Chemical Components of Volatile Oils and Hydrosols Derived from Different Plant Organs of Three Scutellaria L. Species

The genus Scutellaria L. occupies an isolated position within the family Lamiaceae, whereas the aerial organs of many species remain largely unexplored despite their potential as sources of bioactive metabolites. This study provides the first comprehensive comparison of 20 volatile oils and their corresponding 20 hydrosols obtained by hydrodistillation from different organs of three Scutellaria species cultivated at GBNI (Republic of Moldova). GC–MS analysis identified eleven classes of secondary metabolites. S. altissima L. was characterized by linalool as the principal constituent in volatile oils (20.24–29.96%) and hydrosols (55.36–61.72%). S. baicalensis Georgi produced sesquiterpene-rich volatile oils primarily composed of β-caryophyllene (23.44–37.99%) and germacrene D (6.83–22.42%), whereas its hydrosols contained high relative abundances of 1-octen-3-ol (24.54–59.32%). The volatile oils of S. supina L. were characterized by high relative abundances of germacrene D (up to 33.16%), β-caryophyllene (up to 21.72%), linalool (up to 21.95%), and spathulenol (up to 11.36%). In contrast, hydrosols contained high relative abundances of 1-octen-3-ol (17.39–71.10%) and linalool (5.86–45.49%). Hierarchical cluster analysis distinguished volatile oils from hydrosols and revealed species-specific volatile profiles, with organ-related variation being primarily quantitative. These results underscore the potential of aerial organs and hydrosols for future investigations.