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 β-caryophyllene (30.5%), β-pinene (12.4%), germacrene D (10.0%), β-phellandrene (9.8%) and α- 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 α- isocomene (13.8%), α-pinene (7.4%), β-isocomene (5.2%), β-pinene (4.3%) and β-caryophyllene (4.3%). This is the first report of the chemical composition of the essential oils obtained from this species. [ABSTRACT FROM AUTHOR]