WARNING: This product is for research use only, not for human or veterinary use.

MedKoo CAT#: 314225

CAS#: 873857-62-6

Description: Fidaxomicin is the first in a new class of narrow spectrum macrocyclic antibiotic drugs. It is a fermentation product obtained from the actinomycete Dactylosporangium aurantiacum subspecies hamdenesis. Fidaxomicin is non-systemic, meaning it is minimally absorbed into the bloodstream, it is bactericidal, and it has demonstrated selective eradication of pathogenic Clostridium difficile with minimal disruption to the multiple species of bacteria that make up the normal, healthy intestinal flora. The maintenance of normal physiological conditions in the colon can reduce the probability of Clostridium difficile infection recurrence. (Source:

Chemical Structure

CAS# 873857-62-6

Theoretical Analysis

MedKoo Cat#: 314225
Name: Fidaxomicin
CAS#: 873857-62-6
Chemical Formula: C52H74Cl2O18
Exact Mass: 1056.42522
Molecular Weight: 1058.04
Elemental Analysis: C, 59.03; H, 7.05; Cl, 6.70; O, 27.22

Price and Availability

Size Price Availability Quantity
10.0mg USD 250.0 2 Weeks
50.0mg USD 550.0 2 Weeks
100.0mg USD 850.0 2 Weeks
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Synonym: OPT80; OPT-80; OPT 80; PAR101; PAR 101; PAR-101; Dificid; Dificlir; Clostomicin B1; Difimicin; Lipiarmycin; Tiacumicin B.

IUPAC/Chemical Name: (2R,3S,4S,5S,6R)-6-({(3E,5E,8S,9E,11S,12R,13E,15E,18S)-12-{[(2R,3S,4R,5S)-3,4-Dihydroxy-5-(isobutyryloxy)-6,6-dimethyltetrahydro-2H-pyran-2-yl]oxy}-11-ethyl-8-hydroxy-18-[(1R)-1-hydroxyethyl]-9,13,15- trimethyl-2-oxooxacyclooctadeca-3,5,9,13,15-pentaen-3-yl}methoxy)-4-hydroxy-5-methoxy-2-methyltetrahydro-2H-pyran-3-yl 3,5-dichloro-2-ethyl-4,6-dihydroxybenzoate


InChi Code: InChI=1S/C52H74Cl2O18/c1-13-30-22-26(6)33(56)18-16-15-17-31(23-66-51-45(65-12)42(61)44(29(9)67-51)69-49(64)35-32(14-2)36(53)39(58)37(54)38(35)57)48(63)68-34(28(8)55)20-19-25(5)21-27(7)43(30)70-50-41(60)40(59)46(52(10,11)72-50)71-47(62)24(3)4/h15-17,19,21-22,24,28-30,33-34,40-46,50-51,55-61H,13-14,18,20,23H2,1-12H3/b16-15+,25-19+,26-22+,27-21+,31-17+/t28-,29-,30+,33+,34+,40-,41+,42+,43+,44-,45+,46+,50-,51-/m1/s1

SMILES Code: O=C(O[C@@H]1[C@@H](C)O[C@@H](OC/C2=C\C=C\C[C@H](O)/C(C)=C/[C@H](CC)[C@@H](O[C@H]3[C@@H](O)[C@@H](O)[C@H](OC(C(C)C)=O)C(C)(C)O3)/C(C)=C/C(C)=C/C[C@@H]([C@H](O)C)OC2=O)[C@@H](OC)[C@H]1O)C4=C(O)C(Cl)=C(O)C(Cl)=C4CC

Appearance: Solid powder

Purity: >98% (or refer to the Certificate of Analysis)

Shipping Condition: Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition: Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Solubility: Soluble in DMSO.

Shelf Life: >2 years if stored properly

Drug Formulation: This drug may be formulated in DMSO

Stock Solution Storage: 0 - 4 C for short term (days to weeks), or -20 C for long term (months).

HS Tariff Code: 2934.99.9001

Certificate of Analysis:

Safety Data Sheet (SDS):

Preparing Stock Solutions

The following data is based on the product molecular weight 1058.04 Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Recalculate based on batch purity %
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
1 mM 1.15 mL 5.76 mL 11.51 mL
5 mM 0.23 mL 1.15 mL 2.3 mL
10 mM 0.12 mL 0.58 mL 1.15 mL
50 mM 0.02 mL 0.12 mL 0.23 mL

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 1: Gallagher JC, Reilly JP, Navalkele B, Downham G, Haynes K, Trivedi M. Clinical and economic benefits of fidaxomicin compared to vancomycin for Clostridium difficile infection. Antimicrob Agents Chemother. 2015 Aug 31. pii: AAC.00939-15. [Epub ahead of print] PubMed PMID: 26324268.

2: Snydman DR, McDermott LA, Jacobus NV, Thorpe C, Stone S, Jenkins SG, Goldstein EJ, Patel R, Forbes BA, Mirrett S, Johnson S, Gerding DN. A US Based National Sentinel Surveillance Study for the Epidemiology of Clostridium difficile Associated Diarrheal Isolates and their Susceptibility to Fidaxomicin. Antimicrob Agents Chemother. 2015 Aug 3. pii: AAC.00845-15. [Epub ahead of print] PubMed PMID: 26239985.

3: Mizusawa M, Doron S, Gorbach S. Clostridium difficile Diarrhea in the Elderly: Current Issues and Management Options. Drugs Aging. 2015 Aug;32(8):639-47. doi: 10.1007/s40266-015-0289-2. PubMed PMID: 26233437.

4: Knight DR, Giglio S, Huntington PG, Korman TM, Kotsanas D, Moore CV, Paterson DL, Prendergast L, Huber CA, Robson J, Waring L, Wehrhahn MC, Weldhagen GF, Wilson RM, Riley TV. Surveillance for antimicrobial resistance in Australian isolates of Clostridium difficile, 2013-14. J Antimicrob Chemother. 2015 Jul 28. pii: dkv220. [Epub ahead of print] PubMed PMID: 26221017.

5: Srinivas NR. Fidaxomicin Pharmacokinetics in Humans: Is There a Role of Biliary Excretion? Clin Drug Investig. 2015 Aug;35(8):531-2. doi: 10.1007/s40261-015-0305-7. PubMed PMID: 26135594.

6: Kaufmann E, Hattori H, Miyatake-Ondozabal H, Gademann K. Total Synthesis of the Glycosylated Macrolide Antibiotic Fidaxomicin. Org Lett. 2015 Jul 17;17(14):3514-7. doi: 10.1021/acs.orglett.5b01602. Epub 2015 Jun 30. PubMed PMID: 26125969.

7: Marra F, Ng K. Controversies Around Epidemiology, Diagnosis and Treatment of Clostridium difficile Infection. Drugs. 2015 Jul;75(10):1095-118. doi: 10.1007/s40265-015-0422-x. PubMed PMID: 26113167.

8: Vaishnavi C. Fidaxomicin--the new drug for Clostridium difficile infection. Indian J Med Res. 2015 Apr;141(4):398-407. doi: 10.4103/0971-5916.159251. PubMed PMID: 26112840; PubMed Central PMCID: PMC4510719.

9: Péju E, Arcizet J, Fillion A, Chavanet P, Prudent C, Piroth L. Multiple Recurrences of Clostridium difficile Infection Treated With Crushed Fidaxomicin Administered Through a Percutaneous Endoscopic Gastrostomy Tube. Ann Pharmacother. 2015 Jul;49(7):853-4. doi: 10.1177/1060028015581010. PubMed PMID: 26089544.

10: Chilton CH, Crowther GS, Todhunter SL, Ashwin H, Longshaw CM, Karas A, Wilcox MH. Efficacy of alternative fidaxomicin dosing regimens for treatment of simulated Clostridium difficile infection in an in vitro human gut model. J Antimicrob Chemother. 2015 Sep;70(9):2598-607. doi: 10.1093/jac/dkv156. Epub 2015 Jun 14. PubMed PMID: 26078392.