ABSTRACT
The essential oil obtained from the leaves of Eugenia uniflora L., Myrtaceae, which grows in the Brazilian savannah, was studied by gas chromatography mass spectrometry (GC-MS). Furanodiene (1.2 percent) was thermally rearranged to curzerene (85.1 percent) to produce a combined content of 86.3 percent. GC analysis carried out under mild conditions (with a constant temperature of 100 ºC) showed that the furanodiene concentration was three-fold greater than the curzerene concentration, i.e., the essential oil contained 64.7 percent furanodiene and 21.6 percent curzerene. Germacrene B also rearranged to γ-elemene and the concentration of both was 2.3 percent. Special care should be taken when conventional gas chromatography analysis is used for quantifying compounds that can rearrange at high temperatures.