Theoretical-computational modelling of the L-alanine CD spectrum in water.

[Display omitted] • Electronic and magnetic properties of L-alanine in cationic form in water have been studied combining experimental measurements and theoretical-computational calculations. • The calculated Circular Dichroism spectrum well reproduces the corresponding experimental data. • The conformational effects, which are explicitly treated in our theoretical approach, determine the CD spectral behavior. • The absorption essential features, absorption maximum position and intensity, are in line with the experimental data. • Our approach can be easily extended to the modelling of the CD spectrum of more complex solutes. Here we present an advanced theoretical-computational approach to model the electronic circular dichroism (CD) spectrum of the smallest chiral amino acid in water solution. Combining quantum–mechanical calculations with molecular dynamics simulations the electronic and magnetic properties of L-alanine (L-Ala) in solution are obtained and compared with the corresponding experimental measurements in the same conditions. The calculation of the CD spectrum, in good agreement with the experimental data, revealed a remarkable dependence on the conformational behavior of the molecule in solution, which was properly treated by our approach. [ABSTRACT FROM AUTHOR]