Hypericum androsaemum L. essential oils: characterization of their variation profiles

H. androsaemum L. has particular interest in the popular medicine as it is one the most used medicinal plant in the Northern of Portugal being associated to the natural History of the Gerês mountain ridge. Traditionally, H. androsaemum is sold dried, under the designation of „hipericão do Gerês“ and is used as an infusion, in cases of nephritic colic impaired digestion, boredom, and liver disturbances. As one of the major groups of the infusion constituents takes part of the essential oils (EO) we decided to research its composition separately for the different type of organs from in vivo plants as well as in vitro plantlets and leaves, in this case over an year period in order to characterize the respective variation profiles. More than eighty components were found in leaves the most of which were sesquiterpene hydrocarbons whose total amount in the EO ranged from 43% in September to 73% in February. Other compounds accumulated in high concentration were n-alkanes and 1-alkenes, with 1-octene and 2-hexenal representing 38% in September. In H. androsaemum in vitro shoots, the total amount of sesquiterpene hydrocarbons represented >80% of the respective EO. Ripened seed capsules showed the highest EO content (0.8% of biomass dry weight), the monoterpene hydrocarbons being the major EO compound group, and the stems were the poorest in EO accumulation composed almost at 50% of n-alkanes.

Acknowledgements: This work was sponsored by EU (FSE/FEDER) and Portuguese Government (FCT) through the Project PTDC/AGR-AAM/70418/2006 and the Grant SFRH/BD/13283/2003.