Morphological and Diurnal Variability of Essential Oil in Lemon Verbena (Lippia citriodora H.B.K.)

The purpose of this paper is to analyze the composition of the essential oil from leaves and flowers of lemon verbena (Lippia citriodora H.B.K.) cultivated in Menemen-İzmir/Turkey and determine the effect of morphological and diurnal variability on the composition of essential oil. The essential oils from leaves and flowers lemon verbena were isolated by hydrodistillation with clevenger type apparatus. The chemical compounds of essential oil were identified by using a gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS) systems. The yields of essential oils in leaves was found to be highest and lowest value in the lower part of leaves, with 1.64% at 4:00 pm and 0.78% at 10:00 am. Essential oil yield in flowers was varied 1.17% at 4:00 pm to 0.86% at 10:00 am in the day time. Main components of the all essential oils were found as limonene, neral and geranial. The ratio of those components were changed according to day time and the part of plant. The minimum and maximum ratio of limonene, neral and geranial were obtained between 12.2-22.6%, 15.6-23.6%, 22.7-35.8% in the leaves and 16.3-28.5%, 20.2-16.2%, 30.3-23.8% in the flowers respectively.