Yu Liangli
Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, Colorado 80523, USA.
J Agric Food Chem. 2003 Apr 9;51(8):2344-7. doi: 10.1021/jf0208379.
The inhibition of (R)-, (S)-, and (+/-)-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acids (HTCCA) on mushroom tyrosinase was evaluated. All HTCCAs inhibited the tyrosinase activity. The ID(50) values were 1.88, 1.84, and 1.88 for the (R)-, (S)-, and (+/-)-HTCCAs, respectively. The inhibition kinetics analyzed by Hanes-Woolf plots indicated that both (R)- and (S)-HTCCAs are competitive inhibitors of the tyrosinase, with K(i) values of 0.83 and 0.61 mM, respectively. Dimethyl sulfoxide (DMSO) was also tested for its direct inhibitory activity against the tyrosinase and its potential influence on the tyrosinase inhibitory effects of (R)- and (S)-HTCCAs. DMSO, a widely used solvent for tyrosinase inhibitors, was found to dose-dependently inhibit the tyrosinase activity. Addition of DMSO in a tyrosinase digest containing either (R)- or (S)-HTCCA further dose-dependently reduced the tyrosinase activity. These data indicated a potential to use a HTCCA as a tyrosinase inhibitor in food, cosmetic, and medicinal products and a need to improve the solvent system for the studies of tyrosinase inhibitions.
评估了（R）-、（S）-和（±）-6-羟基-2,5,7,8-四甲基色满-2-羧酸（HTCCA）对蘑菇酪氨酸酶的抑制作用。所有HTCCA均抑制酪氨酸酶活性。（R）-、（S）-和（±）-HTCCA的半数抑制浓度（ID50）值分别为1.88、1.84和1.88。通过Hanes-Woolf图分析的抑制动力学表明，（R）-和（S）-HTCCA均为酪氨酸酶的竞争性抑制剂，其抑制常数（Ki）值分别为0.83和0.61 mM。还测试了二甲基亚砜（DMSO）对酪氨酸酶的直接抑制活性及其对（R）-和（S）-HTCCA酪氨酸酶抑制作用的潜在影响。DMSO是一种广泛用于酪氨酸酶抑制剂的溶剂，发现其对酪氨酸酶活性具有剂量依赖性抑制作用。在含有（R）-或（S）-HTCCA的酪氨酸酶消化液中添加DMSO会进一步使酪氨酸酶活性剂量依赖性降低。这些数据表明HTCCA有潜力用作食品、化妆品和药品中的酪氨酸酶抑制剂，并且需要改进用于酪氨酸酶抑制研究的溶剂系统。
