Spasmolytic Activity of Chiral Monoterpene Esters

The present study aimed to investigate the correlation between structure and spasmolytic activity of racemate and enantiomers of linalyl and citronellyl acetates, chemical constituents of several bioactive essential oils, such as Thymus leptophyllus essential oil, which contains linalyl acetate as major constituent. The monoterpene esters showed significant spasmolytic activity in guinea-pig isolated ileum. Therefore, these result confirm that linalyl acetate should be involved at spasmolytic activity of the Thymus leptophyllus essential oil. The (+)-, (-)-, and (±)-linalyl acetates exhibited a relaxant effect equipotent. (+)- and (-)-Citronellyl acetates also showed a similar effect, however, synergistic action was presented on constituents of citronellyl acetate racemate. The study showed that the racemate and enantiomers of linalyl and citronellyl acetates are bioactives and that the position of the functional group on the molecule structures influences the effect of relaxation of the ileum.