Effects of Different Sample Preparation Methods on Total Flavonoids and Puerarin Content from Puerariae Lobatae Radix and Puerariae Thomsonii Radix in South Anhui Province / 中国中医药信息杂志

ABSTRACT

Objective To establish UV spectrophotometry and HPLC methods for content determinations of total flavonoids and puerarin from Puerariae Lobatae Radix and Puerariae Thomsonii Radix; To compare the ultrasonic method at room temperature, conventional refluxing method and ultrasonic method at heating conditions at the aspect of content determinations. Methods The content determinations of total flavonoids was determined by UV spectrophotometry at 250 nm; the content of puerarin was determined by HPLC with octadecylsilane-bonded silica gel as the stationary phase, a mixture of methanol and water (2575) as the mobile phase, 256 nm as the detection wavelength, 1.0 mL/min as the flow rate. Results Contents of total flavonoids in Puerariae Lobatae Radix by ultrasonic method at room temperature, conventional refluxing method and ultrasonic method were15.09%, 14.48%, and 12.71% (n=3), respectively. The contents of puerarin were 4.37%, 4.09%, and 3.80% (n=3), respectively. Contents of total flavonoids in Puerariae Thomsonii Radix were 2.09%, 2.23%, and 2.17% (n=3), respectively. The contents of puerarin were 0.50%, 0.53%, and 0.52% (n=3), respectively. Conclusion Ultrasonic method at room temperature can replace conventional refluxing method for content determinations of total flavonoids and puerarin from Puerariae Lobatae Radix, and ultrasonic method at heating conditions also can replace conventional refluxing method for content determinations of total flavonoids puerarin from Puerariae Thomsonii Radix. Puerarin contents from Puerariae Lobatae Radix and Puerariae Thomsonii Radix in South Anhui Province are all in line with the Pharmacopoeia standards.