Complexation between oleanolic and maslinic acids with native and modified cyclodextrins

Abstract

Oleanolic (OA) and maslinic (MA) acids are two natural triterpenoids with a wide range of beneficial effects for human health. However, their low solubility and permeability make their application in the food, or pharmaceutical, industry difficult. The complexation of OA and MA with α- β-, γ-, HP-α-, HP-β- and HP-γ-CDs, under different pH and temperature conditions, has been studied. Neither α- nor HP-α-CDs formed inclusion complexes, while β-, HP-β- and HP-γ-CDs provided A_L type and γ-CDs B_S phase solubility diagrams. Complexation was shown to be more stable in the case of MA but complexation efficiency was greater for OA. Increasing the pH and temperature of the complexation media tended to improve the complexation process with triterpenic acids.

Keywords: Complexation; Complexation constant; Cyclodextrin; Efficiency; Maslinic acid; Oleanolic acid; Thermodynamic parameters.