Comparative study of stirred and fluidized tank reactor for hydroxyl-kojic acid derivatives synthesis and their biological activities

Abstract

AbstractBackground:Study on the synthesis of kojic acid derivatives (KADs) in solvent-free system using scalable reactors and their biological activities is still lacking.Methods:In this study, two types of KADs, were synthesized using saturated-fatty acid [lauric acid (LA)] and unsaturated-fatty acid [oleic acid (OA)] in stirred tank reactor (STR) and fluidized tank reactor (FTR). The yield and biological activities of the synthesized KADs were evaluated and compared.Results:The highest yield of KADs (42.95%) was obtained in the synthesis using OA, with molar ratio of 1:1, enzyme loading of 5% (w/v), temperature of 70°C, using immobilized lipase N435 in STR. However, FTR may provide biocatalyst protection and reusability with reduced loss of KADs yield up to three cycles. In antioxidant assay, the hydroxyl-unsaturated-fatty acid of kojic acid (HUFA-KA) showed better activity as compared to hydroxyl-saturated-fatty acid of kojic acid (HSFA-KA) at concentrations ranging from 125 to 2000 μg/mL. In contrast, HSFA-KA showed better cytotoxicity effect against G361 melanoma cell as compared to HUFA-KA.Conclusion:The yield of KADs obtained in STR was higher than that obtained in FTR. HUFA-KA could be used as potential lipophilic antioxidant while HSFA-KA has the potential to be used to treat melanoma skin disorder.