Abstract: Objective: To optimize conditions for simultaneous microwave-ultrasonic assisted extraction of phenolic compounds from Senecio cannabifolius using ethanol as extraction solvent and to determine total phenol content in Senecio cannabifolius based on optimized microwave-ultrasonic assisted extraction process. Methods: Process conditions optimization was performed using one-factor-at-a-time and orthogonal array design methods. The extraction yield of phenolic compounds was investigated with respect to three process parameters such as microwave power, microwave treatment time and ethanol concentration. Determination of total phenol content was performed respectively using ultraviolet spectrophotometry and thin layer chromatography (TLC) scanning method. Results: The optimal extraction conditions were microwave treatment time of 120 s, microwave power of 90 W and ethanol concentration of 75%. In the ultraviolet spectrophotometeric determination, a mean spike recovery rate of 92.30%, a precision of 2.204% and a total phenol content of 0.1276% were observed, and those obtained by TLC scanning determination were 98.52%, 1.011% and 0.2044%, respectively. Conclusion: Both analytical methods above are applicable for the determination of phenolic compounds, and TLC scanning is a more accurate method.

Key words: Senecio cannabifolius, extraction, polyphenols, thin layer chromatography(TLC) scanning, ultraviolet spectrophotometry