VOLATILE SECONDARY METABOLITES FROM SPILANTHES AMERICANA OBTAINED BY SIMULTANEOUS STEAM DISTILLATION SOLVENT-EXTRACTION AND SUPERCRITICAL-FLUID EXTRACTION

Secondary volatile metabolites were isolated by simultaneous distillat ion-solvent extraction (SDE) and supercritical (CO2) extraction (SFE) from flowers, leaves and stems of Spilanthes americana (Mutis) Hieron (Compositae). The extracts were analyzed by capillary gas chromatograp hy using flame ionization, nitrogen-phosphorus (NPD) or mass spectrome tric detection. Compounds were identified according to their Kovats in dexes, mass spectra (EI, 70 eV), or by comparison with standard substa nces. The method of extraction (SDE, SFE) and the source of the plant material (flowers, stems, leaves) affected the composition of the extr acts. SFE extracts from stems were rich (>40%) in sesquiterpenes (alph a- and beta-bisabolenes, caryophyllene and cadinenes), while those fro m leaves and flowers were abundant in nitrogenated (43 and 27%) and ox ygenated (36 and 23%) compounds. N-(isobutyl)-2E,6Z,8E-decatrienamide, N-(2-methylbutyl)-2E,6Z,8E-decatrienamide, N-(isobutyl)-6Z,8E-decadie namide and N-(2-phenylethyl)-2E,6Z,8E-decatrienamide are examples of t he nitrogenated compounds found. SDE extracts from stems, leaves, and flowers of S. americana contained sesquiterpene levels of 32, 28 and 2 0%, and a generally higher proportion of oxygenated compounds (28, 52 and 32%) and monoterpenes (27, 10 and 42%) than their SFE counterparts . Only trace-level contents of nitrogenated compounds were found using NPD in SDE extracts. Some heavy hydrocarbons (C-n>20) originated from flower pigments and waxes were isolated by SFE but not by SDE. SFE wa s both selective and highly efficient in the isolation of sesquiterpen es, heavy hydrocarbons and nitrogenated compounds (amides).