A method for extracting Proanthocyanidine, comprising the following steps:
(1) After the raw material grape seeds or pine bark are pretreated, they are heated and extracted with a solvent, and concentrated under reduced pressure to obtain a concentrated solution; grape seeds contain a large amount of water-soluble impurities, such as sugars, proteins, etc., but these impurities are insoluble in Acetone, so use acetone to extract the raw materials to remove the impurities to the greatest extent, reduce the pollution to the macroporous resin, and achieve the purpose of improving the purity of the product. In step (1), the method of heating reflux with acetone is used to replace the conventional method of extracting with water or ethanol, and the above-mentioned solvent is acetone, an organic solvent, which is heated and refluxed, and then concentrated under reduced pressure to obtain concentrated solution I; in addition, in the above Add refining operation between step (1) and step (6), its step comprises:
(2) the concentrated solution I is cooled and precipitated;
(3) packing macroporous resin in the chromatographic column;
(4) Put the supernatant of concentrated solution I on the column, add ethanol into the chromatographic column for desorption, and collect the desorption solution;
(5) Concentrate the stripped solution under reduced pressure by heating, and extract the concentrated solution II. In the refining process, the supernatant of the concentrated solution I is put on the column, so that the macroporous resin can selectively adsorb substances to achieve further purification of the product.
(6) carry out drying treatment;
For production, specific process steps can be selected according to needs. For example, when the above step (1) is heated and refluxed in acetone, it can be carried out twice, and the first time is heated and refluxed for 3 hours. After extracting the leaching solution, the residue Add acetone again and heat to reflux for 2 hours, and extract the leachate for the second time; then combine the leachate extracted twice. In the step (1), the dosage of the acetone aqueous solution is 3 to 5 times (V/W) of the amount of the plant material. The concentration of acetone is 60-75%, the optimum concentration is 65-70%; the heating temperature is 55-70°C, the optimum temperature is 60-65°C. During the desorption process with ethanol, the volume ratio of ethanol to resin is 3:1 (V/W), and the ethanol concentration is 60-75% according to different requirements of different products.
And in the process of step (5) heating and concentrating under reduced pressure, the concentrating heating temperature is 60-80°C, preferably 65-70°C. According to different raw materials, the ratio of acetone to raw materials also changes accordingly, for example: for using grape seeds as raw materials, the volume ratio of raw materials to acetone in the step (1) is 1:3. And take pine bark as raw material, the volume ratio of raw material and acetone in the described step (1) is 1: 5.