The invention relates to a novel
Avermectin derivative and a preparation method thereof. The preparation method comprises the following steps: A, dissolving
Avermectin B1a or
Avermectin B2a into an
organic solvent; B,
cooling down the solution, adding a substitution
reagent and dripping an acid-capturer; C, adding the reaction solution into a
sulfuric acid solution, regulating pH, stilling, layering, extracting, adding an organic phase into an
ammonia solution, regulating pH to be neutral, stilling, layering, extracting and merging the organic phase; D, performing
distillation of the organic phase under reduced pressure to obtain the product. According to the invention, on the basis of the Avermectin B2a or B1a, C5-OH is subject to further
chemical modification, and compared with the common Avermectin product, the novel Avermectin derivative has the advantages of high
drug effect, broad insecticidal spectrum, good persistence, no residues, no
pollution, high efficiency and no resistance. The novel Avermectin derivative has extremely
high activity on many pests and
mite, has the function of not only
stomach toxicity but also killing and has a very good insecticide effect at a very low dosage.