Day A J, DuPont M S, Ridley S, Rhodes M, Rhodes M J, Morgan M R, Williamson G
Department of Biochemistry, Institute of Food Research, Colney, Norwich, UK.
FEBS Lett. 1998 Sep 25;436(1):71-5. doi: 10.1016/s0014-5793(98)01101-6.
Flavonoid and isoflavonoid glycosides are common dietary phenolics which may be absorbed from the small intestine of humans. The ability of cell-free extracts from human small intestine and liver to deglycosylate various (iso)flavonoid glycosides was investigated. Quercetin 4'-glucoside, naringenin 7-glucoside, apigenin 7-glucoside, genistein 7-glucoside and daidzein 7-glucoside were rapidly deglycosylated by both tissue extracts, whereas quercetin 3,4'-diglucoside, quercetin 3-glucoside, kaempferol 3-glucoside, quercetin 3-rhamnoglucoside and naringenin 7-rhamnoglucoside remained unchanged. The Km for hydrolysis of quercetin 4'-glucoside and genistein 7-glucoside was approximately 32+/-12 and approximately 14+/-3 microM in both tissues respectively. The enzymatic activity of the cell-free extracts exhibits similar properties to the cytosolic broad-specificity -glucosidase previously described in mammals.
黄酮类和异黄酮类糖苷是常见的膳食酚类物质，可从人类小肠吸收。研究了人小肠和肝脏的无细胞提取物对各种（异）黄酮类糖苷进行去糖基化的能力。槲皮素4'-葡萄糖苷、柚皮素7-葡萄糖苷、芹菜素7-葡萄糖苷、染料木素7-葡萄糖苷和大豆苷元7-葡萄糖苷在两种组织提取物中均迅速去糖基化，而槲皮素3,4'-二葡萄糖苷、槲皮素3-葡萄糖苷、山奈酚3-葡萄糖苷、槲皮素3-鼠李糖葡萄糖苷和柚皮素7-鼠李糖葡萄糖苷则保持不变。在两种组织中，槲皮素4'-葡萄糖苷和染料木素7-葡萄糖苷水解的Km分别约为32±12和14±3 microM。无细胞提取物的酶活性表现出与先前在哺乳动物中描述的胞质广泛特异性β-葡萄糖苷酶相似的特性。
