[Seasonal variation of Rosmarinus officinalis L. essential oils]

ABSTRACT

Rosmarinus officinalis L. [Rosemary] is one of the essential oil containing plants from Lamiaceae family. Rosemary is a native of the Mediterranean region of Europe and the Near East. It has been used as a food spice and as a medicine since ancient times. Today rosemary is cultivated in nearly all countries as a medicinal and ornamental plant. There are some reports about the effect of environmental conditions and genetic on rosemary essential oil. The goal of this work was to investigate the seasonal variation on rosemary essential oil composition. Aerial parts of plants were dried after collection from Evin, Tehran. Essential oils were obtained by using Clevenger type apparatus for 90 min and analyzed by GC and GC-MS. Rosemary essential oil showed 52 compounds, where 31 of those were similar in different seasons, alpha -Pinene, Limonene, Camphene, Camphor, 1, 8-Cineol and Bornyl acetate were major components of rosemary oil. The content of 1, 8-Cineol was the highest in September [14.15%]. The elevated levels of alpha-Pinene and Limonen were observed in February [28.8% and 17.29% respectively]. At least in various seasons from spring to winter constituent of alpha-Pinene [18.5%, 24.7%, 20% and 28.3%], Limonene [11%, 6.1%, 8.6% and 17.3%], Camphene [7.5%, 8.3%, 7.3% and 8.1%] and Camphor [7.4%, 13.4%, 8.3% and 4.7%] were compared respectively. Except alpha-Pinene, Limonene, 1, 8-Cineol and Bornyl acetate, most of these components did not affected by seasonal change. Some of these essential oils components converted to others, thus their concentrations decreased in summer but their amounts were at the highest levels in winter