The synthesis of isofagomine lactams (2-oxoisofagomines) corresponding to the biologically important hexoses is presented. The D-glucose/D-mannose analogue (3S,4R,5R)-3,4-dihydroxy-5-hydroxymethylpiperidin-2-one (9) was synthesised in 9 steps from D-arabinose, the D-galactose analogue (3S,4S,5R)-3,4-dihydroxy-5-hydroxymethylpiperidin-2-one (10) was synthesised in 11 steps from D-arabinose and the L-fucose analogue (3R,4R,5R)-3,4-dihydroxy-5-methylpiperidin-2-one (11) was synthesised in 12 steps from L-arabinose. The three lactams 9–11 were found to be glycosidase inhibitors with micro- to nanomolar inhibition constants. The lactam 10 showed slow onset inhibition of β-galactosidase from A. Oryzae. The rate constants for this process were determined to be kon
= 2.55 × 104 M−1 s−1 and koff
= 1.7 × 10−3 s−1. The activation energies and standard thermodynamic functions were also determined.
本文介绍了与具有重要
生物学意义的己糖相对应的异
异抗坏血酸内酰胺(2-oxoisofagomines)的合成。以
D-阿拉伯糖为原料,通过 9 个步骤合成了
D-葡萄糖/D-甘露
糖类似物 (3S,4R,5R)-3,4-二羟基-
5-羟甲基哌啶-2-酮 (9)、
D-半乳
糖类似物 (3S,4S,5R)-3、4-二羟基-
5-羟甲基哌啶-2-酮 (10) 由
D-阿拉伯糖经 11 个步骤合成,L-岩藻
糖类似物 (3R,4R,5R)-3,4-二羟基-5-甲基
哌啶-2-酮 (11) 由
L-阿拉伯糖经 12 个步骤合成。研究发现,三种内酰胺 9-11 都是糖苷酶
抑制剂,具有微摩尔至纳摩尔的抑制常数。内酰胺 10 对来自 A. Oryzae 的
β-半乳糖苷酶具有缓慢的抑制作用。这一过程的速率常数被确定为 kon = 2.55 × 104 M-1 s-1 和 koff = 1.7 × 10-3 s-1。活化能和标准热力学函数也已确定。