Skip to Content
Merck
All Photos(3)

Documents

R9904

Sigma-Aldrich

Rifaximin

Synonym(s):

4-Deoxy-4′-methylpyrido[1′,2′-1,2]imidazo[5,4-c]rifamycin SV, Rifacol

Sign Into View Organizational & Contract Pricing
All Photos(3)

About This Item

Empirical Formula (Hill Notation):
C43H51N3O11
CAS Number:
80621-81-4
Molecular Weight:
785.88
MDL number:
MFCD00864973
UNSPSC Code:
51283604
PubChem Substance ID:
329824049
NACRES:
NA.85

form

powder

storage condition

(Keep container tightly closed in a dry and well-ventilated place.)

color

red to orange

antibiotic activity spectrum

Gram-negative bacteria
Gram-positive bacteria

Mode of action

protein synthesis | interferes

storage temp.

2-8°C

SMILES string

CO[C@H]1\C=C\O[C@@]2(C)Oc3c(C)c(O)c4c(O)c(NC(=O)C(C)=C\C=C\[C@@H](C)[C@@H](O)[C@@H](C)[C@H](O)[C@H](C)[C@H]([C@H]1C)C(=O)OC)c5c(nc6cc(C)ccn56)c4c3C2=O

InChI

1S/C43H51N3O11/c1-19-14-16-46-27(18-19)44-32-29-30-37(49)25(7)39-31(29)40(51)43(8,57-39)56-17-15-26(54-9)22(4)28(42(53)55-10)23(5)36(48)24(6)35(47)20(2)12-11-13-21(3)41(52)45-33(34(32)46)38(30)50/h11-18,20,22-24,26,28,35-36,47-50H,1-10H3,(H,45,52)/b12-11+,17-15+,21-13-/t20-,22+,23-,24-,26+,28+,35-,36-,43+/m1/s1

InChI key

HIYLTQREEOINNF-HTEWPBCCSA-N

Looking for similar products? Visit Product Comparison Guide

General description

Chemical structure: macrolide

Application

Rifaximin is a semisynthetic analog of rifamycin with poor absorptivity. It selectively inhibits (E. coli, B subtilis) bacterial DNA-dependent RNA polymerase by a mechanism similar to rifabutin, β subunit binding. It is effective against aerobic and anaerobic Gram-positive and Gram-negative bacteria. It is active against species of Staphylococcus, Streptococcus and Enterococcus. It is less active against species of Enterobacteriaceae. Rifaximin is a non-systemic, gastrointestinal site-specific antibiotic. It has a pyridoimidazole ring, making it non-absorbable. Rifaximin is a pregnane X receptor (PXR) activator.

Biochem/physiol Actions

Rifaximin is a semisynthetic analog of rifamycin with poor absorptivity. Mode of action: selectively inhibits (E. coli, B subtilis) bacterial DNA-dependent RNA polymerase by mechanism similar to rifabutin, β subunit binding.
Antimicrobial spectrum: Aerobic and anaerobic Gram-positive and Gram-negative bacteria. Active against species of Staphylococcus, Streptococcus and Enterococcus; less active against species of Enterobacteriaceae.†

Preparation Note

Practically insoluble in water, soluble in acetone and methanol.

Other Notes

Keep container tightly closed in a dry and well-ventilated place.

Storage Class Code

11 - Combustible Solids

WGK

WGK 3

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

Already Own This Product?

Find documentation for the products that you have recently purchased in the Document Library.

Visit the Document Library

Marina Ferrer et al.
International journal of molecular sciences, 22(2) (2021-01-10)
Rifaximin is a broad-spectrum antibiotic that ameliorates symptomatology in inflammatory/functional gastrointestinal disorders. We assessed changes in gut commensal microbiota (GCM) and Toll-like receptors (TLRs) associated to rifaximin treatment in mice. Adult C57BL/6NCrl mice were treated (7/14 days) with rifaximin (50/150
J C Gillis et al.
Drugs, 49(3), 467-484 (1995-03-01)
Rifaximin is a derivative of rifamycin which acts by inhibiting bacterial ribonucleic acid (RNA) synthesis. It is virtually unabsorbed after oral administration; thus it is used primarily to treat local conditions within the gastrointestinal tract. In vitro data indicate rifaximin
Vishesh Kothary et al.
Antimicrobial agents and chemotherapy, 57(2), 811-817 (2012-11-28)
Escherichia coli is implicated in the pathogenesis of inflammatory bowel disease (IBD). Rifaximin, a nonabsorbable derivative of rifampin effective against E. coli, improves symptoms in mild-to-moderate IBD. However, rifaximin resistance can develop in a single step in vitro. We examined
P Meyrat et al.
Alimentary pharmacology & therapeutics, 36(11-12), 1084-1093 (2012-10-17)
While rifaximin was able to improve symptoms in patients with irritable bowel syndrome (IBS) in phase III trials, these results are yet to be repeated in phase IV studies. To evaluate the treatment response to rifaximin in IBS patients in
E Mattila et al.
Alimentary pharmacology & therapeutics, 37(1), 122-128 (2012-10-26)
Clostridium difficile can cause severe antibiotic-associated colitis. Conventional treatments with metronidazole and vancomycin improve symptoms, but after discontinuation of treatment, C. difficile infection (CDI) recurs in a number of patients. Rifaximin is a rifamycin-based non-systemic antibiotic that has effect against
View All Related Papers

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service