GC-MS, FT-IR and NMR Spectroscopy Analysis for Metabolome Profiling of Thyme Oil

The tracking of phytoconstituents is an important step for isolation of biologically active compounds from vegetal source. In this study GC-MS, FT-IR and NMR spectroscopic tools were used to characterize various secondary metabolites of thyme oil. The information provided by various spectrophotometric data enabled the indepth characterisation of thyme oil. The phytochemical screening of thyme oil (TO) revealed the presence of Terpinene-4-ol (32.7%) followed by Thymol (18.1%), α-Terpinene (7.4%), Carvacrol (5.6%) and α-pinene (3.5%), but the levels of other compounds were low. FT -IR analysis mainly revealed the presence of Alkyl, Aromatic, Phenolic, Amines, Nitro, Aldehyde,functional Groups and Alpha, and beta unsaturated aliphatic compounds. Particular emphasis has been given to the use of NMR as a fast and reliable tool to analyse thyme oil using 1H, 13C, NMR (on Bruker DRX300 spectrophotometer). The present study demonstrates that thyme oil metabolome profiling by GC-MS combined with FT-IR and NMR is useful for characterising the secondary metabolites of volatile essential oil.