Study On The Extract Technology Of Asiaticoside, 2,3,5,4'-Tetrahydroxystilbene-2-O-Beta-D-g Lucoside And Chemical Constituents In Polygonum Multiflorum Thunb.

In this essay, the extract and purification technology of asiaticoside from Centella asiatica (L.) Urb. was investigated. The optimal extraction method was investigated with the orthogonal design by using asiaticoside as index. Ethanol concentration, extract method and extract time was the three factors studied in the test. The optimal extract process was 95% ethanol refluxed for 1 hour. The extract obtained by optimal process was concentrated and solved by adequate water. Water solution was extracted by a P.ether-n-BuOH system. Concentrated n-BuOH extract was solved by MeOH, and than dripped with acetone to crystallize asiaticoside. Crude asiaticoside was purified by silica gel and eluted by chlorum-mehthol-H2O system (70:30:3). As a result, the purity of asiaticoside was up to 90.0%. PR-HPLC method to detect asiaticoside content in the extract was also established. Using zorbax C18 reserved-phase column, mobile phase as acetonitrile-water (28:72) elution, detect wavelength at 205nm. The average recovery of asiaticoside is 101.6%, and RSD is 2.43%. This method is simple and accurate for control quality of asiaicoside extract.Moreover, the extract and purification technology of 2,3,5,4'-tetrahydroxystilbene-2-O-beta-D-glucoside (THSG) from Polygonum multiflorum Thunb. was also investigated. The optimal infiltration extract method was investigated with the orthogonal design by using THSG as index. Solvent volume, soak time and velocity were three factors studied in the test. Concerned with actual conditions, the optimal extract process was that crude herb was being soaked for 24 h by 12BV water and then released at speed of 10ml/crude drug kg/min. The water extract was purified by D101 macro porous resin then. The optimal parameters were as followed: absorption ratio was 17mg THSG/ml resin, elution concentration was 25% ethanol, and elution volume was 5BV. The THSG extract purified by resin was up to 67.6%. Crude THSG was purified by silica gel in further process, which elution system was chlorum-mehthol-H2O system (200:4:3). As a result, the purity of THSG was 92.2%. PR-HPLC method to detect THSG content in the extract was also established. Using HIQ C18 reserved-phase column, mobile phase as acetonitrile-water (21:79) elution, detect wavelength at 320nm. The average recovery of THSG is 98.4%, and RSD is 2.68%. This method is simple and accurate for control quality of THSG extract.Chemical constituents from Polygonum multiflorum Thunb. were studied. By...