Chemical Constituents and Biological Activities of the Aerial Parts of Cyperus rotundus (Cypereaceae)

Abstract

The present study reports the chemical constituents, antioxidant, anticonvulsant and α-amylase activities of the aerial part of Cyperus rotundus collected in Cameroon. Phytochemical study leads to the isolation of six known compounds alongwith lupeol (1), stigmasterol (2), tetracosanoic acid (3), a mixture of β-sitosterol (4a) and stigmasterol (4b), ursolic acid (5) and saikogenin F (6). Compounds 3, 5 and 6 were isolated for the first time from this species. The structures of these compounds were determined using spectroscopic analysis including 1D and 2D NMR, mass spectrometry and comparison with the literature data. Biological activities carried out on the extracts showed that the methanol extract exhibited good antiradical scavenging activity against DPPH radical (IC₅₀ = 2.873 μg/mL) and very good ferric reducing antioxidant power (FRAP) (IC₅₀ = 7.535 μg/mL). It appeared that the mixture of hexane and ethyl acetate extract at the dose 100 mg/kg protected 66% of mice against convulsion induced by the pentylenetetrazol and 50% of protection when using picrotoxin at the same dose. All the extracts and compounds from this plant showed no inhibition against α-amylase related to antidiabetic activity.