Nicotine as a Catalyst for Chlorination Promoted by Hypochlorous Acid: Experimental and Theoretical Studies

Journal of the Brazilian Chemical Society

article

Ximenes, Valdecir F.¹  Pavan, Nathalia M.¹  Souza, Aguinaldo R. de¹  Barros, Gabriel A.²  Morgon, Nelson H.² 

[1] Universidade Estadual Paulista;Universidade Estadual de Campinas

关键词: hypochlorous acid;    nicotine;    chlorination of biomolecules;    DFT calculations;   

DOI  :  10.21577/0103-5053.20220088

学科分类：内科医学

来源: SciELO

【 摘 要 】

There is robust evidence of the hypochlorous acid (HClO)-mediated damage in biomolecules, and nicotine boosts the chlorination potency of HClO. We present experimental and theoretical evidence of the mechanism by which nicotine catalyzes the chlorination of pyranine. The rate constants for chlorination of pyranine by HClO were measured in the presence (5.3 × 105 mol 11 Schaal, C.; Chellappan, S. P.; Mol. Cancer Res. 2014, 12, 14. [Crossref]Crossref... L s-1) and absence of nicotine (4.2 × 103 mol-1 L s-1), revealing the catalytic effect of the alkaloid. Density functional theory (DFT) calculations, based on B3LYP-GD3(BJ)/6-311++G(3df,2p)/SMD(Water)//B3LYP-GD3(BJ)/6-311++G(2d,p)/SMD(Water) level of theory, were performed and showed a decreased activation energy for chlorine transfer and hydrogen abstraction when nicotine chloramine intermediated the reaction. The atomic polar tensor (APT) charges on the chlorine atom of HClO (+0.084) were lower than the chlorine of nicotine chloramine (+0.149), revealing the higher electrophilic character of nicotine chloramine. In conclusion, the increased electrophilic nature of HClO provoked by nicotine explains its catalytic effect.

【 授权许可】

CC BY