Variation of essential oil yield and relative amounts of enantiomers of α-pinene in leaves and unripe cones of Juniperus communis L. growing wild in Lithuania

Abstract

The variations in essential oil yields and enantiomeric composition of α-pinene in leaves and unripe cones of Juniperus communis between populations as well as at individual plant level were studied. Leaf and cone samples of total 110 J. communis individuals were collected from eleven habitats (in ten individuals from each habitat) representing a variety of edaphoclimatic conditions across Lithuania. Essential oils were analyzed by chiral-phase capillary gas chromatography (GC). The amount of essential oil yield varied from 0.3% to 4.2% in unripe cones and from 0.1% to 0.9% in leaves. (1R)-(+)-α-pinene prevailed over the (1S)-(−)-α-pinene amounting to 74±13% in leaves and 69±17% in unripe cones, and 26±13% in leaves and 31±17% in unripe cones, respectively. Only the total yield of essential oils in leaves varied significantly between populations (F=3.1, p<0.05). The highest averages of yields of essential oils were established in habitats with lower precipitation, higher temperatures and lower solar radiation.

Keywords:

• Juniperus communis L
• leaves
• unripe cones
• α-pinene enantiomers
• chiral gas chromatography

Acknowledgement

This research was funded by a grant (No. MIP-56/2010) from the Research Council of Lithuania.