A new leaf essential oil from the Andean species Gynoxys szyszylowiczii Hieron. of southern Ecuador: chemical and enantioselective analyses.

The essential oil obtained from the dry leaves of Gynoxys szyszylowiczii Hieron. was described in this study for the first time. The chemical analysis, conducted on two stationary phases of different polarity, permitted to identify sixty-four compounds, that were quantified with at least one column. The main components, on a non-polar and polar stationary phase respectively, were germacrene D (21.6-19.2%), α-pinene (4.4-4.9%), n-tricosane (4.3% on both columns), (E)-β-caryophyllene (3.3-4.3%), 1-docosene (3.2-2.8%), α-cadinol (2.8-3.1%), and cis-β-guaiene (2.6-3.0%). This investigation was complemented by the enantioselective analysis of some major chiral compounds, carried out on two chiral selectors based on β-cyclodextrines. As a result, (S)-( +)-α-phellandrene, (S)-( +)-β-phellandrene, and (1S,2R,6R,7R,8R)-( +)-α-copaene appeared enantiomerically pure, whereas α-pinene, β-pinene, terpinen-4-ol, and germacrene D were detected as scalemic mixtures. Finally, linalool was practically racemic. The distillation yield, analytically calculated by weight of dry plant material, was 0.03%.