All Photos(3)




4-Deoxy-4′-methylpyrido[1′,2′-1,2]imidazo[5,4-c]rifamycin SV, Rifacol
Empirical Formula (Hill Notation):
CAS Number:
Molecular Weight:
MDL number:
PubChem Substance ID:



Quality Level

storage condition

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


red to orange

Mode of action

protein synthesis | interferes

antibiotic activity spectrum

Gram-negative bacteria
Gram-positive bacteria

storage temp.


SMILES string




InChI key


Looking for similar products? Visit Product Comparison Guide

Related Categories

General description

Chemical structure: macrolide


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.


1, 5 g in poly bottle

Biochem/physiol Actions

Rifaximin is a semisynthetic antibiotic used to treat diarrhea caused by E. coli. It is also used to treat hepatic encephalopathy by reducing blood ammonia concentrations. Rifaximin is a potential treatment for inflammatory bowel disease.

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

13 - Non Combustible Solids



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificate of Analysis

Certificate of Origin

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
Jiannis Vlachogiannakos et al.
Journal of gastroenterology and hepatology, 28(3), 450-455 (2012-12-12)
Cirrhotic patients are predisposed to intestinal bacterial overgrowth with translocation of bacterial products which may deteriorate liver hemodynamics. Having shown that short-term administration of rifaximin improves liver hemodynamics in decompensated cirrhosis, we conducted this study to investigate the effect of
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

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