| abstract |
A method of producing a melanin comprises oxidising a phenolic compound at one or more hydroxyl groups thereof, wherein the phenolic compound is selected from 5-hydroxyindole and derivatives thereof and compounds of formula (1) and the oxidation is provided by biotransformation in the presence of an oxidoreductase enzyme, the compound of formula (1), wherein R1 is H or OH; R2 is H, OH or OCH¿3; R?3 is H or OH at least one of R?1 and R3¿ being OH; R4 is selected from H, R, -COOX and R7-COOX, wherein R is an optionally substituted saturated or unsaturated alkyl group having from 1 to 12 carbon atoms, R7 is an optionally substituted saturated or unsaturated alkylene group having from 1 to 12 carbon atoms and X is selected from H and aliphatic and aromatic ester forming groups; and R?5 and R6¿ is each independently selected from H, OH, NH¿2?, OCH3, CH3, SH, NHCO2, NHCH3, COOH and saturated or unsaturated alkyl groups having up to 8 carbon atoms. |