A novel γ-lactone isolated from the leaves of Pithecellobium dulce (Roxb.) Benth. and its xanthine oxidase activity

A novel 3-(hydroxymethyl)-4-(methylamino)-dihydrofuran-2(3H)-one (1) was isolated for the first time from the leaves of Pithecellobium dulce (Roxb.) Benth., along with kaempferol (2) and kaempferol-3-rhamnoside (3). It demonstrated a promising xanthine oxidase inhibitory activity with IC₅₀ values of 79.0, 0.38, and 70.4 μg/mL (allopurinol = 0.4 µg/mL). This is the first paper to describe the presence of 3-(hydroxymethyl)-4-(methylamino)dihydrofuran-2(3H)-one (1) in the Fabaceae family. The structure elucidation of 3-(hydroxymethyl)-4-(methylamino)dihydrofuran-2(3H)-one (1), kaempferol (2), and kaempferol-3-rhamnoside (3) was determined primarily based on the analyses of MS and NMR results.