Conformationally tailored N-[(2-methyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl)carbonyl]proline templates as molecular tools for the design of peptidomimetics. Design and synthesis of fibrinogen receptor antagonists
作者:Petra Štefanič、Zvone Simončič、Matej Breznik、Janez Plavec、Marko Anderluh、Elisabeth Addicks、Athanassios Giannis、Danijel Kikelj
DOI:10.1039/b400490f
日期:——
The proline peptide bond was shown by 2D proton NMR studies to exist exclusively in the trans conformation in benzyl (2S)-1-[(2S)-2-methyl-6-nitro-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl]carbonyl}-2-pyrrolidinecarboxylate [(S,S)-11], benzyl (2S)-1-[(2S)-2-methyl-7-nitro-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl]carbonyl}-2-pyrrolidinecarboxylate [(S,S)-9], and in the corresponding 6-amino and 7-amino carboxylic acids (S,S)-3 and (S,S)-4. On the other hand, the diastereomers (R,S)-11 and (R,S)-9 containing an (R)
[2-methyl-6/7-nitro-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl]carbonyl moiety, and the diastereoisomers (R,S)-3 and (R,S)-4 incorporating an (R)
[6/7-amino-2-methyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl]carbonyl moiety were found to exist as equilibria of trans
(63–83%) and cis
(17–37%) isomers. These conformationally defined templates were applied in the construction of RGD mimetics possessing antagonistic activity at the platelet fibrinogen receptor.
二维质子核磁共振研究表明,在(2S)-1-[(2S)-2-甲基-6-硝基-3-氧代-3,4-二氢-2H-1,4-苯并恶嗪-2-基]羰基}-2-吡咯烷羧酸苄酯[(S.S)-11]中,脯氨酸肽键完全以反式构象存在、(S,S)-11]、(2S)-1-[(2S)-2-甲基-7-硝基-3-氧代-3,4-二氢-2H-1,4-苯并恶嗪-2-基]羰基}-2-吡咯烷羧酸苄酯[(S,S)-9],以及相应的 6-氨基和 7-氨基羧酸 (S,S)-3 和 (S,S)-4。另一方面,非对映异构体 (R,S)-11 和 (R,S)-9 含有一个 (R) [2-甲基-6/7-硝基-3-氧代-3,4-二氢-2H-1,4-苯并恶嗪-2-基]羰基,非对映异构体 (R,S)-3 和 (R、S)-4 包含一个 (R) [6/7-氨基-2-甲基-3-氧代-3,4-二氢-2H-1,4-苯并恶嗪-2-基]羰基,它们以反式(63-83%)和顺式(17-37%)异构体的平衡形式存在。这些构象明确的模板被用于构建对血小板纤维蛋白原受体具有拮抗活性的 RGD 拟效物。