Application of linear multivariate calibration techniques to identify the peaks responsible for the antioxidant activity of Satureja hortensis L. and Oliveria decumbens Vent. essential oils by gas chromatography–mass spectrometry

•Indication of peaks responsible for the antioxidant activity.•Investigation of a of peak alignment effect based on correlation optimized warping.•GC–MS analyses of the potential peaks.

Satureja hortensis L. and Oliveria decumbens Vent. are known for their diverse effects in drug therapy and traditional medicine. One of the most interesting properties of their essential oils is good antioxidant activity. In this paper, essential oils of aerial parts of S. hortensis L. and O. decumbens Vent. from different regions were obtained by hydrodistillation and were analyzed by gas chromatography–mass spectrometry (GC–MS). Essential oils were tested for their free radical scavenging activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay to identify the peaks potentially responsible for the antioxidant activity from chromatographic fingerprints by numerous linear multivariate calibration techniques. Because of its simplicity and high repeatability, orthogonal projection to latent structures (OPLS) model had the best performance in indicating the potential antioxidant compounds in S. hortensis L. and O. decumbens Vent. essential oils. In this study, P-cymene, carvacrol and β-bisabolene for S. hortensis L. and P-cymene, Ç-terpinen, thymol, carvacrol, and 1,3-benzodioxole, 4-methoxy-6-(2-propenyl) for O. decumbens Vent. are suggested as the potentially antioxidant compounds.