The antioxidant compounds isolated from the fruits of chinese wild raspberry <i>Rubus Chingii</i> Hu

Abstract

Raspberry, the fruit of <i>Rubus Chingji</i> Hu, is a widely distributed economic staple food in China. It has long been used as a traditional medicine in mainland China to treat kidney enuresis, nocturnal emission and premature ejaculation in clinic. In this paper, six known compounds (<b>1 </b>-<b> 6</b>) were purified from the fruits of <i>Rubus chingji</i>. Their structures were elucidated as (16α)-16,17-dihydroxy-<i>ent</i>-kauran-2-one17-O-<i>β</i>-D-glucopyranoside (<b>1</b>), (16<i>R</i>) -16,17-dihydroxy-<i>ent</i>-kaurane-2-one (<b>2</b>), 3,3'-di-O-methylellagic acid 4-(5''-acetyl)-<i>α</i>-L-arabinofuranoside (<b>3</b>), quercilicoside A (<b>4</b>), esculetine (<b>5</b>) and ethyl-<i>β</i>-D-glucoside (<b>6</b>). All the compounds were isolated from <i>Rubus Chingji</i> Hu for the first time. Compounds <b>3</b> and <b>5</b> shown distinctive free radical scavenging activities in DPPH and FRAP assays. In addition, no cytotoxicity was observed for compounds <b>3</b> and <b>5</b> against different cancer cells, suggesting that they might be useful as potential antioxidant agents against various reactive oxygen species.[Formula: see text].