Kinetic study of stereochemical and other factors governing hydrolytic cleavage of a peptide ligand in binuclear palladium(II) complexes
作者:Xiaohua Chen、Longgen Zhu、Hong Yan、Xiaozeng You、Nenad M. Kosti?
DOI:10.1039/dt9960002653
日期:——
complex cis-[Pd(dtco)(H2O)2]2+(dtco = 1,5-dithiacyclooctane) yields [Pd2(µ-MeCO-Met-Gly)2(dtco)2]4+, D. These reactions and hydrolytic cleavage of the methionine–glycine amide bond in the co-ordinated MeCO-Met-Gly are conveniently monitored by 1H NMR spectroscopy. The rate of cleavage decreases in the order A > B≈C > D, in which the number of aqua ligands per peptide ligand decreases. Intramolecular attack
二肽N-乙酰甲硫基甘氨酸(MeCO-Met-Gly)通过甲硫基侧链中的硫醚基与五种不同的钯(II)水络合物反应。配合物顺式-[Pd(en)(H 2 O)2 ] 2+(en = H 2 NCH 2 CH 2 NH 2)和顺式-[Pd(pn)(H 2 O)2 ] 2+(pn = H 2 NCH 2 CH 2 CH 2 NH 2)产率[Pd 2(µ-MeCO-Met-Gly)2(H 2 O) 4 ] 4+ A,顺式-[Pd(Met- S, N)(H 2 O) 2 ] 2+产生反式-[Pd 2(µ-MeCO-Met-Gly) 2(H 2 O) 2(HMet) 2 ] 6+, B和反式-[Pd 2 Cys(Me) -S, N } 2(H 2 O) 2 ] 4+ [Cys(Me)= S-methylcysteine]产生反式- [钯2 μ-HCys(ME)} 2(H 2 O)2(梅科-MET-GLY)2