Vibrational spectroscopy study of essential oils from Plectranthus amboinicus Lour. Spreng and Vanillosmopsis arborea Baker

[Display omitted] Essential oils are aroma compounds extracted from plants with pharmacology and mecial uses, being also utilized as perfumes, cosmetics and for flavoring foods. In this work, Fourier Transform-Raman and Attenuated Total Reflection-infrared spectra of essential oils from Plectranthus amboinicus Lour. Spreng (Labiateae) and Vanillosmopsis arborea Baker (Asteraceae) were investigated at room temperature. The analysis of the vibrational spectra of the major constituents performed on the basis of density functional theory (DFT) calculations allowed us to assign the normal modes of these essential oils. Our analyses show that vibrational spectra of these essential oils in the spectral region of lower wavenumber (