Organ and season dependent variation of the Hypericum undulatum essential oils composition

In the Portuguese popular medicine several Hypericum species are popularly used, the most demanded being H. androsaemum, H. perforatum and H. undulatum [1]. In what concerns H. undulatum, the respective scientific studies are almost absent, even at phytochemical level, as demonstrated in a search to the main data bases available on line. Recently it was included in a screening for acetylcholinesterase inhibition and antioxidant activity [2] as well as in the project entitled New bio-products and technologies for valorization of Hypericum species (HypericumBiotech.)* conducted under our responsibility. Through the GC and GC-MS analysis of the essential oils (EO) obtained by hydrodistillation, over of ninety compounds were found in the vegetative aerial parts as well as in flowers of H. undulatum. Sesquiterpene hydrocarbons constituted the main group of compounds in the EO from leaves while the n-alkanes constituted the main group of the compounds in the stems, ripened seed capsules and flowers with the n-nonane being the major compound in all the studied organs. This n-alkane accounted for more than 40% in the major samples of the aerial part of the plants harvested over the year with intervals of two months. The sesquiterpene hydrocarbons constituted the second major compound group with percentages ranging from around 25 to 35% in the aerial parts, while the oxygen-containing monoterpenes was the less represented group of compounds in the all samples.

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.

References:1 Nogueira MTDDM (2002), O Género Hypericum L. Em Portugal Continental. Contribuição para o Estudo Quimiotaxonómico, Ph.D. Thesis, ISA-UTL, Lisboa.

2 Ferreira A, et al. (2006)J. Ethnopharmacol. 108: 31–37