Essential oil components of Hypericum androsaemum infusions and their nematotoxic effects against Meloidogyne javanica (Treub) Chittwood.

Hypericum androsaemum L. is one of the most demanded plant species in the Portuguese popular medicine being associated to the natural History of the Gerês mountain ridge (Northern of Portugal), due to its ethnobotanical uses given by the local people [6]. Traditionally, H. androsaemum is sold dried, under the designation of “hipericão do Gerês ” and is used as an infusion [7], in cases of nephritic colic impaired digestion, boredom, and liver disturbances. The essential oils of Hypericum androsaemum L. were isolated by separated hydrodistillation of its leaves, stems and ripened seed capsules and by pentane extraction of the respective leaves infusion. Subsamples of fresh leaves (10g), stems (10g) and ripened seed capsules (10g) were hydrodistilled with 500 ml of boiling water in a Clevenger type apparatus over 1h, using volumes of 1.0 mL of n-hexane, containing 5-α-cholestane (1mg/mL), for retention of the hydrodistillate components. The infusion was prepared by adding 150 ml of boiling water onto 15 g of the dried plant leaves keeping it submersed during 5 minutes. The infusion was left to cool for 15 minutes and then it was filtered and the respective essential oil constituents were extracted with 5 ml of n-pentane containing 5-cholestane (0.1 mg/ml). The hydrodistillates and n-pentane fraction of the leaves infusion extract were analysed by GC and GC-MS in order to identify and quantify the respective components. The EO yield of leaves was 0.85 mg/g of biomass dry weight distributed in 103 compounds, 82 % of which were identified. From the 92 compounds detected in the EO of ripened seed capsules, 96 % were identified. The EO from stems, with only 63 compounds identified, had a narrower range o