A new arbutin derivative from the leaves of Vaccinium dunalianum wight.

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

A new catechin derivative from the fruits of Rosa sterilis S. D. Shi.

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

HPLC simultaneous determination of arbutin, chlorogenic acid and 6'-O-caffeoylarbutin in different parts of Vaccinium dunalianum Wight.

Arbutin (1), chlorogenic acid (2) and 6'-O-caffeoylarbutin (3) are three major components in Vaccinium dunalianum Wight with various promising bioactivities. A reliable, reproducible and accurate method for simultaneous and quantitative determination of 1-3 is developed by RP-HPLC analysis. This method should be appropriate for the quality assurance of unprocessed and processed materials of V.

6'-O-Caffeoylarbutin inhibits melanogenesis in zebrafish.

6'-O-Caffeoylarbutin, an arbutin derivative, is a naturally occurring glucoside of hydroquinone from Vaccinium dunalianum. On anti-melanogenic effect assay, 6'-O-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'-O-caffeoylarbutin.