The Research Of Veratrum Alkaloid Green Extraction Technology

With the increasing chemical pollution and the demands of improved quality of human living environment, chemical products extracted from natural sources, especially from plants, have been increasingly concerned by the community. Veratrum belongs to liliaceae plants. Veratrum alkaloids in this plant have the effects of contact and stomach toxicity on a variety of insects. Therefore, these compounds have been widely used as green pesticides. The topic of the paper aims at exploring the best extraction technology of a kind of Veratrum alkaloids.Based on the contrasts of various alkaloids'extraction technology, this topic focuses on the supercritical CO₂ fluid extraction technology and modified alkaline alkaloids solvent extraction technology. The topic obtains the optimal experimental parameters of these two technologies and makes the contrasts about the two methods:(1) The best experimental parameters of supercritical CO₂ fluid extraction technology: The sizes of Veratrum raw materials used in experiment are 30 head. The raw materials are treated by pre-alkali using alkali agent ammonia (NH3 w=25%²8%). Supercritical fluid extraction entrainer is volume fraction of 95% ethanol and the amount is 50mL/150g; The best equipment for extraction conditions determined by experiment are: extraction pressure 38MPa,extraction temperature 60℃, extraction time 3h, CO₂ flow rate of 40⁴5Kg/h. The best equipment results: extraction rate of veratridine crude is 3.13% and the alkaloids of the mass fraction in crude is w (Veratrum alkaloids / crude) =14.38%.(2) The experiment using the traditional ethanol as extraction solvent, combining with its own characteristics alkaloids, improves solvent extraction method for the alkaline. The best experimental parameters of alkaline solvent extraction are: ratio of extraction solid to liquid (w/v): 0.1; extraction volume fraction of ethanol 80%, adjusting extraction pH 12; extraction soaking time for 2 days (twice per 24-hour soak). Best results: the yield of crude base veratridine through alkaline ethanol immersion is 13.22% and the alkaloids of the mass fraction is w (Veratrum Alkaloids / crude) = 4.35%.(3) The experiment studies the post-acid purification method of crude alkaloid extract and makes the supercritical fluid extraction for IR characterization using alkaloids as the reference standard. The results show that supercritical fluid extraction of veratrum alkaloids, compared with standard product from the analysis of IR spectrums.