| Ligustrum Lucidum Ait is dry mature fruit of oleaceae plants. The resource of it is very rich, it has diverse chemical composition such as oleanolic acid and its isomeric ursolic acid, salidroside, aglycone tyrosol and protein, amino acids, flavonoids, polysaccharides, polyphenols, etc. Modern pharmacology study shows that Ligustrum Lucidum Ait and its active components have many activities, such a hepatoprotective, antidiabetic, antiatherosclerotic, cardiovascular protection, neuroprotective and antimicrobial action, and so on.Oleanolic acid is a pentacyclic triterpenoid compound. It has shown many biological activities, such as anti-bacterial, anti-inflammatory, antiviral, anti-tumor etc. But its bioavail ability is not high, so in order to improve the bioavailability, this paper will structural modifications were performed with natural product of oleanolic acid, to obtain a variety of oleanolic acid derivatives.The three main research contents and results are as follows:1. Determination of chemical composition of Ligustrum Lucidum Ait(1) Determination of amino acids of Ligustrum Lucidum Ait: To determine the contents of 21 free and hydrolyzed amino acids from Ligustrum Lucidum by pre-column derivatization RP-HPLC. The samples were derived with phenylisothiocyanate(PITC) and HPLC method was adopted. Gradient elution chromatography was applied to determine free and hydrolyzed amino acids contents in Ligustrum Lucidum. Results: The 21 amino acids showed good linearity in the ranges of 0.125～1.25 μmol·m L-1 with the correlation coefficients over 0.999. The average recoveries of free amino acids were 87.98%～100.09% with relative standard deviation of 0.61%～2.59%(n=6); and the average recoveries of total amino acids were 91.79%～100.03% with relative standard deviation of 0.48%～1.97%,(n=6).(2) Determination of oleanolic acid of Ligustri Lucidi Ait: To optimize of the extraction process of oleanolic acid from Ligustri Lucidi Ait under ultrasound assistance was achieved by response surface method to maximize oleanolic acid extraction ratio. The optimum conditions were found to be: ethanol concentration 95%, ultrasonic extraction time 45 min, and liquid-solid ratio 60 m L·g-1. Under these optimum conditions, the yield of oleanolic acid was 4.26%.2 Research on pharmacological activity of Ligustri Lucidi Ait(1) Research on the hypoglycemic and antioxidant activity of Ligustri Lucidi Ait: To investigate the protective effects of hypoglycemic and antioxidant activity of Ligustrum lucidum Ait on experimental diabetic. The hypoglycemic and antioxidant activity of Ligustrum lucidum Ait were determined in vitro at first, than combined STZ with high fat diet to induced diabetic mice. The mice were administered with distilled water for 3 weeks. Results showed that TC、TG、LDL-C、Hb A1c、MDA of treatment group were reduced than the diabetic group while the Insulin、HDL-C、SOD and GSH-PX of treatment group were increased than the diabetic group.(2) Research on the hypolipidemic and antioxidant activity of Ligustri Lucidi Ait: To research its antihyperlipidemic, the mice was feed high fat diet to induced hyperlipidemic mice. The results showed that no matter prophylactic administration or remedial administration, in high fat diet induced hyperlipidemic mice, oral treatment with the extract produced a decrease in the levels of serum total cholesterol(TC), triglycerides(TG), low-density lipoprotein-cholesterol(LDL-C), and increase in high-density lipoprotein-cholesterol(HDL-C) and it has highly antioxidant activity.3 Derivatization of oleanolic acid and determination of derivatives activity in vitro: Structural modifications were performed with natural product of oleanolic acid. Twenty oleanolic acid derivatives were designed and determination these derivatives activity in vitro include inhibition of alpha glucose glycosidase, ACh E, HMG-Co A, ACE and removal of nitrite ion. Results showed that majority derivatives have good activities. |
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