First Self-Assembly of Dihydroxy Triterpenoid Maslinic Acid Yielding Vesicles

Maslinic acid, a naturally occurring dihydroxy triterpenoid having a 6-6-6-6-6 fused pentacyclic structure, is extractable from the fruits of olive (Olea europaea). As part of our ongoing investigations on the self-assembly of natural products, herein, we report the results of our detailed investigation on the self-assembly of maslinic acid in different liquids. The triterpenoid self-assembled in aqueous binary liquid mixtures yielding vesicles of nano to micrometer diameters. Detailed characterization of the self-assemblies was carried out by scanning electron microscopy, high-resolution transmission electron microscopy, atomic force microscopy, optical microscopy, Fourier-transform infrared spectroscopy, and low-angle X-ray diffraction studies. The vesicular self-assemblies were capable of entrapping fluorophores including the chemotherapeutic anticancer drug doxorubicin. Triton X-100-triggered release of the encapsulated drug was also demonstrated via rupture of vesicles.