| The dry root of Scutellaria Baicalensis Georgi has a function of clearingheat and eliminating dampness, purging intense heat and detoxifying,stopping bleeding and preventing miscarriage, etc. In addition, there areprecise clinical effects in it: anti-oxidation, anti-inflammatory, calcium ionchannel prevention, Aldose Reductase inhibition, antiviral, anti-allergic andalso protective for systems of immunity, heart-brain vessel, digestion andnerve. The modernization of Chinese Medicine is a inevitable trend for thedevelopment of traditional Chinese Medicine, as the basic research of which,the extraction and purification of active constituents plays a prominent role.Scutellaria, a Chinese herbal medicine, needs developing and usingforcefully. The optimizing of extraction and purification technology ofBaicalin is of great significance in the improvement of Baicalin.On one hand, flavonoids was extracted from Scutellaria baicalensisGeorgi with ethanol as the solvent and futher more Baicalin was separatedand purified from flavonoids. Afterwards, an anti-oxidation experiment wasmade on flavonoids and baicalin with DPPH respectively; on the other hand,Baicalin was prepared through an overall extraction, separation andpurification directly from Scutellaria Baicalensis Georgi. Results wereobtained as follows:1.An extraction technology of flavonoids was obtained. Totalflavonoids were extracted by heat reflux with ultrasonic pretreatment fromscutellaria baicalensis georgi. The technology of extraction was optimizedby orthogonal experiment with the result that ethanol55%, ratio of materialto liquid1:8, temperature85℃, time1h on the basisof the influence ofethanol concentrate, ratio of material to liquid, extraction temperature, timeon the yield of flavonoids. The yield and content of total flavonoids were33.25%,32.75%respectively;2.The separation and purification of Baicalin. Baicalin was prepared byacid precipitation and etnanol washing with extract from Scutellariabaicalensis obtained by ultrasonic pretreatment and hot refluxing ethanolextraction as materials; the technology of acid precipitation was optimizedby orthogonal experiment with the result of pH=1.5~2.0, temperature of heat preservation85℃, time of heat preservation30min, and holding time1h. The yield and content of the dried yellowish crude baicalin were10.12%,80.32%respectively with a method of UV detection. In order to achieve theminimum purity of baicalin (80%), the product obtained above need alcoholprecipitating, filtering and evaporating in addition to washing by water andethanol then coupling to pH6.5~7.0. Finally a crystalline of Baicalin(79.50%)was obtained through resolving in methanol and crystallizing fromit with HPLC;3.An overall extraction, separation and purification technology ofBaicalin. The final product baicalin was crystallized in ehanol of95%afterthe process that the resolution of flavonoids was obtained in the optimizedtechnology above, Solvent was evaporated till there was none of ethanol,the crude of baicalin was precipited in the optimized technology above amdthe further purification was made: water washing, twice; alcohol washing,little amount; coupling to pH6.5-7.0, mixed with equivalent volume ofethanol; heat preserving, precipiting, filtering and evaporating;4. An oxidation experiment of flavonoids and product of baicalin. Thereaction ratio between the extract of flavonoids and DPPH was1:3and thereaction time is20min; at the same time, the reaction ratio between theproduct of Baicalin and DPPH was1:4and the reaction time is20min whichboth met the need of clearing rate50%.The extraction and purification technology of Baicalin from Scutellariabaicalensis Georgi as well as the Baicalin product of80%are obtained.Further fefinement can meet the higher requirement of the pharmaceuticalindustry on this basis. |
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