Ontogenetic and diurnal variations of essential oil content of hypericum montbretii spach, cultivated in Kazdaği (Edremit/Balikesir), Turkey

Abstract

This research was carried out to determine the Hypericum montbretii Spach types essential oil content and composition, and its diurnal variations (9.00 am, 12.00 am and 16.00 pm) during the growing season of 2012. The plant was cultivated in the area of Mount Ida (Balikesir-Edremit), Turkey. The oil composition was determined with GC-MS. During the plant developmental stages the highest quantity of essential oil content (0.30-0.39%) was found at the full plant flowering stage and the lowest one at fresh fruiting stage (0.03-0.04%). Diurnal fluctuation in essential oils of whole plant was also observed – higher were the levels at noon (12.00 am) – 0.04-0.39% compared to the morning (9.00 am) and in the afternoon (16.00 pm). The oils consisted mainly of: at the vegetative stage - germacrene-D (6.9-11.7 %), gamma-Gurjunene (6.1-11.6%), 2-methyl octane (3.8-4.9%), δ-cadinol (2.7-4.8%) and phytol (2.9-4.5%); at the flowering stage - α-pinene (26.4-28.0%), undecane (14.1-16.0%), β-pinene (12.8-14.3%), delta-cadinene (6.8-8.0%) and caryophyllene (4.9-6.0%); at the fresh fruiting stage - amorphene (6.8-8.2%), β- caryophyllene (4.1-5.3%), delta-cadinene (5.0-5.5%) and α-cadinene (4.3-6.1%).