ISOPROTERENOL STRUCTURE, ANTIOXIDATIVE PROPERTIES, AND INTERACTIONS WITH PROTEINS

Abstract

Isoprenaline (isoproterenol) is a non-selective β-adrenoreceptor agonist known for its therapeutic effects, which include increased heart rate and cardiac output, bronchodilation, and improved peripheral circulation. Apart from its primary functions in the nervous system and physiological regulation, isoproterenol exhibits antioxidant properties. This study employed a combination of experimental techniques (UV–vis, FTIR, and Raman spectroscopy) and theoretical calculation methods (molecular docking and DFT) to investigate the structural and functional properties of isoproterenol. The appropriate level of theory (M05-2X/6-311++G(d,p)) was determined by comparing experimental and theoretical bond lengths and angles. The antioxidative activity of isoproterenol towards DPPH• was assessed using UV-VIS spectroscopy and further analyzed by DFT methods to elucidate the most probable antiradical mechanism. Compared to its natural analogs (epinephrine and norepinephrine), isoproterenol demonstrates energetically more stable orthosteric binding to the β-adrenergic receptor. Molecular analysis revealed that - contacts with amino acids and hydrogen bonding involving hydroxyl and amino groups play an important role in its binding. This study enhances our understanding of the antioxidant properties of isoproterenol, providing insights into its potential relevance in oxidative stressrelated conditions. Moreover, the structural findings contribute to the future development of novel therapeutic agents with enhanced antioxidant activity and pharmacological profiles.