N-CBZ-L-isoleucylglycine

• 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: N-CBZ-L-isoleucylglycine
• 英文别名: 2-[[(2R,3S)-3-methyl-2-(phenylmethoxycarbonylamino)pentanoyl]amino]acetic acid
• 化学式: C₁₆H₂₂N₂O₅
• 分子量: 322.361
• InChiKey: RWAYODJQGJVQGX-SMDDNHRTSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.1
• 重原子数：
  23
• 可旋转键数：
  9
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.44
• 拓扑面积：
  105
• 氢给体数：
  3
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  N-CBZ-L-isoleucylglycine 在 palladium on activated charcoal 氢气 作用下， 以 乙醇 为溶剂， 生成 L-isoleucylglycyl-L-(ε-BOC)-lysine
  参考文献：
  名称：

  摘要：

  Purpose. The purpose of this study was to identify four major degradation products, which were formed during a stress study of pexiganan (a 22-mer peptide) in a 1% formulation.Methods. The degradation products were isolated and characterized by LC/MS, tryptic and aminopeptidase digests.Results. One of the degradation products was shown to be des-gly(1)-pexiganan. The other three are structural isomers of N-glyoxylyl-des-gly(1)-pexiganan. These isomers undergo reversible inter-conversions, as well as decompose irreversibly to des-gly(1)-pexiganan. Thus, all the impurities were formed from a single oxidation product of pexiganan, N-glyoxylyl-des-gly(1)-pexiganan. The aldehyde group of the glyoxylyl residue and the NH-amide of the adjacent isoleucine residue form a piperazinedione derivative of des-gly(1)-pexiganan. This heterocyclic compound rearranges to other tautomers or back to the N-glyoxylyl compound (see Fig. 3). Tryptic digests of the three degradation products showed that their N-terminal segment produced N-glyoxylyl-I-G-K whereas the N-terminal segment of pexiganan produced G-I-G-K. All the other tryptic-digest segments were identical to those formed in pexiganan. The LC/MS of the N-terminal segment and of synthetic N-glyoxylyl-I-G-K were identical. The enzymatic resistance of the three impurities to undergo aminopeptidase-M cleavage further supported the conclusion that their N-terminal amino residues are substituted.Conclusions. After a year under stress conditions 1% pexiganan cream lost about 15% of the active component to oxidative-deamination,(4) where the N-terminal glycine residue was oxidized to N-glyoxylyl-des-gly(1)-pexiganan. The other nine E-amino lysine-residues of the peptide stayed intact. This oxidation product inter-converted and formed two additional impurities, tautomers of piperazinedionyl-des-gly(1)-pexiganan, and decomposed to des-gly(1)-pexiganan, the forth impurity.

  DOI：

  10.1023/a:1007521515109