Authors: N.E. Polyakov, T.V. Leshina, E.S. Meteleva, A.V. Dushkin, T.A. Konovalova, L.D. Kispert
Affilation: University of Alabama, United States
Pages: 312 - 315
Keywords: carotenoids, arabinogalactan, glycyrrhizic acid, drug delivery, radicals, photostability, solubility, ESR
We present first example of water soluble conjugates of carotenoids with a triterpene glycoside, glycyrrhizic acid (GA), and natural polysaccharide arabinogalactan (AG), studied by various physicochemical techniques. Carotenoids are well known as a class of pigments wide-spread in nature and as antioxidants. At the same time, wide practical application of carotenoids as antioxidants is substantially hampered by their hydrophobic properties, instability in the presence of oxygen and metal ions, and high photosensitivity. The preparation of supramolecular conjugates allows to minimize the aforementioned disadvantages when carotenoids are used in food processing (colors and antioxidant capacity) as well as for production of therapeutic formulations considering the better solubility and consequently higher bioavailability. An important result for using in photodynamic therapy was obtained on the study of photoinduced hydroxyl radical generation on the surface of TiO2 nanoparticles in aqueous solution. A considerable increase in the yield of free radicals was detected in the presence of carotene-AG complex. On the other hand, complexes of some carotenoids with glycyrrhizic acid show enhanced ability (in orders of magnitude) to scavenge free radicals. In addition, several examples of AG and GA conjugates with various drugs will be demonstrated.