What is "carminic acid"

Carmine \Car"mine\, n. [F. carmin (cf. Sp. carmin, It. carminio), contr. from LL. carmesinus purple color. See Crimson.]

1. A rich red or crimson color with a shade of purple.

2. A beautiful pigment, or a lake, of this color, prepared from cochineal, and used in miniature painting.

3. (Chem.) The essential coloring principle of cochineal, extracted as a purple-red amorphous mass. It is a glucoside and possesses acid properties; -- hence called also carminic acid.

   Carmine red (Chem.), a coloring matter obtained from carmine as a purple-red substance, and probably allied to the phthale["i]ns.

n. (context chemistry English) a phenolic quinone that is the main constituent of cochineal

Carminic acid (CHO) is a red glucosidal hydroxyanthrapurin that occurs naturally in some scale insects, such as the cochineal, Armenian cochineal, and Polish cochineal. The insects produce the acid as a deterrent to predators. Carminic acid is the colouring agent in carmine. Synonyms are C.I. 75470 and C.I. Natural Red 4.

The chemical structure of carminic acid consists of a core anthraquinone structure linked to a glucose sugar unit. Carminic acid was first synthesized by organic chemists in 1991.