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Study on Extraction, Purification, Antibacterial Activity and Safety Evaluation of Ginkgolic Acid from Ginkgo Bilobal Peel

Author: HanJunCheng
Tutor: LeiHong
School: Hefei University of Technology
Course: Of Food Science
Keywords: Ginkgo bilobal peel Ginkgolic acid Purification antimicrobial safety
CLC: R284.2
Type: Master's thesis
Year: 2013
Downloads: 25
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Abstract

The ginkgo tree species in China is unique and it is also the preciousme dicinal plant resources. The ginkgolic acids exists in ginkgo bilobalpeel, ginkgo leave and gi nkgo nut. They are active ingredients worth ofresearch and deve lopment which are wi dely used in anti mi crobialpesticides, allergy, drug cosmetics and so on.In order to observe the extraction of ginkgolic acid, using ginkgobiloba l peel as the raw ma terial, et hanol as extraction solvent, and theme thod of mi xing extraction ginkgolic acid in from ginkgo bilobal peelare investigated. This study researched the optimum technologicalpurification of ginkgoli c acids from ginkgo bilobal peel through thesingle factor experime nt and orthogonal test. This study set up five singlefactor, as follows: extraction times, extracting time, extractionte mperature, ma terial to liquid rati o, ethanol concentrati on. Co mp ar edwith the standard sample of ginkgolic acid, the content of ginkgolic acidin samples was de tected by HPLC. According to the best results of eachsingle factor, we designed and then carries on the orthogonal experime nt.According to the content of ginkgo acid, we ulti ma tely get the bestextraction technology conditions through analysis of variance andverifying test:85%ethanol, ma terial to liquid ratio is1:5(W:V),extraction temperatur e60℃, extract two times, each time for5h.Underthe best extraction technology conditions, the rate of ginkgolic acids is8.95%, the purity33.34%.It is suitable for D101to purify the ginkgolic acid by carrying on thetest of different ma croporous resin column chroma tography. And also thepurification process of using ethanol extracting ginkgo bilobal peel isstudied. By carrying on the dyna mic adsorption and the desorption experiment with D101, the result indicates that the higher the sample concentration, the bigger the adsorption, and the less injection velocity is more advantageous to the adsorption. It’s a much better effect by using100%ethyl alcohol desorption, and reasonable amount of desorption liquid is10times the volume of the column (BV), and if the elution speed is smaller, the higher content ginkgolic acid can be obtained by desorption. Taking everything into consideration, it is more appropriate to select injection velocity and elution velocity for1.0ml/min. The purity of ginkgolic acid is from the extract of33.34%up to80.79%by macroporous resin purification.Ginkgolic acids were found to be bactericidal against E.coli, S.aureus and B.subtilis. The inhibitory test in vitro results indicate that ginkgolic acids has the best inhibitory effects on B.subtilis and better effects on S.aureus, but has the less suppression on E.coli. Using the doubling dilution to test the minimal inhibitory concentrations(MIC) of ginkgolic acids. The minimal inhibitory concentration(MIC) of ginkgolic acids is244.90μg/ml、122.45μg/ml and30.62μg/ml。The animal in vivo resist bacteria experiment indicated that the mouse hypodermic injection different density S.aureus, the observation mouse skin has the inflammation situation and determined causes the mouse skin inflammation with the fungus quantity, then indicated injects the0.1ml1.0×108CFU/ml S.aureus, the mouse skin infects sends the inflammation disease incidence rate100%. The clinical symptom changed obviously and appeared the obvious pathological changes of the mous, no mouse died, the mice model of S.aureus skin infections was established successfully.This study verified that the ginkgo acids has curative effect on skin inflammation of S.aureus infection. It can alleviate the clinical symptoms of infected animals, and diminished the skin damage area, the white blood cells and lymphocytes decreased obviously in the blood. Skin pathological histology observation results showed that ginkgolic acids low dose group and high dose group can obviously reduce the extent of the S.aureus skin infections in mice caused by pathological changes.The partial animal experiments on ginkgolic acids have been done, including tests of acute dermal toxicity, multiple dermal irritation, skin sensitization and skin phototoxicity for understanding safety. The acute dermal toxicity test of ginkgo acids adopted a method of set limit to ginkgo acids, then accorded to the skin toxicity grading table. There was an equivalent dosage for rats about20times of that used in clinic and showed no toxicity. The multiple dermal irritation test of ginkgolic acids accorded to the scoring table for each animal skin irritation skin stimulus intensity integral mean value of1.93, It accorded to skin stimulation intensity ratings table, there was an equivalent dosage for rats about5times of that used in clinic and showed slightly stimulus. The skin sensitization test of ginkgolic acids observed animal response, the scoring tables based on experimental skin allergic reaction and skin sensitization strength evaluation criteria, there was an equivalent dosage for rats about5times of that used in clinic and showed slightly allergenic. The skin phototoxicity test of ginkgolic acids observed the recording phenomena and skin irritation score table, there was an equivalent dosage for rats about5times of that used in clinic and showed no light toxicity. The acute dermal toxicity, multiple dermal irritation, skin sensitization and skin phototoxicity test on the guinea pig skin were carried. The results show that the ginkgolic acids possesses has no toxicity, slightly irritating and allergic, no light toxicity effects on the guinea pig skin

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CLC: > Medicine, health > Chinese Medicine > Of Pharmacy > Traditional Chinese medicine chemical > Separation and extraction of active ingredients
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