| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1229218 | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2015 | 9 Pages |
•In vivo studies of essential oils as alternative to pesticides in agriculture.•FTIR spectroscopy for the investigation of essential oils effects on the protein structure of Vicia faba.•Curve fitting methods for the investigation of essential oils effects on the protein structure of Vicia faba.•Two-dimensional correlation analysis and double two-dimensional correlation analysis application to FTIR spectra.
In this study we investigated the effects of essential oil treatments on the secondary protein structure of the Vicia faba roots, a bioindicator plant, in order to obtain information for the potential allelopathic uses of these oils as alternative to the use of pesticides in agriculture. We tested two mixtures of essential oils consisting of Tween 20-emulsions of tea tree oil (TTO) and Tween 20-emulsion of Clove and Rosemary (GARROM) essential oils respectively at three different oil concentrations each. The molecular modifications caused in Vicia faba by exposure to oil emulsions were investigated by FTIR spectroscopy in diffuse reflectance (DRIFT) mode. We considered the specific Amide I, Amide II and Amide VI bands by ordinary and second derivative spectroscopy and the results showed that both Tween 20-emulsion of GARROM and Tween 20-emulsion of TTO oils cause transitions among the secondary (α-helix, β-sheet and β-turn) structures with in addition the appearance of random coil structures in exposed samples. The Amide VI bands, placed between 500 and 600 cm−1, confirmed the structural transitions observed for the Amide I bands. In addition we observed the presence of a protein oxidation effect for TTO treated samples, oxidation which resulted negligible instead for the GARROM oil samples. At last, FTIR spectra were also submitted to two-dimensional correlation analysis (2DCORR) and double two-dimensional correlation analysis (D2DCORR); the results confirmed the different effects caused by the two typologies of essential oils on the secondary protein structures of Vicia faba roots.
Graphical abstractExamples of better resolution by D2DCORR (right side asynchronous spectral maps with respect to 2DCORR (left side asynchronous spectral maps).Figure optionsDownload full-size imageDownload as PowerPoint slide
