{{DISPLAYTITLE:''p''-Dimethylaminocinnamaldehyde}} {{Chembox | Name = ''p''-Dimethylaminocinnamaldehyde | Watchedfields = changed | ImageFile = Dimethylaminocinnamaldehyde.svg | ImageSize = 200px | IUPACName = 3-[4-(Dimethylamino)phenyl]prop-2-enal | OtherNames = DMAC<br /> 4-Dimethylaminocinnamaldehyde |Section1={{Chembox Identifiers | Abbreviations = DMACA | CASNo_Ref = {{cascite|correct|CAS}} | CASNo = 20432-35-3 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 9RSI7WZ9F0 | PubChem = 5284506 | PubChem_Comment = (''E'') | PubChem1 = 25310830 | PubChem1_Comment = (''Z'') | PubChem2 = 92224 | PubChem2_Comment = | ChemSpiderID = 4447567 | ChemSpiderID_Comment = (''E'') | ChemSpiderID1 = 23646677 | ChemSpiderID1_Comment = (''Z'') | ChemSpiderID2 = 83262 | ChemSpiderID2_Comment = | EINECS = 228-267-0 | MeSHName = 4-Dimethylaminocinnamaldehyde | SMILES = [H]C(=O)C=CC1=CC=C(C=C1)N(C)C | InChI = 1/C11H13NO/c1-12(2)11-7-5-10(6-8-11)4-3-9-13/h3-9H,1-2H3/b4-3+ | InChIKey = RUKJCCIJLIMGEP-ONEGZZNKBZ | StdInChI = 1S/C11H13NO/c1-12(2)11-7-5-10(6-8-11)4-3-9-13/h3-9H,1-2H3/b4-3+ | StdInChIKey = RUKJCCIJLIMGEP-ONEGZZNKSA-N | Beilstein = 972369}} |Section2={{Chembox Properties | Formula = C<sub>11</sub>H<sub>13</sub>NO | MolarMass = 175.22 g/mol | Appearance = white to light yellow crystal powder | Density = 1.057 g/mL | MeltingPtC = 138 | BoilingPtC = 329 | SolubleOther = 50 g/L | Solvent = dioxane }} |Section3={{Chembox Hazards | MainHazards = | FlashPt = | AutoignitionPt = }} }}

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

==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<ref>{{Cite journal | last1 = Porubsky | first1 = P. | last2 = Scott | first2 = E. | last3 = Williams | first3 = T. | doi = 10.1016/j.abb.2008.03.035 | title = P-Dimethylaminocinnamaldehyde derivatization for colorimetric detection and HPLC–UV/vis–MS/MS identification of indoles | journal = Archives of Biochemistry and Biophysics | volume = 475 | issue = 1 | pages = 14–17 | year = 2008 | pmid = 18423367| pmc =2504418 }}</ref> * 1 g DMACA, 1 mL conc. hydrochloric acid and 99 mL water<ref name='sigma'>{{cite web | url = http://www.sigmaaldrich.com/catalog/product/fluka/49825?lang=en®ion=GB | title = DMACA Reagent for microbiology | access-date = 2013-10-29 | author = Sigma-Aldrich Co. LLC}}</ref> * 1 g DMACA in 99 mL conc. hydrochloric acid.<ref name="Indole derivatives produced by C. acutatum">{{Cite journal | last1 = Chung | first1 = K. R. | last2 = Shilts | first2 = T. | last3 = Ertürk | first3 = Ã. M. | last4 = Timmer | first4 = L. W. | last5 = Ueng | first5 = P. P. | title = Indole derivatives produced by the fungusColletotrichum acutatumcausing lime anthracnose and postbloom fruit drop of citrus | doi = 10.1016/S0378-1097(03)00605-0 | journal = FEMS Microbiology Letters | volume = 226 | issue = 1 | pages = 23–30 | year = 2003 | pmid = 13129603| doi-access = free }}</ref>

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|date=October 2013}} It is also particularly useful for localization of proanthocyanidins compounds in plants, resulting in a blue staining. It has been used for grapevine fruit<ref>{{Cite journal | last1 = Bogs | first1 = J. | last2 = Jaffe | first2 = F. W. | last3 = Takos | first3 = A. M. | last4 = Walker | first4 = A. R. | last5 = Robinson | first5 = S. P. | title = The Grapevine Transcription Factor VvMYBPA1 Regulates Proanthocyanidin Synthesis during Fruit Development | doi = 10.1104/pp.106.093203 | journal = Plant Physiology | volume = 143 | issue = 3 | pages = 1347–1361 | year = 2007 | pmid = 17208963| pmc =1820911 }}</ref> or for legumes foliage<ref>{{Cite journal | last1 = Li | first1 = Y. G. | last2 = Tanner | first2 = G. | last3 = Larkin | first3 = P. | title = TheDMACA-HCl Protocol and the Threshold Proanthocyanidin Content for Bloat Safety in Forage Legumes | doi = 10.1002/(SICI)1097-0010(199601)70:1<89::AID-JSFA470>3.0.CO;2-N | journal = Journal of the Science of Food and Agriculture | volume = 70 | pages = 89–101 | year = 1996 }}</ref> histology.

A colorimetric assay based upon the reaction of A-rings{{clarify|date=October 2013}} with the chromogen. ''p''-Dimethylaminocinnamaldehyde has been developed for flavanoids in beer that can be compared with the vanillin procedure.<ref>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}}</ref> The DMACA reagent may be superior to the vanillin procedure for the detection of catechins.<ref>{{Cite journal | doi = 10.1016/j.chroma.2009.03.026| pmid = 19339019| title = Densitometric determination of (+)-catechin and (−)-epicatechin by 4-dimethylaminocinnamaldehyde reagent| journal = Journal of Chromatography A| volume = 1216| issue = 20| pages = 4485–91| year = 2009| last1 = Glavnik | first1 = V. | last2 = Simonovska | first2 = B. | last3 = Vovk | first3 = I. }}</ref>

The DMACA reagent changes color over several days when exposed to air but when refrigerated can be stored for up to two weeks.<ref name="Oxidation of indole-3-acetic acid">{{Cite journal | doi = 10.1104/pp.42.10.1395| title = Studies on the Oxidation of Indole-3-Acetic Acid by Peroxidase Enzymes. I. Colorimetric Determination of Indole-3-Acetic Acid Oxidation Products| year = 1967| last1 = Meudt | first1 = W. J.| last2 = Gaines | first2 = T. P.| journal = Plant Physiology| volume = 42| issue = 10| pages = 1395–9 | pmid=16656668 | pmc=1086736}}</ref>

The DMACA reagent may also be referred to as the Renz and Loew reagent.<ref name="Indole derivatives produced by C. acutatum"/><ref>{{Cite journal | last1 = Ehmann | first1 = A. | title = The van URK-Salkowski reagent — a sensitive and specific chromogenic reagent for silica gel thin-layer chromatographic detection and identification of indole derivatives | doi = 10.1016/S0021-9673(00)89300-0 | journal = Journal of Chromatography A | volume = 132 | issue = 2 | pages = 267–276| year = 1977 | pmid = 188858| url = https://erowid.org/psychoactives/testing/testing_field_article2.pdf}}</ref>

== See also == * Ehrlich's reagent, a simple spot-test to presumptively identify alkaloids

==References== {{reflist|2}}

{{DEFAULTSORT:Dimethylaminocinnamaldehyde, p-}} Category:Conjugated aldehydes Category:Anilines Category:Drug testing reagents Category:Histology Category:Staining dyes Category:Dimethylamino compounds