Hair Dyeing by Using Catechinone Obtained from (+)-Catechin

Abstract

A novel colourant for hair dyeing was prepared by an enzymatic reaction with (+)-catechin and its characteristics as a hair dyestuff were studied. The study is aimed at inventing the hair dyestuff that is human-and eco-friendly. One potentially powerful dyestuff was obtained from (+)-catechin treated with tyrosinase after screening experiments using biobased materials. The obtained reddish orange colourant, 4-(3,4-dihydro-3α,5,7-trihydroxy-2H-1-benzopyran-2α-yl) 1,2-benzoquinone named "catechinone", shows enough dyeability for decolourised white hair. Catechinone does not cause erythema or oedema on skin of rabbits. The colour is controlled by the addition of other biobased materials and a variety of colours of dyed hair are acquired. The colour fastness to light or washing for hair dyed by catechinone is high enough for practical use.

The Relationships between Dyeing Methods and Dyeability in Hair Colouring by Utilising Enzymatic Oxidation of (+)-Catechin

“…The catechinone dyes hair orange, reddish orange or deep yellowish brown depending on dyeing conditions such as the oxidation method, dye concentration, temperature, pH and additives [7] [8]. The colour fastness of the hair dyed by catechinone to washing and light (daylight and ultraviolet light) is high enough as same as that of oxidation hair dyes [7] [8].…”

“…The colour fastness of the hair dyed by catechinone to washing and light (daylight and ultraviolet light) is high enough as same as that of oxidation hair dyes [7] [8]. However, the dyeability of catechinone is not high enough for practical use, because the hair dyeing by using it is mild way and the dye colourant molecules do not vigorously penetrate into hair.…”

“…The main compound of catechinone is 4-(3, 4-dihydro-3α,5,7-trihydroxy-2H-1-benzopyran-2α-yl)-1,2-benzoquinone (Figure 1(b)) and the dyestuff contains a small amount of chromatic side products [7]. The colour of powder and solution of catechinone are red, and the absorption peak and the strength change with solution pH and concentration of added salts.…”

“…It was found that the oxidation product of Cat, which was named catechinone, works as hair dyestuff and the dyestuff does not cause erythema or oedema on skin of rabbits [7]. The main compound of catechinone is 4-(3, 4-dihydro-3α,5,7-trihydroxy-2H-1-benzopyran-2α-yl)-1,2-benzoquinone (Figure 1(b)) and the dyestuff contains a small amount of chromatic side products [7].…”

“…The catechinone is obtained by the enzymatic [7] [9] or chemical [10] [11] treatment of Cat, and the oxidation reactions are occurred at the catechol (o-dihydroxybenzene) group of Cat to give a corresponding o-quinone. The enzymatic technique shows generally the advantage in the reactivity and selectivity.…”