Chemical characterization of the essential oil from the leaves of Tithonia diversifolia (Hemsl.) A. Gray: A combined GC/MS and ¹³C NMR approach

The essential oil from the leaves of Tithonia diversifolia, collected in Daloa (Côte d’Ivoire), was extracted by hydrodistillation and analyzed using gas chromatography coupled with mass spectrometry (GC/MS) and carbon-13 nuclear magnetic resonance (¹³C NMR). The extraction yield reached 0.044 ± 0.001%. Fifty-one compounds, accounting for 99.58% of the total oil, were identified and classified into seven chemical groups dominated by hydrocarbon monoterpenes (71.27%), followed by hydrocarbon sesquiterpenes (17.10%) and oxygenated sesquiterpenes (4.00%). The major constituents were sabinene (39.25%), α-pinene (29.66%), β-caryophyllene (8.61%), caryophyllene oxide (3.04%), α-farnesene (3.03%), a farnesene isomer (2.96%), phytol (2.36%), and α-cedrene (1.12%). The combined GC/MS–¹³C NMR approach enabled the confirmation of the structures of the main constituents and the distinction of certain isomers that could not be differentiated by mass spectrometry alone. These results reveal a chemotype rich in hydrocarbon monoterpenes, suggesting potential biological activities, notably antimicrobial, antioxidant, and insecticidal. The study, through the complementary use of two analytical techniques, enhances the chemical knowledge of T. diversifolia and opens perspectives for valorization in pharmacy, agriculture, and cosmetics.