The effect of natural deep eutectic solvents on laccase activity and oligomerization of rutin

Natural deep eutectic solvents (NADESs) were investigated for the activity and stability of the laccase enzyme. Laccase was found to be active only in a low amount of choline chloride containing NADESs while it maintained its activity both in high and low amounts of betaine containing NADESs. Rutin, as a flavonoid monomer shows high antioxidant, antibacterial, antiviral and anti-inflammatory properties and these properties are enhanced in the polymerised form. In this study, the organic co-solvent that is conventionally used in the oligomerization of rutin was replaced with two different green solvents, choline chloride-ethylene glycol (1:2 molar ratio) and betaine-mannose (5:2 molar ratio). LC-MS results revealed spontaneous derivatization of rutin as well as the oligomerization of the derivatives besides rutin. The final products were found to have enhanced superoxide radical activity. In this study, enzymatic oligomerization of rutin was investigated for the first time in the presence of eco-friendly green solvents presenting an alternative pathway without any toxic components.