Antioxidant Properties of Ferulic Acid Salts with Nicotine, Thionicotine and Selenonicotine

Background: Ferulic acid salts of nicotine and cotinine chalcogen analogs (thionicotine and selenonicotine) were characterized by spectroscopic methods. Antioxidant properties of all compounds prepared were evaluated. The obtained results indicated that thionicotine salt with ferulic acid was the most efficient to prevent the induced-oxidative haemolysis. Methods: The structure of salts was determined by ESI-MS and NMR methods. The antioxidant properties of all compounds prepared were evaluated by their reducing power, free radical scavenging activity and chelating capacity. Antioxidant and protective activities of compounds tested were compared with butylated hydroxytoluene (BHT) and Trolox, as standards. The capacity of all compounds to protect in vitro human erythrocytes from oxidative damage induced by 2,2'-azobis (2-methylpropionamidine) dihydrochloride (APPH) or tert-butyl hydroperoxide (t-BuOOH) was also estimated. Results: Ferulic acid forms the 1:1 salts with thionicotine and selenonicotine while 2:1 salt is formed with nicotine. Thionicotine salt with ferulic acid was the most efficient antioxidant (61.4% DPPH scavenging activity), as effective as standard Trolox (63%), and two times more effective than BHT (32.1%) at 1 mg/mL. Neither nicotine alkaloids and ferulic acid alone nor their salts, did not induce modification in the RBC shape or in their cell membrane permeability up to the concentration 1 mg/mL after 60 min or 24 h incubation Thionicotine salt with ferulic acid was the most potent inhibitor, as effective as Trolox and about 4 times more efficient than BHT at 1 mg/mL. Conclusion: Nicotine alkaloids salts with ferulic acid characterize an antioxidative potential and protect erythrocytes against oxidative-damage, therefore, they can be take into account for the further structureactivity studies in searching for new effective antioxidants. Keywords: Nicotine, thio- and selenoanalogs, ferulic acid, antioxidant properties, human erythrocytes, haemolysis