Studies On Extraction And Separation Of The Active Components In Chinese Medicinal Plant

The extraction of action components plays a very important role in Chinese medicine plant research. Therefore it is important to develop a fast and effective extraction method.1. The non–polar solvent dynamic microwave–assisted extraction (DMAE), was applied to the extraction of shikonin andβ,β'–dimethylacrylshikonin from root of Arnebia euchroma (Royle) Johnst.. By adding microwave absorption medium into extraction system, the non–polar solvent was heated and the target compounds were extracted. A TM010 microwave resonant cavity was employed as energy coupler and the determination of shikonin andβ,β'–dimethylacrylshikonin was performed by HPLC. Several parameters of non–polar solvent DMAE, including microwave absorption medium, extraction solvent, flow rate of extraction solvent, irradiation power and sample particle diameter were optimized separately. The extraction yields of target compounds obtained by non–polar solvent DMAE were comparable with those obtained by different extraction methods, including ultrasonic extraction (UE), soxhlet extraction (SE) and polar solvent DMAE. Compared with the other extraction methods, non–polar solvent DMAE has the more advantageous in extraction time (5min) and solvent consumption (10mL).2. A dynamic ultrasonic extraction (DUE) coupled with on-line detection by spectrophotometry was applied to determine total flavonoids (calculated against acutellarin) in Scutellaria barbata D. Don. A common self-assembled extraction vessel placed in an ultrasonic bath and a peristaltic pump used to deliver the solvent was applied in this experiment. Several parameters of DUE, including flow rate of extraction solvent, ultrasonic power and sample amount and concentration of extraction solvent were optimized. In this work an on-line method was provided with the advantages of minimum sample amount (5 mg), on-line monitoring the extraction process and time-saving (12.5 min). Compared with off-line method, the proposed method would be more convenient for obtaining continuous measurements and rapid optimization of the extraction process.