Abamectin.

Monograph number: Title: Abamectin. CAS Registry number: [71751-41- CAS name(s): Avermectin B 1 Additional name(s): 5- O- demethylavermectin A 1a and 5- O- demethyl-25-de(1-methylpropyl)-25-(1-methylethyl)avermectin A 1a (4:1); avermectin B 1a/b Drug code(s): MK-936 Trade name(s): Agri-Mek (Novartis) ; Avid (Novartis) ; Zephyr (Novartis) Literature references: Mixture of avermectins, q.v., containing at least 80% of avermectin B 1a ( C 48 H 72 O 14 ) and not more than 20% of avermectin B 1b ( C 47 H 70 O 14 ). Isoln from Streptomyces avermitilis: G. Albers-Schoumlnberg et al., Ger. pat. 2,717,040; eidem, U.S. pat. 4,310,519 (1977, 1982 both to Merck and Co.). Separation of components: T. W. Miller et al., Antimicrob. Ag. Chemother. 15, 368 (1979); by semi-preparative HPLC: C. C. Ku et al., J. Liq. Chromatog. 7, 2905 (1984). Structure determn: G. Albers-Schoumlnberg et al., J. Am. Chem. Soc. 103, 4216 (1981). Absolute configu ration: J. P. Springer et al., ibid. 4221. Partial synthesis of B 1a : K. C. Nicolaou et al., ibid. 106, 4189 (1984). Total synthesis: S. Hanessian et al., ibid. 108, 2776 (1986). Ant helmintic activity: L. S. Blair, W. C. Campbell, J. Parasitol. 64, 1032 (1978); J. R. Egerton et al., Antimicrob. Ag. Chemother. 15, 372 (1979); K. S. Todd et al., Am. J. Vet. Res. 45, 976 (1984). Pesticidal activity: I. Putter et al., Experientia 37, 963 (1981); R. A. Dybas, A. St. J. Green, Brit. Crop. Prot. Conf. - Pests Dis. 1984, 947. Control of red imported fire ants: J. A. Greenblatt et al., J. Agr. Entomol. 3, 233 (1986). Interaction with GABA receptors: S. S. Pong et al., J. Neurochem. 34, 351 (1980); T. N. Mellin et al., Neuropharmacol. 22, 89 (1983) . Receptor binding studies: S. S. Pong, C. C. Wang, ibid. 19, 311 (1980); G. Drexler, W. Sieghart, Eur. J. Pharmacol. 99, 269 (1984). Fate in soil and plants: D. L. Bull et al., J. Agr. Food Chem. 32, 94 (1984); H. A. Moye et al., ibid. 35, 859 (1987); M. S. Maynard et al., ibid. 37, 178, 184 (1989). Review: J. R. Babu, ACS Symposium Series 380, 91-108 (1988). Reviews of modes of action: C. C. Wang, S. S. Pong, Prog. Clin. Biol. Res. 97, 373-395 (1982); D. J. Wright, Biochem. Soc. Trans. 15, 65-67 (1987); of insecticidal activities and use: L. Strong, T. A. Brown, Bull. Ent. Res. 77, 357-389 (1987). Book: Ivermectin and Abamectin, W. C. Camp bell, Ed. (Springer-Verlag, New York, 1989) 363 pp. Properties: Odorless, off-white to yellow crystals from methanol, mp 150-155degrees (dec) . [alpha] D +55.7degrees plus or minus2degrees (c = 0.87 in CHCl 3 ) . uv max (methanol): 237 , 245 , 253 nm (log epsi 4.48, 4.53, 4.34) . Vapor pressure: 1.5 times 10 minus9 torr. Soly at 21degrees (mug/l): water 10; (mg/ml): acetone 100; n- butanol 10; chloroform 25; cyclohexane 6; ethanol 20; isopropanol 70; kerosene 0.5; methanol 19.5; toluene 350. Hydrolysis does not occur in aq soln at pH 3, 5, 7. LD 50 (technical grade) orally in sesame oil in mouse, rat: 13.5 , 10.0 mg/kg ; dermally in rabbit: >2000 mg/kg . LD 50 in mallard duck, bobwhite quail: 84.6 , >2000 mg/kg . LC 50 (96 hr) in rainbow trout, bluegill: 3.6 , 9.6 mug/l ; LC 50 (48 hr) in Daphnia magna: 0.34 mug/l (Merck Technical Data Sheet) . Melting Point: 150-155degrees UV Maxima: 237; 245; Rotation: +55.7degrees plus or minus2 USE: Acaricide; insecticide. THERAP CAT (VET): Anthelmintic.