- Conformational analysis of 1,2-Di-O-octanoyl-ethylene-glycerol during aggregation
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Conformational analysis of 1,2-di-O-octanoyl-ethylene-glycerol during aggregation by 600 MHz 1H NMR is described. In monomeric states, 1,2-di-O-octanoyl-ethylene-glycerol exists in 75% anti-conformer and 25% gauche-conformer. The first critical
- Lin, Gialih,Lu, Chin-Ping
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- Kinetics and quantitative structure-activity relationships for pseudomonas sp. Lipase-catalyzed hydrolysis of both monoesters and diesters of ethylene glycol
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The goal of this work is to study kinetics and quantitative structure-activity relationships for steady states of Pseudomonas sp. lipase-catalyzed hydrolysis of both diesters and monoesters of ethylene glycol. Based on the steady-state kinetics of the enzyme-catalyzed hydrolysis of the diesters of ethylene glycol, the diesters and the monoesters react simultaneously as soon as monoester has started to build up in the reaction medium. In other words, the apparent Km values of the diesters are the Km values of the diesters (KmA) plus the Km values of the monoesters (KmB), and all Vmax values are about the same. Moreover, the pH-stat titration curve of the enzyme-catalyzed hydrolysis of the diesters of ethylene glycol is initially hyperbolic, then there is a sharp falloff in the hydrolysis rate. The abrupt stoppage of the reaction (relaxation stage) may be due to the existence of two phases in the reaction medium, that is, the product (ethylene glycol) and the substrates (the diesters of ethylene glycol) are not miscible. Furthermore, quantitative structure-activity relationships for varied acyl groups of mono- and diesters of ethylene glycol are studied. The fact that both pKmA and pK mB values are linearly correlated with the hydrophobicity constant (π) but not with the electronic substituent constants (σ*) indicates that the affinity of these substrates for the enzyme depends only on the hydrophobicitv of substrates. Copyright
- Chiou, Shyh-Ying,Cheng, Yu-Ru,Lu, Chun-Ping,Lin, Yan-Fu,Lin, Long-Yau,Lin, Gialih
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p. 201 - 207
(2007/10/03)
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- Process for alkoxylation of esters and products produced therefrom
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A process for producing alkoxylated mono-, di-, and tri-esters in which a starting material ester and an alkylene oxide are reacted in the presence of selected calcium based catalysts.
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- Capryloyloxyalkyl acrylates, polymers and copolymers thereof and their preparation
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This invention relates to capryloyloxyalkyl acrylates of the general formula, CH2=CH-CO-O-R-O-CO-(CH2)6-CH3,wherein R is an alkylene group of 2 to 6 carbon atoms, and their polymers and copolymers containing structure units of the general formula where R are identical or different alkylene groups as defined above, and the polymer contains either 100 % of the capryloyloxyalkyl acrylate structure units or additional vinyl monomer and particularly vinyl chloride structure units in the main chain or side chains. The invention also pertains to methods for the preparation of capryloyloxyalkyl acrylates corresponding intermediates and to methods for producing the polymers and copolymers containing capryloyloxyalkyl acrylate structure units either by polymerization or copolymerization of capryloyloxyalkyl acrylates with the respective vinyl comonom ers or by polymerization of the vinyl comonomers, particularly vinyl chloride, in the presence of a poly(capryloyloxyalkyl acrylate). The invention is particularly applicable to the production of new types of plasticized PVC where migration and extraction of the plasticizing component is excluded.
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