• Food Science and Biotechnology
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• v.18 no.1
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• pp.190-196
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• 2009

The inhibition effects of an Alpinia officinarum (AO, Zingiberaceae) on the formation of advanced glycation end products, aldose reductase, and scavenging effect on 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical for the prevention and/or treatment of diabetic complications were investigated. The ethyl acetate fraction of AO was the most effective among all fractions. Through the tests with electron impact-mass spectrometry and nuclear magnetic resonance, two compounds (compound 1 and 2) finally obtained from the ethyl acetate fraction of AO were identified as galangin (1) and kaempferide (2), respectively. In addition, the compound 1 and 2 and the ethyl acetate fraction were compared for the prevention effect on advanced glycation end products, aldose reductase, and the scavenging effect on DPPH radical. The ethyl acetate fraction was significantly more effective than the 2 compounds for those preventive activities.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.656-659
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• 2005

Hot water extracts of Angelica keiskei aerial parts were solvent-fractionated with ethyl acetate (EtOAc) and buffers (5% $NaHCO_3$, pH 8.0; 1.0 N HCl, pH 3.0) to obtain EtOAc-soluble acidic and neutral fractions. EtOAc-soluble neutral fraction was purified by Sephadex LH-20 column chromatography and reverse phase HPLC. Assay for purification of antioxidative compounds was performed by spraying DPPH solution on thin layer chromatography. Two isolated substances were identified as pseudoisopsoralen and 8-methoxypsoralen(xanthotoxin) by FAB-MS and NMR analyses.

• Bulletin of the Korean Chemical Society
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• v.10 no.1
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• pp.75-80
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• 1989

The approximate rates and stoichiometry of the reaction of excess potassium 9-sec-amyl-9-boratabicylco[3.3.1]nonane (K 9-sec-Am-9-BBNH) with selected organic compounds containing representative functional goups under standardized conditions (tetrahydrofuran, $0^{\circ}C)$ were examined in order to explore the reducing characteristics of the reagent for selective reductions. The reagent readily reduces aldehydes, ketones, acid chlorides and epoxides to the corresponding alcohols. However, carboxylic acid, aliphatic nitriles, t-amides, and some sulfur compounds show very little reactivity or no reactivity to this reagent. The most interesting feature of the reagent is that aromatic nitriles are reduced moderately to the corresponding aldehyde stage, wheras aliphatic nitriles are inert. In addition, the reagent shows a high stereoselectivity toward cyclic ketones at $0^{\circ}C$ and - $25^{\circ}C.$ The selectivity exhibited at $0^{\circ}C$ is comparable to that by lithium trisiamylborohydride at that temperature.

• Bulletin of the Korean Chemical Society
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• v.18 no.8
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• pp.890-895
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• 1997

The approximate rates and stoichiometry of the reaction of excess lithium tripiperidinoaluminum hydride (LTPDA), an alicyclic aminoaluminum hydride, with selected organic compounds containing representative functional groups under the standardized conditions (tetrahydrofuran, 25°) were examined in order to define the reducing characteristics of the reagent for selective reductions. The reducing ability of LTPDA was also compared with those of the parent lithium aluminum hydride (LAH) and lithium tris(diethylamino)aluminum hydride (LTDEA), a representative aliphatic aminoaluminum hydride. In general, the reactivity of LTPDA toward organic functionalities is weaker than LTDEA and much weaker than LAH. LTPDA shows a unique reducing characteristics. Thus, benzyl alcohol, phenol and thiols evolve a quantitative amount of hydrogen rapidly. The rate of hydrogen evolution of primary, secondary and tertiary alcohols is distinctive. LTPDA reduces aldehydes, ketones, esters, acid chlorides and epoxides readily to the corresponding alcohols. Quinones, such as p-benzoquinone and anthraquinone, are reduced to the corresponding diols without hydrogen evolution. Tertiary amides and nitriles are also reduced readily to the corresponding amines. The reagent reduces nitro compounds and azobenzene to the amine stages. Disulfides are reduced to thiols, and sulfoxides and sulfones are converted to sulfides. Additionally, the reagent appears to be a good partial reducing agent to convert primary carboxamides into the corresponding aldehydes.

• Bulletin of the Korean Chemical Society
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• v.16 no.5
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• pp.416-421
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• 1995

The approximate rates and stoichiometry of the reaction of excess lithium gallium hydride with selected organic compounds containing representative functional groups were examined under the standard conditions (diethyl ether, 0 $^{\circ}C)$ in order to compare its reducing characteristics with lithium aluminum hydride and lithium borohydride previously reported, and enlarge the scope of its applicability as a reducing agent. Alcohols, phenol, and amines evolve hydrogen rapidly and quantitatively. However lithium gallium hydride reacts with only one active hydrogen of primary amine. Aldehydes and ketones of diverse structure are rapidly reduced to the corresponding alcohols. Conjugated aldehyde and ketone such as cinnamaldehyde and methyl vinyl ketone are rapidly reduced to the corresponding saturated alcohols. p-Benzoquinone is mainly reduces to hydroquinone. Caproic acid and benzoic acid liberate hydrogen rapidly and quantitatively, but reduction proceeds slowly. The acid chlorides and esters tested are all rapidly reduced to the corresponding alcohols. Alkyl halides and epoxides are reduced rapidly with an uptake of 1 equiv of hydride. Styrene oxide is reduced to give 1-phenylethanol quantitatively. Primary amides are reduced slowly. Benzonitrile consumes 2.0 equiv of hydride rapidly, whereas capronitrile is reduced slowly. Nitro compounds consumed 2.9 equiv of hydride, of which 1.9 equiv is for reduction, whereas azobenzene, and azoxybenzene are inert toward this reagent. Cyclohexanone oxime is reduced consuming 2.0 equiv of hydride for reduction at a moderate rate. Pyridine is inert toward this reagent. Disulfides and sulfoxides are reduced slowly, whereas sulfide, sulfone, and sulfonate are inert under these reaction conditions. Sulfonic acid evolves 1 equiv of hydrogen instantly, but reduction is not proceeded.

• Journal of Integrative Natural Science
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• v.15 no.4
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• pp.137-144
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• 2022

This paper presents the effect of the supramolecular complex of GA (Glycyrrhizic acid) and Mt(menthol) and GA: Mt (4: 1) obtained on their basis can restore functional dysfunction of the liver mitochondria in alloxan diabetes, ie, inhibit lipid peroxidation. The hypoglycemic activity and mitochondrial membrane stabilizing properties of the supramolecular compound GA: Mt (4: 1) in alloxan diabetes were more pronounced than those of menthol, GA and its GK: Mt (2: 1) and GA: Mt (9: 1) compounds. According to the results obtained, the concentration of GA did not affect the peroxidation of lipid membranes of the liver mitochondria. However, a concentration of 15 μM of GA was found to reduce LPO (lipid peroxidation) formed by the effect of Fe²+ / ascorbate on the mitochondrial membrane by 58.0 ± 5.0% relative to control. The inhibitory effect of GA and its supramolecular compounds in different proportions with menthol on the peroxidation of lipids in rat heart and brain tissue has been studied

• Journal of Applied Biological Chemistry
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• v.66
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• pp.81-89
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• 2023

The purpose of this study is to demonstrate the potential enhancement of the flavonoid contents from Agastache rugosa, which can be obtained as raw materials for functional products in the food medicine industry by identifying important factors for efficient preparation to save costs and time in terms of economic factors. For this reason, response surface methodology using Box-Behnken design was used to optimize the extraction conditions for the maximum yield of seven major compounds from A. rugosa. The optimum conditions were obtained with an ethanol concentration of 60.0%, a temperature of 50 ℃, and an extraction time of 33.6 min, meaning that the regression analysis fits the experimental data well. Under these conditions, the seven major compounds 1-7 had observed values of 2.169, 2.135, 0.697, 2.485, 0.105, 1.247, and 0.551%, respectively. These results show that the observed values are in good agreement with the predicted values in the regression model. This process for optimization study exhibited a basic protocol for obtaining stable ingredients from A. rugosa that are appropriate for the development of effective functional products.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.230-230
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• 2006

Density functional theory (DFT) calculations using the B3LYP hybrid functional and the 6-311++G(d,p) basis set have been performed to predict the wavelength dispersion of optical absorbance and refractive indices for organic compounds and polymers in the range between the vacuum UV (${\sim}157\;nm$) and near-IR (${\sim}850\;nm$). The DFT calculations can reproduce the experimental dispersions of absorbance and refractive indices with high accuracy and low costs. The calculated dispersions demonstrate that the judicious introductions of $-F\;and\;-CF_{3}$ into alicyclic and heterocyclic compounds are effective in reducing the absorption at shorter wavelengths. In addition, the calculated Abbe numbers that represent the refractive index dispersion in the visble region are linearly proportional to the calculated refractive indices at 589 nm.

• Natural Product Sciences
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• v.20 no.4
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• pp.281-284
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• 2014

In this study, twenty-one oleanane-type triterpenoid saponins were isolated from a methanol extract of the roots of Pulsatilla koreana. Antagonistic activities were measured in these compounds by the aequorin based cellular functional assay system for the corticotropin releasing factor receptor (CRF1). Of them, compounds 7 - 10 showed the highest degree of CRF1 inhibition further at the concentration of $10{\mu}M$. Moreover, by the analysis based on the structure-activity relationship of isolated saponins, a sugar chain at C-3 and a carboxyl group at C-28, as well as a methyl group at C-23 seems to be key functional elements. To our knowledge, this is the first report on CRF1 inhibition of saponins from P. koreana.

• Rapid Communication in Photoscience
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• v.2 no.3
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• pp.76-78
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• 2013

Photoaddition reactions of aromatic carbonyl compounds with silyl thioketene acetals have been explored. The results of this study show that the acetonphenone react with dimethyl substituted silyl thioketene acetal competitively via either single electron transfer (SET)-desilylation or [2+2]-cycloaddition pathways to produce b-hydroxyester and oxetanes. In contrast, photochemical reactions of the benzaldehyde with dimethyl substituted silyl thioketene acetal mainly lead to the formation of oxetanes arising by [2+2] cycloaddition. A comparison of the results with those of silyl ketene acetal revealed that replacement of sulfur atom in ${\alpha}$-silyl donor substrate bring about dramatic changes in chemoselectivities as well as excited state reaction mechanism.