Method for extracting usnic acid from cladonia alpestris

Abstract

The invention discloses a method for extracting usnic acid from cladonia alpestris. The method comprises the following steps: (1) reflux extraction: smashing dry cladonia alpestris into powder, adding ethyl acetate, carrying out reflux extraction for two to three times at the temperature of 70 to 80 DEG C, filtering, merging a filter liquor, and concentrating to obtain a dry extract; (2) recrystallization: dissolving the dry extract with ethyl acetate at the temperature of 70 to 80 DEG C, after cooling to 25 DEG C, quickly (shorter than 1 h), dissolving out and separating usnic acid coarse grain, and then using ethyl acetate for recrystallization so as to obtain usnic acid crystal. The yield of the extracted and separated product is high, the purity is high, meanwhile few types of solvents are used, special equipment is not needed, the preparation period is short, preparation quantity is large, and the method is applicable for mass production.

Description

technical field [0001] The invention belongs to the field of natural medicine chemistry, and relates to a method for extracting, separating and purifying natural products, in particular to a method for extracting usnic acid from Taibai flowers. Background technique [0002] The Qinling Mountains run across my country from east to west, and are the dividing line between the north and the south of my country's geography and climate and the watershed between the two major rivers of the Yangtze River System and the Yellow River System. It has formed a plant resource bank with a wide variety and rich reserves, and is the most abundant terrestrial biodiversity in the world. It is also an important resource bank of medicinal plants and a production area of ​​traditional Chinese medicinal materials in my country. Known as the "Kingdom of Herbal Medicine" and "Asian Natural Botanical Garden", Mount Taibai is the main peak of the Qinling Mountains, with an altitude of 3767.2m. There ar...

AI Technical Summary

Problems solved by technology

Its extraction cycle is long and the cost is high. What is more important is that usnic acid is extremely difficult to dissolve in cold water and hot water, and is also extremely difficult to dissolve in cold ethanol or hot ethanol. The rate is extremely low, and it also causes a great waste of crude drug resources, making it difficult to carry out large-scale industrial production

This traditional production process has many problems that are difficult to overcome in production practice but have to be encountered in the production process: first, the viscosity of the obtained extract is relatively high, and it is difficult for organic solvents to penetrate into the extract liquid and affect the detoxification process. Miscellaneous effects, but also easier to emulsify; the second is to use a variety of different organic solvents in the extraction process, which not only lengthens the process, increases production costs, but also brings great safety hazards, and uses different organic solvents many times , it is easy to form cross-mixing of solvents, which leads to the difficulty of solvent recycling and high solvent loss rate; third, the labor intensity of workers is high, which increases labor costs. Due to excessive production steps in the production process, the utilization rate of raw materials is reduced, which is not conducive to expanding production scale, the purity of the product is difficult to guarantee, which affects the output of the product

However, this method takes too long and requires two long-term recrystallizations. During the recrystallization process, it needs to be cryogenically frozen for several hours, which requires high energy consumption, and requires the use of chloroform to remove impurities before obtaining a product with high purity. The production cost higher

Moreover, high-purity usnic acid can only be obtained by recrystallization with chloroform, but chloroform is a toxic solvent, has narcotic properties, and has the possibility of carcinogenicity, so it is not suitable for large-scale production

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