- 作者: 王維賢 ; 鄭靜枝 ; 李明昭 等
- 作者服務機構: 中山大學海洋資源系
- 中文摘要: The kinetics of phosphate-catalyzed proton exchange have been measured with NMR lineshape analysis for a series of amides, ureas, and carbamates. A hypothetical energy profile for transition structures of concerted phosphate catalysis .dbldag./sub c/ and of stepwise phosphate catalysis .dbldag./sub 1/, .dbldag./sub 2/ is used for discussion of the substituent effects. The concerted mechanism of phosphate catalysis operates only for amides RCONHCH/sub 3/ for which the electron-donating ability of the substituent R is comparable with, or better than, that of the methyl group. We conclude that concerted phosphate catalysis is inoperative in proteins or polypeptides.
- 英文摘要: --
- 中文關鍵字: Proton Exchange; Concerted Mechanism; Phosphate; Amide; Substituent
- 英文關鍵字: 質子交換;磷酸鹽;醯胺;取代基