Chemodiversity studies on Cleome L. genera by chemical characterization of Cleome pallida Kotschy and C. fimbriata Vicary essential oils with subsequent hierarchical cluster (HCA) and principal component analysis (PCA)

Cleome genus, belonging to the Cleomaceae family, distributed in several countries and many of which are used extensively. In fact, many of these specimens are consumed in the form of infusions or salads. In this study, the qualitative chemical composition of the essential oils obtained by hydrodistillation from Cleome ssp. was studied. Two species, two different accessions (CP1, and CP2) of C. pallida Kotschy, and one of C. fimbriata Vicary (CF), were collected in Oman and chemically investigated for the first time. The three essential oils were analyzed by gas chromatography and mass spectrometry (GC-MS). In total, 169 compounds were identified. Sesquiterpenoids were the major chemical group of CP1 and CP2 samples (56.4–58.8%); CF, instead, consisted essentially of nitrogen derivatives (30.2%), with 1-isothiocyanato-3-methylbutane (20.7%) as the most abundant class’. Furthermore, a new review of the chemical compositions’ literature, never studied, was carried out on all other Cleome species. Statistical studies such as Hierarchical cluster (HCA) and principal component analysis (PCA) were used to establish chemo-similarities and to highpoint possible correlations between the chemical compositions of CP1, CP2, and CF, and the reported Cleome ssp. essential oils.