Aromatic plants of tropical central Africa.: Part XLVII.: Chemical and biological investigation of essential oils of ocimum species from Gabon

Volatile compounds from leaves of Ocimum gratissimum L. (two chemotypes) and O. minimum L. were isolated by hydrodistillation and analyzed by GC and GUMS. Twenty, 35 and 31 constituents were identified, respectively, for O. gratissimum (var. I and II) and O. minimum, of which eugenol (75.5%) and germacrene D (6.2%), p-cymene (33.3%), thymol (31.3%) and methyl chavicol (36.3%) and linalool (17.8%) were the most abundant, respectively. The oils of O. gratissimum present a significant radical scavenging activity whereas O. minimum oil was found to be much less efficient.