Chemical constituents of Angiopteris esculenta including two new natural lactones

Angiopteris species (Angiopteridaceae) have been widely used in traditional Chinese medicine to treat many diseases. A. esculenta Ching was endemic to north-west of Yunnan Province, China, its rhizomes were used as a foodstuff by the local people for the extraction of starch. From the extracts of the aerial parts of the plant, two new natural lactones (5R,6R)-5,6-dihydro-5-hydroxy-6-methyl-2H-pyran-2-one (1) and (5R,6R)-5-(1-hydroxyethyl)-2(5H)-furanone (2), two known lactones, (5R,6R)-5-(1-hydroxyethyl)-dihydro-2-furanone (3) and angiopteroside (4), and six known compounds, coumarin (5), 5-(hydroxymethyl)furfural (6), 9(11)-fernene (7), β-sitosterol (8), d-fucose (9) and l-arabinose (10) were isolated and identified by using combination of mass spectrometry and various 1D and 2D NMR techniques. This is the first report of the chemical constituents of A. esculenta.