5,5'-Disulfobis(2-nitrobenzoic acid) (DTNB)
Time：2023-12-04 Hits：250
5,5′ -Dithiobis (2-nitrobenzoic acid), also known as DTNB or Ellman's reagent, reacts with thiol groups to produce a colored product, making it a reliable method for measuring cysteine and other free thiols in solution. DTNB can be used for the detection of acetylcholinesterase.
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DTNB basic properties
Chinese name: 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB)
English name: 5,5'-Dithiobis(2-nitrobenzoic acid)
Alias: DTNB, Ellman's reagent, bis(3-carboxy-4-nitrophenyl)disulfide, dithionitrobenzoic acid, 6,6′-dinitro-3,3′-dithiobenzoic acid
Molecular formula: [-SC6H3(NO2)CO2H]2
molecular weight：396.35
Brand: Seebio
CAS：69-78-3
Structural formula：
DTNB Mechanism and application of reaction with sulfhydryl group
DTNB structure contains compounds with free thiol groups (such as cysteine), along with sulfide anion (RS-) and DTNB2-. The reaction generates a colored substance, 2-nitro-5-thiobenzoate anion (TNB2-), and a mixed disulfide (RS-TNB-). The rate of this reaction depends on various factors: (1) reaction pH, (2) the pKa' of the sulfhydryl group, and (3) steric and electrostatic effects.
TNB2- at 412nm14,150M-1 cm-1 Has a higher molar absorption coefficient. At pH>7.3, absorption and pH changes have minimal impact.The thiol content in the sample can be calculated by comparison with a standard curve for compounds containing thiol groups (such as cysteine).whenpH value between 7.6 and 8.6，The extinction value of TNB is not affected by changes in pH. However, the extinction value of TNB differs in other solvents.
DTNB features
• Determination of sulfhydryl groups — Quantitatively reacts with free (reduced) sulfhydryl groups (—SH) to produce detectable TNB product
• Colorimetric detection — Colored products can be measured spectrophotometrically in cuvettes or microplates
• Mature analytical methods — Peptide or protein sulfhydryl groups can be quantitatively determined using extinction coefficient calculations or by comparison to cysteine standards.
DTNB application
Determine the content of proteins, peptides and tissues free sulfhydryl group ；
used for acetylcholinesterase detection；
determine Alkyl mercaptan with pre-column derivativeHPLC method；
Specific label cysteine residue.
DTNB Product List
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Item number
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Product name
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Packaging specifications
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AGZ0002A
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5,5'-Disulfobis(2-nitrobenzoic acid)) ，98.0%
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1g、5g、25g
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DTNB Quality Index
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Purity (HPLC）
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98%
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Active ingredients
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98.0-101.0%
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Solubility
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Clear and transparent (1% methanol solution)
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Exterior
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Light yellow to yellow powder
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References
[1] Bio-Claisen condensation catalyzed by thiolase from Zoogloea ramigera. Masamune, S, et al. Active site cysteine residues Chemtracts-Organic Chem (1989) 2:247-51
[2] Ellman's reagent: 5, 5'-dithiobis(2-nitrobenzoic acid) - a reexamination. Riddles, P.W., et al. Anal Biochem (1979) 94:75-81
[3] Fractionation of chicken liver mevalonate 5-diphosphate decarboxylase by sulfhydryl-directed reagents: evidence of a functional dithiol. Alvear, M., et al. Biochem Biophys Acta (1989) 994:7-11
[4] Staphylococcal extracellular adherence protein induces platelet activation by stimulation of thiol isomerases. Anne Bertling et al. Arteriosclerosis, thrombosis, and vascular biology, 32(8), 1979-1990 (2012-04-28)
[5] Reassessment of Ellman's reagent. P W Riddles et al. Methods in enzymology, 91, 49-60 (1983-01-01)
[6] Quick measurement of protein sulfhydryls with Ellman's reagent and with 4,4'-dithiodipyridine. Christian K Riener et al. Analytical and bioanalytical chemistry, 373(4-5), 266-276 (2002-07-12)
[7] Gene therapy delivering a paraoxonase 1 variant offers long-term prophylactic protection against nerve agents in mice. Venkaiah Betapudi et al. Science translational medicine, 12(527) (2020-01-24)