<b>Dye</b>

Abstract

Lac, a natural resin of insect

origin, is used extensively for natural food

additives, cosmetics and as a colorant for

silk and cotton dyeing. Lac dye, which is

the soluble part of stick lac, is composed

mainly of two major anthraquinone-based

components: laccaic acids A and B; the

minor components, laccaic acids C, D and

E, have also been isolated. The UV–VIS

spectrum of laccaic acid A is very similar

to the spectrum of crude laccaic acid in

ethanol, with absorption maxima for

laccaic acid A reported at 290, 340,

500 and 530 nm in this solvent; in

water, λmax values were reported at 292

and 490nm and at 500nm in acetone

for this acid (referred to as laccaic acid.