Composition and seasonal variation of essential oils of Myrcia obtecta (O. Berg) Kiaersk. var. obtecta, Myrtaceae

Abstract

The essential oils isolated by hydrodistillation from leaves and flowers of Myrcia obtecta (O. Berg) Kiaersk. var. obtecta, Myrtaceae, collected bimonthly in Curitiba, Paraná state, Brazil, from October/2005 to August/2006 were analyzed by capillary GC and GC/MS. Fifty-five components were identified in the leaf oils, which were characterized by predominance of cyclic sesquiterpenes (around 70%) and variable amounts of monoterpenes (5.6-16.7%), aliphatic compounds (0.4-5.5%) and methyl salicylate (0.1-1.5%). The major component in all samples was trans-calamenene (17.0-29.3%). The composition did not show significant seasonal variation, except in October (flowering) when α-terpineol and trans-calamenene peaked (11.2% and 29.3%, respectively). The flower oil was characterized by high content of methyl salicylate (89%).