Extraction And Preparations Of Reducing-blood-lipid Triterpenoids From Alisma Orientalis

The tuber of Alisma orientalis ( Sam.) Juzep is a traditional Chinese crud drug under the name of Zexie which was permitted to use as the stuff of healthy food in China in March, 2002. It has been believed to have a diuretic activity and used to remedy diabetes and swelling, recent study showed it also had the activities of anti-fatty liver, reducing blood lipid and hypoglycemia.Many researches demonstrated that the effective constituents for reducing blood lipid are triterpenoids in Alisma orientalis. With the purpose of developing healthy food for reducing blood lipid with Alisma orientalis, extensive research on triterpenoids was done, including its new extraction process and preparation. The results were as follows:1. Using single factor and orthogonal experiments, ethanol refluxing extraction, microwave pretreatment technique, enzymic treatment method, ultrasonic wave extraction and supercritical carbon dioxide extraction (SFE-CO₂) were applied to extract triterpenoids from Alisma orientalis. The optimum extraction technology was SFE-CO2. The optimal extraction conditions were as follows: the modifier dosage used for 1.5 mL per gram rhizoma powder, the extraction pressure was at 25 MPa, the extraction temperature was at 45℃, and the extraction time lasted 20min. The extract obtained by SFE-CO2 had optimum property.2. With the extract from Alisma orientalis by SFE-CO₂, the microcapsule was prepared byβ-cyclodextrin (β-CD) and spray drying, respectively. The results showed that the microcapsule prepared byβ-CD was better than that by spray drying. The optimal inclusion procedure byβ-CD were as follows: the ratio ofβ-CD and water was 7:100, the ratio ofβ-CD and extract was 6:1, stirring for 1 h at 40℃, with ethanol as solution medium, encapsulation efficiency was 61.05%. The inclusion compound was infirmed by IR scanning.3. With the microcapsule of the extract from Alisma orientalis by SFE-CO₂, the reducing-blood-lipid tablet was prepared by wetting granulating procedure. Taking the microcapsule prepared byβ-CD and the microcapsule prepared by spray drying as main components respectively, two kinds of tablets were prepared. The parameters of the tablet, such as the appearance, difference in weight, hardness and disintegrating time, met the demands of Chinese Pharmacopeia.4. With the extract from Alisma orientalis by SFE-CO₂, the reducing-blood-lipid emulsion was prepared by grinding. The optimal condition were as follows: the hydrophile and lipophile balance (HLB) of emulsifiers was 11～16.7, grinding 3 min at 25℃to prepare the first emulsion, water was added to full dosage, the mixture was grinded for 2 min. The delamination of emulsion was not observed after centrifugation (4000 r/min for 30 min). The preparation method was simple and feasible.