The importance of the amide bond nearest the thiol group in enzymatic reactions of coenzyme A
作者:Jin Xun、Haidong Huang、Kurt W. Vogel、Dale G. Drueckhammer
DOI:10.1016/j.bioorg.2004.10.002
日期:2005.4
Analogues of coenzyme A (CoA) and of CoA thioesters have been prepared in which the amide bond nearest the thiol group has been modified. An analogue of acetyl-CoA in which this amide bond is replaced with an ester linkage was a good substrate for the enzymes carnitine acetyltransferase, chloramphenicol acetyltransferase, and citrate synthase, with K(m) values 2- to 8-fold higher than those of acetyl-CoA
A Facile and Selective Procedure for Transesterification of β-Keto Esters Promoted by Yttria-Zirconia Based Lewis Acid Catalyst
作者:Pradeep Kumar、Rajesh Kumar Pandey
DOI:10.1055/s-2000-6496
日期:2000.2
An yttria-zirconia based strong Lewis acid efficiently catalyses the transesterification of β-keto esters under environmentally safe, heterogeneous reaction conditions with high selectivity and in good to excellent yields.
METHOD OF LABELING SULFENIC ACID-CONTAINING PROTEINS AND PEPTIDES
申请人:Wake Forest University Health Sciences
公开号:US20150346209A1
公开(公告)日:2015-12-03
A method of labeling a sulfenic acid (—SOH) group of a cysteine residue in a protein or peptide, comprises contacting said protein or peptide with a beta-ketoester to covalently couple said beta-ketoester to said cysteine residue and form a beta-ketoester-labeled cysteine residue in said protein or peptide.
This invention relates to mercaptoalkyl acetoacetates and a process for preparing mercaptoalkyl acetoacetates. The process embraces the reaction of TKD (a diketene-acetone adduct) with hydroxy-functional mercaptans. Preferred is the reaction of TKD with 2-mercaptoethanol to yield mercaptoethyl acetoacetate. Mercaptoethyl acetoacetate is an effective chain transfer agent in free radical polymerization reactions with the benefit of introducing reactive acetoacetate functionally into the formed polymer.
Selective Catalytic Transesterification, Transthiolesterification, and Protection of Carbonyl Compounds over Natural Kaolinitic Clay
作者:Datta E. Ponde、Vishnu H. Deshpande、Vivek J. Bulbule、Arumugam Sudalai、Anil S.Gajare
DOI:10.1021/jo971404l
日期:1998.2.1
Transesterification and transthiolesterification of beta-keto esters with variety of alcohols and thiols and selective protection of carbonyl functions with various protecting groups catalyzed by natural kaolinitic clay are described. The clay has been found to be an efficient catalyst in transesterifying long chain alcohols, unsaturated alcohols, and phenols to give their corresponding beta-keto esters in high yields. For the first time, transthiolesterification of beta-keto esters with a variety of thiols has been achieved under catalytic conditions. Clay also catalyzes selective transesterification of beta-keto esters by primary alcohols in the presence of secondary and tertiary alcohols giving corresponding beta-keto esters. A systematic study involving the reactivity of different nucleophiles (alcohols, amines, and thiols) toward beta-keto esters is also described. Sterically hindered carbonyl groups as well as alpha,beta-unsaturated carbonyl groups underwent protection without the deconjugation of the double bond. Chemoselective protection of aldehydes in the presence of ketones has also been achieved over natural kaolinitic clay.