Sabirov A N, Ofitserov V I, Shval'e A F, Samukov V V
Bioorg Khim. 1987 Jun;13(6):754-9.
Solution syntheses of [Leu]enkephalin and its [D-Ala2]analogue were accomplished using a new 2-(4-chlorophenyl)sulfonylethoxycarbonyl (Cps) base-labile group for amino protection and a chromogenic acid-labile 4-(4-phenylazo)benzyloxybenzyl (Abz) group for carboxyl protection. The syntheses were performed by stepwise attachment of Cps-amino acids, which were introduced as pentachlorophenyl esters or as dicyclohexylammonium salts in the presence of tris(dimethylamino)chlorophosphonium perchlorate. To remove Cps-group, Abz-esters of Cps-peptides were treated with two molar equivalents of 1,8-diazabicyclo[5.4.0]undec-7-ene in dimethylformamide followed by neutralization of the base with an excess of 1-hydroxybenzotriazole; the deblocked amino components were then used without isolation. Fully deblocked pentapeptides were purified and characterized by HPLC, FAB mass spectra and amino acid composition.
使用一种新型的用于氨基保护的2-(4-氯苯基)磺酰基乙氧基羰基（Cps）碱不稳定基团和用于羧基保护的生色酸不稳定的4-(4-苯基偶氮)苄氧基苄基（Abz）基团，完成了亮氨酸脑啡肽及其[D-Ala2]类似物的溶液合成。合成通过逐步连接Cps-氨基酸进行，这些氨基酸以五氯苯基酯或二环己基铵盐的形式在高氯酸三(二甲氨基)氯鏻存在下引入。为了去除Cps基团，将Cps-肽的Abz酯在二甲基甲酰胺中用两摩尔当量的1,8-二氮杂双环[5.4.0]十一碳-7-烯处理，然后用过量的1-羟基苯并三唑中和碱；然后不经分离使用去保护的氨基组分。完全去保护的五肽通过高效液相色谱、快原子轰击质谱和氨基酸组成进行纯化和表征。
