Synthesis of the putative l-arginine metabolite L-NG-hydroxyarginine
摘要:
Syntheses of L-N(G)-hydroxyarginine (1), the putative biosynthetic precursor of nitric oxide, and the N-15 labelled analogs 9 and 10 using L-ornithine as the enantiopure starting material is reported.
Synthesis of15Nω-Hydroxy-L-arginine and ESR and15N-NMR Studies for the Elucidation of the Molecular Mechanism of Enzymic Nitric Oxide Formation from L-Arginine
Nω‐Hydroxy‐L‐arginine (2) was prepared by a multi‐stage synthesis; the key step was the addition of hydroxylamine to the protected cyanamide 8. The presence of N‐hydroxyguanidines was confirmed, above all, by 15N‐NMR investigations. 15Nω‐Hydroxy‐L‐arginine (2) was converted quantitatively to 15NO by NO synthases from macrophages. 15NO was identified by ESR‐spectroscopy. These experiments confirm that 15N
Nω-羟基-L-精氨酸(2)采用多步合成法制备;关键步骤是将羟胺添加到受保护的氰胺 8 中。首先,通过 15N-NMR 研究证实了 N-羟基胍的存在。15Nω - 羟基 - L - 精氨酸 (2) 被巨噬细胞的 NO 合酶定量转化为 15NO。15NO通过ESR光谱鉴定。这些实验证实 15Nω - 羟基 - L - 精氨酸 (2) 是从精氨酸 (1) 生物合成 NO 的中间体,并且 N - 羟基化的 N - 原子存在于形成的 NO 中。
Methodology for the preparation of N-guanidino-modified arginines and related derivatives
作者:Frank L. Wagenaar、James F. Kerwin
DOI:10.1021/jo00068a031
日期:1993.7
Methods for the preparation of N(G)-modified arginines and N(delta)-heterocyclic ornithines are described. The reactive cyanamide intermediate tert-butyl N(alpha)-Boc-N(delta)-cyano-L-ornithinate (2). prepared either by treatment of tert-butyl N(alpha)-BOC-L-ornithinate (5) with cyanogen bromide or by dehydration of tert-butyl N(alpha)-Boc-L-citrullinate (6), was utilized to prepare N(G)-hydroxy-L-arginine, N(G)-amino-L-arginine, and N(G)-methoxy-L-arginine. Intermediates 3a and 3b, derived from treatment of 5 with diphenyl cyanocarbonimidate (19), reacted with nitrogen nucleophiles to produce novel N(G)-cyano-L-arginine and N(delta)-heterocyclic L-ornithine analogs.
Synthesis and effects on arginase and nitric oxide synthase of two novel analogues of N<sup>ω</sup>-hydroxyarginine, N<sup>ω</sup>-hydroxyindospicine and p-hydroxyamidinophenylalanine
Two novel amino acids, N-omega-hydroxy-D,L-indospicine and p-hydroxyamidino-D,L-phenylalanine, have been synthesized in four steps from tert-butoxycarbonylglycine. Both compounds act as good inhibitors of arginase, N-omega-hydroxyindospicine being one of the best inhibitors of this enzyme known so far (IC50 = 50 mu mol dm(-3)). In contrast, with brain NO synthase the two compounds are almost without effect.