Quantum chemical investigation of the detection properties of alternariol and alternariol monomethyl ether

Alternariol and alternariol monomethyl ether are mycotoxins occasionally found in food and beverages that have been contaminated by certain fungi of the Alternaria genus. Conformers, tautomers, anions, and analogs of alternariol were geometry optimized using the Becke, three-parameter, Lee-Yang-Parr (B3LYP) density functional. Electronic structural analysis provided frontier orbitals, molecular electronic potential maps, and vibrational assignments. Optimized conformations of alternariol are within 5.2 kJ mol(-1) of the most stable conformation and share very similar molecular orbital properties. Vibrational assignments for the calculated infrared and Raman spectra are reported and correspond with experimental spectra. Tautomers are 130-180 kJ mol(-1) higher in energy and possess unique molecular orbital properties. Methylated and demethylated analogs shared similar properties to alternariol. Deprotonation of hydroxyl groups of alternariol, alternariol monomethyl ether, and methylated analogs influences the molecular orbital properties and molecular electrostatic potential maps.