Two New α‐Glucosidase Inhibitory Depsidones from the Lichen Parmotrema cristiferum (Taylor) Hale

Abstract

AbstractA bioactivity‐guided investigation of the lichen Parmotrema cristiferum (Taylor) Hale (Parmeliaceae) led to the isolation of two new depsidones, cristifones A and B (1 and 2). The structures of the isolated compounds were identified by spectroscopic methods and comparison with the literature data. Compound 1 showed the initial combined structures of depsidone and depside cores. The two isolated compounds were then evaluated for α‐glucosidase inhibition. Compounds 1 and 2 were confirmed as potent, with IC50 values of 21.5 and 18.4 μM, respectively. Compound 2 was a non‐competitive inhibitor against α‐glucosidase, as indicated by the intersect in the second quadrant of each respective plot.