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

MedKoo CAT#: 319556

CAS#: 308362-25-6

Description: Ridinilazole, also known as SMT-19969, is a novel narrow-spectrum nonabsorbable antibiotic currently in development for the treatment of Clostridium difficile infection. SMT19969 showed potent inhibition of C. difficile (MIC90=0.125 mg/L) and was markedly more active than either metronidazole (MIC90 = 8 mg/L) or vancomycin (MIC90 = 2 mg/L). SMT19969 is highly effective at treating both acute infection and preventing recurrent disease and support continued investigation of SMT19969 as a potential therapy for CDI.

Chemical Structure

CAS# 308362-25-6

Theoretical Analysis

MedKoo Cat#: 319556
Name: Ridinilazole
CAS#: 308362-25-6
Chemical Formula: C24H16N6
Exact Mass: 388.1436
Molecular Weight: 388.434
Elemental Analysis: C, 74.21; H, 4.15; N, 21.64

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Synonym: SMT-19969; SMT 19969; SMT19969; Ridinilazole

IUPAC/Chemical Name: 2,2'-di(pyridin-4-yl)-1H,1'H-5,5'-bi(benzimidazole)


InChi Code: InChI=1S/C24H16N6/c1-3-19-21(29-23(27-19)15-5-9-25-10-6-15)13-17(1)18-2-4-20-22(14-18)30-24(28-20)16-7-11-26-12-8-16/h1-14H,(H,27,29)(H,28,30)

SMILES Code: C1(C2=CC=NC=C2)=NC3=CC(C4=CC=C5C(N=C(C6=CC=NC=C6)N5)=C4)=CC=C3N1

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, not in water

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

Preparing Stock Solutions

The following data is based on the product molecular weight 388.434 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: Freeman J, Vernon J, Vickers R, Wilcox MH. Susceptibility of Clostridium difficile isolates of varying antimicrobial resistance phenotypes to SMT19969 and 11 comparators. Antimicrob Agents Chemother. 2015 Nov 9. pii: AAC.02000-15. [Epub ahead of print] PubMed PMID: 26552981.

2: Vickers R, Robinson N, Best E, Echols R, Tillotson G, Wilcox M. A randomised phase 1 study to investigate safety, pharmacokinetics and impact on gut microbiota following single and multiple oral doses in healthy male subjects of SMT19969, a novel agent for Clostridium difficile infections. BMC Infect Dis. 2015 Feb 25;15:91. doi: 10.1186/s12879-015-0759-5. PubMed PMID: 25880933; PubMed Central PMCID: PMC4349307.

3: Corbett D, Wise A, Birchall S, Warn P, Baines SD, Crowther G, Freeman J, Chilton CH, Vernon J, Wilcox MH, Vickers RJ. In vitro susceptibility of Clostridium difficile to SMT19969 and comparators, as well as the killing kinetics and post-antibiotic effects of SMT19969 and comparators against C. difficile. J Antimicrob Chemother. 2015;70(6):1751-6. doi: 10.1093/jac/dkv006. Epub 2015 Feb 3. PubMed PMID: 25652750; PubMed Central PMCID: PMC4498293.

4: Sattar A, Thommes P, Payne L, Warn P, Vickers RJ. SMT19969 for Clostridium difficile infection (CDI): in vivo efficacy compared with fidaxomicin and vancomycin in the hamster model of CDI. J Antimicrob Chemother. 2015;70(6):1757-62. doi: 10.1093/jac/dkv005. Epub 2015 Feb 3. PubMed PMID: 25652749; PubMed Central PMCID: PMC4498292.

5: Baines SD, Crowther GS, Freeman J, Todhunter S, Vickers R, Wilcox MH. SMT19969 as a treatment for Clostridium difficile infection: an assessment of antimicrobial activity using conventional susceptibility testing and an in vitro gut model. J Antimicrob Chemother. 2015 Jan;70(1):182-9. doi: 10.1093/jac/dku324. Epub 2014 Sep 3. PubMed PMID: 25190720; PubMed Central PMCID: PMC4267497.

6: Weiss W, Pulse M, Vickers R. In vivo assessment of SMT19969 in a hamster model of clostridium difficile infection. Antimicrob Agents Chemother. 2014 Oct;58(10):5714-8. doi: 10.1128/AAC.02903-14. Epub 2014 Jul 14. PubMed PMID: 25022586; PubMed Central PMCID: PMC4187990.

7: Goldstein EJ, Citron DM, Tyrrell KL. Comparative in vitro activities of SMT19969, a new antimicrobial agent, against 162 strains from 35 less frequently recovered intestinal Clostridium species: implications for Clostridium difficile recurrence. Antimicrob Agents Chemother. 2014;58(2):1187-91. doi: 10.1128/AAC.02184-13. Epub 2013 Nov 18. PubMed PMID: 24247123; PubMed Central PMCID: PMC3910813.

8: Goldstein EJ, Citron DM, Tyrrell KL, Merriam CV. Comparative in vitro activities of SMT19969, a new antimicrobial agent, against Clostridium difficile and 350 gram-positive and gram-negative aerobic and anaerobic intestinal flora isolates. Antimicrob Agents Chemother. 2013 Oct;57(10):4872-6. doi: 10.1128/AAC.01136-13. Epub 2013 Jul 22. PubMed PMID: 23877700; PubMed Central PMCID: PMC3811411.