5-[4-(1-Hydroxyethyl)phenyl]-10,15,20-triphenylporphyrin as a Probe of the Transition-State Conformation in Hydrolase-Catalyzed Enantioselective Transesterifications
作者:Tadashi Ema、Masahito Jittani、Kenji Furuie、Masanori Utaka、Takashi Sakai
DOI:10.1021/jo0109063
日期:2002.4.1
5-[4-(1-Hydroxyethyl)phenyl]-10,15,20-triphenylporphyrin (1a) and zinc porphyrin 1b were designed and synthesized to experimentally examine the validity of the transition-state model previously proposed for the lipase-catalyzed kinetic resolution of secondary alcohols. The lipases from Pseudomonas cepacia (lipase PS), Candida antarctica (CHIRAZYME L-2), Rhizomucor miehei (CHIRAZYME L-9), and Pseudomonas
设计并合成了5- [4-(1-羟乙基)苯基] -10,15,20-三苯基卟啉(1a)和卟啉锌1b,以实验检验先前提出的用于脂肪酶催化动力学的过渡态模型的有效性。仲醇的拆分。来自洋葱假单胞菌(脂肪酶PS),南极假丝酵母(CHIRAZYME L-2),米氏根瘤菌(CHIRAZYME L-9)和铜绿假单胞菌(脂肪酶LIP)的脂肪酶表现出优异的对映选择性(在30摄氏度时E> 100)。来自地衣芽孢杆菌的枯草杆菌蛋白酶Carlsberg(ChiroCLEC-BL)也显示出1a的高对映选择性(E = 30在30摄氏度下),并确定了热力学参数:DeltaDeltaH = -6.8 +/- 0.8 kcal mol(-1),DeltaDeltaS = -13 +/- 3 cal mol(-1)K(-1)。脂肪酶和枯草杆菌蛋白酶分别显示R优先级和S优先级。根据过渡状态模型对实验观察的基础机制进行了解释。大仲