title: Antibacterial activities of 4-substituted-2-[(E)-{(1S,2R)/(1R,2S)-1-hydroxy-1-phenylpropan-2-ylimino}methyl]phenol.
abstract: A series of norephedrine-based Schiff bases (1a-6a and 1b-6b) were synthesized by reacting substituted salicylaldehydes with d-norephedrine or l-norephedrine. The structure of these compounds was confirmed by elemental analyses and spectroscopic techniques. The molecular structures of 5a and 6a have been determined by X-ray crystallography, which revealed that the compounds are in the oxoamino form, with bent intramolecular N-H···O (N···O ≈ 2.58 Å) hydrogen bonds and that they are associated in dimers bridged by linear intermolecular O-H···O (O···O ≈ 2.69 Å) hydrogen bonds. The density functional theory calculations on 5a confirmed that the oxoamino form is more stable than the phenolimino form by 12.2 kcal/mol. All the compounds were evaluated for their antibacterial activity using resazurin dye as indicator by twofold dilution method against four bacteria namely, Bacillus subtilis (NCIM2718), Staphylococcus aureus (NCIM5021), Escherichia coli (NCIM2931), and Proteus vulgaris (NCIM2813).
authors.affiliation: Department of Chemistry, National Institute of Technology, Tiruchirappalli 620 015, India.
authors.forename: Manoharan Muthu
authors.initials: MM
authors.lastname: Tamizh
authors.forename: Devarayan
authors.initials: D
authors.lastname: Kesavan
authors.forename: Ponnurengam Malliappan
authors.initials: PM
authors.lastname: Sivakumar
authors.forename: Kurt
authors.initials: K
authors.lastname: Mereiter
authors.forename: Mohan
authors.initials: M
authors.lastname: Deepa
authors.forename: Karl
authors.initials: K
authors.lastname: Kirchner
authors.forename: Mukesh
authors.initials: M
authors.lastname: Doble
authors.forename: Ramasamy
authors.initials: R
authors.lastname: Karvembu
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects*; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000187:drug effects; D006860:Hydrogen Bonding; D008826:Microbial Sensitivity Tests; D008968:Molecular Conformation; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology; D010665:Phenylpropanolamine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D011514:Proteus vulgaris / Q000187:drug effects; D012545:Schiff Bases / Q000737:chemistry* / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects; D013237:Stereoisomerism
chemical_list: D000900:Anti-Bacterial Agents; D010636:Phenols; D012545:Schiff Bases; D010665:Phenylpropanolamine