Acyl-CoA derivatives of several hydroxylated cinnamic acids have been synthesized in 30 to 50% yield via a. acyl phenyl thiol esters, b. acyl N-hydroxysuccinimide esters, and c. glucocinnamoyl derivatives. Properties of the intermediates have been determined. The cinnamyol-CoA thiol esters were characterized by their chromatographic behaviour and UV spectra. The molar extinction coefficients of...

The catalytic action of two non commercial lipases (E.C. 3.1.1.3) in the synthesis of isoamyl acetate in a solvent-free system, were tested using an experimental design in order to better understand the relationship between the reaction variables. Yields ranging from 67 to 77 % molar conversion were achieved. The synthesis of isoamyl acetate catalyzed by the chosen lipase (Rhizopus sp.) was opt...

based on the {s+, i-} pathway, the concentration of surfactant and surface charge density of silanolate groups control the phase transition from lamellar, to hexagonal through cubic form. the high surface charge density of silanolate groups was observed for the lamellar phase. with decrease of molar concentration of surfactant on the gel, the yield of reaction decreases and the stability of mes...

The ultrasound-assisted synthesis of lutein disuccinate from all-trans lutein (AL) and succinic anhydride (SA) was investigated in this study. Triethylamine was used as the catalyst. Based on the single-factor experiments, a 7-level-3-factor uniform design and response surface analysis were further employed to evaluate the effects of the selected variables including molar ratio of SA/AL, reacti...

The production of biodiesel through batch and existing continuous-flow processes requires the use of a much higher excess alcohol, typically 100%, than the stoichiometric molar requirement in order to drive the transesterification reaction to completion. This excess alcohol must be recovered in a separate process, which involves additional capital and operating costs. In this study, a novel rea...

introdouction: impacted mandibular third molar surgery may affect periodontal status of the adjacent second molar. the purpose of this study was to evaluate the changes in periodontal health parameters distal to the adjacent second molar following surgical extraction of an impacted mandibular third molar. materials and methods: we selected 50 subjects with a mean age of 22.8 (ranging from 18 to...

objective: the present study assessed the association of size, axial angulation, developmental stage and bud position of the mandibular third molar with the second molar impaction in patients with mandibular second molar impaction. methods: in this descriptive-analytical study (case-control design), dental records of 5,420 patients in the age range of 12-15 years who underwent orthodontic treat...

The refolding of denatured hen egg white lysozyme (HEWL) was examined by surfactants at a high final refolded HEWL concentration (1 mg/mL). Hexadecyltrimethylammonium bromide (CTAB) and sucrose fatty acid monoester (DK-SS) were used to dissolve denatured HEWL without denaturants such as guanidine hydrochloride (GuHCl) and urea. When denatured HEWL was perfectly dissolved in buffer solutions con...

We have developed a direct, asymmetric Michael reaction that can be performed in brine or seawater without addition of organic solvents. A bifunctional catalyst with long hydrophobic alkyl chains efficiently catalyzed Michael reactions and afforded the desired products in excellent yield with high enantiomeric excess, even when only an equal molar ratio of the donor to acceptor was used.