Synthesis, characterization and application of a new biomass-based antioxidant derived from vanillin and methyl ethyl ketone

A bio-based antioxidant with a similar chemical structure to ferulic acid (FA) was synthesized by Aldol condensation of biomass-derived vanillin and methyl ethyl ketone (MEK). The synthesized product, 1-(4-hydroxy-3-methoxyphenyl) pent-1-en-3-one (HMPPEO) was purified and characterized by FTIR, MS, 1H-NMR and 13C-NMR, providing the data that have not been previously reported. Kinetic modelling revealed that the major reactions taking place in the systems were the Aldol condensation between vanillin and MEK to form HMPPEO and self-condensation of HMPPEO to form heavier product with observed activation energy of 51.7 kJ/mol and 48.3 kJ/mol, respectively. Compared with FA, HMPPEO had similar ability to scavenge HO. and DPPH. free radicals but stronger ability to inhibit tyrosinase activity. Oxidation stability of palm oil biodiesel could be greatly improved to meet the corresponding standard with addition of 1000 mg/kg HMPPEO. This work demonstrates that biomass-derived HMPPEO shows promising application as a green antioxidant or intermediate for industrial or pharmaceutical purpose.

Automated summary

A bio-based antioxidant similar to ferulic acid, HMPPEO, was synthesized from biomass-derived vanillin and MEK through Aldol condensation. It showed strong antioxidant and tyrosinase inhibition abilities, potentially improving the oxidation stability of biodiesel. This work highlights the promising application of biomass-derived HMPPEO in green antioxidant or pharmaceutical fields.