Thermal Conversion of Pregeijerene into Geijerene in Essential Oil of Chromolaena Odorata L. King & Robinson (Asteraceae)
Year: 2024
Type: article
Abstract: It is well-known that geijerene is mostly associated with pregeijerene. These terpenes are believed to be thermoconvertible by a type of sigmatropic transposition order supra or antarafaciale. Our contribution to the study of the molecular pair consisted on a combination of statistical and analytical approach to the chemical composition of Chromolaena odorata essential oil. A compilation of chemical compositions of the samples obtained by steam distillation and analyzed by GC, presented a variation of this binomial proportions in different countries. For Ivory Coast, the results of analysis of 71 samples showed a dominance of geijerene proportion. We carried out a two-stage sampling by chemical variability factors (effects of site and period). We chose, at random, three different samples we submitted separately to chromatographic analysis (GC) and spectroscopic analysis (13C-NMR). It appears from this study that pregeijerene and geijerene were found in the essential oil with a relationship characterized by a polynomial degree 6 between these both molecules. Then during the chromatographic analysis, thermal conversion of pregeijerene into geijerene with the ratio 85.8% was observed. This result supported the idea of the coexistence of pregeijerene and geijerene in the essential oil of Chromolaena odorata. We intend to help clarify the kinetics and complete thermodynamics of this equilibrium.
Source: Science Journal of Chemistry
Language: English
Subfield: Food Science
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W4406105786