Studies on the Antioxidant and Tyrosinase Inhibitory Activityof N-(Hydroxy-phenyl)polyhydroxy benzamides

• Main Authors: Chia-ling Chang, 張嘉苓
• Other Authors: Dr.Chau-Chen Yang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/88454407835704692214

碩士 === 嘉南藥理科技大學 === 化妝品科技研究所 === 95 === Abstract This research utilizes the method of organic synthesis to put different amount of aminophenol into hydroxybenzoic acid or caffeic acid so as to produce a series of high yield of polyhydroxy benzamides (1~40).Through the following different activity tests, discussing the applied value of cosmetics.Ⅰ. The experiment of their ability to scavenge DPPH free radical, Ⅱ. The test of inhibitory activity of H2O2, Ⅲ. The activity test of inhibit Tyrosinase. The result of scavenging DPPH free radical by the polyhydroxy benzamides: The ability to scavenge DPPH free radical which is related to the amount of substitution of hydroxy groups and their positions. The more hydroxy groups substituted at the carboxylic acid benzene ring, the scavenging of DPPH free radical is more stronger, otherwise, the substitution of two hydroxy groups are at the ortho-position or para-position of carboxylic acid benzene ring, the ability of antioxidant is apparently more stronger. And the ability of antioxidant of polyhydroxy benzamides don’t have too many differences with Trolox (IC50 =13.90 μg/ml), the substition of hydroxy group at amino benzene ring doesn’t affect the whole ability of antioxidant apparently, but while the single hydroxy group at carboxylic acid benzene ring, they are apparently decrease to scavenge the ability of free radical, as a result, the hydroxy at amino benzene ring substitutes its function, without the hydroxy group, the ability of antioxidant is worst, but it upgrades its function while the hydroxy and amino are in the ortho-position or para-position. In the evaluation of polyhydroxy benzamides inhibit H2O2, both of them have better depressing effect and related to the amount of the substitution of hydroxy groups at the carboxylic acid benzene ring for the antioxidant activity are more stronger than Trolox (IC50 = 12.06 μg/ml), but a few of them is exception, (ex: IC50 = 53.96 μg/ml of compound 25, IC50 =45.77 μg/ml of compound 28 and IC50 =30.56 μg/ml of compound 33). The result of polyhydroxy benzamides for whitening, the activity evaluation of tyrosinase inhibitory, it has apparently effect on the caffeic acid, gallic acid and 2, 5-dihydroxybenzoic acid of amide derivatives (IC50 = 62.41~130.28 μg/ml), but some of the compounds show apparently the activity of tyrosinase inhibitory, (ex:IC50 = 71.70 μg/ml of compound 12 and 57.26 μg/ml of compound 24) inhibitory efficacy. Form the experiment, the compounds 20、24、34、37、39 and 40 of Poly- hydroxy benzamides have powerful activity to scavenge of DPPH free radical, inhibitory activity of H2O2 and tyrosinase, They are worthy to discuss the effective function which applied for anti-aging and whitening cosmetics.