Title: Rifaximin
CAS Registry Number: 80621-81-4
CAS Name: (2
S,16
Z,18
E,20
S,21
S,22
R,23
R,24
R,25
S,26
R,27
S,28
E)-25-(Acetyloxy)-5,6,21,23-tetrahydroxy-27-methoxy-2,4,11,16,20,22,24,26-octamethyl-2,7-(epoxypentadeca[1,11,13]trienimino)benzofuro[4,5-
e]pyrido[1,2-
a]benzimidazole-1,15(2
H)-dione
Synonyms: 4-deoxy-4¢-methylpyrido[1¢,2¢-1,2]imidazo[5,4-
c]rifamycin SV; rifamycin L 105; rifaxidin
Manufacturers' Codes: L-105
Trademarks: Fatroximin (Fatro); Flonorm (Schering-Plough); Normix (Alfa); Rifacol (Formenti); Xifaxan (Salix)
Molecular Formula: C43H51N3O11
Molecular Weight: 785.88
Percent Composition: C 65.72%, H 6.54%, N 5.35%, O 22.39%
Literature References: Nonabsorbable semisynthetic rifamycin antibiotic. Prepn:
BE 888895; E. Marchi, L. Montecchi,
US 4341785 (1981, 1982 both to Alfa); E. Marchi
et al., J. Med. Chem. 28, 960 (1985); and NMR study: M. Brufani
et al., J. Antibiot. 37, 1611 (1984). X-ray crystal structure:
idem et al., ibid. 1623.
In vitro and
in vivo antibacterial activity: A. P. Venturini, E. Marchi,
Chemioterapia 5, 257 (1986). Toxicological study: G. Borelli, D. Bertoli,
ibid. 263. Clinical trial in travelers' diarrhea: R. Steffen
et al., Am. J. Gastroenterol. 98, 1073 (2003). Review of activity, pharmacokinetics and clinical experience in gastrointestinal infections: J. C. Gillis, R. N. Brogden,
Drugs 49, 467-484 (1995); D. B. Huang, H. L. DuPont,
J. Infection 50, 97-106 (2005).
Properties: Red orange powder, mp 200-205° (dec). uv max: 232, 260, 292, 320, 370, 450 nm (E1%1cm 489, 339, 295, 216, 119, 159). Sol in alcohols, ethyl acetate, chloroform, toluene. Insol in water. LD50 orally in rats: >2000 mg/kg (Borelli, Bertoli).
Melting point: mp 200-205° (dec)
Absorption maximum: uv max: 232, 260, 292, 320, 370, 450 nm (E1%1cm 489, 339, 295, 216, 119, 159)
Toxicity data: LD50 orally in rats: >2000 mg/kg (Borelli, Bertoli)
Therap-Cat: Antibacterial.
Therap-Cat-Vet: Antibacterial.
Keywords: Antibacterial (Antibiotics); Ansamycins.