Heterocyclic analogues of l -citrulline as inhibitors of the isoforms of nitric oxide synthase (NOS) and identification of N δ -(4,5-dihydrothiazol-2-yl)ornithine as a potent inhibitor
作者:Saraj Ulhaq、Edwin C Chinje、Matthew A Naylor、Mohammed Jaffar、Ian J Stratford、Michael D Threadgill
DOI:10.1016/s0968-0896(99)00136-4
日期:1999.9
synthesised. In two of these, the S-substituent was 'tied back' sterically by cyclisation to the nitrogen remote from the amino-acid unit. N(delta)-(4,5-Dihydrothiazol-2-yl)ornithine was identified as an inhibitor of rat inducible and constitutive isoforms of NOS and of a constitutive NOS derived from a human tumour xenograft. Analogous N(delta)-(thiazol-2-yl)ornithines were less active, whereas the corresponding
L-硫代瓜氨酸是已知的几种一氧化氮合酶 (NOS) 同种型的强效抑制剂。为了比以前报道的更深入地探索该分子的构效关系 (SAR),合成了三种取代异硫脲硫的类似物。在其中两个中,通过环化到远离氨基酸单元的氮,S-取代基被空间“束缚”。N(delta)-(4,5-Dihydrothiazol-2-yl)ornithine 被确定为大鼠诱导型和组成型 NOS 和源自人类肿瘤异种移植物的组成型 NOS 的抑制剂。类似的 N(delta)-(thiazol-2-yl)ornithines 活性较低,而相应的 N(delta)-(oxazol-2-yl)ornithine 和 N(delta)-(pyrimidin-2-yl)ornithine 完全失效抑制 NOS。已开发出一种新的有效制备关键合成中间体 N(α)-Boc-硫代瓜氨酸叔丁酯的方法。用 2-氨基-5-(杂环硫基)戊酸(由 2-(Boc-