Identification of two chemotypes for essential oils and floral waters of Mentha spicata L. from two localities of Senegal

The aim of the study is to determine the chemical composition of essential oils (EOs) and
floral waters (FWs) in Mentha spicata L. from Senegal. For this purpose, extractions were
conducted by steam distillation from both fresh (F) and dried (D) plants harvested in
Dakar and Kaolack regions, Senegal. Essential oils and floral waters obtained were
analyzed by gas chromatography GC/FID-MS Results showed that EOs and FWs were
characterized by the same prominent components. In the oils from Dakar, it is noted an
abundance of carvone which represented 64.4 (F) and 59.8% (D), limonene 11.7 (F) and
11.9% (D) and 1.8-cineole 4.4 (F) and 4.4% (D). This composition is typical for M. spicata.
The corresponding FWs also contained mainly carvone 81.1 (F) and 80.2% (D). For
Kaolack, EOs were dominated by pulegone 35.3 (F) and 35.8% (D), piperitenone 24.5 (F)
and 24.6% (D), 1.8-cineole 11.5 (F) 11.0% (D) and limonene 5.5 (F) and 6.6 % (D). In our
best knowledge, this chemotype was not reported for M. spicata. Their FWs contained:
66.1 (F) and 67.2% (D) of piperitenone, (19.2 (F) and 18.8% (D) of pulegone. Futhermore,
chiral chromatography revealed the presence of pure enantiomers: (S)-(-)-limonene, (R)-
(-)-carvone and (R)-(+)-pulegone in the oils.