Chemical Composition of the Leaf and Branch Oils of Perymenium grande Hemsl. var. nelsonii (Robins. & Greenm.) Fay (Asteraceae-Heliantheae) from Costa Rica

 The chemical composition of the essential oils of Perymenium grande Hemsl. var nelsonii (Robins. & Greenm.) Fay (Asteraceae) growing wild in Costa Rica was analyzed by capillary GC-FID and GC-MS. One hundred and two and one hundred and seven compounds were identified in the leaf and branch oils, respectively, corresponding to about 94.9% and 79.3% of the total amount of the oils. The leaf oil consists mainly of sesquiterpene hydrocarbons (50.3%) and monoterpene hydrocarbons (33.8%). The major components of the leaf oil were b -caryophyllene (30.5%), b -pinene (12.4%), germacrene D (10.0%), b -phellandrene (9.8%) and a -pinene (8.9%). The branch oil consists mainly of sesquiterpene hydrocarbons (38.3%), monoterpene hydrocarbons (21.6%) and oxygenated sesquiterpenes (20.4%). The major components of the branch oil were a -isocomene (13.8%), a -pinene (7.4%), b -isocomene (5.2%), b -pinene (4.3%) and b -caryophyllene (4.3%). This is the first report of the chemical composition of the essential oils obtained from this species.