Partition study of caffeic and p-coumaric acids from aqueous two-phase system composed of ethanol + ammonium sulfate + water at 298 K

Resumo

Vascular plants synthesize attractive pharmacological compounds of which phenolic acids stand out. Caffeic acid and p-coumaric acids belonged to that category of compounds and they are found in almost every plant. Since their importance and wide range of applications, the aim of this study is to evaluate the partition coefficient (K) and the separation efficiency (?) of the two acids from an aqueous two-phase system (ATPS) composed of ethanol + ammonium sulfate + water at 298 K. Liquid-liquid equilibrium (LLE) data were obtained by the determination of the binodal curve and the tie-lines, using cloud point and gravimetric methods, respectively. After that, using known concentrations in the biphasic region, the partition coefficient and the separation efficiency were determined. For the caffeic acid, the values obtained were, in order, 14.95 and 90.75%. And, for the p-coumaric acid, the values were 22.20 and 94.47%. Both compounds showed more affinity with the alcoholic phase and can be extracted using the ATPS studied.