• The Journal of Natural Sciences
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• v.19 no.1
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• pp.45-55
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• 2008

Alzheimer's disease is charaterized by the acetylcholine depletion, amyloid b-protein aggregation and neurofibrillary tangles. The prevention of the breakdown of acetylcholine by acetylcholinesterase (AChE) inhibitor has the best clinically therapeutic efficacy for Alzheimer's disease patients. To develop new antidementia alternative drugs or nutraceuticals, methanol extracts of Sorghum bicolor was screened from various extracts of cereals and legumes as a potent AChE inhibitor-containing extract in previous paper. In this paper, physicochemical properties of the methanol extracts was investigated. The methanol extracts was soluble by water, methanol and DMSO and had 215 nm and 282nm of maximum absorption spectra. It was also stable at 20-$100^{\circ}C$ and pH 2.0-10.0 for 1 hr. Test product was prepared by using methanol extracts from Sorghum bicolor and changes of its quality during storge at $20^{\circ}C$ and $40^{\circ}C$ were investigated. It was very stable for 8 weeks at $40^{\circ}C$.

• Journal of the Korean Chemical Society
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• v.25 no.1
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• pp.7-12
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• 1981

Solvolysis of $p-CH_3, p-H, p-Cl and p-NO_2$-benzenesulfonyl chlorides have heen studied in MeOH-MeCN mixtures. A nonlinear Hammett plot with a ratio order of p-NO_2 > p-CH_3 > p-H > p-Cl was obtained; the reaction was thought to proceed by an S_N1-S_N2 borderline mechanism. In all cases the reactivity was a maximum at 90∼95%(v) methanol, whereas methanol monomer selectivity defined as fi = \frac{k1}{ki}i (k1; observed pseudo-first order rate constant: ki; hypothetical rate constant for MeOH solution having the same polymer structure as in the pure MeOH) was a maximum at 80% methanol with a decreasing order of fi as p-NO_2 > p-Cl > p-H > p-CH_3.$ This was interpreted as the decrease in tightness of transition state; the larger the fi, the tighter is the MeOH attached to the substrate, and hence the more susceptible the substrate becomes to the approaching monomer methanol.

• Food Science and Preservation
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• v.7 no.3
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• pp.291-296
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• 2000

The present study was conducted to investigate antioxidant, nitrite scavenging and alcohol degradation effects of extracts from leaf and fruit stalk of Hovenia dulcis. Yields of various solvent extracts for Hovenia dulcis leaf and fruit stalk of were higher in water and methanol extract layer, respectively. Ethanol extracts of Hovenia dulcis leaf and fruit stalk of were fractionated with different solvents such as hexane, chloroform, ethyl acetate, butanol and water, yields of water fraction were highest. In the solvent extracts using methanol, ethanol, hexane, chloroform and water, ethanol extracts showed the most effective antioxidant and nitrite-scavenging effects. Ethanol extracts from Hovenia dulcis leaf and fruit stalk of were fractionated, the most natioxidant and nitrite-scavenging effects were ethyl acetate fraction. Alcohol degradation effects from different parts of Hovenia dulcis showed higher leaf and fruit stalk than xylem, branch and seed. Alcohol degradation effects from leaf and fruit stalk increased as time passed.

• Journal of the Korean Ceramic Society
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• v.38 no.7
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• pp.660-666
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• 2001

수용계를 이용하여 졸겔법으로 중성 TiO$_2$졸을 제조하였다. 용매로 에탄올을 사용한 경우 메탄올에 비해 졸의 안정성이 우수하였다. 졸 제조시 에탄올을 사용하면, 메탄올을 용매로 사용할 경우보다 중심 금속에 부착되는 알콕시족의 크기가 작아져서 티타늄알콕사이드의 가수분해 속도가 빨라지기 때문이다. TTIP : AcAc : EtOH : $H_2O$ : PEG : HCl의 몰비가 1 : 1 : 8 : 50 : 0.5 : 0.15의 조성을 갖는 에탄올 용매 졸은 30일까지도 안정한 상태를 유지하였고 코팅성이 양호하였다. 10회 반복 침지, 건조 및 50$0^{\circ}C$에서 열처리된 두께 약 $1.5mu extrm{m}$의 TiO$_2$박막은 표면이 균질하고 치밀한 미세구조를 보였다. 제조한 TiO$_2$박막은 가시광선 영역에서 약 70%의 투과도를 나타내었다.

• The Korean Journal of Food And Nutrition
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• v.23 no.3
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• pp.318-323
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• 2010

아세틸콜린에스터라아제(AChE) 저해제에 의한 아세틸콜린 분해 억제는 알츠하이머 질병의 가장 확실한 치료 방법 중의 하나로 알려져 있다. 본 연구는 최근 웰빙 건강 소재로 각광을 받고 있는 과일과 채소로부터 새로운 AChE 저해제를 개발하여 항치매 식품이나 대체 의약품 생산에 응용하기 위해 과일과 채소로부터 AChE 저해 활성이 우수한 시료를 선별하고, AChE 저해 물질의 추출조건을 최적화하였다. AChE 저해 활성은 호두의 메탄올 추출물에서 72.6% ($IC_{50}=14.2\;{\mu}g$)로 가장 높았고, 호두의 AChE 저해 물질은 80% 메탄올로 $40^{\circ}C$에서 12시간 동안 처리하였을 때 가장 많이 추출되었다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.2
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• pp.186-192
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• 1997

Increased activities of phase 2 enzymes including quinone reductase(QR) have been reported to be associated with protection of animals from neoplastic, mutagenic, and other toxic effects of many carcinogens. In previous study, we found that methanol extract of roasted and defatted perilla meal induced the activity of quinone reductase, an anticarcinogenic marker enzyme, in murine hepalc1c7 cells. Current study showed that unroasted perilla had a limited QR-inducing activity, suggesting that roasting cause the generation of active component(s). Thus we hypothesized that QR inducer in perilla might be covalently linked to sugar moiety and released during roasting process. Methanol extract of defatted raw perilla was subject to acid treatment in order to hydrolyze the potential sugar moiety. Prolonged hydrolysis of methanol extract of defatted raw perilla at $98{\sim}100^{\circ}C$ increased the ability to induce cytosolic QR activity of hepalclc7 cells. Furthermore roasting at 180 and $200^{\circ}C$ resulted in significant induction of QR activity. The result strongly support the idea that QR inducer(s) is present in bound form in raw perilla and released during roasting. Cellular QR activity was induced proportionately with the increase of concentration of methanol extract of roasted perilla. The induction of QR by defatted perilla was also examined in the cytosols of liver, small intestine, stomach, lung and kidney of male ICR mice. Induction patterns showed specificity with respect to target tissue and roasting of perilla. Unroasted perilla meal (defatted) significantly induced QR in liver and lung, while roasted perilla meal induced QR in liver and stomach. The observation that raw perilla showed similar QR induction patterns to roasted perilla is consistent with our proposal that QR inducer(s) is present in bound form and released by physical and chemical treatments as digestive or microbial enzymes could release the inducers from inactive glycoside forms in gastrointestinal tract of mice. In conclusion, perilla could exert protective effect against chemically induced carcinogenesis by inducing phase 2 enzymes in biological systems regardless of chemical and physical process such as roasting.

• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.956-960
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• 1998

Cu-Zn and Cu-Zn-Ti catalysts for the steam reforming of methanol were prepared. This reaction was carried out at atmospheric pressure, $250^{\circ}C$, steam/methanol molar ratio 1.5, and contact time 0.1 g-cat.hr/mL-feed. In case of the catalyst with 3 mol% of $TiO_2$, the activity was superior to that of catalysts without $TiO_2$. The reaction products were mainly hydrogen and carbon dioxide. It was found that catalytic activity was not related to specific surface area but affected by metallic copper area which was measured by $N_2O$ decomposition and increased with the addition of $TiO_2$ content. XPS and XRD showed that the oxidation state of zinc was not changed during reaction, but oxidation states of copper existed in Cu(0) or Cu(I).

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2017.10a
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• pp.74-74
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• 2017

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2007.11a
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• pp.175-180
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• 2007

• Journal of the Korean Chemical Society
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• v.14 no.3
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• pp.237-242
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• 1970

Effect of Added 1-hexene on the yield of hydrogen produced from Co-60 gamma radiolysis of methanol was investigated at room temperature. The results indicated that the yield of hydrogen decreased rapidly with increasing 1-hexene concentrations. Effect of added methyl borate on the radiolysis of methanol was also studied in the presence of oxygen. The results revealved that methyl borate acted as a less effective scavenger than oxygen towards the precursors of the radiolysis products. Experimental data previously obtained on the systems with oxygen added were treated more quantitatively to re-examine mechanism of the radiolysis of methanol in detail.