制备了三个在其侧链上带有炔烃的二肽(9(源自二赖氨酸),14(源自二半胱氨酸)和17(源自二甘氨酸)),并与W(CO)3(dmtc)2 [dmtc =二甲基二硫代氨基甲酸酯]反应得到,分别为3个metallacyclicpeptides,18,19和20。金属环肽通过HPLC,ES-MS和1 H NMR进行表征。使用1 H NMR评估炔烃关于钨中心的构象行为。发现所有三个金属环肽相对于钨都具有炔烃的多种构象。两个都18和19似乎采用了所有8种可能的构象,而20则采用了数量有限的构象。通过使用可变温度1 H NMR检查炔烃氢共振来评估炔烃在顺式和反式构象之间平衡的能力。发现18和19中的炔配体将在顺式和反式构象之间平衡。18中的炔烃氢共振在343 K附近合并为一个信号,而19中的炔烃氢共振甚至在360 K时也无法完全合并。配合物18的环比配合物19大。,而19的较高聚结温度归因于其较小的环尺
the caspase-3 pathway in molecular level. These results indicated that 1a had the potential to be a newclass of multifunctional anti-myocardial ischemia agent. Most importantly, these results provided us important clues for the further design and modification of this type of Leonurine-cysteine analog conjugates in future.
Photoinduced Addition of Glycosyl Thiols to Alkynyl Peptides: Use of Free-Radical Thiol−Yne Coupling for Post-Translational Double-Glycosylation of Peptides
作者:Mauro Lo Conte、Salvatore Pacifico、Angela Chambery、Alberto Marra、Alessandro Dondoni
DOI:10.1021/jo1008178
日期:2010.7.2
peptides has been carried out by a one-pot two-step sequence comprising selective S-propargylation followed by photoinduced (λ max 365 nm) free-radical hydrothiolation with glycosyl thiols. Conditions were established for the sequential introduction of two different thiol residues such as a glycosyl and a biotinyl derivative.