1. Molecular formula: B1A C₄₈H₇₂O₁₄ (R= C₂H₅), B1B C₄₇H₇₀O₁₄ (R= CH₃)

2. Formula weight: B1A: 872, B1B: 858

3. Description: Light yellow or white crystalline powder, freely soluble in methanol, ester and practically insoluble in water.

Specification:

The product contains not less than 93.0% of 22, 23 dihydro-avermectin B1A and the sum of B1A and B1B is not less than 97.0%.