• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.38 no.2
• /
• pp.118-128
• /
• 2005

Surface sediment samples from 31 stations in Jinhae Bay were analyzed to evaluate the pollution by sewage from the spatial distribution of the fecal sterol, coprostanol. The sums of eight sterols (coprostanol, epicholestanol, epicoprostanol, cholesterol, cholestanol, brassicasterol, stigmasterol and $\beta$-sitosterol) were in the range of $2,703-27,154{\cal}ng/{\cal}g$ dry weight. The concentrations of the coprostanol in the sediments, which is a good tracer of sewage-derived organic contamination, were in the range of $76-3,964{\cal}ng/{\cal}g$ dry weight. The levels of coprostanol were much higher (almost one order of magnitude) at stations close to the big cities such as Masan and Jinhae. However, those levels were comparable to or lower than those previously reported in other foreign locations. Some ratios of coprostanol to other sterols and multivariate analysis could provide us with the information on the origin of the sterols being from sewage, plankton, and/or benthos. Those showed sewage dominance at the stations near the cities Masan and Jinhae, plankton dominance at the center of Jinhae Bay and mainly marine fauna origin at the mouth of Jinhae Bay. These results suggest that the contents of sterols and some ratios of these components are quite powerful tracer for the detection of the origin of the organic contaminants in the coastal environments.

• The Korean Journal of Food And Nutrition
• /
• v.10 no.4
• /
• pp.564-573
• /
• 1997

The addition of antioxidants to fats and oils is one of the most effective ways to prevent oxidation of lipids. The popularity of natural antioxidants has increased because of the possible toxicity of synthetic antioxidants. Common natural antioxidants, tocopherols, retard oxidation at ambient temperatures, but they are ineffective at retarding oxidation at frying temperatures. The need for the development of novel natural antioxidants which are effective at frying temperatures is obvious. Sterols present in vegetable oils and certain herbal plant extracts have been reported to have antioxidant properties. Some sterols have been shown to retard thermal changes at frying temperatures. All the sterol effective at preventing oxidation at frying temperatures have an ethylidene group in their side chain. These effects can be explained by the hypothesis that sterols with a structure that allows them to react with lipid free radicals to form relatively stable free radicals are effective as antioxidants. (Key words :natural antioxidants, sterols, ethylidene group, herbal plant extracts)

• Ocean and Polar Research
• /
• v.32 no.2
• /
• pp.165-175
• /
• 2010

Dietary lipid biomarkers (fatty acids, fatty alcohols, and sterols) in adult specimens were analyzed to compare and understand the feeding ecology of the euphausiid, Euphausia pacifica, from three geographically and environmentally diverse Korean waters (Yellow Sea, East China Sea, and East Sea). Total lipid content of E. pacifica from Korean waters was about 10% dry weight (DW) with a dominance of phospholipids (>46.9% of total lipid content), which are known as membrane components. A saturated fatty acid, C16:0, a monounsaturated fatty acid, C18:1(n-9), and two polyunsaturated fatty acids, C20:5(n-3) and 22:6(n-3), were most abundant (>60% of total fatty acids) in the fatty acid composition. Some of the fatty acids showed slight differences among regions although no significant compositional changes of fatty acids were detected between these regions. Phytol, originating from the side chain of chlorophyll and indicative of active feeding on phytoplankton, was detected all samples. Trace amounts of various fatty alcohols were also detected in E. pacifica. Specifically, krill from the Yellow Sea showed relatively high amounts of longchain monounsaturated fatty alcohols (i.e. 20:1 and 22:1), generally found in herbivorous copepods. Three different kinds of sterols were detected in E. pacifica. The most dominant of these sterols was cholest-5-en-$3{\beta}$-ol (cholesterol). The lipid compositions and ratios of fatty acid trophic markers are indicative of herbivory in E. pacifica from the Yellow Sea and East Sea (mainly feeding on dinoflagellates and diatoms, respectively). The lipid compositions and ratios of fatty acid trophic markers are indicative of carnivory or omnivory in E. pacifica from the East China Sea, mainly feeding on microzooplankton such as protozoa. In conclusion, lipid biomarkers provide useful information about krill feeding type. However, further analyses and experiments (i.e. gut content analysis, in situ grazing experiment, etc.) are needed to better understand the feeding ecology of E. pacifica in various marine environments.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.46 no.4
• /
• pp.437-444
• /
• 2013

Eight fecal sterols were analyzed in surface sediments collected from shellfish farming areas in Yeoja Bay and Gangjin Bay, Korea, to evaluate sewage-derived fecal pollution. The concentrations of coprostanol, a good marker of sewage-derived organic contamination, in sediments were in the range of 10-530 ng/g-dry in Yeoja Bay, and 10-190 ng/g-dry in Gangjin Bay. Coprostanol levels were markedly higher in the inner bay than in the outer bay. These levels were lower than those reported in urbanized bays in Korea, however, they were comparable to levels in other shellfish farming areas including Gamak Bay. A multivariate analysis of the ratios of other sterols suggested that the sterols originated from sewage and plankton/benthos. Sewage was the dominant source at stations located close to the river mouth and wastewater treatment plant (WWTP) outfalls, and plankton/benthos was the primary source in the outer bay. These results suggest that management of point sources, e.g., WWTP as well as non-point sources, e.g., riverine inputs is important for improving the water quality in Yeoja Bay and Gangjin Bay.

• Korean Journal of Pharmacognosy
• /
• v.26 no.1
• /
• pp.1-7
• /
• 1995

The bark of Ulmus parvifolia Jacq. (Ulmaceae) has been used for the treatment of gonorhea, edema, scabies and eczema marginatum. Previous investigations conducted with the heartwood and leaves have demonstrated it to contain sesquiterpenes as well as fat acids from the heartwood and flavonol glycosides from leaves. However, no phytochemical work has been done on the bark parts of this plant. Investigation of the phytochemical constituents in the barks of U. parvifolia has resulted in the isolation of sterols, sterol glucoside and a catechin glycoside, $(+)-catechin\;7-O-{\alpha}-{_L}-rhamnopyranoside$, all of which were isolated for the first time from this plant. Sterols were consisted of the three components, ${\beta}-sitosterol$, stigmasterol and campesterol in a ratio of 92.1:4.1:3.8, and sterol glucoside was identified as ${\beta}-sitosterol\;3-O-{\beta}-{_D}-glucoside$. The structure of the catechin $7-O-{\alpha}-{_L}-rhamnoside$ was established primarily by analysis of $^1H-and$ COSY-45 NMR, HMQC and HMBC and EI mass spectra of the heptaacetate. Especially, HMBC spectrum provides effective way for the determination of the point of attachment of the rhamnosyl group to catechin moiety.

• Journal of the Korean Applied Science and Technology
• /
• v.10 no.2
• /
• pp.19-27
• /
• 1993

Levels of sterols including ${\Delta}^7$-dehydrogenase isolated from the tissues of marine animal products (20 species) were determined on 1.5% OV-17 columm of gas-liquid chromatography. The composition showed that the mussels and clams contained various sterols in their tissues : cholesterol, brassicasterol. 24-methylenecholesterol with some minor components such as 22-trans-norcholesta-5,22-dien-3${\beta}$-ol, 22-cis-dehydrocholesterol, 22-trans-dehydrocholesterol, desmosterol, 7-dehydrocholesterol, campesterol, stigmasterol, ${\beta}$-sitosterol, isofucosterol, and 7-dehydrocholesterol which could be converted into vitamin $D_3$ in the skin tissue of animal was present in the muscle of oyster, Crassostrea gigas. On the other hand, the others including gastropoda were predominantly composed of cholesterol. The minor sterols such as 24-methylenecholesterol, stigmasterol and ${\beta}$-sitosterol in the fish intestines are supposed to be derived from dietary plankton. Cholesterol ${\Delta}^7$-dehydrogenase which could convert cholesterol into ${\Delta}^7$-dehydrogenase was present in the pickles of Tricurus haumela intestine.

• Preventive Nutrition and Food Science
• /
• v.5 no.2
• /
• pp.109-113
• /
• 2000

In this study, a potential mechanism through which the hesperidin might work on the effect was examined in vivo. Male rats were fed a high cholesterol synthetic diet (1%, wt/wt) with hesperidin (0.1%, wt/wt) for 42 days. Activity of hepatic HMG-CoA reductase was significantly lowered by the hesperidin supplement compared to the control. Hesperidin did not significantly alter plasma or hepatic lipids, but tended to lower those lipid levels. Hesperidin also subsequently reduced the fecal neutral sterols compared to the control(253.3mg/d vs.521.9 mg/d). The inhibition of HMG-CoA reductase resulting from the hesperidin supplementation could count for the reduction in fecal neutral sterols that appears to compensate for the decreased cholesterol biosynthesis. The dose of hesperidin in a high choles-terol diet should apparently be more than 0.1% to exhibit the hypocholesterolemic response in these rats. It remains to be determined whether the observed alterations in cholesterol metabolism are specific to the rat or also could be applied to the humans.

• Journal of Nutrition and Health
• /
• v.10 no.2
• /
• pp.44-53
• /
• 1977

The Korean origin edible oil sterol part of the rape, sesame and perilla oil can be separated from the other constituents of the non-saponifiable fraction, by the thin layer chromatography on the preparative Plates. The composition of sterols have been determined by gas liquid chromatography and thin layer chromatographic anlysis. Two sterols, ${\beta}$-sitosterol and campesterol were present in all of the oils. And brassicasterol were found in rapeseed oil in addition to the two sterols that were common to all of the oils studied. It was noted that ${\beta}$-sitosterol was the major sterol in the Korean original edible oils. The results showed that contents of sterols were campesterol 24.31%, ${\beta}$-sitosterol 58.90% ana Brassicasterol 11.54%, and $\Delta^7$-sterol 5.25% by method of triangulation and campesterol 26.16%, ${\beta}$-sitosterol 57.50%, brassicasterol 11.70% and ${\Delta}^7$-sterol 4.64% by method of Planimetry of rape seed oil. By sesame seed oil sterol compositions were campesterol 20.35%, stigmasterol 9.15%, ${\beta}$-sitosterol 43.49%, ${\Delta}^7$-sterol 11.25% and others 15.76% by method of triangulation and campesterol 16.79%, stigmasterol 8.69%, ${\beta}$-sitosterol 44.58%, ${\Delta}^7$-sterol 14.28% and others 15.56% by method of planimetry. Campesterol 12.45%, stigmasteriol 5.40%, ${\beta}$-sitosterol 72.32% and ${\Delta}^7$-Sterol 9.83% by method of triangulation-and campesterol 13.00%, stigmasterol 3.76%, ${\beta}$-sitosterol 74.57% and ${\Delta}^7$ sterols 8.67% by method of planimetry of perilla oil. Contents of totalsterol in Korean edible oils were 0.82% by rape, 0.58% by sesame and 0.45% by perilla, respectively.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.2
• /
• pp.683-687
• /
• 2015

Aloe vera gel exhibits protective effects against insulin resistance as well as lipid-lowering and anti-diabetic effects. The anti-diabetic compounds in this gel were identified as Aloe-sterols. Aloe vera gel extract (AVGE) containing Aloe-sterols has recently been produced using a new procedure. We previously reported that AVGE reduced large-sized intestinal polyps in Apc-deficient Min mice fed a high fat diet (HFD), suggesting that Aloe vera gel may protect against colorectal cancer. In the present study, we examined the effects of Aloe vera gel powder (AVGP) and AVGE on azoxymethane-induced colorectal preneoplastic aberrant crypt foci (ACF) in mice fed a HFD. Male C57BL/6J mice were given a normal diet (ND), HFD, HFD containing 0.5% carboxymethyl cellulose solution, which was used as a solvent for AVGE (HFDC), HFD containing 3% or 1% AVGP, and HFDC containing 0.0125% (H-) or 0.00375% (L-) AVGE. The number of ACF was significantly lower in mice given 3% AVGP and H-AVGE than in those given HFD or HFDC alone. Moreover, 3% AVGP, H-AVGE and L-AVGE significantly decreased the mean Ki-67 labeling index, assessed as a measure of cell proliferation in the colonic mucosa. In addition, hepatic phase II enzyme glutathione S-transferase mRNA levels were higher in the H-AVGE group than in the HFDC group. These results suggest that both AVGP and AVGE may have chemopreventive effects on colorectal carcinogenesis under the HFD condition. Furthermore, the concentration of Aloe-sterols was similar between 3% AVGP and H-AVGE, suggesting that Aloe-sterols were the main active ingredients in this experiment.

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