Bioassay-guided isolation and characterisation of α-glucosidase inhibitors from .

Bioassay-guided fractionation of the isopropanol extract of the medicinal mushroom led to the isolation and characterisation of a new acorane-type sesquiterpenoid bauminene () and seven known compounds -. The planar structure of was elucidated on the basis of extensive spectroscopic analysis, including 1D, 2D NMR and HR-ESI-MS. The relative configuration of was determined by a combination of ROESY experiment, density functional theory calculation of C NMR, and DP4+ probability analysis, while the absolute configuration of was established by comparative electronic circular dichroism (ECD) spectra analysis. In the bioassay, compounds - exhibited potent to moderate α-glucosidase inhibitory activity with IC values ranging from 6.8 ± 0.68 to 221.4 ± 6.57 µM. The presences of these bioactive constituents in the sclerotia of may be related to the use of the fungus as 'Sanghuang' for the adjuvant treatment of DM.