Chemical Composition and Evaluation of the Antioxidant Activity of Essential Oils from the Leaves and Bark of Alstonia boonei De Wild
Mon-Sang César AKOUALA BOUANGA
Unité de Chimie du Végétal et de la Vie (UC2V), Faculté des Sciences et Techniques, Université Marien NGOUABI, BP : 69, Brazzaville, Congo.
Hermeline NTALANI
*
Unité de Chimie du Végétal et de la Vie (UC2V), Faculté des Sciences et Techniques, Université Marien NGOUABI, BP : 69, Brazzaville, Congo.
Kevin BIKINDOU
Laboratoire de Chimie des Extraits des Végétaux (LCEV), Ecole Normale Supérieure, Université Marien NGOUABI, BP : 69, Brazzaville, Congo and Laboratoire de Chimie des Substances Naturelles (LCSN), Institut National de Recherche en Sciences Exactes et Naturelles, Cité scientifique de Brazzaville, BP : 2400, Congo.
Béril Fabrice MAVOUBA
Laboratoire de Chimie et des Biomolécules Organiques et de Pharmacodynamique (LCBOP), Institut National de Recherche en Sciences de la Santé, Cité scientifique de Brazzaville, BP : 2400, Congo.
Koudrath Sauveur DIOUTELA MOUSSOUNDA
Unité de Chimie du Végétal et de la Vie (UC2V), Faculté des Sciences et Techniques, Université Marien NGOUABI, BP : 69, Brazzaville, Congo.
Gilles FIGUEREDO
Laboratoire d’analyse des Extraits Végétaux et des Arômes (LEXVA), Biopôle, Clermont-Limagne, 63360 Saint-Beauzire, France.
Pascal Robin ONGOKA
Unité de Chimie du Végétal et de la Vie (UC2V), Faculté des Sciences et Techniques, Université Marien NGOUABI, BP : 69, Brazzaville, Congo.
*Author to whom correspondence should be addressed.
Abstract
Alstonia boonei De Wild is used in traditional medicine to treat several diseases according to the literature. This study aimed to characterise the chemical composition of essential oils obtained from the leaves and bark of Alstonia boonei De Wild acclimatised in Congo and to evaluate their antioxidant potential. In this study, the essential oils of the leaves and bark of Alstonia boonei were analysed by GC-MS and GC/FID, and their antioxidant activity was tested by TLC. Fifty and sixty-one chemical compounds were identified, including alkanes (24.60%), fatty acids (17.59%), aldehydes (12.01%), sesquiterpenes (4.10%), oxygenated sesquiterpenes (6.16%) as major families in the essential oil of the leaves, and fatty acids (32.32%), oxygenated monoterpenes (12.96%) in that of the bark. n-heptane (15.25%), palmitic acid (13.72%), pentadecanal (8.68%), n-nonacosane (5.79%), hexahydrofarnesyl acetone (2.94%) and phytol (2.15%) are the most abundant compounds in the essential oil of the leaves, and hexadecanoic acid (32.32%), α-terpineol (7.66%) and eugenol (6.28%) in that of the bark. Thin-layer chromatography (TLC) analysis of the essential oils from Alstonia boonei. revealed spots with retention factors (Rf) of 0.44 for the leaves and 0.83 for the bark, confirming the presence of antioxidant compounds.
Keywords: Alstonia boonei De Wild, essential oils, chemical composition, antioxidant activity