Isoquinuclidine Mimics ofβ-D-Glucopyranosides: Differences and Similarities in the Mechanism of Action of someβ-D-Glucosidases and aβ-D-Mannosidase
作者:Matthias Böhm、Edwige Lorthiois、Muthuppalaniappan Meyyappan、Andrea Vasella
DOI:10.1002/hlca.200390321
日期:2003.11
much stronger inhibitor in the manno-series. A consideration of the pKHA values of the isoquinuclidines 1–4 and the pH value of the enzyme assays suggests that the D-gluco-isoquinuclidines are poor mimics of the shape of a reactive, enzyme-bound gluco-conformer, while the D-manno-analogues are reasonably good mimics of a reactive, enzyme-bound manno-conformer. The inhibition results may also suggest
制备了D-葡萄糖-异喹核苷3和4,并作为来自解糖卡尔多氏菌和甜杏仁的β-葡萄糖苷酶的抑制剂进行了测试。将该结果与D-甘露糖异氰酸核苷1和2对蜗牛β-甘露糖苷酶的抑制作用进行了比较。外消旋系列的探索性实验表明,用苄基醇盐处理酯环氧化物6仅导致差向异构,酯交换反应和环丙烷9的形成。NaN 3还原的环氧化合物13的开环进行区域选择性提供14。用AcOCs处理C(6)O-三氟甲磺酸16引起重排; 与NaN 3的反应得到C(5)-叠氮基衍生物14。然而,乙酰氧基三氟甲磺酸酯18与AcOCs反应,以提供所需的葡萄糖-异喹核苷19。类似地,对映体纯的三氟甲磺酸乙酰氧基酯22提供了D-葡萄糖-异喹核苷24,其被还原和脱保护得到3和4。脱氧类似物30和31通过对22衍生的碘化物27进行还原脱碘获得。的D-葡糖-isoquinuclidines 3,4,30,和31是弱得多的抑制剂的β葡糖苷酶比D-甘露-analogues