Study On Extraction Kinetics And Extraction Techniques Of Flavonoids From Scutellaria Radix

Scutellaria Radix is a kind of traditional Chinese medicinal herbs which is curatively effective for some diseases. The flavonoids from Scutellaria Radix, which have important pharmacological and hygienical functions, are widely used in pharmacy, foodstuff and commodity chemical industry. Now that "returning to nature" and "green" consumption have been in fashion, extraction of functional components from officinal plants is becoming a tendency and will give birth to profound social and economic significances.The extraction kinetics for flavonoids of Scutellaria Radix was first investigated in this article. According to the kinetic models witch were established on the basis of Fick' first law & second law, the extraction kinetic models for flavonoids of Scutellaria Radix were established. The factors influencing flavonoids concentration in extracts, such as particle size, extraction temperature, liquor-solid ratio and extraction time were simulated with the 50% ethanol as solvent and the authentic Scutellaria Radix as experimental material, and the apparent diffusive velocity constant, activation potential, as well as the semi-experimental kinetic equation for flavonoids from Scutellaria Radix were obtained. The model parameters were determined and the models were validated by means of rational treatment. The experimental results proved that the models could preferably describe the kinetic process; the relative errors occurred between calculational values and experimental values were less than 10%.Reflux extraction method was introduced to study the influences of extraction time, extraction temperature, particle size of the matrix and liquor-solid ratio on yields and contents of four kinds of predominant flavonoids from Scutellaria Radix with 50% ethanol as extraction solvent. The results proved that extraction time and temperature were the two main influencing factors. By means of quadratic orthogonal regression experiments, the technologic parameters were optimized and the regression equations concerning extraction time, temperature, particle size and liquor-solid ratio were educed. The optimal technologic parameters were: extraction time, 2.0 h; extraction temperature, 62.3℃; powder granularity, 80 mesh; liquor-solid ratio, 27.3 mL/g; the highest yield of flavonoids was 12.52%. The relative errors occurred between calculational values and experimental values were less than 10%.Airtight digestion/extraction system was adopted to investigate the factors influencing on percentage extraction of flavonoids from Scutellaria Radix, such as solvent nature, extraction temperature, extraction time, liquor-solid ratio, powder granularity and microwave power. Single factor experiments were conducted to evaluate the solvent nature, liquor-solid ratio, extraction temperature, extraction time, microwave-power output and powder granularity. The results indicated that solvent nature, extraction temperature and extraction time were the dominating factors influencing on percentage extraction of flavonoids from Scutellaria Radix percentage extraction. The microwave-assisted extraction techniques were optimized with 4-factor quadratic orthogonal regression experiments and the regression equations concerning ethanol concentration, temperature, time and liquor-solid ratio were educed. The analysis results on regression equations indicated that the ethanol concentration is the most effective factor to the percentage extraction; the interaction between ethanol concentration and liquor-solid ratio is the mostremarkable. The optimal technologic parameters were: ethanol concentration, 47.9%; extraction time, 3.4 min; extraction temperature, 88.3℃; liquor-solid ratio, 25.0 mL/g; the highest the percentage extraction of flavonoids was 97.52%. The relative errors occurred between calculational values and experimental values were less than 1.6%.The in vitro bacteria-restraining effects of different Scutellaria Radix extracts on Staphylococcus aureus, avaian Escherichia coli, pig coliform, Salmonella pullorum, Bacillus sablils and the prophylaxis...