Characterization Of Lipoxygenase Inhibitor From Jasminum Sambac
| Autor: | Yu-Hung Wang, 王玉虹 |
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| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 The objective of present study is to characterize lipoxygenase (LOX) inhibitor from jasmine. Jasmine was extracted with various solvent, and LOX inhibition activity was examined and compared. The optimal conditions of solvent extraction for LOX inhibitor were listed as follows: extracted solvent, 95 % ethanol; extraction time, 2 h. The concentration caused 50 % inhibition of LOX activity (IC50) was 0.138 mg/mL, and recovery was 8.85 %. The optimal conditions of the supercritical CO2 extraction for LOX inhibitor from jasmine were listed in the following: temperature, 50 ℃; pressure, 450 Bar; CO2 flow rate, 3 L/min; time for static extraction, 10 min.; time for dynamic extraction, 15 min.; modifer added in static extraction, 6 %, modifer flow rate in dynamic extraction, 2 mL/min. The crude extract of LOX inhibitor from jasmine was stepwise fractionated with Si and C18 column. Two fractions with higher LOX inhibition activity were obtained, and named JSB and JSB-4 respectively. The IC50 of JSB and JSB-4 was 0.036 mg/mL and 0.016 mg/mL, recovery was 4.4 % and 0.47 %. The total phenol and flavonoid content of JSB-4 was 2109.00 ± 0.06 μg/mL and 424.90 ± 0.02 μg/mL. When 15-LOX incubate with LOX inhibitor from jasmine, the amount of 15-HETE (oxidation product of 15-LOX) decrease significantly. IC50 of DPPH radical scavenging ability for JSB-4 was 0.718 mg/mL. IC50 of antioxidative activity in liposome model system for JSB-4 was 1.598 mg/mL. The IC50 for superoxide radical scavenging activity of JSB-4 was 11.62 mg/mL. Kinetics studies of JSB-4 showed the inhibition of JSB-4 on LOX belonged to a non-competitive reaction. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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