Abstract:

Objective: To optimize Soxhlet and combined microwave and ultrasonic extraction procedures of alkaloid from Senecio cannabifolius Less using methanol as an extraction solvent and to develop two methods using UV spectrophotometry and HPLC for the determination of alkaloid in Senecio cannabifolius Less. Methods: Orthogonal array design was employed to maximize yields of alkaloid by the two extraction methods and the optimized extraction procedures were applied to determine alkaloid content in Senecio cannabifolius Less by the two analytical methods. Results: A maximum yield of alkaloid was obtained by the 5 h Soxhlet extraction at 100 ℃ with a ratio of material to liquid of 1:30, and the optimal conditions for the improved combined microwave and ultrasonic extraction using a CW-2000A ultrasonic-microwave cooperative extractor were: power 120 W, extraction time 180 s, and material/liquid ratio 1:30. For the determination by UV spectrophotometry, the average recovery of alkaloid at three spiked levels was 92.49% (n = 3) and the precision RSD was 3.15% (n = 6), and the contents of alkaloid in Senecio cannabifolius Less extracted by Soxhlet and combined microwave and ultrasonic methods were 0.05212% and 0.03573%, respectively; for the determination by HPLC, the average recovery of alkaloid at three spiked levels was 89.60% (n = 3) and the precision RSD was 3.75%, and the contents of alkaloid extracted by the two methods were 0.04234% and 0.02750%, respectively. Conclusion: UV spectrophotometry and HPLC methods both are accurate and feasible for the determination of alkaloid content in Senecio cannabifolius Less.

Key words: Senecio cannabifolius Less, extraction, alkaloid, HPLC, UV spectrophotometry