A new catechin derivative from the fruits of <i>Rosa sterilis</i> S. D. Shi

<p>A new catechin derivative named as sterilin A (<b>1</b>), and three known compounds, (+)-catechin (<b>2</b>), kaji-ichigoside F1 (<b>3</b>) and 2α,3α,19α-trihydroxyurs-12-en-28-oic acid-28-<i>O</i>-β-D-xylopyranosyl-(1 → 2)-β-D-glucopyranoside (<b>4</b>), was isolated from the fresh fruits of <i>Rosa sterilis</i>. Their structures were elucidated by means of extensive spectroscopic analysis and by comparison with data reported in the literatures.</p

HPLC simultaneous determination of arbutin, chlorogenic acid and 6′-<i>O</i>-caffeoylarbutin in different parts of <i>Vaccinium dunalianum</i> Wight

<div><p>Arbutin (<b>1</b>), chlorogenic acid (<b>2</b>) and 6′-<i>O</i>-caffeoylarbutin (<b>3</b>) are three major components in <i>Vaccinium dunalianum</i> Wight with various promising bioactivities. A reliable, reproducible and accurate method for simultaneous and quantitative determination of <b>1</b>–<b>3</b> is developed by RP-HPLC analysis. This method should be appropriate for the quality assurance of unprocessed and processed materials of <i>V. dunalianum</i>. The contents of <b>1</b>–<b>3</b> in different parts of <i>V. dunalianum</i> from different origins were analysed. The content of <b>3</b> was much higher than those of <b>1</b> and <b>2</b>, accounting for up to 31.76% in the dried leaf buds. Moreover, the leaf buds, flower buds and leaves showed a tendency towards higher contents of <b>1</b>–<b>3</b> than the other plant parts.</p></div

A new arbutin derivative from the leaves of <i>Vaccinium dunalianum</i> wight

<p>A new arbutin derivative, namely dunalianosides J (<b>1</b>), along with six known compounds, arbutin (<b>2</b>), robustaside A (<b>3</b>), 6′-<i>O</i>-caffeoylarbutin (<b>4</b>), dunalianoside D (<b>5</b>), kaempferol 3-<i>O</i>-<i>β</i>-D-glucopyranoside (<b>6</b>) and kaempferol 3-<i>O</i>-<i>β</i>-D-sambubioside (<b>7</b>) were isolated from the leaves of <i>Vaccinium dunalianum</i> Wight (Ericaceae). The structure of <b>1</b> was elucidated by extensive 1D and 2D NMR, HR-MS and CD spectroscopic analyses. In which, kaempferol 3-<i>O</i>-<i>β</i>-D-sambubioside (<b>7</b>) was isolated from the genus <i>Vaccinium</i> for the first time.</p

6′-<i>O</i>-Caffeoylarbutin inhibits melanogenesis in zebrafish

<div><p>6′-<i>O</i>-Caffeoylarbutin, an arbutin derivative, is a naturally occurring glucoside of hydroquinone from <i>Vaccinium dunalianum</i>. On anti-melanogenic effect assay, 6′-<i>O</i>-caffeoylarbutin expressed a stronger anti-melanin activity in a dose-dependent manner with about a two-fold more than that of arbutin, but with less toxicity about a two-fold lower than that of arbutin. In addition, melanin synthesis could be fully recovered after the removal of 6′-<i>O</i>-caffeoylarbutin. The result suggested that 6′-<i>O</i>-caffeoylarbutin could be a candidate natural product to serve as a skin-whitening ingredient with the merits of potent melanin inhibition, less toxicity and reversible melanin synthesis after stopping use.</p></div