Chemical name: 5-O-demethylavermectin A1a (i) mixture with 5-O-demethyl-25-de (1-methylpropyl)-25-(1-methylethyl) avermectin A1a (ii)
Chemical class: Avermectin
CAS No.: 71751-41-2(abamectin), 65195-55-3(i), 65195-56-4(ii)
Properties:
Form (appearance): A mixture containing > 80% avermectin B1a (i) and < 20% avermectin B1b (ii). Colourless to pale yellow crystals. M.P.: 161.8-169.4 (decomp). V.P.: <3.7×10-3 mPa (25). S.G.: 1.18 (22). In water 7-10 μg/l (20). In toluene 350, acetone 100, isopropanol 70, chloroform 25, ethanol 20, methanol 19.5, n-butanol 10, cyclohexane 6 (all in g/l, 21). Stable to hydrolysis in aqueous solutions at pH 5, 7, and 9 (25). Sensitive to stronger acid and base. U.v. irradiation causes conversion first to the 8,9-Z-isomer, then to unidentified decomposition products.
Toxicity:
Acute oral LD₅₀ for rats 10, mice 13.6 mg/kg (in sesame oil). Acute percutaneous LD₅₀ for rabbits >2000 mg/kg. Mild eye irritant; non-irritating to skin (rabbits).
Ecotoxocology:
Acute oral LD₅₀ for mallard ducks 84.6, bobwhite quail >2000 mg/kg. LC₅₀ (96 h) for rainbow trout 3.2, bluegill sunfish 9.6 μg/l. Daphnia EC₅₀ (48 h) 0.34 ppb. Algae LC₅₀ >100 mg/l. LC₅₀ (96 h