旋花茄苷B1和B2糖苷的酶促合成及其糖苷酶抑制活性。

Enzymatic synthesis of the glycosides of calystegines B1 and B2 and their glycosidase inhibitory activities.

作者信息

Asano N, Kato A, Kizu H, Matsui K, Griffiths R C, Jones M G, Watson A A, Nash R J

机构信息

Faculty of Pharmaceutical Sciences, Hokuriku University, Kanazawa, Japan.

出版信息

Carbohydr Res. 1997 Nov 10;304(2):173-8. doi: 10.1016/s0008-6215(97)00227-9.

DOI:10.1016/s0008-6215(97)00227-9

PMID:9449768

Abstract

Several glycosides of calystegines B1 and B2 were synthesized by use of rice alpha-glucosidase and the whole cells of Rhodotorula lactosa, and their glycosidase inhibitory activities were investigated. Incubation of mixture of calystegine B1 and maltose with rice alpha-glucosidase gave 3-O-alpha-D-glucopyranosylcalystegine B1 (2, 11.3%). An enzymatic beta-transglucosylation reaction of calystegines B1 or B2 with cellobiose using the whole cells of R. lactosa gave 3-O-beta-D-glucopyranosylcalystegine B1 (1) (0.9%) or 4-O-beta-D-glucopyranosylcalystegine B2 (3, 11.2%), respectively, while similar beta-transgalactosylation of calystegine B2 from lactose gave 4-O-beta-D-galactopyranosylcalystegine B2 (4, 10.1%). The glycosylation of calystegines B1 and B2 markedly decreased or abolished their inhibition against beta-glucosidase, alpha- or beta-galactosidase. Compound 4 however retained more or less the potency of calystegine B2 against trehalase. Interestingly, compound 1 was a noncompetitive inhibitor of rice alpha-glucosidase, with a Ki value of 0.9 +/- 0.1 microM.

摘要

利用水稻α-葡萄糖苷酶和乳酸红酵母全细胞合成了几种旋花茄苷B1和B2的糖苷，并对其糖苷酶抑制活性进行了研究。将旋花茄苷B1与麦芽糖的混合物与水稻α-葡萄糖苷酶一起孵育，得到3-O-α-D-吡喃葡萄糖基旋花茄苷B1（2，产率11.3%）。利用乳酸红酵母全细胞使旋花茄苷B1或B2与纤维二糖发生酶促β-转糖基化反应，分别得到3-O-β-D-吡喃葡萄糖基旋花茄苷B1（1，产率0.9%）或4-O-β-D-吡喃葡萄糖基旋花茄苷B2（3，产率11.2%），而旋花茄苷B2与乳糖发生类似的β-转半乳糖基化反应得到4-O-β-D-吡喃半乳糖基旋花茄苷B2（4，产率10.1%）。旋花茄苷B1和B2的糖基化显著降低或消除了它们对β-葡萄糖苷酶、α-或β-半乳糖苷酶的抑制作用。然而，化合物4或多或少保留了旋花茄苷B2对海藻糖酶的活性。有趣的是，化合物1是水稻α-葡萄糖苷酶的非竞争性抑制剂，其Ki值为0.9±0.1μM。