P-Dimethylaminocinnamaldehyde

p-Dimethylaminocinnamaldehyde (DMACA) is an aromatic hydrocarbon. It is used in an acidic solution to detect indoles.

p-Dimethylaminocinnamaldehyde

Names
IUPAC name 3-[4-(Dimethylamino)phenyl]prop-2-enal
Other names DMAC 4-Dimethylaminocinnamaldehyde
Identifiers
CAS Number	20432-35-3 Y
3D model (JSmol)	Interactive image
Abbreviations	DMACA
Beilstein Reference	972369
ChemSpider	4447567 (E) 23646677 (Z) 83262
EC Number	228-267-0
MeSH	4-Dimethylaminocinnamaldehyde
PubChem CID	5284506 (E) 25310830 (Z) 92224
UNII	9RSI7WZ9F0 Y
CompTox Dashboard (EPA)	DTXSID9022237
InChI InChI=1S/C11H13NO/c1-12(2)11-7-5-10(6-8-11)4-3-9-13/h3-9H,1-2H3/b4-3+ Key: RUKJCCIJLIMGEP-ONEGZZNKSA-N InChI=1/C11H13NO/c1-12(2)11-7-5-10(6-8-11)4-3-9-13/h3-9H,1-2H3/b4-3+ Key: RUKJCCIJLIMGEP-ONEGZZNKBZ
SMILES [H]C(=O)C=CC1=CC=C(C=C1)N(C)C
Properties
Chemical formula	C11H13NO
Molar mass	175.22 g/mol
Appearance	white to light yellow crystal powder
Density	1.057 g/mL
Melting point	138 °C (280 °F; 411 K)
Boiling point	329 °C (624 °F; 602 K)
Solubility in dioxane	50 g/L
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Use as a testing reagent

The DMACA is any of a number of acidified DMACA solutions:

• 0.117 g of DMACA, 39 mL of ethanol, 5 mL of conc hydrochloric acid and diluted to 50mL with water^[1]
• 1 g DMACA, 1 mL conc. hydrochloric acid and 99 mL water^[2]
• 1 g DMACA in 99 mL conc. hydrochloric acid.^[3]

It is primarily used as a histological dye used to detect indoles, particularly for production in cells. It is used for the rapid identification of bacteria containing tryptophanase enzyme systems.^{[citation needed]} It is also particularly useful for localization of proanthocyanidins compounds in plants, resulting in a blue staining. It has been used for grapevine fruit^[4] or for legumes foliage^[5] histology.

A colorimetric assay based upon the reaction of A-rings^{[clarification needed]} with the chromogen. p-Dimethylaminocinnamaldehyde has been developed for flavanoids in beer that can be compared with the vanillin procedure.^[6] The DMACA reagent may be superior to the vanillin procedure for the detection of catechins.^[7]

The DMACA reagent changes color over several days when exposed to air but when refrigerated can be stored for up to two weeks.^[8]

The DMACA reagent may also be referred to as the Renz and Loew reagent.^[3][9]

See also

• Ehrlich's reagent, a simple spot-test to presumptively identify alkaloids

References

1. Porubsky, P.; Scott, E.; Williams, T. (2008). "P-Dimethylaminocinnamaldehyde derivatization for colorimetric detection and HPLC–UV/vis–MS/MS identification of indoles". Archives of Biochemistry and Biophysics. 475 (1): 14–17. doi:10.1016/j.abb.2008.03.035. PMC 2504418. PMID 18423367.
2. Sigma-Aldrich Co. LLC. "DMACA Reagent for microbiology". Retrieved 2013-10-29.
3. Chung, K. R.; Shilts, T.; Ertürk, Ã. M.; Timmer, L. W.; Ueng, P. P. (2003). "Indole derivatives produced by the fungusColletotrichum acutatumcausing lime anthracnose and postbloom fruit drop of citrus". FEMS Microbiology Letters. 226 (1): 23–30. doi:10.1016/S0378-1097(03)00605-0. PMID 13129603.
4. Bogs, J.; Jaffe, F. W.; Takos, A. M.; Walker, A. R.; Robinson, S. P. (2007). "The Grapevine Transcription Factor VvMYBPA1 Regulates Proanthocyanidin Synthesis during Fruit Development". Plant Physiology. 143 (3): 1347–1361. doi:10.1104/pp.106.093203. PMC 1820911. PMID 17208963.
5. Li, Y. G.; Tanner, G.; Larkin, P. (1996). "TheDMACA-HCl Protocol and the Threshold Proanthocyanidin Content for Bloat Safety in Forage Legumes". Journal of the Science of Food and Agriculture. 70: 89–101. doi:10.1002/(SICI)1097-0010(199601)70:1<89::AID-JSFA470>3.0.CO;2-N.
6. A new colourimetric assay for flavonoids in pilsner beers. Jan A. Delcour and Didier Janssens de Varebeke, Journal of the Institute of Brewing, January–February 1985, Volume 91, Issue 1, pages 37–40, doi:10.1002/j.2050-0416.1985.tb04303.x
7. Glavnik, V.; Simonovska, B.; Vovk, I. (2009). "Densitometric determination of (+)-catechin and (−)-epicatechin by 4-dimethylaminocinnamaldehyde reagent". Journal of Chromatography A. 1216 (20): 4485–91. doi:10.1016/j.chroma.2009.03.026. PMID 19339019.
8. Meudt, W. J.; Gaines, T. P. (1967). "Studies on the Oxidation of Indole-3-Acetic Acid by Peroxidase Enzymes. I. Colorimetric Determination of Indole-3-Acetic Acid Oxidation Products". Plant Physiology. 42 (10): 1395–9. doi:10.1104/pp.42.10.1395. PMC 1086736. PMID 16656668.
9. Ehmann, A. (1977). "The van URK-Salkowski reagent — a sensitive and specific chromogenic reagent for silica gel thin-layer chromatographic detection and identification of indole derivatives" (PDF). Journal of Chromatography A. 132 (2): 267–276. doi:10.1016/S0021-9673(00)89300-0. PMID 188858.

External links

• DMACA on www.bd.com