Preparation and characterization of liprotides prepared from protein extracts of mung beans (Vigna radiata (L.))

Abstract

Liprotides are protein-fatty acid complexes that have been shown to exhibit promising drug carrier and anti-cancer activities. Most published studies have focused thus far on animal serum albumin proteins, and there is scarce data on liprotides prepared from other protein molecules, particularly those derived from plants. Therefore, to explore new liprotide preparations, mung bean albumins and globulins were extracted, and their complexation with oleic acid at 40 °C and 80 °C was investigated. The prepared complexes were then subjected to ATR-FTIR spectroscopy, particle size, and zeta potential analyses. The FTIR spectra of the liprotides showed that the proteins' characteristic amide I and II bands shifted to higher wavenumbers, indicating changes in secondary structure in the presence of oleic acid. This was also accompanied by changes in the characteristic bands for C=O and C-H stretching of oleic acid in the presence of the protein. Particle size analysis showed that the prepared liprotides were highly polydispersed (PdI > 0.4), ranging from 658.7 nm and 1946 nm in diameter, that was also larger than those reported previously. Finally, zeta-potential measurement revealed that the liprotides had values ranging from -24.19 mV and -34.88 mV, which generally suggested an incipient to moderate stability of the colloidal suspension against aggregation. These data suggest that the preparation temperature employed in the study resulted in liprotides prepared from the crude albumin and globulin extracts having comparable characteristics.