Antioxidation and tyrosinase inhibition of polyphenolic curcumin analogs.

A series of polyphenolic curcumin analogs were synthesized and their inhibitory effects on mushroom tyrosinase and the inhibition of 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical formation were evaluated. The results indictated that the analogs possessing m-diphenols and o-diphenols exhibited more potent inhibitory activity on tyrosinase than reference compound rojic acid, and that the analogs with o-diphenols exhibited more potent inhibitory activity of DPPH free-radical formation than reference compound vitamin C. The inhibition kinetics, analyzed by Lineweaver-Burk plots, revealed that compounds B(2) and C(2) bearing o-diphenols were non-competitive inhibitors, while compounds B(11) and C(11) bearing m-diphenols were competitive inhibitors.

[Study on inhibitive effect of extracts from Scindapsus aureus on alpha-glucosidase and its antioxidant activity].

Objective: To study the inhibitive effect of extracts from Scindapsus aureus on alpha-glucosidase and its antioxidant activity.

Methods: The 70% ethanol extracts was extracted by petroleum, ethyl acetate and n-butanol, and the inhibitory activity against alpha-glucosidases and antioxidative effects of each fraction were determined in vitro, and the inhibitory kinetics of ethyl acetate fraction was investigated.

Results: The inhibitory activity of ethly acetate fraction against alpha-glucosidase was higher as its IC50 was 43.