title: Theoretical studies on sulfanilamide and derivatives with antibacterial activity: conformational and electronic analysis.
abstract: Quantum chemical methods have been used to study the conformational and electronic properties of sulfanilamide and derivatives with antibacterial activity. Calculations at B3LYP/6-311++G(3df,2p) level of theory predict the existence of four conformers for sulfanilamide depending on the orientation of p-amino and amide groups. Focusing on the sulfonamide moiety, amide NH(2) and SO(2) groups could exist either in an eclipsed or staggered arrangement. Gas-phase results predict the eclipsed conformer to be most stable but opposite to what has been rationalized previously, no stabilizing hydrogen bonds between those groups has been found through NBO analysis. When solvent effect is taken into account through the IEF-PCM method, staggered conformer is preferred; in fact, eclipsed conformation changed when explicit solvent molecules were included. Conformational analysis of all derivatives has shown two global minima which are specular images. Five out of the seven derivatives studied adopted a particular minimum energy conformation with very similar geometries.
authors.affiliation: Departamento de Química, Facultad de Química, Bioquímica y Farmacia, Universidad Nac. de San Luis, San Luis, Argentina. egvega@unsl.edu.ar
authors.forename: Esteban G
authors.initials: EG
authors.lastname: Vega-Hissi
authors.forename: Matías F
authors.initials: MF
authors.lastname: Andrada
authors.forename: Graciela N
authors.initials: GN
authors.lastname: Zamarbide
authors.forename: Mario R
authors.initials: MR
authors.lastname: Estrada
authors.forename: Francisco
authors.initials: F
authors.lastname: Tomás-Vert
mesh_terms: D000465:Algorithms; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D003198:Computer Simulation; D004563:Electrochemistry; D004583:Electrons; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D013424:Sulfanilamides / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D000900:Anti-Bacterial Agents; D013424:Sulfanilamides
references.citation: J Biol Chem. 1962 Feb;237:536-40
references.pmid: 13873645
references.citation: J Org Chem. 2006 Apr 14;71(8):2952-6
references.pmid: 16599587
references.citation: J Mol Model. 2008 Aug;14(8):689-97
references.pmid: 18458968
references.citation: J Org Chem. 2004 Aug 6;69(16):5448-53
references.pmid: 15287795
references.citation: Bioorg Med Chem. 2008 Apr 1;16(7):3519-29
references.pmid: 18316193
references.citation: J Med Chem. 2007 Dec 27;50(26):6535-44
references.pmid: 18052117
references.citation: J Chem Theory Comput. 2007;3(2):407-433
references.pmid: 19002267
references.citation: J Phys Chem A. 2008 Apr 3;112(13):2969-76
references.pmid: 18302350
references.citation: Chem Rev. 2005 Aug;105(8):2999-3093
references.pmid: 16092826
references.citation: J Org Chem. 2009 Jul 3;74(13):4740-6
references.pmid: 19558179
references.citation: Chemosphere. 2008 Jun;72(5):836-43
references.pmid: 18396316