Study on the Transesterification of Phosphatidylcholine over Diethylamine

2014 ◽  
Vol 997 ◽  
pp. 93-96
Author(s):  
Biao Yan ◽  
Tian Tian Zhang

The catalyst diethylamine with low boiling point can be separated combined with the recovery of ethanol by distillation in the transesterification of phosphatidylcholine, and it was an effective catayst for preparing GPC from natural lecithin via transesterification. Under the conditions of: the catalyst content was 3.6% of the total reaction volume, lecithin concentration was 100 mmol/L , reaction temperature was 60 °C and reaction time was 260 min, the phosphatidylcholine was reacted completely and the yield of GPC can reach about 80%

2014 ◽  
Vol 884-885 ◽  
pp. 603-606
Author(s):  
Hong Ya Li ◽  
Biao Yan ◽  
Xiao Li Zhang ◽  
Bin Xia Zhao

The isopropylamine with low boiling point was used for preparing GPC from natural lecithin under mild conditions, it was confirmed as an effective catalyst and the recovery can be combined with the recovery of methanol by distillation. The mechanism of the transesterification reaction was proposed and the experiments obtained the better effect under the conditions of: catalyst content was 2.4% of the total reaction volume, lecithin concentration was 0.05-0.10mol L1 , reaction temperature was 60 °C and reaction time was 260 min.


2014 ◽  
Vol 997 ◽  
pp. 73-76
Author(s):  
Hong Ya Li ◽  
Tian Tian Zhang

The propylamine with low boiling point was confirmed as effective catayst for preparing GPC from natural lecithin via transesterification. The catalyst can be separated combined with the recovery of methanol by distillation. Under the conditions of: the catalyst content was 2.4% of the total reaction volume, lecithin concentration was 0.05-0.10mol L–1 , reaction temperature was 60 °C and reaction time was 4 h, the conversion of phosphatidylcholine could reach over 98%.


2020 ◽  
Vol 19 (04) ◽  
pp. 73-79
Author(s):  
Cuong V. Bui

The objective of this research was to use Protamex enzyme as a catalyst to hydrolyze chicken leg cartilage for production of amino acid hydrolysate. The proximate composition of chicken cartilage was analyzed. The results indicated that the major components in the dry matter of chicken leg cartilage were lipid (19.72 ± 0.05%) and protein (13.34 ± 0.08%). The main parameters affecting the hydrolysis reaction of chicken leg cartilage with Protamex enzyme were selected for investigation: reaction temperature (oC), pH, enzyme ratio (%, based on the weight of substrate), reaction time (min), and the ratio of reaction volume (v/v). The significant difference was analyzed by ANOVA One-Way to identify the optimal point of each parameter toward amino acid yield. The results revealed that the hydrolysis degree and amino acid yield reached the maximal values of 22.93 ± 4.01% and 30.25 ± 1.86%, respectively, when the reaction temperature, pH, enzyme ratio, reaction time, and ratio of reaction volume (v/v) were 40oC, 4, 0.52%, 40 min, and 1/18, respectively.


Author(s):  
Anna Fajdek-Bieda ◽  
Agnieszka Wróblewska ◽  
Piotr Miądlicki ◽  
Jadwiga Tołpa ◽  
Beata Michalkiewicz

AbstractThis work presented the studies with the natural zeolite—clinoptilolite as the catalyst for the isomerization of geraniol. During the research, it turned out that the studied process is much more complicated, and not only isomerization takes place in it, but also dehydration, oxidation, dimerization, cyclization and fragmentation of the carbon chain. Geraniol is an organic raw material which can be obtained not only by a chemical synthesis but also from plants (renewable biomass) by distillation or extraction method, for example a source of geraniol can be a plant—geranium. Before catalytic tests clinoptilolite was characterized by the instrumental methods, such as: XRD, porosity studies—nitrogen adsorption at 77 K, SEM, EDXRF, and FT-IR. Gas chromatography analyses showed that the main products of geraniol isomerization process were 6,11-dimethyl-2,6,10-dodecatrien-1-ol and thumbergol. The selectivity of 6,11-dimethyl-2,6,10-dodecatrien-1-ol and thumbergol depended on the temperature, catalyst content and reaction time. These parameters were changed in the following ranges: 80–150 °C (temperature), 5–15 wt% (catalyst content) and 15–1440 min. (reaction time). The most favorable conditions for 6,11-dimethyl-2,6,10-dodecatrien-1-ol and thumbergol obtaining were: temperature 140 ºC, catalyst content 12.5 wt% and reaction time 180 min. At these conditions, the conversion of geraniol amounted to 98 mol%, and the selectivities of 6,11-dimethyl-2,6,10-dodecatrien-1-ol and thumbergol amounted to 14 and 47 mol%, respectively.


2011 ◽  
Vol 366 ◽  
pp. 366-369
Author(s):  
Feng Gao ◽  
Rong Fu ◽  
Ming Yang Qian ◽  
Zhu Min Wang ◽  
Xiang Zhang

Response surface methodology was used to optimize the soaking Mg leaching ratio from the boron slurry screened by 25 fractional factorial design. Five effective factors such as H2SO4 concentrations, reaction time, reaction temperature and stir velocity were tested by using 25 fractional factorial design criterion and three effective factors H2SO4 concentrations, reaction time and reaction temperature showed significant effect(P2SO4 concentrations of 0.29mol/l, reaction time of 90 min and reaction temperature of 50°C. Three runs of additional confirmation experiments were conducted. The mixture magnesium leaching value was 58.20%.


2014 ◽  
Vol 915-916 ◽  
pp. 713-716
Author(s):  
Qing Zhang ◽  
Jing Tian ◽  
Zhi Qi Cao ◽  
Ru Xia Xu ◽  
Zhen Zhen Sun ◽  
...  

In this investigation, Schiff bases aluminum complex was synthesized and used as the initiator in the polymerization of D,L-lactide. The aluminum complex was characterized by infrared spectroscopy (IR), and nuclear magnetic resonance spectroscopy (NMR). The influences of different factors, including reaction time, reaction temperature, and the ratio of D, L-lactide/Al3+ on the synthesis of polylactide were described. The results showed that Schiff bases aluminum complex could be successfully applied in the ring opening polymerization. The optimum condition of the ring opening polymerization of D,L-lactide, which included D,L-lactide/Al3+ (mol/mol) ratio of 250, reaction temperature of 120 °C, and reaction time of 16 hours.


2011 ◽  
Vol 17 (3) ◽  
pp. 323-331 ◽  
Author(s):  
Jiancheng Zhou ◽  
Wu Dongfang ◽  
Birong Zhang ◽  
Yali Guo

A series of single-metal carbonates and Pb-Zn mixed-metal carbonates were prepared as catalysts for alcoholysis of urea with 1,2-propylene glycol (PG) for the synthesis of propylene carbonate (PC). The mixed carbonates all show much better catalytic activities than the single carbonates, arising from a strong synergistic effect between the two crystalline phases, hydrozincite and lead carbonate. The mixed carbonate with Pb/Zn=1:2 gives the highest yield of PC, followed by the mixed carbonate with Pb/Zn=1:3. Furthermore, Taguchi method was used to optimize the synthetic process for improving the yield of PC. It is shown that the reaction temperature is the most significant factor affecting the yield of PC, followed by the reaction time, and that the optimal reaction conditions are the reaction time at 5 hours, the reaction temperature at 180 oC and the catalyst amount at 1.8 wt%, resulting in the highest PC yield of 96.3%.


2010 ◽  
Vol 65 (8) ◽  
pp. 1038-1044 ◽  
Author(s):  
Kazumichi Yanagisawa ◽  
Jae-Hyen Kim ◽  
Chisato Sakata ◽  
Ayumu Onda ◽  
Eri Sasabe ◽  
...  

Calcium-deficient hydroxyapatite (CDHA) prepared by the coprecipitation method was solidified by the hydrothermal hot-pressing technique, and compacts of CDHA with high bulk density beyond 80% were obtained at 200 ℃. Each reaction parameter, viz. reaction temperature, pressure, and time, was systematically changed from the standard conditions to investigate its effects on density, Vickers hardness, and Ca/P ratio of the compacts obtained. The reaction temperature and pressure had a large effect on densification, but not the reaction time because the densification proceeds in a short time. The densification by hydrothermal hot-pressing involved dissolution and precipitation of the starting CDHA powder, so that the Ca/P ratio changed from 1.52 of the starting powders to 1.61 of the compact obtained by hydrothermal hot-pressing at 200 ℃ and 35 MPa for 24 h with the addition of 10 wt.-% water


2015 ◽  
Vol 17 (4) ◽  
pp. 23-31 ◽  
Author(s):  
Agnieszka Wróblewska ◽  
Edyta Makuch ◽  
Małgorzata Dzięcioł ◽  
Roman Jędrzejewski ◽  
Paweł Kochmański ◽  
...  

Abstract This work presents the studies on the optimization the process of allyl alcohol epoxidation over the Ti-SBA-15 catalyst. The optimization was carried out in an aqueous medium, wherein water was introduced into the reaction medium with an oxidizing agent (30 wt% aqueous solution of hydrogen peroxide) and it was formed in the reaction medium during the processes. The main investigated technological parameters were: the temperature, the molar ratio of allyl alcohol/hydrogen peroxide, the catalyst content and the reaction time. The main functions the process were: the selectivity of transformation to glycidol in relation to allyl alcohol consumed, the selectivity of transformation to diglycidyl ether in relation to allyl alcohol consumed, the conversion of allyl alcohol and the selectivity of transformation to organic compounds in relation to hydrogen peroxide consumed. The analysis of the layer drawings showed that in water solution it is best to conduct allyl alcohol epoxidation in direction of glycidol (selectivity of glycidol 54 mol%) at: the temperature of 10–17°C, the molar ratio of reactants 0.5–1.9, the catalyst content 2.9–4.0 wt%, the reaction time 2.7–3.0 h and in direction of diglycidyl ether (selectivity of diglycidyl ether 16 mol%) at: the temperature of 18–33°C, the molar ratio of reactants 0.9–1.65, the catalyst content 2.0–3.4 wt%, the reaction time 1.7–2.6 h. The presented method allows to obtain two very valuable intermediates for the organic industry.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Yu-Bin Ji ◽  
Fang Dong ◽  
Miao Yu ◽  
Long Qin ◽  
Dan Liu

The response surface methodology was employed to optimize the synthesis conditions of seleno-Sargassum fusiforme(Harv.) Setch. polysaccharide. Three independent variables (reaction time, reaction temperature, and ratio of Na2SeO3to SFPSI) were tested. Furthermore, the characterization and antioxidant activity of Se-SFPSIin vivowere investigated. The result showed that the actual experimental Se content of Se-SFPSI was 3.352 mg/g at the optimum reaction conditions of reaction time 8 h, reaction temperature 71°C, and ratio of Na2SeO3to SFPSIB 1.0 g/g. A series of experiments showed that the characterization of Se-SFPSIB was significantly different from that of SFPSIB. Additionally, antioxidant activity assay indicated that the Se-SFPSIB could increase catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activity of mice bearing tumor S180in blood, heart, and liver while decreasing malondialdehyde (MDA) levels. It can be concluded that selenylation is a feasible approach to obtain seleno-polysaccharide which was utilized as highly biological medicine or functional food.


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