VINEGAR WEED VOLATILE CONSTITUENTS

The essential oil from vinegar weed (Trichostema lanceolatum) was prepared from the leaves and stems by steam distillation and solvent extraction (yield 0.6%). The oil was analyzed by combined gas chromatography-mass spectrometry and GC retention time. Identified constituents (with rough quantitative indications) were terpinen-4-ol (55%), .gamma.-terpinene (15%), .alpha.-terpinene (7.7%), terpinolene (3.2%), p-cymene (1.9%), .beta.-phellandrene (1.4%), .alpha.-pinene (1.3%), .alpha.-terpineol (1.3%) and caryophyllene (1.2%). Twelve other constituents were also identified, at concentrations less than 1%. Acetic acid was identified in the aqueous phase of the distillate, and its abundance in the leaves and stems was estimated to be about 0.2%.