Differences in Bioactivity between the Enantiomers of α-Pinene

Abstract

Many terpenes used therapeutically or as flavor and fragrance materials are chiral compounds. Chiral separations have been advocated for the identification of adulteration of commercial oils as different essential oils and synthetic components contain different proportions of each enantiomer. An alternative method of assessing enantiomeric composition and thereby adulteration was tested using several biological parameters versus the bioactivity of the enantiomers of α-pinene. It was found that 18 out of 25 different bacteria were more affected by the (−) enantiomer of α-pinene; 19 out of 20 different L. monocytogenes strains were affected more by the (+) isomer and two of three filamentous fungi were affected more by the (+) enantiomer. The (−) enantiomer was more spasmogenic on smooth muscle than the (+) enantiomer. This suggests that differing bioactivities can indicate adulteration and also that medicaments containing chiral components should be formulated using the most suitable enantiomeric forms for each particular medical condition.

Key Word Index:

• Enantiomers
• α-pinene
• biological activity
• antimicrobial action
• pharmacological action