The Experts below are selected from a list of 171 Experts worldwide ranked by ideXlab platform
David G. Rethwisch - One of the best experts on this subject based on the ideXlab platform.
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scale up of pseudo solid phase enzymatic synthesis of α Methyl Glucoside acrylate
Biotechnology and Bioengineering, 2002Co-Authors: David G. RethwischAbstract:The successful scale-up of the enzymatic synthesis of alpha-Methyl Glucoside acrylate from laboratory-scale (milliliter) to pilot-scale (liter) was examined. Specifically, Candida antarctica lipase B (Novozym 435) was used as a biocatalyst to produce alpha-Methyl Glucoside acrylate via the transesterification of alpha-Methyl Glucoside (MG) with vinyl acrylate (VA) using acetone as a solvent. This is a pseudo-solid-phase synthesis; only a fraction of the alpha-Methyl Glucoside and the product are soluble in acetone. Molecular sieves were used to remove traces of water in the reaction medium and to increase enzyme stability by removing the acetaldehyde by-product. A general method was also developed to purify and recover the monoacrylate product from unreacted sugar and undesired diester by a simple crystallization and precipitation process.
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Scale‐up of pseudo solid‐phase enzymatic synthesis of α‐Methyl Glucoside acrylate
Biotechnology and bioengineering, 2002Co-Authors: David G. RethwischAbstract:The successful scale-up of the enzymatic synthesis of alpha-Methyl Glucoside acrylate from laboratory-scale (milliliter) to pilot-scale (liter) was examined. Specifically, Candida antarctica lipase B (Novozym 435) was used as a biocatalyst to produce alpha-Methyl Glucoside acrylate via the transesterification of alpha-Methyl Glucoside (MG) with vinyl acrylate (VA) using acetone as a solvent. This is a pseudo-solid-phase synthesis; only a fraction of the alpha-Methyl Glucoside and the product are soluble in acetone. Molecular sieves were used to remove traces of water in the reaction medium and to increase enzyme stability by removing the acetaldehyde by-product. A general method was also developed to purify and recover the monoacrylate product from unreacted sugar and undesired diester by a simple crystallization and precipitation process.
Adelaide F. Alario - One of the best experts on this subject based on the ideXlab platform.
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Study of terbium(III)-dextran and terbium(III)-α-Methyl Glucoside interactions
Journal of Polymer Science Part B: Polymer Physics, 1993Co-Authors: Sandra De Aguiar Soares, Judith F. Rodrigues, Adelaide F. AlarioAbstract:The interaction of dextran with terbium(III) was studied in aqueous solution, pH 3.0–6.6, by fluorescence and optical rotatory dispersion. The polysaccharide enhances Tb(III) fluorescence intensity when the system is excited at the 290-nm hypersensitive transition (7F6 → 5H4). The dextran rotatory power is decreased in the presence of the metal ion. The results indicate that a 38% maximum of the polymer repeat units are coordinated. Complex formation occurs with displacement of water from the cation coordination sphere by hydroxyl groups at the second and third carbon atoms of the pyranoside ring. As the pH increases, a more asymmetric complex is formed. The α-Methyl Glucoside, low molecular weight dextran analogue, interacts with Tb(III) less strongly than dextran. Fluorimetric titrations indicated that the order of binding ability to polysaccharide is Tb(III) > Al(III) > Ca (II). © 1993 John Wiley & Sons, Inc.
Yu-fu Lai - One of the best experts on this subject based on the ideXlab platform.
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Formulation of physical properties of Methyl Glucoside polyester by mixture response surface methodology.
Journal of agricultural and food chemistry, 2001Co-Authors: Yu-fu Lai, Chwen-jen ShiehAbstract:Methyl Glucoside polyester (MGPE), consisting of a Methyl Glucoside molecule esterified with four fatty acids, is a potential fat substitute. A mixture response surface methodology was employed to model the physical properties (melting point, density, and viscosity) of MGPE prepared from composite blends of fatty acid Methyl esters (FAME). The measured physical properties were similar to those of soybean oil, except for a higher viscosity. The physical properties correlated significantly with the degree of saturation of their composite fatty acids. Results showed that the physical properties of MGPE prepared from a FAME mixture derived from high oleic acid safflower oil and soybean oil (molar ratio 1:1) was similar to those of soybean oil. The physical properties of MGPE can be adjusted by modifying the saturated fatty acids of synthesized MGPE to simulate the physical properties of soybean oil.
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Application of response surface methodology to the study of Methyl Glucoside polyester synthesis parameters in a solvent-free system.
Journal of agricultural and food chemistry, 2000Co-Authors: Chwen-jen Shieh, Yu-fu LaiAbstract:Response surface methodology (RSM) and 3-level-3-factor fractional factorial design were used to evaluate the effects of synthesis parameters, including reaction time (4 to 8 h), temperature (110 to 130 °C), and substrate molar ratio of fatty acid Methyl esters (FAME) from soybean oil to Methyl Glucoside (4:1 to 6:1) on the percent molar conversion to Methyl Glucoside polyester (MGPE), utilizing 15 g of Methyl Glucoside as the reactant in a solvent-free system. All synthesis variables (reaction time, temperature, and substrate molar ratio) exhibited significant effects on percent molar conversion to MPGE in the experimental range. Optimization of the synthesis reaction was suggested by ridge max analysis to compute the estimated ridge of optimum response for increasing radii from the center of the original design. Based on the ridge max analysis, optimum conditions were: reaction time 6.3 h, synthesis temperature 123.8 °C, and substrate molar ratio 5.9:1. The predicted molar conversion was 55.68% (i.e., ...
Kenichi Suto - One of the best experts on this subject based on the ideXlab platform.
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Possible roles of Methyl Glucoside and myo-inositol in the opening of cut rose flowers
Annals of Botany, 1999Co-Authors: Kazuo Ichimura, Yuji Mukasa, Takahiro Fujiwara, Katsunori Kohata, Rie Goto, Kenichi SutoAbstract:Abstract Methyl Glucoside andmyo-inositol are present in all organs of rose (Rosa hybridaL.). To investigate the possible role of these carbohydrates in the opening of cut roses, flowers with a 10, 20 or 40-cm-long stem and a single flower bud (about 1.5 cm in diameter) were placed in water and flower opening and changes in sugar content in flowers and stems examined for 7 d. The longer the stem of the cut flower, the larger was the flower diameter. In stems, the concentration of carbohydrates, including Methyl Glucoside andmyo-inositol markedly decreased before flower opening. In petals, contents of glucose, Methyl Glucoside andmyo-inositol also decreased before flower opening, but those of fructose, sucrose and xylose did not. When glucose and Methyl Glucoside were added to the vase water (4%) flower opening was clearly promoted; this was accompanied by an increase in Methyl Glucoside and fructose concentrations in petals. On the contrary,myo-inositol inhibited flower opening, and this was accompanied by an increase inmyo-inositol and xylose concentrations in petals. These results suggest that Methyl Glucoside and/or its metabolites are transported into the petal cells, thereby lowering the osmotic water potential and promoting flower opening.Myo-inositol is not readily metabolized, and exogenousmyo-inositol given at a high concentration may act as an extracellular osmolyte, which inhibits water uptake and flower opening.
Chwen-jen Shieh - One of the best experts on this subject based on the ideXlab platform.
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Formulation of physical properties of Methyl Glucoside polyester by mixture response surface methodology.
Journal of agricultural and food chemistry, 2001Co-Authors: Yu-fu Lai, Chwen-jen ShiehAbstract:Methyl Glucoside polyester (MGPE), consisting of a Methyl Glucoside molecule esterified with four fatty acids, is a potential fat substitute. A mixture response surface methodology was employed to model the physical properties (melting point, density, and viscosity) of MGPE prepared from composite blends of fatty acid Methyl esters (FAME). The measured physical properties were similar to those of soybean oil, except for a higher viscosity. The physical properties correlated significantly with the degree of saturation of their composite fatty acids. Results showed that the physical properties of MGPE prepared from a FAME mixture derived from high oleic acid safflower oil and soybean oil (molar ratio 1:1) was similar to those of soybean oil. The physical properties of MGPE can be adjusted by modifying the saturated fatty acids of synthesized MGPE to simulate the physical properties of soybean oil.
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Application of response surface methodology to the study of Methyl Glucoside polyester synthesis parameters in a solvent-free system.
Journal of agricultural and food chemistry, 2000Co-Authors: Chwen-jen Shieh, Yu-fu LaiAbstract:Response surface methodology (RSM) and 3-level-3-factor fractional factorial design were used to evaluate the effects of synthesis parameters, including reaction time (4 to 8 h), temperature (110 to 130 °C), and substrate molar ratio of fatty acid Methyl esters (FAME) from soybean oil to Methyl Glucoside (4:1 to 6:1) on the percent molar conversion to Methyl Glucoside polyester (MGPE), utilizing 15 g of Methyl Glucoside as the reactant in a solvent-free system. All synthesis variables (reaction time, temperature, and substrate molar ratio) exhibited significant effects on percent molar conversion to MPGE in the experimental range. Optimization of the synthesis reaction was suggested by ridge max analysis to compute the estimated ridge of optimum response for increasing radii from the center of the original design. Based on the ridge max analysis, optimum conditions were: reaction time 6.3 h, synthesis temperature 123.8 °C, and substrate molar ratio 5.9:1. The predicted molar conversion was 55.68% (i.e., ...