Methyl 2,3,4-tri-O-acetyl-β-D-arabinopyranoside (1), methyl 2,3,4-tri-O-acetyl-β-D-ribopyranoside (2), and methyl 2,3,5-tri-O-acetyl-β-D-ribofuranoside (3) were deacetylated in porcine liver esterase-catalyzed reactions. Triacetate 1 gave methyl 3,4-di-O-acetyl-β-D-arabinopyranoside in 70% preparative yield while the regioselectivities found for the substrates 2 and 3 were substantially lower. Both the Michaelis constant and maximum rate were calculated for deacetylation of 1, 2, and 3. The results were interpreted using an active site model for the esterase proposed by Jones.
甲基2,3,4-三<斜体>O斜体>-乙酰基-β-D-阿拉比诺吡喃糖苷(<粗体>1粗体>)、甲基2,3,4-三<斜体>O斜体>-乙酰基-β-D-核糖吡喃糖苷(<粗体>2粗体>)和甲基2,3,5-三<斜体>O斜体>-乙酰基-β-D-核糖呋喃糖苷(<粗体>3粗体>)在猪肝酯酶催化反应中被脱乙酰化。三乙酸酯<粗体>1粗体>以70%的制备收率得到甲基3,4-二<斜体>O斜体>-乙酰基-β-D-阿拉比诺吡喃糖苷,而对于底物<粗体>2粗体>和<粗体>3粗体>发现的区域选择性明显较低。计算了<粗体>1粗体>、<粗体>2粗体>和<粗体>3粗体>的脱乙酰化的米氏常数和最大速率。结果使用Jones提出的酯酶活性位点模型进行了解释。