title: Spectroscopic and structural studies on lactose species in aqueous solution combining the HATR and Raman spectra with SCRF calculations.
abstract: In this work, the α and β isomers, the α-lactose monohydrate and dihydrate and the dimeric species of lactose were studied from the spectroscopic point of view in gas and aqueous solution phases combining the infrared, Horizontal Attenuated Total Reflectance (HATR) and Raman spectra with the density functional theory (DFT) calculations. Aqueous saturated solutions of α-lactose monohydrate and solutions at different molar concentrations of α-lactose monohydrate in water were completely characterized by infrared, HATR and Raman spectroscopies. For all the species in solution, the solvent effects were studied using the solvation polarizable continuum (PCM) and solvation (SM) models and, then, their corresponding solvation energies were predicted. The vibrational spectra of those species in aqueous solution were completely assigned by employing the Scaled Quantum Mechanics Force Field (SQMFF) methodology and the self-consistent reaction field (SCRF) calculations. The stabilities of all those species were studied by using the natural bond orbital (NBO), and atoms in molecules (AIM) calculations.
authors.affiliation: Cátedra de Química General, Instituto de Química Inorgánica, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, 4000 San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: María Jimena
authors.initials: MJ
authors.lastname: Márquez
authors.affiliation: Cátedra de Bromatología, Instituto de Bioquímica Aplicada, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Lorenzo 456, 4000 San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: Alicia Beatriz
authors.initials: AB
authors.lastname: Brizuela
authors.affiliation: Instituto de Investigaciones para la Industria Química (INIQUI, CONICET), Universidad Nacional de Salta, Av. Bolivia 5150, 4400 Salta, Argentina.
authors.forename: Lilian
authors.initials: L
authors.lastname: Davies
authors.affiliation: Cátedra de Química General, Instituto de Química Inorgánica, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, 4000 San Miguel de Tucumán, Tucumán, Argentina. Electronic address: sbrandan@fbqf.unt.edu.ar.
authors.forename: Silvia Antonia
authors.initials: SA
authors.lastname: Brandán
mesh_terms: D002236:Carbohydrate Conformation; D007785:Lactose / Q000737:chemistry*; D008956:Models, Chemical; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D007785:Lactose
keywords: DFT calculations; Force field; Lactose; Molecular structure; Vibrational spectra