Murakami S, Muramatsu M, Otomo S
Research Center, Taisho Pharmaceutical Co. Ltd, Ohmiya, Japan.
J Pharm Pharmacol. 1992 Nov;44(11):926-8. doi: 10.1111/j.2042-7158.1992.tb03238.x.
Five catechins, (+)-catechin, (-)-epicatechin, (-)-epicatechin gallate, (-)-epigallocatechin and (-)-epigallocatechin gallate, inhibited gastric H+, K(+)-ATPase activity with IC50 values ranging from 1.7 x 10(-4) to 6.9 x 10(-8) M, with (-)-epigallocatechin gallate as the most potent inhibitor. The intensity of inhibitor activity paralleled the number of phenolic hydroxy groups in the molecule. The inhibition of the enzyme by (-)-epicatechin was competitive with respect to ATP and noncompetitive with respect to K+. These findings suggest that the anti-secretory and anti-ulcerogenic effects of catechins previously reported, are due to their inhibitory activity on gastric H+, K(+)-ATPase.
五种儿茶素，（+）-儿茶素、（-）-表儿茶素、（-）-表儿茶素没食子酸酯、（-）-表没食子儿茶素和（-）-表没食子儿茶素没食子酸酯，抑制胃H⁺，K⁺-ATP酶活性，IC50值范围为1.7×10⁻⁴至6.9×10⁻⁸M，其中（-）-表没食子儿茶素没食子酸酯是最有效的抑制剂。抑制剂活性的强度与分子中酚羟基的数量平行。（-）-表儿茶素对该酶的抑制作用在ATP方面是竞争性的，在K⁺方面是非竞争性的。这些发现表明，先前报道的儿茶素的抗分泌和抗溃疡作用，是由于它们对胃H⁺，K⁺-ATP酶的抑制活性。
