''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
Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...
, 5 mL of conc
hydrochloric acid
Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungency, pungent smell. It is classified as a acid strength, strong acid. It is ...
and diluted to 50mL with water
* 1 g DMACA, 1 mL conc. hydrochloric acid and 99 mL
water
Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...
* 1 g DMACA in 99 mL conc. hydrochloric acid.
It is primarily used as a histological dye used to detect
indole
Indole is an organic compound with the formula . Indole is classified as an aromatic heterocycle. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered pyrrole ring. Indoles are derivatives of indole ...
s, particularly for production in cells. It is used for the rapid identification of bacteria containing
tryptophanase enzyme systems. It is also particularly useful for localization of
proanthocyanidin
Proanthocyanidins are a class of polyphenols found in many plants, such as cranberry, blueberry, and grape seeds. Chemically, they are oligomeric flavonoids. Many are oligomers of catechin and epicatechin and their gallic acid esters. More complex ...
s compounds in plants, resulting in a blue staining. It has been used for grapevine fruit or for legumes foliage histology.
A colorimetric assay based upon the reaction of A-rings with the chromogen. ''p''-Dimethylaminocinnamaldehyde has been developed for
flavanoids in beer that can be compared with the
vanillin
Vanillin is an organic compound with the molecular formula . It is a phenolic aldehyde. Its functional groups include aldehyde, hydroxyl, and ether. It is the primary component of the ethanolic extract of the vanilla bean. Synthetic vanillin ...
procedure. The DMACA reagent may be superior to the vanillin procedure for the detection of
catechins.
The DMACA reagent changes color over several days when exposed to air but when refrigerated can be stored for up to two weeks.
The DMACA reagent may also be referred to as the Renz and Loew reagent.
See also
*
Ehrlich's reagent
Ehrlich's reagent or Ehrlich reagent is a reagent containing ''p''-dimethylaminobenzaldehyde (DMAB) and thus can act as an indicator to presumptively identify indoles and urobilinogen. Several Ehrlich tests use the reagent in a medical test; so ...
, a simple spot-test to presumptively identify alkaloids
References
External links
DMACA on www.bd.com
{{DEFAULTSORT:Dimethylaminocinnamaldehyde, p-
Conjugated aldehydes
Anilines
Drug testing reagents
Histology
Staining dyes