Microwave Extraction of Total Flavonoids in Herba Bupleuri by Orthogonal Test Method

Aim To extract total flavonoids from Herba Bupleuri using microwave-assisted extraction.Methods Factors influencing the extraction percentage were examined,including extraction solvent, material grade size, microwave time and power, solid-liquid ratio and pH.The orthogonal experimental design was also be used to optimize the condition.Results The optimized conditions of microwave-assisted extraction were as follows:the extraction solvent was 60% alcohol;the sample was above 120 Meshed;pH was 7~8;solid-liquid was 1∶30;the power of extraction irradiation was 640W and the extraction time was 3min.The extraction yield of total flavonoids was 8.5%,16.1% higher than that of heat recirculation of 2hours.Conclusion Microwave-assisted extraction is a rapid and efficient extraction technique for total flavonoids in Herba Bupleuri.