METHOD FOR EXTRACTION AND PREPARATION OF AVERMECTIN B2A

摘要

Disclosed is a method for extraction and preparation of avermectin B2a. The method comprises: an avermectin fermentation solution is prepared into a dry mycelium and leached; a leach liquor is concentrated, and extraction agents such as toluene are added for extraction; extract liquor I is crystallized; a mother liquor acquired is concentrated into a paste; toluene is added into the paste to acquire extract liquor II; a filter aid is added into extract liquor II, same is stirred, cooled, and crystallized, then subjected to crystal growth and filtration; an filter cake acquired is dissolved by adding toluene, a filtrate is cooled again, devitrified, and then subjected to crystal growth and filtration; an avermectin B2a crystal crude product is acquired; the avermecting B2a crystal crude product is re-crystallized to acquire an avermectin B2a crystal refined product. The method of the present invention allows for effective isolation of avermectin B2a from the avermectin fermentation solution and provides a high yield and a great purification effect.