• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1312-1320
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• 1998

Some commercial beef loins in raw state were packaged with PVDC as aerobic and vacuum condition. The other beef samples were cooked until core temperature arrived at $70^{\circ}C$ and then packaged immediately in the same way as the raw state. These samples were irradiated by electron beam (0, 1, 2 kGy), and then stored in refrigerator $(2{\sim}4^{\circ}C)$. Identity and quantity of cholesterol oxides were analysed at the 0, 7th, 14th day of storage. In the samples that were raw and packaged aerobically, $7{\alpha}-hydroxycholesterol,\;{\beta}-epoxide,\;7{\beta}-hydroxycholesterol$ and 7-ketocholesterol were detected over $0.5\;{\mu}g/g$. Cholestanetriol and${\alpha}-epoxide$ were detected at levels below $0.5\;{\mu}g/g$ during storage. In the samples that were raw and vacuum-packaged, $7{\alpha}-hydroxycholesterol$, 7-ketocholesterol and cholestanetriol were detected. In the samples that were cooked and packaged aerobically, cholestanetriol and ${\alpha}-epoxide$ were detected below $0.5\;{\mu}g/g$ during storage. $7{\alpha}-hydroxycholesterol,\;{\beta}-epoxide,\;7{\beta}-hydroxycholesterol$and 7-ketocholesterol were detected as $1.53{\sim}26.81,\;1.07{\sim}5.23,\;40.64{\sim}101.30\;and\;7.16{\sim}33.91\;{\mu}g/g$, respectively. In all results, total amounts of cholesterol oxide increased significantly as irradiation dose and storage time increased (P<0.05).

• Biomolecules & Therapeutics
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• v.23 no.1
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• pp.84-89
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• 2015

We investigated the question of whether 7-oxygenated cholesterol derivatives could affect inflammatory and/or immune responses in atherosclerosis by examining their effects on expression of IL-23 in monocytic cells. $7{\alpha}$-Hydroxycholesterol ($7{\alpha}OHChol$) induced transcription of the TLR6 gene and elevated the level of cell surface TLR6 protein in THP-1 monocytic cells. Addition of an agonist of TLR6, FSL-1, to TLR6-expressing cells by treatment with $7{\alpha}OHChol$ resulted in enhanced production of IL-23 and transcription of genes encoding the IL-23 subunit ${\alpha}$ (p19) and the IL-12 subunit ${\beta}$ (p40). However, treatment with 7-ketocholesterol (7K) and $7{\beta}$-hydroxycholesterol ($7{\beta}OHChol$) did not affect TLR6 expression, and addition of FSL-1 to cells treated with either 7K or $7{\beta}OHChol$ did not influence transcription of the genes. Pharmacological inhibition of ERK, Akt, or PI3K resulted in attenuated transcription of TLR6 induced by $7{\alpha}OHChol$ as well as secretion of IL-23 enhanced by $7{\alpha}OHChol$ plus FSL-1. Inhibition of p38 MAPK or JNK resulted in attenuated secretion of IL-23. These results indicate that a certain type of 7-oxygenated cholesterol like $7{\alpha}OHChol$ can elicit TLR6-mediated expression of IL-23 by monocytic cells via PI3K/Akt and MAPKs pathways.

• Food Science of Animal Resources
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• v.22 no.2
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• pp.137-144
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• 2002

Pork loins that retailed in market were used as experimental samples. Some pork samples in raw state were packaged with PVDC in either aerobic or vacuum condition. The other pork samples were cooked until core temperature reached at 70$\^{C}$ and then packaged immediately in the same way with the raw samples. After these samples were irradiated by electron beam 6 kGy, the samples were stored in a refrigerator (2∼4$\^{C}$). Identification and quantification of cholesterol oxides were performed at 0 and 7 days. The results were following. During the early stage of storage, cholesterol oxides were not produced from the raw meat samples, but with the passage of storage time,7 $\alpha$-hydroxycholesterol, 7$\beta$-hydroxycholesterol, 7-ketocholesterol, 20 $\alpha$-hydroxycholesterol, $\beta$-epoxide and $\alpha$-epoxide, which were not produced during the early stage of storage, were produced. The production of cholesterol and lipid oxidation products were significantly higher (P<0.05) in the meats with aerobic packaging than those with vacuum packaging, Cooked meat after irradiation showed 7 $\alpha$-hydroxycholesterol, 7 $\beta$-hydroxycholesterol, $\alpha$-epoxide and cholestanetriol on the 7th day of storage, although those chemicals were not produced during the early stage of storage. Production of cholesterol oxides was significantly increased (P<0.05) with the passage of storage time for all treatments, and showed significantly lower value (P<0.05) with the vacuum packaging than these for aerobic packaging. Species of cholesterol oxides from irradiated meat after cooking were similar to those from cooked meat after irradiation. Collectively, it was found that the production of cholesterol oxides was more easily affected by packaging condition than irradiation.

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.762-766
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• 1990

The effect of storage conditions on the oxidative stability of cholesterol in butter was studied by identifing cholesterol oxides by TLC. Experimental variables for storage conditions were packaging(packaged and unpackaged), storage temperature(ambient and refrigerated), light source(dark, fluorescent and ultraviolet), and storage period(2, 4, 6, and 8 weeks). No cholesterol oxides were detected from packaged butter under all storage conditions. When unpackaged butter was stored under darkness at ambient and refrigerated temperatures, cholesterol oxides were not detected even after 6 weeks of storage, but small amounts of $7{\alpha}-and\;7{\beta}-hydroxycholesterols$ were detected after 8 weeks of storage. When unpackaged butter was stored under ultraviolet light at ambient temperature, $7{\alpha}-hydroxycholesterol,\;7{\beta}-hydroxycholesterol$ cholestane-triol, and cholesterol epoxide were detected after 2 weeks of storage, and when fluorescent light was used instead of ultraviolet light, the same species of cholesterol oxides were detected after 6 weeks of storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.822-826
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• 1997

This study attempted to establish the basic data for ensuring the safety of dried Alaska pollack. The changes of such compounds in the curse of drying as cholesterol, malonaldehyde, 7-ketocho-lesterol, 7$\alpha$-, 7$\beta$-hydroxycholesterol and 25-hydroxycholesterol were analyzed. The contensts of cholesterol decreased rapidly in the samples durint sun, hot-air and frozen drying and the decreased levels of cholesterol in dried products were about 134.0~191.3mg/100gas compared with 307.1mg/100g in raw samples. 4.8~6.1$\mu\textrm{g}$/100g in dried samples. In the raw samples, oxidized cholesterols were not detected hydroxycholesterol(34.1~41.7$\mu\textrm{g}$), 7$\beta$-hydroxycholesterol(26.8~40.2$\mu\textrm{g}$/g) and 25-hydroxycholesterol(0.3~1.3$\mu\textrm{g}$/g) were detected. Frozen drying was formed to be the most effective to minimize the formation of oxidized cholesterol in Alaska pollacks.

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.767-773
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• 1990

The effect of storage conditions on the oxidative stability of cholesterol in butter was studied by quantifying cholesterol oxides by GC-MS. Experimental variables for storage conditions were packaging, storage temperature, light source, and storage period. No cholesterol oxides were detected from packaged butter under all storage conditions. When unpackaged butter was stored under ultraviolet light at ambient temperature, $7{\alpha}-hydroxycholesterol,\;7{\beta}-hydroxycholesterol$, cholesterol ${\beta}-epoxide$, cholesterol ${\alpha}-epoxide$, cholestane-triol were detected after 2, 4, 6 and 8 weeks of storage. The amounts of cholesterol oxide species produced were different depending on the storage periods. The amounts of each cholesterol oxides, $7{\alpha}-hydroxycholesterol,\;7{\beta}-hydroxycholesterol$, cholesterol ${\beta}-epoxide$, cholesterol ${\alpha}-epoxide$, and cholestane-triol, produced after 2 weeks of storage were 34.2, 14.0, 12.1, 1.30, and 0.50 ppm, respectively, and after 8 weeks of storage were 68.1, 29.1, 56,3, 8.50, and 4.00 ppm, respectively with trace amounts of 3,5-cholestadien-7-one. When fluorescent light was used instead of ultraviolet light with other conditions remained the same, the same species of cholesterol oxides were detected but with lesser amounts.

• Journal of Animal Science and Technology
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• v.44 no.1
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• pp.113-122
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• 2002

Beef loins that retailed in market were used as experimental samples. Some beef samples in raw state were packaged with PVDC as aerobic and vacuum condition. The other beef samples were cooked until core temperature arrived at 70$^{\circ}C$ and then packaged immediately in the same way of raw samples. After these samples were irradiated by electron beam 6kGy, irradiated samples were stored in refrigerator(2～4$^{\circ}C$). Identify and quantity of cholesterol oxides were analysed stored at 0 and 7 days, respectively. During the early stage of storage, 7$\beta$-hydroxycholesterol and 7-ketocholesterol were respectively produced from the raw meat samples, and the production of these chemicals were significantly higher (P$<$0.05) from the meats with aerobic packaging than those with vacuum packaging. With the passage of storage time, 7$\alpha$-hydroxycholesterol, 20$\alpha$-hydroxycholesterol, $\beta$-epoxide, $\beta$-epoxide and some other chemicals, which were not produced during the early stage of storage, were produced, Also, the production of these chemicals were significantly increased (P$<$0.05) with the passage of storage time. Cooked meat after irradiation and irradiated meat after cooking produced cholesterol on the 7th day of storage, although this chemical was not produced during the early stage of storage. Production of cholesterol oxides was significantly increased (P$<$0.05) with the passage of storage time for all treatments, and showed significantly lower value (P$<$0.05) with the vacuum packaging than aerobic packaging. Summarizing the aforementioned results, it was found that the production of cholesterol oxides was more easily affected by packaging condition than irradiation.

• Natural Product Sciences
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• v.25 no.1
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• pp.49-58
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• 2019

Eleven steroid hormones (SHs: androstene-3,17-dione, estrone, ${\beta}$-estradiol, ${\alpha}$-estradiol, testosterone, dehydroepiandrosterone, $17{\acute{a}}$-hydroxyprogesterone, medroxyprogesterone, megestrol acetate, progesterone, and androsterone) were detected from New Zealand deer (Cervus elaphus var. scoticus) velvet antler (NZA, 鹿茸 ). A method for the quantification of eleven SHs was established by using ultraperformance liquid chromatography (UPLC)-MS/MS. The linearities ($R^2$ > 0.991), limits of quantification (LOQ values, 0.3 ng/mL to 23.1 ng/mL), intraday and interday precisions (relative standard deviation: RSD < 2.43%), and recovery rates (97.3% to 104.6%) for all eleven SHs were determined. In addition, a method for the quantification of three 7-oxycholesterols (7-O-CSs: 7-ketocholesterol, $7{\alpha}$-hydroxycholesterol, and $7{\beta}$-hydroxycholesterol) in the NZA was established by using an HPLC-photodiode array (PDA) method. The linearities ($R^2$ > 0.999), LOQ values (30 ng/mL to 350 ng/mL), intraday and interday precisions (RSD < 1.93%), and recovery rates (97.2% to 103.5%) for the three 7-O-CSs were determined. These quantitative methods are accurate, precise, and reproducible. As a result, it is suggested that the five steroid compounds of androstene-3,17-dione, androsterone, 7-ketocholesterol, $7{\alpha}$-hydroxycholesterol, and $7{\beta}$-hydroxycholesterol could be marker steroids of NZA. These methods can be applied to quantify or standardize the marker steroids present in NZA.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.21-21
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• 1992

녹용은 한방에서 신경조절 약화, 신체발육부진, 허약체질 등에 사용되는 강장제로서 인삼과 더불어 중요한 약재 중의 하나이지만 아직까지 유효 성분이 밝혀져 있지 않다. 알려진 녹용의 성분으로 collagen, acid mucopolysaccharide, 중성지질, 당지질, ganglioside, 인지질, proteolipid, prostaglandins, estrone, estradiol, cholesterol, its ester, 7-keto-cholesterol, 7$\alpha$-hydroxycholesterol , 7$\beta$-hydroxycholesterol , p-hydroxy-benzaldehyde, uracil, uridine, hypoxanthine, nicotinic acid, creatinine urea 등이 보고되었다. 이와 같은 성분들은 동물조직에서 공통적으로 발견되는 것들로서 녹용의 특이성분이라 부르기 어렵다. 그러나 uracil, uridine, hypoxanthine과 같은 핵산염기 관련 성분은 녹용에 비교적 함량이 많고, 이중에서 hypoxanthine은 monoamine oxidase-B에 대한 저해작용이 있으므로 주목할 필요성이 있다.

• Food Science and Preservation
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• v.8 no.3
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• pp.338-344
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• 2001

The oxidative stability of cholesterol in tallow heated at different frying temperatures (130$\^{C}$, 150$\^{C}$, and 180$\^{C}$) was studied by identifying cholesterol oxides by thin layer chromatography(TLC). And fatty acid compositions in tallow heated were also measured and compared with cholesterol oxides. Unsaturated fatty acid contents slightly decreased as the heating time increased, whereas saturated fatty acid contents increased This phenomenon became excessive especially by heating to higher temperature. It was found that RF value and spot color of the nonsaponifiable lipids from tallow heated on TLC analysis accorded with the synthetic cholesterol oxides in this experiment. Four kinds of cholesterol oxides were detected in tallow heated for 24 hours at three different temperatures. The oxides were identified as 7-$\alpha$-hydroxycholesterol, 7-$\beta$-hydroxycholesterol, 7-ketocholesterol and cholesterol epoxide. It was found that there was a little difference in oxidative pattern of cholesterol between several heating temperatures.