- 學位論文
I.抗氧化中藥材之開發 II.中藥材之品質管制
I.Antioxidant of Chinese Medicines II.Quality Control on Chinese Medicines (V) Pai-Chi
並列摘要
Lipid peroxidation, a general mechanism whereby oxygen free radicals induce tissue damage, has been implicated in diverse pathological conditions, including atherosclerosis, cardiac and cerebral ischemia, irradiation and so on. We have established a method based on the air oxidation of linoleic acid, one of the essential fatty acids, by air bubbling to screen the antioxidative Chinese herbs, and found the n-hexane extract of Angelica dahurica var. pai-chi possessed strong antioxidative activity (IC50=1.48 mg/ml), so we used silica gel chromatography to isolated the antioxidative components. The three purified compounds were identified as Cnidilin, Imperatorin and Isoimperatorin by mass and infared spectrometer as well as their physical constant. A reversed-phase high performance liquid chromatographic method is described for the determination of malonaldehyde in biological materials, liver homogenates and keratinocytes from human foreskin.The standard test for lipid peroxidation is the measurement of the pink, 532nm absorbing chromogen formed upon reaction with 2-thiobarbituric acid.This reaction depends upon the presence of the lipid peroxidation product malondialdehyde(MDA) which reacts with 2-thiobarbituric acid(TBA) to form MDA(TBA)2 adduct and absorption maximun at 532 nm.We found the anti lipid peroxidative activity for liver homogenate, IC50=4.15 mg/ml in Cnidilin, and human skin cell- keratinocytes, IC50=6.96×10-1mg/ml in Isoimperatorin. Seven coumarin,seven flavonoid and five anthraquinone compounds were screened for inhibition of rat lens aldose reductase activity, among which Daidzein and Daidzin exhibit markedly enzyme inhibitary activites with IC50 values of 4.24×10-1mg/ml and 4.71×10-1mg/ml respectively. Increased aldose reductase activity has been implicated in pathogenesis of diabetic complications so that treatment of diabetic complications with aldose reductase inhibitors may be a valid approach. The second part was quality control of Chinese herb Pai-Chi.We used HPLC method to quantify Imperatorin and Isoimperatorin. The yields of Pai Chi in different extraction conditions were investgated. We found that the solution from Pai Chi with 20 times of ethanol in 40 minutes of sonication produced the best yield. The percent of recovery was 97.2~99.2%. The percent of Imperatorin and Isoimperatorin were found in the range of 0.009~0.049% and 0.013~0.055% respectively.