Title: Milbemycins
CAS Registry Number: 51570-36-6
Additional Names: Antibiotic B-41
Literature References: A family of novel macrolide antibiotics with insecticidal and acaricidal activity; structurally related to avermectin, q.v., aglycones. Isoln from Streptomyces hygroscopicus subsp. aureolacrimosus and properties: A. Aoki et al., DE 2329486; eidem, US 3950360 (1973, 1976 both to Sankyo); of a1-a10, b1-b3, D-H: Y. Takiguchi et al., J. Antibiot. 33, 1120 (1980). Isoln and properties of D-H: Y. Takiguchi et al., J. Antibiot. 36, 502 (1983); of J and K: M. Ono et al., ibid. 509. Structures of milbemycins a1-a10, b1: M. Kurabayashi et al., 18th Symp. Chem. Natural Products (Kyoto, 1974) nos. 309-316; of b1-b3: H. Mishima et al., Tetrahedron Lett. 1975, 711; of D-H, J, K: H. Mishima et al., J. Antibiot. 36, 980 (1983). Total synthesis of (±)-milbemycin b3: A. B. Smith et al., J. Am. Chem. Soc. 104, 4015 (1982); of the (+)-form: D. R. Williams et al., ibid. 4708. Prepn of milbemycins from avermectins: H. Mrozik et al., Tetrahedron Lett. 1983, 5333. Total synthesis studies of D: M. T. Crimmins et al., ibid. 28, 3651 (1987). Prophylactic use of milbemycin D against Dirofilaria immitis infection in dogs: M. Tagawa et al., Jpn. J. Vet. Sci. 47, 787 (1985). Toxicity data: N. Matsunuma et al., Sankyo Kenkyusho Nempo 35, 71 (1983), C.A. 101, 32870d (1984). Review of syntheses: T. Blizzard et al., in Recent Prog. Chem. Synth. Antibiotics, G. Lukacs, M. Ohno, Eds (Springer-Verlag, Berlin, 1990) pp 66-102. Review of structure-activity relationships: W. L. Shoop et al., Vet. Parasitol. 59, 139-156 (1995).
Properties: Sol in n-hexane, benzene, acetone, ethanol, methanol, chloroform; very slightly sol in water.
Derivative Type: Milbemycin a1 see Milbemectin
Derivative Type: Milbemycin b1
CAS Registry Number: 51596-16-8
Additional Names: 25a-Methylmilbemycin B; antibiotic B-41A1
Molecular Formula: C32H48O7
Molecular Weight: 544.72
Percent Composition: C 70.56%, H 8.88%, O 20.56%
Properties: Amorphous solid. [a]D20 +160° (c = 0.25 in acetone). uv max (ethanol): 245 nm (e 26500).
Optical Rotation: [a]D20 +160° (c = 0.25 in acetone)
Absorption maximum: uv max (ethanol): 245 nm (e 26500)
Derivative Type: Milbemycin D
CAS Registry Number: 77855-81-3
Additional Names: (6R,25R)-5-O-Demethyl-28-deoxy-6,28-epoxy-25-(1-methylethyl)milbemycin B; antibiotic B-41D
Molecular Formula: C33H48O7
Molecular Weight: 556.73
Percent Composition: C 71.19%, H 8.69%, O 20.12%
Properties: Colorless needles from hexane-ethyl acetate (20:1), mp 186-188°. [a]D27 +107° (c = 0.25 in acetone). uv max (ethanol): 244 nm (31000).
Melting point: mp 186-188°
Optical Rotation: [a]D27 +107° (c = 0.25 in acetone)
Absorption maximum: uv max (ethanol): 244 nm (31000)
Therap-Cat-Vet: Antiparasitic. |