GC-MS Metabolite Profiling of Botanical Extracts

Dried sample extracts were used for GC-MS analysis. Untargeted metabolite profiling was performed by GC-MS using an Agilent 7890A-5975C GC-MSD after derivatization of metabolites with methoxyamine hydrochloride (20 mg/ml in pyridine, both Sigma) and N,O-bis-(trimethylsilyl)trifluoroacetamide (containing 1% trimethylchlorosilane)^{57 (link)}. GC separation was achieved using an Agilent DB-5 MS column (30 m × 0.25 mm × 0.5 μm). The GC oven temperature program was: 70 °C, 2 min hold; ramp 12.5 °C/min to 295 °C, 0 min hold; ramp 25 °C/min to 320 °C, 3 min hold. Other GC parameters were: injection volume 1 μl; inlet temperature 270 °C; Helium was used as a carrier gas at a flow rate of 0.9 ml/min; transfer line temperature 280 °C. Electron impact ionization was used for mass spectrometry detection with scan range m/z 50–565.