Chemical constituents from Picris hieracioides and their α-glucosidase inhibitory activity

Seventeen compounds were isolated from the 95% ethanolic extract of the aerial parts of Picris hieracioides, comprising two novel compounds, picrisicdiolide A (1) and taraxasterol-3-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (2), along with fifteen known compounds (3–17). Their structures were elucidated by comprehensive spectroscopic analyses (NMR and HR-ESI-MS) and by comparison with literature data. All isolated compounds were evaluated for their α-glucosidase inhibitory activity in vitro. Five compounds (2, 3, 7, 12, and 14) exhibited significant inhibitory activity, with IC50 values ranging from 21.6 to 32.8 μM, more potent than the positive control acarbose (IC50 = 84.6 μM). This work represents the first report of compounds 1 and 2, suggesting that Picris hieracioides may serve as a source of natural α-glucosidase inhibitors.