Lipoylcarnosine: Synthesis, Study of Physico-Chemical and Antioxidant Properties, Biological Activity

Abstract

Synthesis of lipoylcarnosine (LipС), a conjugated molecule based on two natural antioxidants, carnosine and α-lipoic acid, is described and its physico-chemical, antioxidant properties and biological activity are characterized. According to reversed-phase HPLC with a UV detector, purity of the final product was 89.3%. The individuality of the obtained sodium salt of LipС was confirmed by tandem HPLC-mass spectrometry. LipC demonstrated high resistance to hydrolysis with serum carnosinase. The antioxidant activity of LipC evaluated by the reaction with the formation of thiobarbituric acid reacting substances and kinetic parameters of iron-induced chemiluminescence was higher than that of carnosine and lipoic acid. LipC did not affect viability of SH-SY5Y human neuroblastoma cells, differentiated to the dopaminergic phenotype, at concentrations not exceeding 5 mM. In the concentration range of 0.1–0.25 mM LipC protected neuronal cells against 1-methyl-4-phenylpyridinium (MPP⁺)-induced toxicity.