Inhibition of tyrosinase activity by polyphenol compounds from Flemingia philippinensis roots

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• 作者：Yan Wang ; Marcus J. Curtis-Long ; Byong Won Lee ; Heung Joo Yuk ; Dae Wook Kim ; Xue Fei Tan ; Ki Hun Park
• 关键词：Flemingia philippinensis ; Tyrosinase ; Dihydrochalcone ; Fleminchalcone
• 刊名：Bioorganic and Medicinal Chemistry
• 出版年：1 February, 2014
• 年：2014
• 卷：22
• 期：3
• 页码：1115-1120
• 全文大小：540 K

文摘

Flemingia philippinensis is used as a foodstuff or medicinal plant in the tropical regions of China. The methanol (95%) extract of the roots of this plant showed potent tyrosinase inhibition (80% inhibition at 30 渭g/ml). Activity-guided isolation yielded six polyphenols that inhibited both the monophenolase (IC₅₀ = 1.01-18.4 渭M) and diphenolase (IC₅₀ = 5.22-84.1 渭M) actions of tyrosinase. Compounds 1-6 emerged to be three new polyphenols and three known flavanones, flemichin D, lupinifolin and khonklonginol H. The new compounds (1-3) were identified as dihydrochalcones which we named fleminchalcones (A-C), respectively. The most potent inhibitor, dihydrochalcone (3) showed significant inhibitions against both the monophenolase (IC₅₀ = 1.28 渭M) and diphenolase (IC₅₀ = 5.22 渭M) activities of tyrosinase. Flavanone (4) possessing a resorcinol group also inhibited monophenolase (IC₅₀ = 1.79 渭M) and diphenolase (IC₅₀ = 7.48 渭M) significantly. In kinetic studies, all isolated compounds behaved as competitive inhibitors. Fleminchalcone A was found to have simple reversible slow-binding inhibition against monophenolase.