Substrate-selective mechanisms in biocatalysis demonstrated with a versatile and efficient aldolase antibody
作者:Hagit Shulman、Ehud Keinan
DOI:10.1016/s0960-894x(99)00292-9
日期:1999.7
A structure-activity relationship study with a series of aldol substrates shows that the mechanism of the antibody 38C2-catalyzed retrograde aldol reaction depends on the nature of the substrate With electron-deficient substrates an early deprotonation precedes the C-C bond cleavage while with electron-rich substrates the catalytic mechanism involves an initial C-C bond cleavage leading to a positively charged intermediate. (C) 1999 Elsevier Science Ltd. All rights reserved.
MnO<sub>2</sub> as a terminal oxidant in Wacker oxidation of homoallyl alcohols and terminal olefins
作者:Rodney A. Fernandes、Gujjula V. Ramakrishna、Venkati Bethi
DOI:10.1039/d0ob01344g
日期:——
PdCl2/CrO3/HCl produced α,β-unsaturated ketonesfrom homoallyl alcohols, the present method provided orthogonally the β-hydroxy-methyl ketones. No overoxidation or elimination of benzylic and/or β-hydroxy groups was observed. The method could be extended to the oxidation of simple terminalolefins as well, to methyl ketones, displaying its versatility. An application to the regioselective synthesis of gingerol is
Chemically Reactive Immunogens Lead to Functional Convergence of the Immune Response
作者:Hagit Shulman、Carina Makarov、Anthony K. Ogawa、Floyd Romesberg、Ehud Keinan
DOI:10.1021/ja000616o
日期:2000.11.1
An aldolase antibody, 24H6, which was obtained from immunization with the large hapten 2, is shown to possess an active-site lysine residue with a perturbed pKa of 7.0. This antibody catalyzes both the aldol addition and the retrograde aldol fragmentation with a broad range of substrates that are structurally different from the hapten. This observation suggests that in reactive immunization with 1