Chemical Stability of the Stem Bark Essential oil of Artabotrys jollyanus Pierre (Annonaceae) Throughout the Phenological Cycle in Côte d’Ivoire
Stéphane Gervais Gooré *
UFR Sciences De la Mer, Université Polytechnique de San-Pedro, BP 1800 San Pedro, Côte d’Ivoire.
Bi Goblé Landry Guessan
Laboratoire de Chimie bio-Organique et de Substances Naturelles (LCBOSN), UFR SFA, Université Nangui ABROGOUA, 02 BP 801 Abidjan 02, Côte d’Ivoire.
Bi Tra Marc Gabin Djié
Laboratoire de Chimie bio-Organique et de Substances Naturelles (LCBOSN), UFR SFA, Université Nangui ABROGOUA, 02 BP 801 Abidjan 02, Côte d’Ivoire.
Zana Adama Ouattara
Laboratoire de Chimie bio-Organique et de Substances Naturelles (LCBOSN), UFR SFA, Université Nangui ABROGOUA, 02 BP 801 Abidjan 02, Côte d’Ivoire.
Yves-Alain Bekro
Laboratoire de Chimie bio-Organique et de Substances Naturelles (LCBOSN), UFR SFA, Université Nangui ABROGOUA, 02 BP 801 Abidjan 02, Côte d’Ivoire.
*Author to whom correspondence should be addressed.
Abstract
This study evaluated the temporal stability of the stem bark essential oil of Artabotrys jollyanus Pierre (Annonaceae) throughout a complete phenological cycle in Côte d’Ivoire. Stem bark was collected monthly for 12 months from the same individual plant, and essential oils were obtained by hydrodistillation using a Clevenger-type apparatus. The oils were analysed by gas chromatography, gas chromatography–mass spectrometry and carbon-13 nuclear magnetic resonance spectroscopy. Fifty-two constituents, comprising 19 monoterpenes and 33 sesquiterpenes, were identified and represented 88.0–92.3% of the total composition. Oil yields ranged from 0.04% to 0.13%. The samples were dominated by sesquiterpenes, particularly trans-calamenene (18.9–27.6%), 7-hydroxycalamenene (8.7–25.1%) and α-copaene (6.7–10.4%). Although the relative proportions of individual compounds varied among sampling months, the main qualitative profile remained broadly consistent across the annual cycle. Comparison with the previously characterised leaf oil indicated a shared sesquiterpene chemotype but organ-related differences in constituent abundance, with the stem bark oil containing higher mean proportions of trans-calamenene and 7-hydroxycalamenene and a lower extraction yield. These findings provide baseline information on the composition and month-to-month stability of A. jollyanus stem bark essential oil. Confirmation across multiple plants and locations is required before the observed stability can be generalised to the species level.
Keywords: Artabotrys jollyanus, stem bark, essential oil, phenological cycle, chemical stability, sesquiterpenes, trans-calamenene, 7-hydroxycalamenene, gas chromatography–mass spectrometry, ¹³C NMR