Chemicals and Drugs

Dithionitrobenzoic Acid

A standard reagent for the determination of reactive sulfhydryl groups by absorbance measurements. It is used primarily for the determination of sulfhydryl and disulfide groups in proteins. The color produced is due to the formation of a thio anion, 3-carboxyl-4-nitrothiophenolate.

National Library of MedicineMedical Subject Headings2026

Structured Summary

Abstract

A standard reagent for the determination of reactive sulfhydryl groups by absorbance measurements. It is used primarily for the determination of sulfhydryl and disulfide groups in proteins. The color produced is due to the formation of a thio anion, 3-carboxyl-4-nitrothiophenolate.

Chemical Identity

Chemical Information

Molecular Formula
C14H8N2O8S2
Molecular Weight
396.4 g/mol
CAS Registry No.
69-78-3
IUPAC Name
5-[(3-carboxy-4-nitrophenyl)disulfanyl]-2-nitrobenzoic acid
InChIKey
KIUMMUBSPKGMOY-UHFFFAOYSA-N
SMILES
C1=CC(=C(C=C1SSC2=CC(=C(C=C2)[N+](=O)[O-])C(=O)O)C(=O)O)[N+](=O)[O-]
MeSH Unique ID
D004228
Source
PubChem CID 6254

MeSH Record

Classification

Broader headings

Related Concepts

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Drug Class

Pharmacological Action

MeSH Record

Synonyms

8 entry terms
  • 5,5'-Dithiobis(2-nitrobenzoic Acid)
  • DTNB
  • Ellman's Reagent
  • Acid, Dithionitrobenzoic
  • Ellman Reagent
  • Ellmans Reagent
  • Reagent, Ellman's
  • 5,5'-Dithiobis(nitrobenzoate)

MeSH Record

Aspects Covered

25 allowable subheadings

Indexed with the subheadings administration & dosage, adverse effects, agonists, analogs & derivatives, analysis, antagonists & inhibitors, blood, cerebrospinal fluid, chemical synthesis, chemistry, classification, economics, history, immunology, isolation & purification, metabolism, pharmacokinetics, pharmacology, poisoning, radiation effects, standards, supply & distribution, therapeutic use, toxicity, urine.

MeSH Record

History Note

91(75); was see under NITROBENZOATES 1975-90

MeSH Record

Previous Indexing

  • Benzoates (1969-1974)
  • Disulfides (1972-1974)
  • Nitro Compounds (1972-1974)

MeSH Hierarchy

Tree Numbers

  1. D02w.241w.223.100.600.300w
  2. D02w.455w.426w.559w.389.127.650.300w

AMA Style

References

  1. National Library of Medicine. Dithionitrobenzoic Acid. Medical Subject Headings (MeSH). 2026. Unique ID D004228. http://id.nlm.nih.gov/mesh/2026/D004228
  2. Dithionitrobenzoic Acid. In: Wikipedia. https://en.wikipedia.org/wiki/Ellman%27s_reagent
  3. Dithionitrobenzoic Acid. In: Wikidata. https://www.wikidata.org/wiki/Q3604488
  4. Dithionitrobenzoic Acid. In: PubChem Compound. CID 6254. https://pubchem.ncbi.nlm.nih.gov/compound/6254