The role of secreting structures position on the leaf volatile organic compounds of Hypericum androsaemum

Abstract

Hypericum androsaemum L. presents typical translucent, essential oil producing glands, which are distributed on the leaf along both margins (margin glands) and on the lamina (lamina glands). The gland secretion was studied by histochemical and chemical analysis; the gland content was sampled directly from the secretory glands, and the volatile organic compounds (VOC) of the margin and lamina glands were separately analyzed. The lipophilic fraction of the lamina glands had as main components: (E)-2-hexenal (15.5%), hexadecanoic acid (14.7%), β-caryophyllene (11.2%), germacrene B (11.0%) and γ-himachalene (9.8%). The lipophilic fraction of the margin glands had as its main components: β-pinene (22.0%), limonene (17.6%), (E)-β-ocimene (6.1%), methyl linoleate (5.7%), terpinolene (5.4 %), (E)-2-hexenal (4.9%) and α-pinene (4.1%).