Enzymatic halogenation of the phenolic monoterpenes thymol and carvacrol with chloroperoxidase

Abstract

Enzymatic halogenation of thymol and its derivatives has been shown using a bioelectrochemical approach with chloroperoxidase.

Thymol Bromination – A Comparison between Enzymatic and Chemical Catalysis

“…Further improvements can be expected from in situ generation of H 2 O 2 to supply the biocatalyst with sufficient but not detrimental amounts of H 2 O 2 for generation of the brominating species. [30,[35][36][37] A simple comparison of the environmental impact of the two methods by using the E-factor [39][40][41] demonstrates that biocatalysis is not per se environmentally more benign than chemical catalysis. In both cases, the relatively high solvent contribution (due to the low product concentrations used) another centrifugation step (2800 rpm, 15 min).…”

“…MS (EI): m/z (%) = 228 (30) Catalytic Procedure: Thymol (15 mg ,0.1 mmol) and KBr (11.9 mg ,0.1 mmol) were dissolved in an aqueous solution of NH 4 VO 3 (960 μL, 5 mm). Then, H 2 O 2 (20 μL, 10.4 m) and perchloric acid (20 μL of 5 m) were added to obtain a pH value of 1.…”

“…To the best of our knowledge, only few examples of thymol bromination reaction are reported in the literature. [4,29,30] To be able to demonstrate the sustainability of our procedures, the chemical and the enzyme-catalyzed bromination of thymol were performed without solvent.…”

Towards electroenzymatic processes involving old yellow enzymes and mediated cofactor regeneration

“…Finally, it can be concluded that electroenzymatic processes under anaerobic conditions can lead to more sustainable processes compared to processes in the presence of oxygen and using oxygenases . The presented productivities are in the same range as in electroenzymatic processes to produce hydrogen peroxide [, ] or the regeneration of oxidized nicotinamide cofactors . It can be concluded that anaerobic regeneration of oxidized cofactors, anaerobic regeneration, or substitution of cofactors as well as the electrochemical production of hydrogen peroxide can be successfully implemented in relevant industrial processes.…”

Seaweeds as Source of New Bioactive Prototypes

“…The monoterpenes are substances with ten carbons formed by two isoprene units, and can be cyclic or aliphatic (acyclic) [68]. Halogenated monoterpenes are found in genres Plocamium, Portieria, and Ochtodes [69]. In general, it is believed that in the marine environment, halogenated monoterpenes serve as chemical defense in response to stressor agents, especially herbivores.…”