92131 Sigma-Aldrich


crystallized, ≥99.0% (HPLC)

Synonym: 2,4-Diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine, NSC 106568

  • CAS Number 738-70-5

  • Empirical Formula (Hill Notation) C14H18N4O3

  • Molecular Weight 290.32

  •  Beilstein/REAXYS Number 625127

  •  EC Number 212-006-2

  •  MDL number MFCD00036761

  •  PubChem Substance ID 57653467

  •  NACRES NA.85



Related Categories Antibacterial, Antibiotics, Antibiotics A to Z, Antibiotics T-Z, Antibiotics by Mechanism of Action,
Quality Level   200
biological source   synthetic
assay   ≥99.0% (HPLC)
form   powder
quality   crystallized
color   white to yellow
mp   199-203 °C
Mode of action   DNA synthesis | interferes
  enzyme | inhibits
antibiotic activity spectrum   Gram-negative bacteria
  Gram-positive bacteria
storage temp.   2-8°C
SMILES string   COc1cc(Cc2cnc(N)nc2N)cc(OC)c1OC
InChI   1S/C14H18N4O3/c1-19-10-5-8(6-11(20-2)12(10)21-3)4-9-7-17-14(16)18-13(9)15/h5-7H,4H2,1-3H3,(H4,15,16,17,18)
Gene Information   human ... DHFRP1(573971), KCNH1(3756)
rat ... Dhfr(24312)


General description

Chemical structure: pyrimidine


Trimethoprim is primarily used as an antibacterial agent. It is used in susceptibility studies of Mycobacterium tuberculosis and mechanism of resistance studies in Haemophilus influenzae .

Primarily used as an antibacterial agent. Dihydrofolate reductase inhibitor with selectivity for the prokaryote enzyme.

Biochem/physiol Actions

Inhibits the synthesis of tetrahydrofolate by procaryote specific dihydrofolate reductase (DHFR).

Trimethoprim is a dihydrofolate reductase inhibitor with selectivity for the prokaryote enzyme.



Other Notes

Keep container tightly closed in a dry and well-ventilated place.Light sensitive. Store under inert gas. Moisture sensitive. Product is sensitive to light and moisture.

Safety & Documentation

Safety Information

GHS07  GHS07
Signal word 
Hazard statements 
Precautionary statements 
Personal Protective Equipment 
NONH for all modes of transport
WGK Germany 
Flash Point(F) 
Not applicable
Flash Point(C) 
Not applicable


Certificate of Analysis (COA)

Please Enter a Lot Number

Frequently Asked Questions

Which document(s) contains shelf-life or expiration date information for a given product?
If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.
How do I get lot-specific information or a Certificate of Analysis?
The lot specific COA document can be found by entering the lot number above under the "Documents" section.
How do I find price and availability?
There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote. USA customers: 1-800-325-3010 or view local office numbers.
What is the Department of Transportation shipping information for this product?
Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product.
Is Trimethoprim stable in solution?
Triemethoprim in a solution of 52% N,N dimethylacetamide:48% propylene glycol at 50 mg/ml is stable when stored at 25° C. There is only a 10% degradation of trimethoprim under these conditions after 885 days.
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Protocols & Articles


Folic Acid Metabolism: A Role in Cancer's Cause and Cure

The mammalian folic acid cycle is a highly complex but crucial process for the transfer of one-carbon units to amino acids, nucleotides, and other biomolecules. Folic acid cannot be synthesized but i...
Biofiles Vol. 5, No. 6
Keywords: Antibiotics, Antitumor agents, Apoptosis, Building blocks, Cancer, Cellular processes, Eliminations, Gastrointestinal, Metabolic Pathways, Metabolism, Metabolites, Methylations, Phosphorylations, Purine synthesis, Reductions, transformation

Peer-Reviewed Papers


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