Molecular and structural changes induced by essential oil treatments in Vicia faba roots detected by FTIR and FTNIR spectroscopy

Abstract

Essential oils have recognized antimicrobial and antifungal properties which allow their utilization in agriculture like an alternative to pesticides, but their utilization requires the knowledge of all the potential structural changes and damages produced by the interaction with the vegetal organisms. In this paper, we investigated the effects of two essential oils, the tea tree oil (TTO) and the mixture of clove and rosemary oils (C + R), on the molecular structure of Vicia faba roots by Fourier transform infrared (FTIR) and Fourier near infrared transform (FTNIR) spectroscopy. FTIR spectroscopy showed structural modifications of the absorption bands related to DNA (1100 and 1050 cm, carbohydrate backbones, and nucleotide bands within 900 and 850 cm), proteins (1700 and 1600 cm amide I band, 1580 and 1520 cm amide II band), and lipids (methylene group of aliphatic chains between 2950 and 2800 cm). The changes in the secondary structures of proteins consisted of a denaturation depending on increased presence of random coil structures. In addition, in the samples treated with TTO oils, we observed the presence of protein oxidation, an effect negligible instead for the C + R-treated samples. The modified shapes of the infrared methyl bands of aliphatic chains suggested an increased lipid disorder which could also determine lipid peroxidation. The changes observed for the DNA structures at the highest concentration of the above essential oils can be related to the genotoxic effect of eugenol, an important constituent of both TTO and C + R mixture oils. FTNIR spectroscopy showed the modified shape of the second overtone bands belonging to methyl and methylene groups, between 8500 and 8000 cm. This confirmed the increased lipid disorders already observed by FTIR spectroscopy. The results obtained on the probe organism V. faba show that FTIR and FTNIR spectroscopy can become a useful support to the conventional cytogenetic tests used in the evaluation of the allelopathic uses of essential oils in agriculture.

Exposure to cadmium and mono‐(2‐ethylhexyl) phthalate induce biochemical changes in rat liver, spleen, lung and kidney as determined by attenuated total reflection‐Fourier transform infrared spectroscopy

“…To investigate the liver, spleen, lung and kidney further, IR was employed to interrogate these four tissues; significant post‐exposure alterations were again observed. IR spectra allowed an estimation of lipid/protein ratio (1740/1400 cm −1 ), C=O stretching/CH 2 methylene ratio (lipid oxidation level) (1745/1468 cm −1 ), amide I/amide II ratio (1655/1545 cm −1 ), α‐helix/β‐sheet ratio (1658/1635 cm −1 ) and CH 3 methyl/CH 2 methylene ratio (acetylation level) [(2960 + 2937 + 2874 cm −1 )/(2924 + 2853 cm −1 )] in tissue (Gautam et al, ; Mecozzi et al, ; Paraskevaidi et al, ; Zhang, Huang, Yan, Zhang, & Li, ).…”

“…In living organisms, structural changes of proteins directly lead to morphological and functional alterations of cellular membranes, such as permeability, ion transport, loss of enzyme activity and inhibition of protein synthesis (Mecozzi et al, ). Research on the structure of proteins leads to a better understanding of the components about protein.…”

Application of infrared spectroscopy for the prediction of nutritional content and quality assessment of faba bean (Vicia faba L.)

“…In addition to transitions in the secondary structure of the proteins (α‐helices, β‐turns and β‐sheets), development of random coil structures and oxidation of proteins was observed. Subsequent work incorporating FT‐NIR demonstrated further alterations in bonds relating to DNA and other nucleotides, carbohydrate backbones, proteins and lipids (Mecozzi et al, 2017).…”