Antidiabetic Constituents from Helminthostachys zeylanica (L) Hook (Ophioglossaceae)

Background: The roots of tunjuk langit (Helminthostacshys zeylanica) have been used traditionally in some villages in Indonesia, particularly in Riau Province. Objective: In this study we reported two flavonoids and their antidiabetic activity. Material and methods: Isolation of the metabolites was based on polarity fractionation method. Purification processes were conducted by vacuum liquid chromatography (VLC). Chemical structures were elucidated based on spectroscopy characteristics, including FTIR and 1D/2D NMR. Results: The isolated compounds were identified as ugonin J and K. The antidiabetic activity was measured by α-glucosidase inhibitor assay. The antidiabetic activity of ugonin J was found at IC₅₀ 273,13±0,402 ppm and Ugonin K was found at IC₅₀ 138,21±0,263 ppm (moderately active). Conclusion: Therefore this plant can be used traditionally as antidiabetic medicine.