. These species were found to produce 33 flavonoids (7 flavones and 26 flavonols), including 11 compounds were isolated in the present study from <i>D. acris</i>. Among them, seven flavonoids were identified for the first time; luteolin (<b>4</b>), kaempferol (<b>8</b>), kaempferol 3-<i>O</i>-<i>β</i>-glucopyranoside-7-<i>O</i>-<i>α</i>-rhamnopyranoside (<b>13</b>), quercetin 3-<i>O</i>-<i>β</i>-glucopyranoside (<b>16</b>), quercetin 7-<i>O</i>-<i>β</i>-glucopyranoside (<b>20</b>), isorhamnetin (<b>22</b>) and isorhamnetin 3-<i>O</i>-<i>β</i>-glucopyranoside-7-<i>O</i>-<i>α</i>-rhamnopyranoside (<b>32</b>). Their structures were recognized on the basis of chemical and spectroscopic techniques (1D & 2D NMR, UV, EI & ESI/MS). The isolated flavonoids may provide useful taxonomic characters at the infraspecific levels of classification where the flavonoid profile of <i>D. acris</i> and <i>D. harra</i> is similar and different from the other species.</p