• Korean Journal of Pharmacognosy
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• v.30 no.4
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• pp.384-396
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• 1999

Acyl-CoA: Cholesterol Acyltransferase (ACAT) is a key enzyme responsible for cholesteryl ester formation in atherogenesis and in cholesterol absorption from the intestines. In addition under pathological conditions, formation and accumulation of cholesteryl ester as lipid droplets by ACAT within macrophages constitute a characteristic feature of early lesions of atherosclerotic plaques. ACAT inhibitors are expected to be effective for treatment of atherosclerosis and hypercholesterolemia. ACAT inhibitors of natural origin have been rarely reported. In our screening program for ACAT inhibitors, 303 plants were extracted with methanol or ethanol, and screened for the inhibitory activity against ACAT from the rat liver microsome. Extracts of 13 plants including Quercus aliena, Diospyros kaki, Platycarya strobilacea and Hibiscus syriacus inhibited more than 90% of ACAT activity and 43 samples in alcohol extracts such as Magnolia obovata and Panax ginseng also inhibited more than 70% of ACAT activity at a concentration of $100\;{\mu}g/ml$.

• The Korean Journal of Food And Nutrition
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• v.11 no.5
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• pp.542-549
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• 1998

Dietary orotic acid is known to induce the fatty liver. Fatty acid profiles in the lipid fraction of the liver and the serum in rats fed with or with orotic acid diet were analyzed. In all the hepatic lipid fraction of rats fed on the supplemented orotic acid diet, there was a significant increased in linoleic acid. In addition, linoleic acid was also increased in the triacylglycerol fraction of hepatic endoplasmic reticulum and the triacylglycerol and diacylglycerol fractions of hepatic Golgi apparatus of the orotic acid-feeding rats. In the time course study of the fatty acid profile in the hepatic triacylglycerol and diacylgycerol fractions, an increase of linoleic acid was observed similarly in the initial stages of orotic acid intake in the both fractions. However, linoleic acid in the serum triacylglycerol fraction of orotic acid-feeding rats increased from day 1, but it began to decrease the increment from day 2, resulting in the lower level of linoleic acid in the serum triacylglycerol fraction of orotic acid-feeding rats than that of rat fed a orotic acid-free diet after 10 days. Oleic acid (18:1) was increased in the only cholesteryl ester fraction of helpatic. However, oleic acid level in other fractions was not changed. The compositions of 14:0, 16:0 and 18:0 was reduced in the hepatic triacylogylcerol, diacylglycerol and cholesteryl ester fractions by orotic acid-feeding. However, these saturated fatty acids were significantly increased in the serum triacylglycerol fractions. The orotic acid indcued changes in linoleic acid level in hepatic triacylglycerol may be explained by the impaired fatty acid metabolism and limited excretion of this fatty acid from liver to serum.

• Korean Journal of Pharmacognosy
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• v.31 no.2
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• pp.149-156
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• 2000

Atherosclerosis is emerging as one of the major causes of death in Korea as well as Western societies. In the present study; hypocholesterolemic and antiatherogenic effects of the ethanol extract of Allium victorialis Makino was investigated using the conventional rabbit and the cholesteryl ester transfer protein (CETP)-transgenic mouse model. Hypercholesterolemia was induced by feeding high cholesterol diet to the animals for 30 days and they were then fed with high cholesterol diet containing 0.5% of the A. victorialis extract for additional 30 (or 40) days. In the experiment using rabbits, treatment with the A. victorialis extract significantly decreased plasma total cholesterol, low density lipoprotein (LDL)-cholesterol, triglyceride levels and lipid peroxidation compared to those in the control group. Total cholesterol contents in the liver and the heart were also significantly decreased. Lipid staining of the aorta isolated from the rabbits showed that treatment with the A. victorialis extract decreased formation of atheromatous plaques on the intima of the aorta. In the experiment employing CETP transgenic mouse model, treatment with the A. victorialis extract decreased the levels of plasma total cholesterol and the tissue triglyceride levels in the heart. These results demonstrated that the ethanol extract of A. victorialis lowered serum cholesterol levels, tissue lipid contents and accumulation of cholesterol in the artery.

• Journal of Nutrition and Health
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• v.19 no.5
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• pp.296-303
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• 1986

Rat lipoprotein-deficient plasma possessed a lipid tramsfer inhibitory activity when it was added to purified human plasma lipid transfer protien, while it lacked a lipid transfer activity. Incubation of whole rat plasma with partially purified human lipid transfer protein resulted in big changes in lipid distribution of rat plasma lipoproteins. There w was a 4-fold increase in cholesteryl ester(CE) and 4 47 % reduction in triglyceride(TG) in very low density lipoproteins after 2싹lour incubation. In high density lipoprotein $2(HDL_2)$ there was a 9­fold increase in TG and 33 % reduction in CEo HDL3 had 82 % reduction in CE. The result indi­c cates that the absence of the lipid transfer activity in rat plasma can be ascribed not to the inability of rat lipoproteins to serve as substrates but to the lack of 야Ie lipid transfer protein in rat plasma. Th­e erefore, species differences in lipid transfer betwe­e en lipoproteins should be taken into consideration to interpret results of studies on lipoprotein m.eta­b bolism using rats.

• Journal of Life Science
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• v.8 no.4
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• pp.381-386
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• 1998

This study was designed to observe the effects of the feeding Gentiana scabra Bunge var.buergeri Max. extract on the improvement of the blood glucose, lipids in the serum of streptozotcin(55mg/kg of body weight, I.P. injection) induced hyperglycemic rats (S.D. strain, ) fed the experimental diets for 4 weeks. Concentrations of blood glucose were significantly higher in the streptozotocin administration(I.P.) groups (group 2(streptozotcin+water), 3(streptozocin+Gentiana scabra Bunge extract), 4(streptozotocin+cholesterol+water), 5(streptozotocin+cholesterol+Gentiana scabra Bunge extract) than those in the control group(group 1(water)). Bolld glucose concentrations were rather lower in the group 3(streptozotocin+Gentiana scabra Bunge extract)than in the group 2(streptozotocin+water), and then those of the group 5 were rather lower than in the group 4. There was almost little significance among the groups. concentrations of total cholesterol in serum were lower in the group 5 than those in the group 4, and the group 3 were rather lower than in the group 2. Concentrations of LDL-cholesterol in serum were significantly lower in the group 3 than those 2. In the ratio of HDL-cholesterol concentrations to total cholesterol concentrations, Gentiana scabra Bunge extract administration groups were higher percentage than the other goups. Concentrations of free cholesterol and cholesteryl ester in serum were rather lower in the groups 3,5 than the other groups, and then those of the group were higher percentage than the other groups. concentrations of free cholesterol and cholesteryl ester in serum were rather lower in the groups 3,5 than the groups, and then those of the group 3 were significantly lower than in the group 4. Concentrations of triglyceride and phospholipid in serum were decreased in the group 3 than in the other groups. The activities of aspartate aminotransferase and alanine aminotransferase in serum were increased in the all experimental groups than in the control group. From the above research, the Gentiana scabra Bunge var.buergeri Max. extracts were effective on the improvement of the lipid compositions in serum of streptozotcin induced hyperglycemic and hypercholosterolemic rats.

• Journal of the Korean Chemical Society
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• v.35 no.1
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• pp.85-89
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• 1991

Various sterols and uncommon fatty acids have been isolated from the three species of Korean marine sponges. Odd-numbered pentadecanoic, heptadecanoic methyl ester and branched 12-methyltetradecanoic, 14-methylpentadecanoic, 15-methylhexadecanoic and 14-methylhexadecanoic methyl ester were isolated along with common tetradecanoic and hexadecanoic methyl ester from Heteropiidae sponge Vosmaeropsis japonica Hozawa collected from Sohuksan island of the Korea sea. Futher elution with more polar solvent gave 5${\alpha}$-cholestan-3${\beta}$-ol along with minor amount of ergost-25-ene-3${\beta}$,5${\alpha}$,6${\beta}$-triol. On the other hand, marine sponge Hymeniacidon sinapium collected from Yesu Dolsan island of the Korea sea was shown to contain 5${\alpha}$-cholestan-3${\beta}$-ol, along with minor amount of cholesterol, palmitic, palmitoleic, oleic, stearic, linolenic, and arachidonic acid ethyl ester. Unknown marin sponge collected from the same region was shown to contain large amount of tetradecanoic tetradecyl and hexadecyl ester and cholesteryl acetic and fatty acid ester.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.87-92
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• 1996

This study describes a stable and simple method for the measurement of cholesteryl ester transfer protein(CETP) activities using reconstituted HDL and LDL as substrates. Apolipoproteins (apo) A-I and -B were purified from hog plasma by a new strategy without ultracentrifugation and delipidation. a simple two-step column chromatography was administered. In the first step of phenyl-sepharose CL-4B column chro-matography, hydrophobic plasma proteins were isolated. The most hydrophobic proteins bound to the column appeared to be A-I and apo-B. Contaminat proteins were efficiently eliminated from the sample by washing the column with 0.3M NaCI containing buffer after loading the plasma on the column. Two pure proteins showing each single band on SDS-PSGE of apo A-I and apo-B were individually obtained by a subsequent gel filtration column chromatography(Sephadex G-200). This two-step purification was simple and inexpensive compared to the ultracentrifugation and/or delipidation method that are most commonly used. Reconstituted hight-density lipoproteins(HDL) and low-density lipoproteins(LDL) were prepared using the purified apo A-I and-B, respectively. When these artificially prepared HDL and LDL were used in the assays for CETP as the cholesteryl ester(CE) donor and acceptor respectively, the specific transfer of CE increased up to two fold compared to that used the native HSL and LDL.

• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.813-820
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• 2019

The influence of cholesterol on the physicochemical properties of the oleic acid was clarified through the measurements of density, viscosity, IR, $^1H$ NMR, self-diffusion coefficient for the oleic acid samples containing a small amount of additives such as cholesterol, cholestanol, cholestane, cholesteryl oleate, benzene, and ethanol. Cholesterol, possessing one OH group and one double bond in its molecular structure, largely increased the viscosity and reduced the self-diffusion coefficient and the intramolecular movement of oleic acid. Oleic acid forms a complex with cholesterol as well as with ethanol. On the basis of these complex formations and the existence of the clusters composed of oleic acid dimers, it was known the role and the fundamental mechanism of cholesterol to the intermolercular and intramolecular movements of oleic acid in the liquid state.

• KIEE International Transactions on Electrophysics and Applications
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• v.11C no.4
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• pp.133-137
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• 2001

In this research, we synthesized various photo-crosslinkable polyimide based polymers. The control of pretilt angles for a nematic liquid crystal (NLC) using the photodimerization method on the photopolymers was studied. A good thermal stability of the photopolymers was measured by thermogravimetric analysis (TGA) measurement until 450C. High pretilt angles of the NLC were otained by polarized UV exposure on the photopolymers containing biphenyl (BP), decyl (de), and cholesteryl (chal) groups, respectively. However, low pretilt angles of the NLC were measured by polarized UV exposure on the photopolymers containing fluorine and chalcone groups. The high NLC pretilt angles generated are attributable to the biphenyl and alkyl moieties, and the photodimerized chalocone group of the photopolymers. Additionally, good voltage-transmittance and response time characteristics were observed by UV exposure on the photopolymers.

• Korean Journal of Pharmacognosy
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• v.12 no.1
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• pp.12-14
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• 1981

${\beta}-Sitosteryl-3-O-{\beta}-D-glucopyranoside$ was isolated from the seeds of Plantago asiatica (Plantaginaceae). The assignments of $^{13}C$ NMR spectra of ${\beta}-sitosterol$ and ${\beta}-sitosteryl-3-O-{\beta}-D-glucopyranoside$ were made by comparing with $^{13}C$ NMR spectra of cholesterol and $cholesteryl-3-O-{\beta}-D-glucopyranoside$. Our data indicate that the revision of previous $^{13}C$ NMR spectral assignment is needed.