• 생명과학회지
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• 제8권4호
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• pp.353-359
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• 1998

This study was initiated to antioxidant activity of silybin on oxidation of human low density lipoproteins(LDL). Siltbin was extracted from Silybum marianum by the combination of fractionation and it was futher purified by silica gel column chromatography, and isolated active substances were identified silybin by IR, NMR and GC-MS. siltbin inhibited the ozidation of human low density lipoprotein(LDL) mediated by 5$^{\mu}$m CU $^{2+}$ ion in a dose dependent manner. LDL oxidation by congugated dines formation was completely inhibited by silybin at a concentration of 5$^{\mu}$M. The results provide a possibility that silybin might protect LDL against oxidation in atherosclerotic lessions.

• 한국식품위생안전성학회지
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• 제14권2호
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• pp.153-159
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• 1999

This study was undertaken to evaluate antioxidative activities of substances isolated from marine resources against human low density lipoprotein (LDL). Methanol-water extract(80 : 20, v/v) of Sargassum ringgoldianum had the highest antioxidant activity and the active substance was purified by silica gel column chromatography by eluting chlorform : methanol mixture (80 : 20 v/v). The active fraction was seperated to several spots on the TLC in chlorofrom : methanol (10 : 1, v/v) mixture. Antioxidative activity of band 4 of fraction 2 on TLC was highest than that of $\alpha$-tocopherol against human LDL oxidation by the method of thiobarbituric acid reactive substance (TBARS). The band 4 of fraction 2 inhibited the copper mediated oxidation of human LDL with almost completely at 1 or 2 mg/ml.

• 한국식품영양학회지
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• 제17권2호
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• pp.138-146
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• 2004

본 연구는 유용식물로부터 DPPH free radical scavenger및 사람의 low density lipoprotein(LDL)의 산화에 대한 항산화 효과를 조사하기 위하여 25종의 식물로부터 메탄올로 추출하여 조사하였다. 각종 유용식물 중 항산화 활성은 우수한 달맞이꽃이 가장 높았으며 다시 메타놀로 추출하여 조사한 결과 $\alpha$-tocopherol과 항산화능이 거의 비슷하였다. 메타놀 추출물을 ethylacetate로 추출한 획분이 항산화 활성이 높았으며 ethylacetate 층 중 acidic soluble 획분을 다시 분리한 후 Sepadex LH-20 column chromatography로 추출한 결과 Fraction F-2가 전자공유능이 가장 높았다. 따라서 항산화 활성이 높은Fraction, F-2의 구조를 동정한 결과 3,4-dihydroxybenzoic acid와 3-hyoxycinnamic acid로 확인되었다.

• 한국식품위생안전성학회지
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• 제12권1호
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• pp.1-8
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• 1997

This study was performed to evaluate the antioxidant activity of silymarin against human low density lipoproteins(LDL) oxidation. Silymarin extracted from Silybum marianum was successively purified with solvent fractionation and followed by silica gel column chromatography. The active substances were separated by HPLC and the isolated active substances, silymarin were identified by IR, NMR, GC-MS as silymarin. Silymarin inhibited at the 5 $\mu$M Cu2+-mediated oxidation of human low density lipoprotein (LDL) in a dose dependent manner. Silymarin completely inhibited LDL oxidation at 50 $\mu\textrm{g}$/$m\ell$ concentration. These findings suggest that silymarin may protect LDL against oxidation in atherosclerotic lessions.

• Journal of Nutrition and Health
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• 제19권5호
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• pp.296-303
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• 1986

흰쥐의 lipoprotein을 제거한 혈장내의 지질전이 활성도와 지진전이를 저해하는 활성도를 측정하였다. 지질전이 활성도의 측정은 방사성 동위원소가 함유된 cholesteryl ester (CE)와 triglyceride (TG) 로 표지된 인체의 혈장 low density lipoprotein 으로부터 high high density lipoprotein(HDL) 으로 전이되는 방사성 동위원소의 양을 측정하여 계산하였다. 지질전이 저해 활성도는 정제한 인체 혈장 지질전이 단백질에 의한 지질전이를 저해하는 정도로서 측정하였다. 흰쥐의 혈장에는 지질전이 활성도가 거의 없으나, 지질전이를 저해하는 활성도는 존재하였다. 지질전이 저해정도는 측정용액내의 lipoprotein 양이 증가할수록 감소하였다. 일반적으로 흰쥐의 HDL은 인체의 HDL에 비하여 CE 의 함량은 높으며 TG의 함량은 낮다. 흰쥐의 혈장에 인체의 혈장으로부터 정제한 지질전이 단백질을 가하여 37$^{\circ}C$에 24시간 두었을 때, HDL 로부터 very low density lipoprotein (VLDL)으로 CE가 이동하여 VLDL 의 CE 함량이 4배나 증가하였다. 반면에 VLDL로부터 HDL$_2$로TG가 이동하여 $HDL_2$의 함량은 TG함량은 9배나 증가하였다. 이와같은 현상은 흰쥐의 혈장 Lipoportein이 지질전이의 기질로서의 결함은 없음을 보여준다. 따라서 지질대사에 관한 실험에서의 흰쥐에 의한 실험결과의 해석에는 인체 혈장에 비하여 혈장에는 lipoprotein사이의 중성지질의 전이나 교환이 거의 없다는 특성이 고려되어야한다.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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• pp.44.2-44.2
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• 2007

See Full Text

• 생명과학회지
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• 제17권10호
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• pp.1330-1335
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• 2007

마늘을 발효시켜 만든 흑마늘의 지질 산화 억제 및 사람 Low Density Lipoprotein (LDL)에 대하여 항산화 활성을 실험하였다. 표준품으로서 마늘의 주성분인 alliin과 흑마늘의 에탄올과 물 추출물의 전자공여능을 각각 비교하여 측정한 결과 흑마늘 에탄을 추출물이 효능이 가장 높았다. 사람 LDL을 $Cu^{2+}$유도 LDL로 산화시킬 때 그 항산화능은 각 시료를 $10\;{\mu}g/ml$ 및 $20\;{\mu}g/ml$ 씩 첨가하며 TSARS를 측정한 결과 에탄을 추출물이 항산화 활성이 가장 높았으며 용량 의존형으로 나타났다. 흑마늘의 에탄올과 물추출물을 $10\;{\mu}g/ml$ 및 $20\;{\mu}g/ml$ 첨가한 후 J774 유도 산화에 대한 항산화 효과를 측정한 결과 각 추출물은 항산화 효과가 있었고 용량 의존형의 항산화 활성을 나타내었다. 흑마늘의 각 추출물을 이용한 실험에서 전기영동 이동상은 대조구에 비하여 $10\;{\mu}g/ml$ 및 $20\;{\mu}g/ml$에서 산화를 억제하였고 공액 2중 결합에 의한 실험에서도 항산화 효과가 있었으며 $20\;{\mu}g/ml$의 농도에서 거의 억제되었다.

• Journal of Life Science
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• 제9권2호
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• pp.57-61
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• 1999

This study was designed to develope the antioxidative activity on oxidation of human low density lipoprotein(LDL) from marine microbials. Bacillus KS-96 producign antioxidant have been isolated and identified from seawater, Bacillus sp. KS-96. The optimal medium pH was 7.0 and incubation temperature was 30$^{\circ}C$. The antiosidant of potential substance produced extracellularly in the culture broth by Bacillus sp. KS-96 was obtained by elution of silica gel culumn chromatography with hexane, ethylacetate and water. The ethylacetate faction are shown at highest level of antioxidant activity using thiocyanate method among them. By IR, NMR, and GC/MS, antioxidant purified from ehtylacetate fraction was identified and named as 2,6-dimethoxyphenol. 2,6-dimethoxyphenol inhibited the metal mediated oxidation of human LDL at concentration of 50∼100 ${\mu}$g/mL in the presence of 5uM CuSO4 with macrophage or J774 cells.

• 한국식품영양학회지
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• 제12권3호
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• pp.320-327
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• 1999

The flavonoids are one of the most numberous and widespread groups of natural consituents. The low molecular weight of benzo-${\gamma}$-pyrone derivative are ubiquitous in plants and are vegetables nuts, seeds, leaves, flowers, and bark. The flavonoids constitute of a large class of compounds ubiquitous in plants containing a number of phenolic hydroxyl groups attached to ring structures conferring the antioxidant activity. Epidemiologic studies suggest that the dietary intake of antioxidants constitutes a risk factor for vasclar disease indicating that oxidation may be important in the pathogenesis of human athero-sclerosis. Elevated plasma low density lipoprotein (LDL) cholesterol concentration are associated with accelerated atherosclerosis, LDL is oxidized by smooth muscle cells resulting in several chemicals and physical changes of LDL. Oxidized LDL is responsible for cholesterol loading of macrophages foam cells formation and atherogenesis. There have been insulficient tests of the protective effects of flavonoids against LDL oxidation to make definitive statements about their structure activity relationships. How-ever hydroxylation of the flavone uncleas can appears to be advantageous because polyhydroxylated aglycone flavonoids are potent inhibitor of LDL modification. This identification may lead to new and more effective antioxidant strategies for abrogating the atherosclerotic process the leading cause of death and disability in industrialized societies.

• 생명과학회지
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• 제7권4호
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• pp.289-296
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• 1997

Antioxidative activity of fraction extracted from cultivation of Aspergillus sp. A-5 against oxidation of human low density lipoprotein(LDL) was investigated. Fractions of Aspergillus sp. A-5 cultivation was sucessively purified with ethyl acetate and silica gel column chromatography. The concentration of fraction 4 inhibited Cu$^{2+}$-induced oxidation of LDL almost completely. Band 3 isolated by the further purification of fraction 4 was higher than that of same concentration of $\alpha$-tocopherol, BHA and BHT. The elcetrophoretic mobility of oxidized LDL by addition of Band 3 was faster than that of native LDL, but slower than that of oxidzed LDL. It is concluded that fraction of Aspergillus cultivation contained antioxidants with the capacity to inhibit oxidative modification of LDL.