The Research Of The Extract From Ginkgo Leaf And Lotus Leaf

Ginkgo leaf and Lotus leaf are two important plant medicines. Many research results on the chemical components and bio-activities of the plants have been reported. Nevertheless, the evaluation of bio-activity basing on molecular level has been limited.Objective:Focusing on the bio-active components in Ginkgo leaves and Lotus leaves, to research the HPLC and HPLC-MS analytical methods and preparative separation assays to the components. Basing on the free radical scavenging and lipase activity inhibition, the pharmacological activities of the components were studied on molecular levels.Methods:Microwave-assisted hydrolysis of flavonol glycosides in Ginkgo biloba leaves was studied. The hydrolysis conditions such as solvents, acids, and energy etc. were optimized. A series of macropore resins were compared on their adsorption properties for flavonoid glycosides from Gingo biloba leaves. The purification conditions to the flavone components in the leaves were optimized. Using DPPH as a model free radical, the anti-oxidant activity of the flavones was evaluated. The separation and analytical methods of alkaloids in the Lotus leaves were studied. The content levels in the Lotus leaves in the different growth periods and different areas were investigated. The lipase activity inhibition of the alkaloids was also investigated.Results:After investigating the effects of solvents, acidity, microwave power and radiation time of microwave on hydrolysis, the optimal hydrolysis conditions were obtained as follows:280W of microwave power,2 min of hydrolysis time,5.7% of hydrochloric acid in whole hydrolysis solution and n-propanol as hydrolysis solvent. After comparing different macropore adsorption resins, it could be found that the adsorption balance times of three resins to the flavones were almost same when the concentration of the flavones was 0.2395mg/ml, and the pH of the solution was 5.05. The adsorption capacity of three type resins, i.e. DM-130, LSA-10, and LSA-20, was 31.13,25.95, and 23.15mg/g, respectively. DM-130 resin owned the highest adsorption capacity. When the pH of the loading solution was 5.02, the adsorption ratio was 81%. The best choice for the eluting flavones from the resin was the 70% aqueous ethanol solution. After investigating the conditions of scavenging free radical, scavenging DPPH free radical of anti-oxidative activity of Ginkgo flavones was affected by ratio of ethanol in the solution and reactive temperature significantly. The ratio and temperature should be 70% and 50-70℃, respectively. On the HPD-100 macropore resin, the adsorption capacity of 1g of dry resin to N-nornuciferine, nuciferine, and O-nornuciferine was 5.919 mg,7.596 mg, and 0.676 mg, respectively. The aqueous methanol solution with different methanol contents had different eluting effects. A novel method has been developed for the analysis of N-nornuciferine, O-nornuciferine, nuciferine, and roemerine in leaves of Lutos by using high-performance liquid chromatography (HPLC)-photodiode array detection(DAD)-electrospray mass spectrometry (ESI-MS). The method was carried out by using a Shimadzu VP-ODS column with a gradient solvent system of 0.1% triethylamine aqueous solution-acetonitrile. N-nornuciferine, O-nornuciferine, nuciferine, and roemerine were identified with authentic standard compounds and with MS-spectra. The contents of these compounds were measured by employing DAD. Linearity of around three orders in the magnitude of concentration was generally obtained and limits of detection for these compounds were in the range of 30-90 pg. The different cone voltages under positive-ion ESI-MS for four of the alkaloids were investigated. Despite their structural similarities and the same molecular mass, N-nornuciferine and O-nornuciferine were well resolved. The signals at m/z 251 and 219 in N-nornuciferine mass spectra indicate fragments [M+H-CH3O]+and [M-2CH3O]+, respectively. The signals at m/z 265 and 250 in O-nornuciferine mass spectra indicate fragments [M+H-OH]+and [M-CH3O]+, respectively. The combination of chromatographic retention data of authentic standard compounds along with mass spectral data that exhibits both a protonated molecular ion ([M+H]+) and structurally significant fragment ions provides a relatively simple method for identification of these compounds. Using the proposed analytical method, the content changes of the alkaloids in the different growth periods and areas were identified. The results of lipase activity inhibition of the alkaloids showed that the inhibition effect of 1 mg/ml Orlistat,1 mg/ml extracts of Lutos leaves, N-nornuciferine, O-nornuciferine, nuciferine, and roemerine was 74.34%,11.25%, 21.37%,24.63%,25.77%, and 13.2%, respectively.Conclusions:Microwave-assisted hydrolysis is the optimal treatment method for the Ginkgo flavones. Macropore resins own high adsorption capacity to the Ginkgo flavones and alkaloids in the Lutos leaves and can be used as the separation medium for the purification of the components. After evaluating the bio-activities of the components, it can be seen that Ginkgo flavones have a high free radical scavenging activity and aporphine alkaloids have a significant lipase inhibition activity. This implies that aporphine alkaloids are the lead compounds of weight controlling medicines.