Carminic acid

[9] Carminic acid is commonly harvested from an American species scaled insects called Dactylopius coccus (or cochineals).

[10][11] Cochineals are parasitic scaled insects which are abundantly found on their host plants, the prickly pear cactus native to Mexico and South America.

[12] For many scaled insects of the genus Dactylopius, carminic acid, thoroughly documented by Thomas Eisner, has been shown to be a highly potent feeding deterrent against ants.

[14][15] In Eisner's 1980 paper, he notes that the red colour of the carminic acid released when the cochineals are crushed could also be a visual aposematic deterrent for predators as well.

[14][16][page needed] Carminic acid is a polyketide secondary metabolite produced by the scale insect Dacylopius coccus.

In terms of its biosynthetic origin, the structure of carminic acid was speculated to be either from type ll polyketide or shikimate pathways.

The acetyl-ACP acts as a priming unit for the decarboxylative condensation with malonyl-CoA catalyzed by a ketoacyl synthase (KS) protein.

The resulting acetoacetyl ACP is the simplest polyketide produced by this pathway, and it is subsequently condensed with six more malonyl-ACP units before cyclizing.

It was the successful isolation and characterization of FKA in wild type coccids that strengthened the evidence of a polyketide mediated biosynthetic pathway.

Chemical structure of carminic acid[citation needed]
Chemical structure of carminic acid [ citation needed ]
Ball-and-stick model of carminic acid[citation needed]
Ball-and-stick model of carminic acid [ citation needed ]
Female Dactylopius coccus on prickly pear cactus photographed by Frank Vincentz.
Carminic acid released as the red substance seen on the person's hand after crushing Dactylopius coccus - by Dick Culbert.
Female (left) and male (right) cochineals
Biosynthesis of carminic acid