Chitosan Metal Complex: An Artificial Metalloprotease Hydrolyzing Trypsin Inhibitor from Soybean

2012 ◽  
Vol 430-432 ◽  
pp. 414-418
Author(s):  
Peng Liang ◽  
Dong Feng Wang ◽  
Xing Yu Wang ◽  
Mei Ding ◽  
Li Zhang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Metal Complex ◽  
Metal Complexes ◽  
Trypsin Inhibitor ◽  
Rate Constants ◽  
Proteolytic Enzymes ◽  
Protein Cleavage ◽  
Reaction Conditions ◽  
Sds Page ◽  
Optimum Reaction

Most popular agents for protein cleavage are proteolytic enzymes, but they require more rigorous hydrolytic conditions, and it is very difficulty to separate them from the productions. In this paper, an new artificial metalloprotease, Cu(II) complex of cyclen (Cu(II)Cyc) using chitosan as supporter, was designed and synthesized successfully. The hydrolytic efficient under different conditions was measured and confirmed with HPLC, SDS-PAGE, further more. Some reaction conditions, such as pH, temperature, were researched, and the results show that the optimum reaction time was 48 h, temperature was 60 °C respectively, The observed rate constants for trypsase inhibitor cleavage was 1.006×10-2 h-1 under above conditions, and the observed rate constants was 2.120×10-2 h-1 when the pH was 9.0. This paper suggested that the chitosan metal complexes could efficiently accelerate the hydrolysis reaction.

Study on the Synthesis of Isoamyl Acetate Catalyzed by Strong Acidic Cation Exchange Resin

2011 ◽  
Vol 396-398 ◽  
pp. 2411-2415 ◽  
Author(s):  
Ping Lan ◽  
Li Hong Lan ◽  
Tao Xie ◽  
An Ping Liao
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Cation Exchanger ◽  
Cation Exchange Resin ◽  
Isoamyl Acetate ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Reaction Conditions ◽  
Optimum Reaction

Isoamyl acetate was synthesized from isoamylol and glacial acetic acid with strong acidic cation exchanger as catalyst. The effects of reaction conditions such as acid-alcohol ratio, reaction time, catalyst dosage to esterification reaction have been investigated and the optimum reaction conditions can be concluded as: the molar ratio of acetic acid to isoamylol 0.8:1, reaction time 2h, 25 % of catalyst (quality of acetic acid as benchmark). The conversion rate can reach up to 75.46%. The catalytic ability didn’t reduce significantly after reusing 10 times and the results showed that the catalyst exhibited preferably catalytic activity and reusability.

Catalytic Synthesis of Isoamyl Acetate Catalyzed by (NH4)6[MnMo9O32]•8H2O Supported Activated Carbon with Waugh Structure

2013 ◽  
Vol 781-784 ◽  
pp. 190-193
Author(s):  
Mei Xu ◽  
Hua Yuan ◽  
Wei Liu ◽  
Jian Wang ◽  
Feng Zhen Yang
Keyword(s):  
Acetic Acid ◽  
Activated Carbon ◽  
Reaction Time ◽  
Conversion Rate ◽  
Isoamyl Alcohol ◽  
Isoamyl Acetate ◽  
Catalytic Synthesis ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Optimum Reaction

The synthesis of isoamyl acetate with ammonium 9-molybdate manganese heteropolyacid salt supported activated carbon as catalyst was studied. The optimum reaction conditions are obtained as follows: isoamyl alcohol to acetic acid molar ratio = 1.646, the weight of catalyst is 40% of total weigh, m (acidulate catalyst)=0.2g, m (water carrying reagent toluene) = 3ml, reaction time is about 63 minutes. Selectivity is 100% and conversion rate is 89.48%.

The influence of laccase/histidine system on the properties of OCC pulp fibers, and of handsheets made thereof

2019 ◽  
Vol 34 (2) ◽  
pp. 211-217
Author(s):  
Yangmei Chen ◽  
Yiqian Mai ◽  
Qitang Wu ◽  
Jiaqian Kang ◽  
Yu Jiang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Physical Properties ◽  
Control Sample ◽  
Pulp Fibers ◽  
Reaction Conditions ◽  
Paper Making ◽  
Recycled Fiber ◽  
Optimum Reaction ◽  
Enzyme Dosage ◽  
Resource Shortage

Abstract For improving the physical properties of old corrugated container (OCC) fiber, the laccase/histidine system was used in this paper. Firstly, the paper studied the optimum conditions that the laccase/histidine system modified the OCC fiber, including enzyme dosage, histidine dosage, reaction time, reaction temperature, and pH. Experimental results showed that the optimum reaction conditions of laccase/histidine system for OCC pulp were: dose of enzyme 1 U·{\text{g}^{-1}}, 4 h reaction time, pH 4.5, dose of histidine 1 %. Under the optimum reaction conditions, the tensile and burst indexes of the sheet made from laccase/histidine treatment were increased by 25.2 % and 34.0 %, compared with that of the control sample. The SEM results showed that compared with the control sample, the fibrillation of the fiber modified with laccase/histidine was more obvious. Finally, the content of acid-insoluble lignin of the fiber was determined. The content of acid-insoluble lignin of the control sample was 29.2 %, and the content of acid-insoluble lignin of the fiber treated by laccase/histidine system in optimum reaction conditions was 16.0 %, which decreased by 13.2 %. Laccase/histidine system could improve the physical properties of recycled fiber, alleviate fiber decay, which are of great significance to solve the resource shortage and environment pollution of the paper-making industry.

OBTENCIÓN DE BIODIESEL POR TRANSESTERIFICACIÓN ALCALINA A PARTOR DE ACEITES VEGETALES RESIDUAL EN LIMA

2016 ◽  
Vol 26 (1) ◽  
pp. 107
Author(s):  
Linda N. Zavaleta Palomino
Keyword(s):  
Reaction Time ◽  
Potassium Hydroxide ◽  
Kinematic Viscosity ◽  
Acid Number ◽  
Optimum Conditions ◽  
Reaction Conditions ◽  
Maximum Conversion ◽  
Optimum Reaction ◽  
Optimum Production ◽  
Do So

RESUMEN El objetivo de esta investigación es conocer el proceso de producción óptimo para generar biodiesel, por transesterificación alcalina, a partir de aceites vegetales residuales de los restaurantes del distrito de San Borja, Lima- Perú. Para ello, se analizó el aceite vegetal residual recolectado, se determinó la concentración de metanol (%v/v), la concentración de hidróxido de potasio (%p/p), el tiempo de reacción óptimo, y por último se determinó la calidad del biodiesel producido.Los resultados mostraron que es posible realizar biodiesel con el aceite recolectado, ya que su grado de acidez (1,56%) fue inferior al 3%. Las condiciones óptimas para lograr la máxima conversión de la reacción se obtuvieron cuando se usó una concentración de metanol del 30%, una concentración de hidróxido de potasio del 0,4% respecto al peso del aceite y un tiempo de reacción de 3 hrs 30 min a una temperatura constante de 60°C. Bajo estas condiciones se obtuvo un rendimiento de biodiesel del 85,97%. Al biodiesel obtenido bajo las mejores condiciones de reacción se le analizaron cuatro propiedades del combustible, encontrándose que la viscosidad cinemática fue 5,5 cSt, el número de acidez fue 0,68 mgKOH/g, la ceniza sulfatada fue 0,0478 % y el carbón conradson fue 0,142%.Palabras claves.- Transesterificación alcalina, grado de acidez, máxima conversión número de acidez, viscosidad cinemática, ceniza sulfatada, carbón conradson y postratamiento del biodiesel. ABSTRACT In this paper, it is presented an experiment carried out with the objective of knowing the optimum production process in order to generate bio diesel by alkaline transesterification, from residual vegetable oils from the Restaurants in San Borja. In order to do so, first of all of the residual vegetal oil collected was analyzed, then it was determined the concentration of methanol (%v/v), the concentration of potassium hydroxide (%p/p) and the optimum reaction time, and lastly, it was determined the bio diesel quality produced.The results showed that it is possible to generate biodiesel from the collected oil, due to its grade of acidity (1,56%) was lower than 3%. The optimum conditions to get the maximum conversion of the reaction were achieved when it was used a methanol concentration of 30%, a concentration of potassium hydroxide of 0,4% regarding the weight of the oil and a reaction time of 3:30 minutes at a constant temperature of 60%. Under these conditions it was obtained a performance of biodiesel of 85,97%. Biodiesel obtained under the best reaction conditions will be analyzed four fuel properties, finding that the kinematic viscosity was 5,5 cSt, the acid number was 0,68 mg KOH / g, the sulfated ash was 0,0478% and Conradson Carbon was 0,142%. Key Words.- Alkaline Transesterification, grade of acidity, maximum conversion, number of acidity, kinematic viscosity,    sulfated ash, conradson carbon and after treatment of biodiesel

Preparation and Electrospinning of Acidified-Oxidized Potato Starch

2012 ◽  
Vol 535-537 ◽  
pp. 2340-2344 ◽  
Author(s):  
Hong Jie Wang ◽  
Xin Jin ◽  
Wen Yu Wang ◽  
Chang Fa Xiao ◽  
Lin Tong
Keyword(s):  
Reaction Time ◽  
Hydrochloric Acid ◽  
Optimum Condition ◽  
Potato Starch ◽  
Ammonium Persulfate ◽  
Modified Starch ◽  
Oxidizing Agent ◽  
Reaction Conditions ◽  
Native Starch ◽  
Optimum Reaction

This paper investigates the preparation and electrospinning of acidified-oxidized potato starch. In this article, acidified-oxidized potato starch was prepared by adding ammonium persulfate as an oxidizing agent and hydrochloric acid as a catalyst. The effect of reaction time, temperature, the concentration of hydrochloric acid and the content of ammonium persulfate on the viscosity and content of carboxyl were discussed. The optimum reaction conditions were as follows: 1.5 hours ,50°C, 0.5mol/l HCl, 2.5% (NH4)2S2O8. And then, the acidified-oxidized potato starch prepared at the optimum condition was dissolved in dimethyl sulfoxide (DMSO) to be electrospinned by contrast to native starch. Electrospinning of 5wt%-21wt% of modified starch in DMSO produced beads, beaded fibers, and smooth fibers, depending on the concentration range. Smooth fibers were observed until the concentration reached 19wt%, while native starch was 5wt%.

Improvement of Foaming Properties of Whole Egg Powder through Maillard Reaction

2012 ◽  
Vol 554-556 ◽  
pp. 1091-1094 ◽  
Author(s):  
Cui Yu ◽  
Yu Jie Chi ◽  
Wei Xu ◽  
Lei Lv ◽  
Chen Chen ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Reaction Time ◽  
Maillard Reaction ◽  
Weight Ratio ◽  
Foaming Properties ◽  
Reaction Conditions ◽  
Sh Groups ◽  
Optimum Reaction ◽  
Egg Powder ◽  
Whole Egg

In attempt to improve foaming properties of whole egg powder(WEP), WEP proteins were covalently attached to polysaccharide (maltodextrin) in a controlled aqueous solution through Maillard reaction. The optimum reaction conditions were as follows: reaction temperature was 50°C, reaction time was 120min, the weight ratio of maltodextrin:protein was 8‰. After modification, the foaming ability (FA) of WEP increased from 62.96% to 86.05%, the foaming stability(FS) increased from 20.67% to 38.97%. As the reaction proceeded, hydrophobicity and Surface SH groups increased, total SH groups and vailable lysine contents of M-WEP decreased. This results demonstrated that the Maillard reaction partially unfolds and polymerizes proteins of M-WEP and, consequently, improved foaming properties of WEP under certain controlled conditions.

Pretreatment of Herbicides Production Wastewater by Spherical Micro-Electrolysis Media

2013 ◽  
Vol 295-298 ◽  
pp. 1079-1083 ◽  
Author(s):  
Ling Zhang ◽  
Jing Liang Xie
Keyword(s):  
Reaction Time ◽  
Biological Treatment ◽  
Low Cost ◽  
Good Effect ◽  
Post Processing ◽  
Reaction Conditions ◽  
Effects Of Ph ◽  
Optimum Reaction ◽  
The Cost ◽  
Operation Cost

[Objective] The aim is to study the pretreatment effect of herbicides production wastewater by spherical micro-electrolysis media. [Method] Spherical micro-electrolysis media is preferred for the pretreatment of herbicides production wastewater and effects of PH, amount of media and reaction time on the pretreatment was investigated. The change of pre- and post-processing herbicides production wastewater was determined; the operation cost was also analyzed. [Result]The optimum reaction conditions are as follows: the PH was 3; the amount of media was 1.0kg/L wastewater; and the reaction time was 3.0h. Under the optimum reaction conditions, the removal of COD, Chromaticity and TP reached 26.3%, 86.4% and 95.6% respectively; BOD5/COD varied from 0.10 to 0.35, and the biodegradability was improved greatly; the cost of pretreatment was 1.0yuan/t, and it was lower than that of electrolysis. [Conclusion] The pretreatment of herbicides production wastewater by spherical micro-electrolysis media has good effect, low cost and no soiling hardening, so it provides a good foundation for subsequent biological treatment.

Alkylation of Phenol with Cyclohexanol Catalyzed by Acidic Ionic Liquid

2011 ◽  
Vol 233-235 ◽  
pp. 188-193 ◽  
Author(s):  
Hai Bing Yu ◽  
Jun Nan ◽  
Jing Cheng Zhang ◽  
Jian Zhou Gui
Keyword(s):  
Ionic Liquid ◽  
Catalytic Activity ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Reactant Ratio ◽  
Temperature Reaction ◽  
Reaction Conditions ◽  
Acidic Ionic Liquid ◽  
Optimum Reaction

Alkylation of phenol with cyclohexanol catalyzed by acidic ionic liquid has been investigated. The influences of reaction temperature, reaction time, reactant ratio (mol ratio of phenol to cyclohexanol), the amount and the recycle of ionic liquid on catalytic activity were studied. The conversion of phenol and the selectivity of paracyclohexylphenol were 75.5% and 61.6%, respectively, under optimum reaction conditions. The ionic liquid was utilized repeatedly over three times without remarkable loss of catalytic activity．

Synthesis of LC Intermediate Containing Trimethyl Silyl Acetylene Group

2013 ◽  
Vol 781-784 ◽  
pp. 280-282
Author(s):  
Zong Cheng Miao ◽  
Yi Wei Wang ◽  
Yuan Yuan Li ◽  
Lei Zhang ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Raw Materials ◽  
Coupling Reaction ◽  
Sonogashira Coupling ◽  
Reaction Conditions ◽  
Sonogashira Coupling Reaction ◽  
Acetylene Group ◽  
Optimum Reaction

In order to obtain the important liquid crystal intermediate with trifluoromethyl substitutent, Sonogashira coupling reaction was used to synthesize the compound. In this paper, the intermediate was synthesized by 4'-Iodo-4-pentyl-biphenyl and trimethyl silyl acetylene (TMSA) as raw materials. During the synthesis, the optimum reaction conditions were obtained, that the mol ratio of 4'-Iodo-4-pentyl-biphenyl and trimethyl silyl acetylene is 1:2, the reaction temperature is 30 oC, and the reaction time is 10 h.

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