Daurisoline is characterized by high performance liquid chromatography. The mobile phase is acetonitrile-water-triethylamine (18: 82: 0.28, adjusted to pH = 3 with phosphoric acid).
The detection wavelength is 284 nm.
The extraction of phenolic alkaloids from menispermum dauricum
1.The extraction of the total alkaloids in the menispermum dauricum:
First pretreated the menispermum dauricum by acid water extraction method and then obtain the crude alkali through alkaline precipitation method according to the propertie that most free alkaloids are insoluble in water. And then extract the fat-soluble part using the method of continuous extraction of benzene reflux. And then use 5% sodium hydroxide to extract the total phenolic alkaloids based on the nature that phenolic alkaloids from menispermum dauricum can be dissolved in a certain amount of lye. The flow chart is as follow:
2.The extraction of phenolic alkaloids from menispermum dauricum:
Extract 1kg of crude alkali (ground) 2 times with benzene (each 2000ml), and then combine the benzene solution and respectively extract 4 times with 5% sodium hydroxide solution (400,300,300, 200 mL). Combine the separated lye and adjust its pH to 4 with 6 mol/L hydrochloric acid. Decolore it with activated charcoal and dropwise add concentrated ammonia to pH=9 to separate out milky white precipitate. Then filter and wash the precipitate with water to neutral. Dry the precipitate in vacuum to obtain 352 g of pale yellow powder (phenolic alkaloids from menispermum dauricum).
Separation of dauricine and daurisoline
Dissolve 100 g of phenolic alkaloids in about 250 ml of chloroform. After dissolved completely, pour them into separatory funnel and extract three times with 3% sodium hydroxide solution (200, 100, 100 mL) to separate the chloroform solution (monophenol) and lye (bisphenol and trisphenol). First wash the chloroform solution containing the monophenol portion with 150 mL of water, and then remove the aqueous layer and extracte four times with 1% hydrochloric acid (200, 200, 100, 100 mL). Combine the acid water and decolor it with activated carbon. Adjust the pH to 9 with concentrated ammonia water to separate out white precipitate. Then filter and wash them to neutral. Dry in vacuum to obtain white powder dauricine 45g, a yield that is 45 % of the total phenolic alkaloid.
Decolor the lye containing bisphenol and triphenol with activated carbon and adjust the pH to 8 with concentrated ammonia water to precipitate milky white polyphenols precipitation.
Dissolve the precipitation with about 200mL of chloroform, and wash them with 0.5% sodium hydroxide 3 times (100ml×3). Then wash them with 1% sodium hydroxide solution (150mL) and combine all the lye (including tricelles, etc.). Extract the chloroform solution (containing bisphenol) with 1% hydrochloric acid 3 times (150mL × 3) and combine the acid water. Decolor them with activated carbon and adjust the pH to 8 with concentrated ammonia water to precipitate milky white precipitation. Filter and wash them to neutral. Dry in vacuum to obtain light grayish yellow powder daurisoline, a yield that is 11.5% of the total phenolic alkaloid.
