Abstract

In this work the supercritical fluid extraction with carbon dioxide was applied to obtain the extracts from roots of Echinacea angustifolia DC. The extracts were evaluated through the antifungal in vitro assay against fungal strain Botrytis cinerea. Furthermore, the active compounds from the extracts were separated by macroporous resin and analyzed using gas chromatography-mass spectrometry (GC-MS). The results show that the extracts, obtained using SC-CO₂ extraction technique, had strong antifungal activity against B. cinerea with EC₅₀ and EC₉₀ values of 948 and 1869 μg/ml, minimum inhibitory concentration (MIC) of 250 μg/ml, and minimum fungicidal concentration (MFC) of 2000 μg/ml, respectively. After separation with macroporous resin chromatography, nine fractions were collected from theSC-CO₂ extracts. At concentration of 2000 μg/ml, fractions 3, 7, and 8 presented highly antifungal activity against B. cinerea, with inhibition ratio of 40.59, 73.04 and 53.37%, respectively. Determined by the GC-MS analysis, the composition of fraction 7 consisted of different kinds of volatile oils, most of which were ketones (82.71%) and unsaturated hydrocarbons (9.59%). The present study has provided the new evidence that the Echinaceaextracts are involved in the antifungal activity.

Key words: Antifungal activity, Echinacea angustifolia DC, gas chromatography-mass spectrometry (GC-MS), SC–CO₂ extraction.