Optimization of Ultrasound-assisted Acidic-solvent Extraction of Colchicine from Colchicum kurdicum (Bornm.) Stef. Using Response Surface Methodology

Background and objectives: Colchicum kurdicum (Bornm.) Stef. is a flowering perennial monocotyledon plant that has many important bioactive compounds especially colchicine and colchicine derivatives. In this study, the ultrasound-assisted acidic-solvent extraction method coupled with response-surface method was presented as the successful method for large scale extraction of colchicine as an alkaloid compound from Colchicum kurdicum. Methods: According to the literatures, methanol/deionized water (70:30) solvent system was selected for the extraction. In addition, the response-surface method was used for analysis and optimization of colchicine extraction by ultrasonic-assisted acidic-solvent extraction method. Subsequently, colchicine was extracted using this method and the effects of solvent pH, extraction time, solvent/plant ratio, power, and temperature were evaluated. Results: After all analysis procedures, 0.99 mg colchicine/g dried corms was achieved with the following conditions: solvent pH 4, Extraction time 120 minutes, solvent/plant ratio 20 mL/g, power 100 W, and temperature 60 ºC. Conclusion: According to this study, ultrasonic-assisted acidic-solvent extraction was found an effective method for extraction of colchicine from Colchicum kurdicum (Bornm.) Stef. compared to other extraction methods.