Synthesis and biological evaluation of novel 4-hydroxybenzaldehyde derivatives as tyrosinase inhibitors
作者:Wei Yi、Rihui Cao、Wenlie Peng、Huan Wen、Qin Yan、Binhua Zhou、Lin Ma、Huacan Song
DOI:10.1016/j.ejmech.2009.11.007
日期:2010.2
A series of novel 4-hydroxybenzaldehyde derivatives were synthesized and their inhibitory effects on the diphenolase activity of mushroom tyrosinase were investigated. Most of target compounds had more potent inhibitory activities than the parent compound 4-hydroxybenzaldehyde (IC50 = 1.22 mM). Interestingly, compound 3c bearing a dimethoxyl phosphate was found to be the most potent inhibitor with IC50 value of 0.059 mM. The inhibition kinetics analyzed by Lineweaver-Burk plots revealed that compound 3c was a non-competitive inhibitor (K-I = 0.0368 mM). In particular, compound 3c showed no side effects at dose of 1600 mg/kg in mice. These results suggested that such compounds might be served as lead compounds for further designing new potential tyrosinase inhibitors. (C) 2009 Elsevier Masson SAS. All rights reserved.
Ring-Opening Reactions of Epoxides Catalyzed by Molybdenum(VI) Dichloride Dioxide
作者:Dillip Chand、Kandasamy Jeyakumar
DOI:10.1055/s-2008-1032163
日期:2008.3
alcohols, acetonides, and α-alkoxy ketones is achieved by using molybdenum(VI) dichloride dioxide (MoO 2 Cl 2 ) as a catalyst. Alcohol, aldehyde, oxime, tosyl, and TERT-butyldimethylsilyl functional groups are tolerated during the methanolysis and acetonidation of the functionalized epoxides. No polymerization product is observed with any of the epoxides. Direct conversion of epoxides devoid of sensitive