Nagai T, Miyaichi Y, Tomimori T, Yamada H
Oriental Medicine Research Center, Kitasato Institute, Tokyo, Japan.
Biochem Biophys Res Commun. 1989 Aug 30;163(1):25-31. doi: 10.1016/0006-291x(89)92093-7.
Flavonoids (103 species) were tested for inhibitory activity against mouse liver sialidase using sodium p-nitrophenyl-N-acetyl-alpha-D-neuraminate (PNP-NeuAc) as substrate. Isoscutellarein-8-O-glucuronide from the leaf of Scutellaria baicalensis showed most potent activity (IC50, 40 microM), and this flavone appeared to be a non-competitive inhibitor of the enzyme. This flavone inhibited the lysosomal solubilized sialidase against PNP-NeuAc and sialyllactose effectively, but not microsomal enzyme against gangliosides and colominic acid, whereas, negligible or weak inhibitory activities were observed for influenza virus sialidase, beta-galactosidase, alpha-mannosidase, and alpha-glucosidase tested. These results indicate that this flavone may be useful to elucidate the function of the lysosomal solubilized sialidase.
以对硝基苯基 - N - 乙酰 - α - D - 神经氨酸（PNP - NeuAc）为底物，对103种黄酮类化合物进行了抗小鼠肝脏唾液酸酶抑制活性测试。黄芩叶中的异黄芩素 - 8 - O - 葡萄糖醛酸表现出最强的活性（IC50，40微摩尔），并且这种黄酮似乎是该酶的非竞争性抑制剂。这种黄酮有效抑制了溶酶体溶解的唾液酸酶对PNP - NeuAc和唾液乳糖的作用，但对微粒体酶对神经节苷脂和聚唾液酸没有抑制作用，而对于所测试的流感病毒唾液酸酶、β - 半乳糖苷酶、α - 甘露糖苷酶和α - 葡萄糖苷酶，观察到的抑制活性可忽略不计或较弱。这些结果表明，这种黄酮可能有助于阐明溶酶体溶解的唾液酸酶的功能。
