Spinosad is a mixture of Spinosyn A and Spinosyn D. Spinosyns (macrocyclic lactones/macrolide insecticides) are extracted from the fermentation broth of Saccharopolyspora spinosa. This bacterial strain was isolated from a soil sample collected at a defunct sugar mill rum still in the Virgin Islands (Mertz and Yao, 1990). Spinosin A is produced in the greatest quantity, followed by Spinosyn D which differs from Spinosyn A by having a methyl group instead of a hydrogen atom at position C6 on the macrolide. The other 21 spinosyns are produced in very small quantities. Spinosad is used as a bio-insecticide as it shows efficacy against a variety of insects. Spinosyn A and D have the highest level of insecticidal activity. The Spinosyns do not have antibiotic effects on bacteria or fungi.
The spinosyns are soluble in organic solvents.