Methyl N-(2,2,5,5-tetramethyl-1-oxypyrrolinyl-3-carboxyl)-L-phenylalanate | 135823-85-7

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 羧酸及其衍生物
• 英文名称: Methyl N-(2,2,5,5-tetramethyl-1-oxypyrrolinyl-3-carboxyl)-L-phenylalanate
• 英文别名: Methyl N-(2,2,5,5-tetramethyl-1-oxypyrrolinyl-3-carbonyl)-L-phenylalanate
• CAS: 135823-85-7
• 化学式: C₁₉H₂₅N₂O₄
• 分子量: 345.418
• InChiKey: KBBGWZZJNFZPFI-HNNXBMFYSA-N

反应信息

• 作为反应物：
  描述：

  Methyl N-(2,2,5,5-tetramethyl-1-oxypyrrolinyl-3-carboxyl)-L-phenylalanate 在 二异丁基氢化铝 作用下， 以 乙二醇二甲醚 、 甲苯 为溶剂， 反应 1.25h， 以14%的产率得到N-(2,2,5,5-Tetramethyl-1-oxypyrrolinyl-3-carboxyl)-L-phenylalaninal
  参考文献：
  名称：

  ENDOR Determined Structure of a Complex of α-Chymotrypsin with a Spin-Labeled Transition-State Inhibitor Analogue

  摘要：

  The conformation of the spin-labeled compound N-(2,2,5,5-tetiamethyl-1-oxypyrrolinyl-3-carboxyl)-L-phenylalaninal (SLPheal), synthesized as a transition-state inhibitor analogue of alpha-chymotrypsin (alpha CT), has been determined by electron nuclear double resonance (ENDOR) and molecular modeling methods for both the free inhibitor in solution and the hemiacetal enzyme:inhibitor adduct. SLPheal exhibited linear, competitive inhibition of alpha CT with K-I = (0.21 +/- 0.03) x 10(-3) M. By a combination of NMR and ENDOR spectroscopy, we have established that 92% of the aldehyde is found as the hydrated aldehyde species RCH(OH)(2) at pH 7.0. From ENDOR spectra, principal hyperfine coupling (hfc) components of specific protons assigned by selective deuteration were determined, and their corresponding dipolar hfc components were computed to estimate electron-proton distances. The principal hfc components of the fluorine substituent of a zeta F-phenylalaninal inhibitor analogue were also determined for estimation of electron-fluorine distances. With these ENDOR determined distances as constraints, the conformation of the inhibitor both free in solution and in the active site of alpha CT was determined on the basis of torsion angle search calculations and molecular graphics analysis. Comparison of the conformation of the inhibitor free in solution and bound to alpha CT showed that formation of the hemiacetal enzyme:inhibitor adduct required positioning of the spin-label group with torsional alteration in inhibitor structure similar to that described for the spin-labeled tryptophanyl moiety in an acylenzyme reaction intermediate of alpha CT [Wells et al., J. Biol. Chem. 1994, 269, 4577-4586]. While the ENDOR results of the hemiacetal formed in neat methanol were distinguishably different for R and S configurations modeled for an sp(3) hybridized C atom of the aldehyde functional group, only an S configuration in the enzyme:inhibitor adduct was compatible with all of the ENDOR constraints. Since the inhibitor in aqueous solution is found largely in its hydrated form, it is probable that this is the predominant species that is initially bound in the active site of the enzyme. Accordingly, a reaction scheme is suggested for dehydration of the active site bound diol species catalyzed by the protonated form of His-57 to allow formation of the hemiacetal adduct with the side chain of Ser-195 having only an S configuration.

  DOI：

  10.1021/jp972742t