Structure and Spasmolytic Activity Relationships of Monoterpene Analogues Found in Many Aromatic Plants

Abstract

Rotundifolone, a monoterpene isolated from the essential oil of the leaves of Mentha ¥ villosa, is a constituent of several essential oils and known to have spasmolytic activity. The present study aimed to investigate the correlation between structure and spasmolytic activity of rotundifolone and its analogues in ileum isolated from guinea-pig. Five of the seven tested analogues were found to have a spasmolytic effect more potent than rotundifolone itself, except for pulegone and (+)-limonene. The comparison between rotundifolone and limonene oxide showed that the absence of the keto group did not decrease the relaxant effect. Comparison of the spasmolytic activity between rotundifolone and (+)-pulegone showed that the absence of the epoxy group did not decrease the relaxation of the ileum. Carvone epoxide was found to be significantly more potent than rotundifolone. The monoterpene (Ð)-carvone produced ileum relaxation and was more potent than its enantiomer (+)-carvone. (+)-Limonene and pulegone oxide showed a similar effect. The study showed that the functional groups and their position at the ring of rotundifolone contributed to the relaxation activity of the ileum. The absence of the oxygenated molecular structure is not a critical requirement for the molecule to be bioactive.

Spontaneous l-glutamate release enhancement in rat substantia gelatinosa neurons by (−)-carvone and (+)-carvone which activate different types of TRP channel

“…Moreover, their values were not so different from half-maximal inhibitory concentration values of (À)-carvone and (þ)-carvone (1.4 mM and 2.0 mM, respectively) in reducing the peak amplitude of compound AP recorded from the frog sciatic nerve [24]. Thus, there was not so difference in the efficacies of sEPSC frequency increase and nerve conduction inhibition between (À)-carvone and (þ)-carvone, observations different from those in human autonomic nervous system function [20], mouse locomotion [21], anticonvulsion [22] and guinea-pig ileum relaxation [23], where there was a difference in extent between (À)-carvone and (þ)-carvone activities.…”

“…A stereoisomer of (À)-carvone, (þ)-carvone, contained in caraway is reported to exhibit actions different from those of (À)-carvone in human autonomic nervous system function [20], mouse locomotive [21], anticonvulsive [22] and guinea-pig ileum relaxation activities [23].…”

Relaxant effects of the essential oil of Mentha pulegium L. in rat isolated trachea and urinary bladder

“…Essential oil of Mentha piperita relaxes carbachol‐contracted rat trachea with prostaglandin and/or NO participation [15] . Essential oil of Mentha X vilosa , as well as its major compound, rotundifolone, are spasmolytic in guinea‐pig ileum [12] . Interestingly, EOMP and pulegone inhibited contractions induced by K60 more potently than those induced by ACh.…”

Evaluation of the cytotoxic and antitumour effects of the essential oil from Mentha x villosa and its main compound, rotundifolone

“…This species also possesses ethnobotanical use in the treatment of worm, influenza, inflammation and pains in general, fever, intestinal infection, indigestion, sinusitis, ophthalmic problems, otalgia, menstrual colic, headache, migraine, and stroke [8]. The literature suggests that the essential oils obtained from Mentha x villosa have various biological activity, such as antinociceptive, hypotensive, spasmolytic, schistosomicidal, antimicrobial and larvicidal [9–14]…”