Laccase-catalysed polymeric dye synthesis from plant-derived phenols for potential application in hair dyeing: Enzymatic colourations driven by homo- or hetero-polymer synthesis.
Bottom Line: We finally used selected materials to dye grey hair.Each material coloured hair appropriately and the dyeing showed excellent resistance to conventional shampooing.Our study indicates that laccase-catalysed polymerization of natural phenols is applicable to the development of new cosmetic pigments.
Affiliation: School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea.Show MeSH
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Mentions: To further characterize the valuable polymeric reactions, we evaluated the extent of monomer removal over time using RP‚ÄźHPLC (Fig.‚ÄÉ5). In colour generation reactions using either catechin and catechol or ferulic acid and syringic acid, both monomer concentrations decreased simultaneously upon laccase catalytic action. However, in polymerization of gallic acid with syringic acid, the two monomers were sequentially removed by laccase. Thus, most gallic acid was removed within 1‚ÄÉh during which time the concentration of syringic acid fell only slightly. Such simultaneous or sequential monomer removal pattern suggests that colouration of gallic acid and syringic acid is based on homopolymer synthesis, whereas in the cases of ferulic acid and syringic acid, and catechin and catechol, heteropolymer is formed by laccase action. To prove experimentally homo‚Äź or hetero‚Äźpolymer synthesis in the selected colourations, we employed ESI‚ÄźMS coupled with CID MS/MS. As shown in Table‚ÄÉ1, the presence of only gallic acid homo‚Äźdimer at initial incubation step was revealed by comparison of CID MS/MS of [M‚ÄÉ‚ąí‚ÄÉH]‚Äź ion of the dimer with CID MS/MS of standard gallic acid. On the other hand, hetero‚Äźdimer and hetero‚Äźtrimer consisting of either ferulic acid and syringic acid or catechin and catechol were observed in the colouration reactions, indicating that hetero‚Äźpolymers were easily formed at oligomer levels. Together with HPLC profiles with incubation times, this CID MS/MS data strongly suggest that colouration with gallic acid and syringic acid proceeds with homo‚Äźpolymer synthesis, whereas colouration with either ferulic acid and syringic acid or catechin and catechol results in hetero‚Äźpolymer synthesis.
Affiliation: School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea.