Studied On Chemical Constituents And Removal Technique Of Ginkgolic Acids From Leaves Of Ginkgo Biloba

The extract of ginkgo biloba leaves (GBE) has being caused people's attention by its special pharmacological activities, but its usage is restricted because there is ginkgolic acid in it. This paper is about the studies on contents of GBE by using chromatographic separation theory and identification technique. At the same time, the technological conditions of removal ginkgolic acid in the extract of ginkgo biloba leaves were studied systematically. The results as follows:The chemical constituents of leaves of ginkgo biloba were studied in this paper , 11 compounds were separated from the leaves Ginkgo biloba by chromatographic on silia gel column, and purification by recrystallization. Eight of them were identified as follow:①kaempferol②quercetin③isorhamnetin④apigenin⑤isoginkgetin⑥ginkgolide A⑦ginkgolide C⑧bilobalide.Ginkgolic acid was determined by reversed-phase high performance liquid chromatography (RP-HPLC). According to the difference of ginkgolic acid in structure and character, an RP-HPLC analytical method was developed for separation of ginkgolic acids. Effects of mobile phase constitute and acidity on retention behaviors of ginkgolic acid in column was discussed. The optimal chromatographic conditions of RP-HPLC were as follows: chromatographic column was Kromasil C18 (250mm×4.6mm, 5μm); mobile phase was Methanol: 3% phosphate liquor (93:7, V/V); UV detection wavelength was at 310nm; flow rate was 1.0ml/min and AUFS was 0.5000; column temperature was 30℃and carrying capacity was 20μl. Results indicate that the developed HPLC can be utilized as a quality control method for ginkgolic acid.On the basis of ionization theory and experiment method, lutin andр-methylsalicylic were opted for simulative object and measured pKa value of lutin andр-methylsalicylic in different ethanol, Different intensity resins were used for removal material of ginkolic acids by experiment results.Different intensity resins were compared in this paper. The results of static and dynamic process show that the D918 anion-resin is the most suitable adsorbent. Flow rate of influenced factors of separating ginkgolic acids by D918 anion-resin were studied. The best conditions were as follows: 2BV/h, ginkgolic acids 5.87mg/mL.A method of removal technology of ginkgolic acids by D918 anion-resin adsorption was reported. All kinds of influenced factors of removal ginkgolic acid by D918 anion-resin were studied. The best conditions were as follows: ginkgolic acids were removed 80% ethanol, flow rate for 2BV/h, temperature for 25℃and once again. The loss of gingko flavonol glycosides was less under the condition of the optimization removal.