The concise synthesis of rhododendrol glycosides 3–8, which are novel derivatives of (+)-epirhododendrin (1) and (−)-rhododendrin (2), has been achieved in six steps from benzaldehyde 9. The key reactions include aldol condensation and trichloroacetimidate glycosylation. From biological studies, it has been determined that synthetic derivatives of 1 and 2 possess potent tyrosinaseinhibitory activity
Rhododendrol glycosides as stereospecific tyrosinase inhibitors
作者:Takehiro Iwadate、Ken-ichi Nihei
DOI:10.1016/j.bmc.2015.09.014
日期:2015.10
Rhododendrol derivatives 3-12 have been synthesized in six steps, including aldol condensation and/or trichloroacetimidate glycosylation as the key reactions. Each derivative showed effective inhibition of tyrosinase-catalyzed oxidation processes. In particular, a series of synthetic derivatives having an R-stereogenic center at C-2 proved to be more potent than their respective epimers. In addition, the glycosylation on the phenylbutanoid scaffold increased the difference in activity between the isomers. This suggests that the sugar moiety plays an important role in eliciting their potent inhibitory activity. (c) 2015 Elsevier Ltd. All rights reserved.