Díaz Natalia, Suárez Dimas, Sordo Tomás L, Tuñón Iñaki, Silla Estanislao
Departamento de Química Física y Analítica Universidad de Oviedo C/ Julian Clavería 8, 33006, Oviedo Asturias, Spain.
Chemistry. 2002 Feb 15;8(4):859-67. doi: 10.1002/1521-3765(20020215)8:4<859::aid-chem859>3.0.co;2-i.
A theoretical study of the water-assisted alkaline hydrolysis of 2-azetidinone, 3-formylamino-2-azetidinone and 3-formylamino-2-azetidine-1-sulfonate ion is carried out at the B3LYP/6-31+G* level. The effect of bulk solvent is taken into account using the PCM solvation model while specific solvent effects are represented by the inclusion of an ancillary water molecule along the reaction profile. The calculated free energy barriers in solution are in reasonable agreement with experimental values. The observed substituent effects due to the presence of the 3-formylamino and the SO(3) groups attached to the beta-lactam ring are crucial factors determining the hydrolysis of monobactam antibiotics.
在B3LYP/6-31+G*水平上对2-氮杂环丁酮、3-甲酰氨基-2-氮杂环丁酮和3-甲酰氨基-2-氮杂环丁烷-1-磺酸根离子的水辅助碱性水解进行了理论研究。使用PCM溶剂化模型考虑了本体溶剂的影响，而特定的溶剂效应则通过沿着反应路径包含一个辅助水分子来表示。计算得到的溶液中的自由能垒与实验值合理吻合。观察到的由于β-内酰胺环上存在3-甲酰氨基和SO(3)基团而产生的取代基效应是决定单环β-内酰胺抗生素水解的关键因素。
