Siparuna guianensis Aublet: COMPOSIÇÃO QUÍMICA E ATIVIDADE NEMATICIDA DO ÓLEO ESSENCIAL E ATIVIDADE ANTIOXIDANTE DOS EXTRATOS VEGETAIS

Abstract

Natural products and essential oils play a longstanding cultural and practical role in health and pest control. In Brazil, traditional knowledge supports investigating Siparuna guianensis Aublet. (“negramina”), a South American species used as a natural repellent whose volatile composition varies seasonally and geographically. Building on prior reports of antioxidant and other bioactivities, this study aimed to characterize the volatile constituents of the leaf essential oil (EO); evaluate the essential oil nematicidal activity against Meloidogyne enterolobii and determine the antioxidant activity of hydroethanolic, ethanolic, and aqueous extracts. The essential oil was obtained by hydrodistillation (Clevenger), yielding 0.19% and a sesquiterpene-rich profile dominated by γ-muurolene (26.2%) and elixene (24.2%). In vitro bioassays showed a concentration-dependent reduction in Meloidogyne enterolobii hatching, reaching 96.75% at 50 μL (5 days), with marked effects already at 2.5–5.0 μL (87.5–89.0%). Antioxidant activity of the crude extracts was low, best results were observed in: DPPH: IC₅₀ = 392.23 μg·mL⁻¹ for the hydroethanolic extract; ABTS: 19.93 μmol TE·g⁻¹ for the hydroethanolic extract; and FRAP: 22.82 μmol FeSO₄·g⁻¹for the aqueous extract. Overall, the essential oil of Siparuna. guianensis Aublet. shows promising nematicidal potential, whereas the extracts exhibit limited antioxidant activity. Future work should broaden seasonal and geographic sampling and advance to in vivo tests, particularly regarding antinematode activity of the essential oil.