• Journal of Applied Biological Chemistry
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• 제52권4호
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• pp.212-215
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• 2009

The inhibitory effects of Curcuma longa rhizome-derived materials against nitric oxide (NO) production were assessed. The inhibitory effect (57%) on NO production was evidenced by the methanol extract of C. longa at $1\;{\mu}g/mL$. In the fractionation of the methanol extract, the ethyl acetate fraction evidenced an inhibitory effect greater than 62.1% at $1\;{\mu}g/mL$. The active constituent was identified as curcumin. Curcumin exerted potent inhibitory effects of 78.7 and 65.7% at concentrations of 1 and $0.5\;{\mu}g/mL$, respectively. Furthermore, the inhibitory effect of ar-turmerone was measured as 31.3 and 15.8% at 1 and $0.5\;{\mu}g/mL$, respectively. The iNOS expression-suppressive effects of curcumin were assessed via western blot analysis. Our results suggest that curcumin and ar-turmerone may prove useful in the development of new types of NO inhibitors.

• 한국미생물·생명공학회지
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• 제17권2호
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• pp.121-125
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• 1989

토양으로부터 분리되고 세포외로 pepsin 저해물질을 생산하는 Actinomycetes GF 155-2의 플라스크 배양에 의한 pepsin 저해물질 최적배양조건은 2% glucose, 0.7% polypeptone, 초기 pH7.0, 배양 60시간, 배양온도 3$0^{\circ}C$였으며 무기염의 효과는 크게 영향이 없었다. 발효조 배양물 5ι를 유안염석하여 methanol로 추출한 후 활성탄에 흡착하고 Amber-lite IR-120, XAD-2 및 silicagel 60 column chromatography한 결과 약 15mg의 무색 침상물질을 수득하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1215-1220
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• 2004

Reactive distillation (RD) is a combination process where both separation and reaction are considered simultaneously in a single vessel. This kind of combination to enhance the overall performance is not a new attempt in the chemical engineering areas. The recovery of ammonia in the classic Solvay process for soda ash of the 1860s may be cited as probably the first commercial application of RD. The RD system has been used for a long time as a useful process and recently the importance of the RD is enlarged more and more. In addition to that, the application fields of RD are diversely diverged. To make the most of the characteristic of RD system, we must decide the best operating condition under which the process shows the most effective productivity and should decide the best control algorithm which satisfies an optimal operating condition. Phosgene which is a highly reactive chemical is used for the production of isocyanates and polycarbonates. Because it has high reactivity and toxicity, its utilization is increasingly burdened by growing safety measures to be adopted during its production. Dimethyl Carbonate (DMC) was proposed as a substitute of phosgene because it is non-toxic and environmentally benign chemical. In this study, RD is used for DMC production process and the transesterification is performed inside of column to produce DMC. In transesterification, the methanol and ethylene carbonate (EC) are used as the reactants. This process use homogeneous catalyst and the azeotrope exists between the reactant and product. Owing to azeotrope, we should use two distillation columns. For this DMC production process, we can suggest two configurations. One is EC excess process and the other is methanol excess process. From the comparison of steady state simulation results where the Naphtali-Sandholm algorithm is used, it showed the better performance to use the methanol excess process configuration than EC excess process. Then, the dynamic simulation was performed to be based on the steady state simulation results and the optimal control system was designed. In addition to that, the optimal operating condition was suggested from previous results.

• 한국응용과학기술학회지
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• 제25권3호
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• pp.299-312
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• 2008

The fat of Tra and Basa catfish (Mekong Delta, Viet Nam) was evaluated for the first time as the potential feedstock for biodiesel production, due to its abundance, availability and cheap cost. The unsaturated fatty acid contents of Tra and Basa fat were 57.97% and 64.17%, respectively. Biodiesel was prepared from Tra and Basa fat by methanolysis reaction using alkali catalysts like sodium hydroxide and potassium hydroxide. Effects of various process parameters on biodiesel production, such as molar ratio of methanol to fat, catalyst concentration, temperature and time were investigated. As those results, the transesterification can be performed under moderate conditions, and the biodiesel yields were shown more than 90%. KOH catalyst was the best catalyst for biodiesel production from both Basa and Tra fat. As the feedstock aspect, Basa fat was indicated more efficiency than that of Tra fat. The maximum yield could be achieved by the transesterification from Basa fat with 5:1 molar ratio of methanol to fat, 0.8% KOH catalyst, $50^{\circ}C$, and 50 min. For Tra fat, the optimal condition were at 6:1 molar ratio of methanol to fat, 0.8% KOH catalyst, $50^{\circ}C$, and 45 min. Nowadays, due to cheaper cost and abundance, Tra fat is a promised resource for cheap biodiesel production in Viet Nam.

• 동의생리병리학회지
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• 제19권2호
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• pp.370-374
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• 2005

Streptococcus mutans (S. mutans) is known as the causative bacterial playing the most important role informing plaque and it is being noticed as major causative bacteria of dental caries. Therefore, development of more effective, substantial and safe preventive agent against dental caries and periodontal disease is honestly required. The present study was designed to investigate the effect of Cyperus rotundus (Cyperaceae) methanol extracts on the growth, acid production, adhesion, and insoluble glucan synthesis of S. mutans. The methanol extract of C. rotundus showed concentration dependent inhibitory activity against the growth and acid production of S. mutans, and produced significant inhibition at the concentration of 0.5, 1, 2 and 4 mg/ml compared to the control group. The extracts markedly inhibited S. mutans adherence to HA treated with saliva, and cell adherence was repressed by more than 50% at the concentration of 0.5 mg/ml and complete inhibition was observed at the concentration of 4 mg/ml. On the activity of glucosyltransferase which synthesizes water insoluble glucan from sucrose, methanol extract of C. rotundus showed more than 10% inhibition over the concentration of 2 mg/ml. Thus, the application of C. rotundus can be considered a useful and a practical method for the prevention of dental caries.

• 한국수소및신에너지학회논문집
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• 제31권5호
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• pp.411-418
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• 2020

A reformer is a device for producing hydrogen used in fuel cells. Among them, methanol steam reformer uses methanol as fuel, which is present as a liquid at room temperature. It has the advantage of low operating temperature, high energy density, and high hydrogen production. The purpose of this study is to improve the internal flow of the pressure vessel when a bundle of methanol steam reformer in the pressure vessel goes out to a single outlet. An analysis of equilibrium reaction to methanol steam reforming reaction was conducted using Aspen HYSYS^® (Aspen Technology Inc., Bedford, USA), and based on the results, computational analysis was conducted using ANSYS Fluent^® (ANSYS, Inc., Canonsburg, USA). For comparison of the results, the height of the pressure vessel, outlet diameter, and fillet was set as variables, and the optimum geometry was selected by comparing the effects of gravity and the amount of negative pressure.

• 한국수소및신에너지학회논문집
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• 제30권3호
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• pp.209-219
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• 2019

Methanol is a liquid fuel which could also be produced from renewable energy sources and has appreciably high energy density. In this work, we investigated the application of $Ce_{0.9}Gd_{0.1}O_{2-x}$ supported Cu and Ni catalysts for hydrogen production via methanol steam reforming. Catalysts were synthesized by solution combustion synthesis. The prepared catalysts with various active materials and Cu loading amounts were tested in a reactor at $200-300^{\circ}C$, 0-5 barg range and steam to methanol molar ratio was 1.5. The catalytic properties of Cu and Ni were compared, and the catalytic performance was shown to depend on the amounts of metal loading and operating conditions such as reaction temperature and pressure.

• 한방안이비인후피부과학회지
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• 제26권1호
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• pp.75-81
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• 2013

Objectives: Hyaluronic acid, high molecular glycosaminoglycan, exists in extracellular matrix of tissue, especially, in skin and has been known to be deeply involved in skin hydration. In this study, we investigated the effect of methanol extract of Hwang-gi, Astragalus membranaceus root, on hyaluronic acid production in human keratinocyte HaCaT cells. Methods: We determined hyaluronic acid synthase 2 gene expression and hyaluronic acid production in HaCaT cells by using RT-PCR and ELISA, respectively. Results: Hwang-gi extract didn't show the toxicity to HaCaT cells within the treated concentration and increased the hyaluronic acid synthase 2 gene expression and hyaluronic acid production. Conclusions: Hyaluronic acid production increased by Hwang-gi could be, partially, contribute to the moisturing effect in skin by it.

• 한국수소및신에너지학회논문집
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• 제15권2호
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• pp.119-128
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• 2004

DME(Dimethyl Ether) was directly produced from the synthesis gas using the slurry phase reactor. The catalyst for DME production prepared two types (A type; Cu:Zn:Al=57:33:10, B type; Cu:Zn:Al=40:45:15, molar ratio). It was evaluated for the effect of the reaction medium oil using the small size slurry phase reactor. DME production yield and the methanol selectivity decreased in the order: n-hexadecane oil> mineral oil> therminol oil. The long-term test of DME production was carried out using A and B type catalyst, and n-hexadecane oil and mineral oil, respectively. It was confirmed that the use of A type for the catalyst and n-hexadecane for the reaction medium oil was very useful for the viewpoint of the DME production form the synthesis gas.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.333-335
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• 2001

A simple control strategy of DO-stat was introduced to the recombinant rGuamerin production process in Pichia pastoris. This induction strategy consisted of two interrelated control loops ‘by which oxygen ratio of inlet gas and methanol feeding rate was controlled. Using this control strategy, over-feeding or under-feeding of methanol could be avoided in concomitance with the efficient control of dissolved oxygen level. As a result, the cell concentration reached 130 g/L and rGuamerin expression level was 450 iu/L, which was more than 40% increased result comparing with the fed-batch process using manual control of methanol feeding rate.