Essential oil composition of six Hypericum species from southern Brazil

The essential oil of six Brazilian Hypericum species (Family Guttiferae) has been obtained by hydrodistillation: H. caprifoliatum Cham. & Schlecht. (0.2%), H. carinatum Griseb. (0.2%), H. connatum Lam. (0.1%), H. myrianthum Cham. & Schlecht. (0.5%), H. polyanthemum Klotzsch ex Reichardt. (0.2%) and H. ternum A. St. Hil. (0.1%). The composition of the oils was determined by GC and GC–MS and 84 compounds in total have been characterized. The principal constituents of each oil are: nonane (56%) in H. caprifoliatum, undecane (21%) in H. myrianthum, β‐caryophyllene (21%) in H. carinatum, caryophyllene oxide (40%) in H. connatum, β‐caryophyllene (12%) in H. ternum and the benzopyran HP1 (6‐isobutyryl‐5,7‐dimethoxy‐2,2‐dimethyl‐benzopyran) (27%) in H. polyanthemum. Copyright © 2005 John Wiley & Sons, Ltd.