Essential oil composition of Dendropanax gonatopodus from Monteverde, Costa Rica. An ab initio examination of aromadendrane sesquiterpenoids

Abstract

The leaf essential oil of Dendropanax gonatopodus from Monteverde, Costa Rica, has been obtained by hydrodistillation and the chemical composition determined by GC-MS. The major components in the leaf oil were (E)-2-hexenal (16.9%), terpinolene (14.8%), δ-cadinene (13.5%), (E)-caryophyllene (9.9%), and α-copaene (7.3%). Minor amounts of the aromadendrane sesquiterpenoids aromadendrene (0.3%), alloaromadendrene (0.3%), spathulenol (0.6%) and globulol (0.6%) were also detected. An ab initio investigation of the aromadendrane sesquiterpenoids has been carried out using both density functional (B3LYP/6-31G*) and post Hartree-Fock (MP2/6-31G**) methods. The calculated relative energies of the aromadendranes belie their relative concentrations generally observed in essential oil compositions.