The sodium salts (5) of four stereoisomeric benzimidazolylsulfoxides, (Ss, 9R)-(-)-4, (Rs, 9S)-(+)-4, (Ss, 9S)-(-)-4 and (Rs, 9R)-(+)-4, were prepared from optically pure sulfides, (+)-8 and (-)-8. The sulfoxides (4) were transformed into sulfenamides (6) and symmetric disulfides (9) under acidic conditions, without any change of stererochemical configuration at the α-carbon bearing the sulfinyl group. No significant difference was observed among the four stereoisomers in inhibitory activity towards (H++K+)-ATPase in vitro. However, (Ss, 9R)-(-)-5 showed more long-lasting antisecretion activity in vivo than that of another enantiomer, (Rs, 9S)-(+)-5.
四种立体异构体
苯并咪唑基亚砜(Ss,9R)-(-)-4、(Rs,9S)-(+)-4、(Ss,9S)-(-)-4和(Rs,9R)-(+)-4的钠盐(5)由光学纯
硫化物(+)-8和(-)-8制备而成。在酸性条件下,亚砜(4)转化为亚磺酰胺(6)和对称二
硫醚(9),但带有亚磺酰基的α-碳的立体
化学结构没有任何变化。体外实验中,四种立体异构体对(H++K+)-
ATP酶的抑制活性没有显著差异。然而,(Ss,9R)-(-)-5在体内表现出比另一种对映异构体(Rs,9S)-(+)-5更持久的抗分泌活性。