Ricerc@Sapienza

A comprehensive study on essential oils (EOs) extracted from different Calamintha nepeta
(L.) Savi subsp. glandulosa (Req.) Ball (CG) samples from Tarquinia (Italy) is reported. In this study,
the 24-hour steam distillation procedure for EO preparation, in terms of different harvesting and
extraction times, was applied. The GC/MS analysis showed that CG essential oils from Tarquinia
(TEOCG) belong to pulegone-rich chemotype. The analysis of 44 samples revealed that along
pulegone (PUL) some other chemicals may participate in exerting the related antifungal activity.
The results indicated that for higher activity, the EOs should be produced with at least 6 hours steam
distillation process. Even it is not so dependent on the period of harvesting, however, it could be
recommended not to harvest the plant in the fruiting stage, since no significant antifungal effect was
shown. The maximum EO yield was obtained in August, with the highest PUL percentage. To obtain
the oil with higher content of menthone (MEN), September and October should be considered as
the optimal periods. Regarding to extraction duration, vegetative stage material gives the oil in the
first 3 hours, while material from the reproductive phase should be extracted at least 6 or even 12
hours