3,5-Dinitrosalicylic acid

3,5-Dinitrosalicylic acid (DNS or DNSA, IUPAC name 2-hydroxy-3,5-dinitrobenzoic acid) is an aromatic compound that reacts with reducing sugars and other reducing molecules to form 3-amino-5-nitrosalicylic acid, which strongly absorbs light at 540 nm. It was first introduced as a method to detect reducing substances in urine by James B. Sumner^[2] and has since been widely used, for example, for quantifying carbohydrate levels in blood.^[3] It is mainly used in assay of alpha-amylase. However, enzymatic methods are usually preferred due to DNS's lack of specificity.^[4]

3,5-Dinitrosalicylic acid^[1]

Names
Preferred IUPAC name 2-Hydroxy-3,5-dinitrobenzoic acid
Other names 3,5-Dinitrosalicylic acid
Identifiers
CAS Number	609-99-4 N
3D model (JSmol)	Interactive image
Beilstein Reference	2220661
ChEBI	CHEBI:53648 Y
ChEMBL	ChEMBL2260697
ChemSpider	11380 Y
ECHA InfoCard	100.009.278
EC Number	210-204-3
Gmelin Reference	5309
KEGG	C11319 Y
PubChem CID	11873
UNII	2ACT5NW8HU Y
CompTox Dashboard (EPA)	DTXSID9060576
InChI InChI=1S/C7H4N2O7/c10-6-4(7(11)12)1-3(8(13)14)2-5(6)9(15)16/h1-2,10H,(H,11,12) Y Key: LWFUFLREGJMOIZ-UHFFFAOYSA-N Y InChI=1/C7H4N2O7/c10-6-4(7(11)12)1-3(8(13)14)2-5(6)9(15)16/h1-2,10H,(H,11,12) Key: LWFUFLREGJMOIZ-UHFFFAOYAQ
SMILES c1c(cc(c(c1C(=O)O)O)[N+](=O)[O-])[N+](=O)[O-]
Properties
Chemical formula	C7H4N2O7
Molar mass	228.116 g·mol−1
Appearance	Yellow needles or plates
Melting point	182 °C (360 °F; 455 K)
Solubility in water	Soluble
Solubility in organic solvents	Soluble in ethanol, diethyl ether, benzene
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H315, H318, H319, H335
Precautionary statements	P261, P264, P270, P271, P280, P301+P312, P302+P352, P304+P340, P305+P351+P338, P310, P312, P321, P330, P332+P313, P337+P313, P362, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Synthesis

3,5-Dinitrosalicylic acid can be prepared by the nitration of salicylic acid.^[5]

References

1. Lide, David R. (1998). Handbook of Chemistry and Physics (87 ed.). Boca Raton, Florida: CRC Press. pp. 3–318. ISBN 978-0-8493-0594-8.
2. Sumner, J.B. Dinitrosalicylic acid: a reagent for the estimation of sugar in normal and diabetic urine. Journal of Biological Chemistry 47, 5, 1921.
3. "Description of lab use from the Department of Chemical Engineering, University of Maryland". Archived from the original on 2007-08-17. Retrieved 2006-03-17.
4. Miller, Gail Lorenz (1959). "Use of dinitrosalicylic acid reagent for determination of reducing sugar". Anal. Chem. 31 (3): 426–428. doi:10.1021/ac60147a030.
5. Thiel, W.; Mayer, R.; Jauer, E.-A.; Modrow, H.; Dost, H.: Synthesis and Spectral Characterization of Blue Dyes of the Benzene Series in J. Prakt. Chem. (Leipzig) 328 (1986) 497-514, doi:10.1002/prac.19863280406.