title: Investigations on Synperiplanar and Antiperiplanar Isomers of Losartan: Theoretical and Experimental NMR Studies.
abstract: Losartan inhibits the renin-angiotensin-aldosterone system by blocking the angiotensin II receptor. It is commonly used in cardiovascular diseases, such as hypertension. Several publications applied the ab initio and density functional theory methods to investigate the molecule of losartan. Only in one of them were the nuclear magnetic resonance spectra calculations carried out, and their results were correlated with the experimental values. The authors focused their attention on calculations of the anion form of losartan, taking into consideration both its synperiplanar and antiperiplanar configurations. Coefficients of determination and mean absolute deviation parameters were calculated for the experimental and calculated chemical shifts for every used basis set. They showed a noticeably stronger correlation for the anti-isomers than for the syn-isomers. Moreover, the solvation model increased the value of this parameter. The results of calculations confirmed that an anti-conformation of the analyte seems to be the preferred one, and such an orientation might be most potent within the receptor cavity, which is in agreement with the results of previous studies.
authors.affiliation: Department of Organic Chemistry, Faculty of Pharmacy, Poznan University of Medical Sciences, Grunwaldzka 6 Street, 60-780 Poznań, Poland. jacekkuj@ump.edu.pl.
authors.forename: Jacek
authors.initials: J
authors.lastname: Kujawski
authors.affiliation: Department of Organic Chemistry, Faculty of Pharmacy, Poznan University of Medical Sciences, Grunwaldzka 6 Street, 60-780 Poznań, Poland. czaja.kornelia@gmail.com.
authors.forename: Kornelia
authors.initials: K
authors.lastname: Czaja
authors.affiliation: Institute of Bioorganic Chemistry Polish Academy of Sciences, Z. Noskowskiego Street 12/14, 61-704 Poznań, Poland. tomaszr@ibch.poznan.pl.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Ratajczak
authors.affiliation: Department of Organic Chemistry, Faculty of Pharmacy, Poznan University of Medical Sciences, Grunwaldzka 6 Street, 60-780 Poznań, Poland. youleadmeastray@gmail.com.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Jodłowska
authors.affiliation: Institute of Bioorganic Chemistry Polish Academy of Sciences, Z. Noskowskiego Street 12/14, 61-704 Poznań, Poland. tomaszr@ibch.poznan.pl.
authors.forename: Marcin K
authors.initials: MK
authors.lastname: Chmielewski
mesh_terms: D007536:Isomerism; D019808:Losartan / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008958:Models, Molecular
chemical_list: D019808:Losartan
keywords: DFT; MP2; NMR calculations; losartan