Multifactorial discriminant analysis of leaf oil of C. odorata L. King and Robinson from Cte dIvoire

Abstract

The chemical composition of 71 essential-oil samples isolated from the leaves of Chromolaena odorata harvested in eight Ivoirian sites (Toumodi, Dougba, Yamoussoukro, Zambakro, Toumbokro, Attiegbakro, Tiebissou and Tie-N’Diekro) was investigated by GC-FID, including the determination of retention indices (RIs), and by 13C-NMR analyses. In total, 31 components accounting for 55.5 - 90.2% of the oil composition were identified. The content of the main components varied from sample to sample namely geijerene (3.2 - 26.4%), germacrene D (1 - 28.5%), (E)-β-caryophyllene (8.1 - 18.3%), α-pinene (0.2 - 8.5%) and δ-cadinene (1.4 - 9.5%). Other constituents present at appreciable contents were β-pinene (0 - 8.3%), α-copaene (2.2 - 8.0%), α-humulene (2.1 - 4.7%). The 71 samples were submitted to factorial discriminant analysis using 40 variables (4 physicochemical constants yield 31 chemical constituents and 4 geographical coordinates), which allowed the distinction of eight groups within the oil samples labeled according to the eight sites of harvest in respect of chemical components.   Key words: Chromolaena odorata, Asteraceae, essential oil composition, factorial discriminant analysis, physico-chemical constants, geijerene, germacrene D, (E)-β-caryophyllene).