• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.94-98
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• 1982

Present investigation was carried out to clarify chemical characteristics, lipid composition, fatty acid components and the sterol composition of the lipids from the fresh-water cockle, Corbicula slatier. The results obtained are as follows :1) The oil content, iodine value and unsaponifiable matter of the total .lipids were 2.17, 119 and $16.6\%$ respectively. 2) The main components of the total lipids were phospholipids (ahout $43\%$), triglyceride and sterol. 3) The main fatty acids of the total lipids were $C_{16:0}\;(48.4\%),\;C_{14:0}\;(10.0\%),\;C_{18:3}\;(8.3\%),\;C_14:1\;(5.4\%)\;and\;C_{18:1}\;(5.3\%)$. 4) Sterols found were 24-methylenecholesterol ($14.1\%$), $\beta-sitosterol(22.5\%)$, fucosterol ($14.9\%$), isofucosterol (?) ($14.0\%$), $\Delta^7-avenasterol (?)(5.2\%)$ and cholesterol ($2.3\%$).

• BMB Reports
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• v.30 no.5
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• pp.370-377
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• 1997

A novel assay method is described for rapid quantitation of reaction rate of sterol ${\Delta}^7$-reductase (${\Delta}^7$-SR) which catalyzes reduction of the ${\Delta}^7$-double bond of sterols. Of six different organ tissues-liver, small intestine, brain, lung, kidney, and testis-. ${\Delta}^7$-SR activity was detected only in liver (2.30 nmol/min/mg protein) and testis (0.11 nmol/min/mg protein). Using a newly developed method which employs diet-induced enzyme proteins and ergosterol as substrate, we assessed both kinetics ($K_m=210\;{\mu}M$, $V_{max}=1.93\;nmol/min/mg$) and inhibition of the rat hepatic ${\Delta}^7$-SR against well-studied cholesterol lowering agents such as triparanol ($IC_{50}=16\;{\mu}M$). 3-$\beta$-[2-(diethylamino)ethoxy]androst-5-en-17-one (U18666A) ($IC_{50}=5.2\;{\mu}M$), and trans-1.4-bis(2-chlorobenzylaminomethyl)cyclohexane dihydrochloride (AY-9944) ($IC_{50}=0.25\;{\mu}M$). Of the three well-known AY-9944-sensitive cholesterogenic enzymes (i.e., ${\Delta}^7$-SR, sterol ${\Delta}^8$-isomerase, and sterol ${\Delta}^14$-reductase). ${\Delta}^7$-SR was found to be the most sensitive enzyme with a noncompetitive inhibition of this compound ($K_i=0.109\;{\mu}M$). Substrate specificity studies of the microsomal ${\Delta}^7$-SR indicate that the relative reaction rate for 7-dehydrocholesterol and ergosterol are 5.6-fold and 1.6-fold higher than that for lathosterol. ${\Delta}^7$-SR activity was also modulated by feeding rats a diet supplemented with 0.5% ergosterol (>2.6-fold) in addition to 5.0% cholestyramine plus 0.1% lovastatin ($\simeq$5.0-fold). Finally, microsomal ${\Delta}^7$-SR was solubilized by 1.5% 3-[3-(cholamidopropyl)-dimethylammonio]-1-propanesulfonate (CHAPS) and enriched on PEG (0~10%) precipitation, which should be suitable for further purification of the enzyme.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.770-775
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• 2014

The green microalga of the genus Nannochloropsis (class Eustigmatophyceae) is a leading candidate for biofuel production due to its ability to accumulate high oil content (28.7% of cellular ash-free dry weight). We investigated the anti-inflammatory and anticancer activities of sterol-rich fraction from nannochloropsis oculata n-hexane (NOH) extract after saponification of the microalga. Among the fractions with n-hexane, chloroform and ethyl acetate, the n-hexane fraction showed the highest anti-inflammatory activity in LPS-stimulated RAW 264.7 macrophage as well as anticancer activity against human leukemia HL-60 cells without the cytotoxity. And the sterol-rich fraction was obtained from the n-hexane fraction by open silica column under the gradient solvent condition with 100% hexane (1L), hexane : ethyl acetate (20 : 1, 10 : 1, 5 : 1, 1 : 1, v/v). Among the four fractions (NOH-1~4), especially NOH-1 contained the highest content of sterols. NOH1 showed the highest HL-60 (about 85%) and NO inhibitory activities at the concentration of $100{\mu}g/mL$. These results demonstrated that the sterol-rich fraction from N. oculata might be a useful candidate as anti-inflammatory and anticancer agents for anti-inflammatory and anticancer activity.

• Korean Journal of Plant Resources
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• v.12 no.3
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• pp.192-197
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• 1999

The contents of total lipids and their components of brown rice grain were studied for 5 colored rice cultivars, 1 aromatic rice cultivar and 1 normal rice cultivar grown in Korea. The total lipid contents ranged 2.04 to 4.69% based on total dry weight. The Tohoku #149 showed the highest content which was followed by Hansanheukmi and Sanghaehyang-hyeolna. The lowest content were observed in three cultivars, Heuknambyeo, Hyangnambyo and Dongjinbyeo which showed no difference among cultivars. The main classes of the total lipid were triglyceride, diglyceride, free sterol, free fatty acid and sterol esters in all cultivars examined. The ratio of triglyceride in total lipid was high in colored rice and aromatic rice compared to Dongjinbyeo which is normal rice cultivars, but the ratio of diglyceride was high in Dongjinbyeo. The major fatty acid compositions in the cultivars examined were linoleic acid, oleic acid and palmitic acid. There was a varietal difference in fatty acid composition, for example, erucic acid was detected in aromatic and colored rices cultivars, while none of this compound was found in Dongjinbyeo.

• KSBB Journal
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• v.16 no.1
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• pp.76-81
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• 2001

Stigmastanol, a functional agent of cholesterol-lowering in humans, was synthesized from stigmasterol. To investigate the usability as a raw material, the contents of sterol in vegetable oils and extract of soybean chaff were analyzed. The total sterol contents showed high values of 213.7 and 209.8 mg/100g in corn and soybean oils respectively. The extract of soybean chaff has played a good role as a raw material with high sterol contents. The kinetics of hydrogenation of stigmasterol was studied using a 5% Pd/AC catalyst in the temperature range of 30~$60^{\circ}$C. Increasing temperature showed a prominent decrease in conversion. The optimum temperature was $40^{\circ}$C for high yield of stigmastanol. The effects of $H_2$ pressure, agitation speed, catalyst loading, and stigmasterol concentration on reaction rate profile were also examined. From the power law model analysis using the initial rates of reaction, the reaction order was calculated as 0.705 for stigmasterol concentration and 0.147 for hydrogen pressure.

• Korean Journal of Pharmacognosy
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• v.31 no.1
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• pp.39-44
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• 2000

A sterol mixture, 3-O-glucosides of these sterols, 6'-O-fattyacyl ester of these sterol glucosides, kaempferol, quercetin and isoquercitrin were isolated from the whole plants of Hypericum ascyron L. The sterols were found to be a mixture of ${\beta}-sitosterol$, campesterol and stigmasterol by GC-MS. The kinds of fatty acids linked at 6'-OH of sterol glucoside ester mixture were shown to be palmitic acid, stearic acid, oleic acid and linoleic acid by GC-MS. Three flavonoids were identified by spectroscopic methods and comparisons of mixed mp and co-TLC with authentic specimens.

• Archives of Pharmacal Research
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• v.26 no.4
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• pp.275-278
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• 2003

A new acylglycosyl Sterol (4) was isolated from the MeOH extract of Quisqualis Fructus together with four known compounds. On the basis of spectroscopic data, their structures were elucidated as clerosterol (1), betulinic acid (2), methylursolate (3), 3-Ο-[6 -Ο-(8Z-octadecenoyl)-$\beta$-D-glucopyranosyl]-clerosterol (4) and $\alpha$-xylofuranosyluracil (5).

• Journal of Ginseng Research
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• v.9 no.1
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• pp.64-71
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• 1985

Free and esterified sterols in neutral lipid fractionated from the free lipid of Korean white ginseng (Panax ginseng C.A. Meyer) were analyzed by TLC and GLC to investigate the contents and composition ratios. Content of each sterol was as follows: ${\beta}$-sitosterol was about 51.60 mg%, stigmasterol, 8.93mg% and campesterol, 2.17mg%. Fine root tended to have slightly higher contents of sterols than main root. Linoleic and palmitic acid as the major fatty acids in esterified sterols occupied 70% of the total composition.

• Microbiology and Biotechnology Letters
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• v.22 no.4
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• pp.340-346
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• 1994

Six bacterial strains capable to grow on medium containing cholesterol as sole carbon source were isolated from soil, pork fat and cheese. Three of them were tentatively identified as Rhodococcus species, Rhodococcus sp. CD-1, R. sp. CD-2, and R. sp. CD-3. All the isolates showed a varying amount of cholest-4-en-3-one as the degradation product, and three strains of Rhodococcus spp. showed rapid degradation of cholesterol. Radioisotopic studies revealed that cholesterol was degraded to non-sterol hydrophilic compounds via cholest-4-en-3-one, and presumably to C0$_{2}$- These strains showed two distinct patterns in further degradation of cholest-4-en-3-one. By one group, R. sp. CD-1 and R. sp. CD-3, cholest-4-en-3-one was rapidly converted to non-sterol inter- mediates without significant accumulation of sterol derivatives in the culture broth. In contrast, by another group, R. sp. CD-2, the substantial amount of cholest-4-en-3-one was accumulated indica- ting a lower conversion of the compound to the next metabolites.

• The Korean Journal of Mycology
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• v.7 no.2
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• pp.87-90
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• 1979

Attempts were made to investigate sterol components of Schizophyllum commune Fr. which is one of medicinal fungi and grows wildly in Korea. Its carpophores were collected in Mountain Gwanak and extracted with chloroform and methanol. A sterol was isolated and identified as ergosterol by TLC, GLC and chemical tests.