Light gray-white solid crystal, with a slight stale earthy odor. Vapor pressure is about 1.3×10-10 Pa. In pH 7.74 aqueous solution, it is relatively stable to metals and metal ions within 28d. In the soil photodegradation half-life of 9 ~ 10d; water photolysis half-life <1d. In the pH value of 5 ~ 7 range, in aqueous solution is relatively stable; in the pH value of 9 when the half-life of >200d. Multi-bactericides is a mixture containing more than ten components, the main components are A and D. Spinosyn A melting point of 84 ~ 99.5 ° C, vapour pressure of 3.2 × 10-10Pa The solubility in water was 290mg/L (pH=5.0), 235mg/L (pH=7.0), 16mg/L (pH=9.0); the partition coefficients were 2.8, 4.0, 5.2 under the corresponding pH conditions, respectively.The melting point of polymicrobialin D was 161.5~170°C, and the vapour pressure was 2.1×10-10 Pa. The solubility in water was 29mg/L (pH=7.0), 4.0, 5.2, respectively. The solubility in water was 29mg/L (pH=5.0), 0.332mg/L (pH=7.0), 0.053mg/L (pH=90.0), and the partition coefficients were 3.2, 4.5, and 5.2 under the corresponding pH conditions.
Spinosyn D is the second most abundant component (comprising up to 15%) of the spinosyn fermentation complex of macrocyclic lactones. Spinosyn D is a more hydrophobic analogue, and is a potent insecticide for crop pathogens and ectoparasite control on animals, albeit less active than spinosyn A. The spinosyns have a unique mechanism of action involving disruption of nicotinic acetylcholine receptors.
