Identification of potential antioxidant compounds in the essential oil of thyme by gas chromatography with mass spectrometry and multivariate calibrationte chniques

چکیده مقاله

Thyme species are u sed i n t raditional m edicine throughout the world and are known for their antiseptic, antispasmodic, and antitussive properties. Also, antioxidant activity is one of the interesting properties of thyme essential oil. I n this research, we aim to identify peaks potentially responsible for the antioxidant activity of thyme oil f rom chromatographic fingerprints. T herefore, the chemical compositions of hydrodistilled essential oil of thyme species f rom different regions were analyzed by gas chromatography with mass spectrometry and antioxidant activities of essential oils were m easured by a 1,1-diphenyl-2-picrylhydrazyl radical scavenging test. S everal linear multivariate calibration t echniques with different preprocessing methods were applied to the chromatograms of thyme essential oils t o i ndicate the peaks r esponsible for the antioxidant activity. T hese techniques were applied on data both before and after alignment of chromatograms with correlation optimized warping. I n this study, orthogonal projection t o latent structures model was found t o be a good technique to indicate the potential antioxidant active compounds in the thyme oil due to its simplicity and r epeatability.