Tyrosinase inhibitor from black rice bran
Tyrosinase inhibitor from black rice bran
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DOI：
10.1021/jf030388s
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发表时间：
2003-11-19
影响因子：
6.1
通讯作者：
Anzai, J
中科院分区：
文献类型：
--
作者：
Miyazawa, M;Oshima, T;Anzai, J
研究了黑米皮中酪氨酸酶活性的抑制物。用正己烷、氯仿、乙酸乙酯或水对黑米皮的甲醇提取物进行了二次提取。乙酸乙酯提取物在浓度为0.4 mg/mL时对酪氨酸酶活性的抑制率最高，为80.5%。采用硅胶柱层析从乙酸乙酯部位分离得到抑制化合物，经GC、GC-MS、IR、H-1和C-13核磁共振波谱鉴定为原儿茶酸甲酯(化合物1)。化合物1对酪氨酸酶活性的抑制率为75.4%，浓度为0.50mumol/mL。化合物1的半数抑制量(ID50)为0.28mumol/mL。为了研究其构效关系，还测定了原儿茶酸(2)、香草酸(3)、香草酸甲酯(4)、异香草酸(5)、异香草酸甲酯(6)、藜芦酸(7)和藜芦酸甲酯(8)。
The inhibitor of tyrosinase activity in black rice bran was investigated. The methanol extract from black rice bran was re-extracted with hexane, chloroform, ethyl acetate, or water. The ethyl acetate extract had the most potent inhibition against tyrosinase activity by 80.5% at a concentration of 0.4 mg/mL. Inhibitory compound in the ethyl acetate fraction was isolated by silica gel column chromatography, and identified as protocatechuic acid methyl ester (compound 1) by GC, GC-MS, IR, and H-1 and C-13 NMR spectroscopy. Compound 1 inhibited 75.4% of tyrosinase activity at a concentration of 0.50 mumol/mL. ID50 (50% inhibition dose) value of compound 1 was 0.28 mumol/mL. To study the structure-activity relationship, protocatechuic acid (2), vanillic acid (3), vanillic acid methyl ester (4), isovanillic acid (5), isovanillic acid methyl ester (6), veratric acid (7), and veratric acid methyl ester (8) were also assayed.