Structure of AcMet-Gly and Its Interaction with Palladium(II)Tetraaqua Complex Studied by Electrospray Mass Spectrome try and Density Functional Theory

• 来源期刊: 中国化学（英文版）
• 年，卷（期）: 2004,（6）
• 页码范围: 537-544
• 页数: 8页
• 语种: 英文

摘要

The structure of dipepide AcMet-Gly was determined by X-ray crystallographic analysis. It possesses monoclinic, space group P21 (No. 4), with cell dimensions of a=0.8571(2) nm, b=0.5871(2) nm, c= 1.197(3) nm,β=99.290(10)°, V=0.5944(15) nm3, Z=2, .μ=2.74 cm-1. Mononuclear chelates, described as [Pd(X)(S,N,O-AcMet-Gly)] +, in which Pd(II) is coordinated by thioether, deprotonated amide nitrogen, carbonyl oxygen of methionine and X (AcMetGly or other ligands present in aqueous solution or in mobile phase solution), were detected 5 min after mixing AcMet-Gly with [Pd(H2O)4]2- at room temperature using electrospray ionization mass spectrometry. The geometry of [Pd(H2O)(S,N,O-AcMet-Gly)]+ is optimized at density functional B3LYP/LanL2DZ level. The fused five- and six-membered chelate is responsible for cleavage of Met-Gly bond. This is the first time to provide a direct evidence for Pd(II)-mediated cleavage of dipeptides via external solvent attack.