Rapid Extraction of Sesquiterpene Lactones from Sagebrush for Use as Taxonomic Markers

The sesquiterpene lsctones of sagebrush occur in glandular trichomes on the leaf surface and can be extracted in 1 to 2 minutes with chloroform. Analysis of this extract by thin-layer chromatography can be used as a taxonomic characteristic. The analysis of sesquiterpene lactones by thin-layer chromatography (Kelsey et al. 1976) can be used as a taxonomic character along with morphology and ecology to help identify or separate species and subspecies of sagebrush (Artemisia, section Tridentatae). Recently it was discovered that these compounds are located in glandular trichomes on the leaf surfaces and can be easily and rapidly isolated with a chloroform wash (Kelsey and Shafizadeh 1980) eliminating the need for the extensive extraction procedures reported previously (Kelsey et al. 1976). Methods Ten to twenty sagebrush leaves from a fresh or air-dried sample were placed into a test tube, covered with one milliliter of chloroform, and shaken for I to 2 minutes. The leaves were removed, discarded, and the chloroform evaporated from the extract. Evaporation was accelerated by blowing a stream of air over thechloro