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Three new cyathane diterpenoids, cyathin W (1), cyathin V (2), and cyathin T (3), were isolated from the solid culture ofCyathus africanus. The structures and configurations of these new compounds were elucidated on the basis of comprehensive spectroscopic analysis including 1D NMR, 2D NMR (HSQC, HMBC, NOESY), and HR-ESI-MS experiments. Compounds1and3showed moderate inhibition against nitric oxide production in lipopolysaccaride-activated macrophages with IC50value of 80.07 and 88.87 μM, respectively. In cytotoxicity assay, compound1showed weak cytotoxicity against K562 cell line with IC50value of 12.1 μM. [ABSTRACT FROM PUBLISHER]

The purpose of this study is to elucidate the bioactive components responsible for the the α-glucosidase inhibitory activity detected in the EtOAc extract of the mushroom Hydnellum concrescens . Two new p -terphenyl derivatives, concrescenins A ( 1 ) and B ( 2 ), in along with six known compounds thelephantins L ( 3 ), I ( 4 ), J ( 5 ), K ( 6 ), dihydroauran-tiacin dibenzoate ( 7 ), and curtisian A ( 8 ) were isolated from the fruiting bodies of H. concrescens . Their chemical structures were elucidated by NMR experiments. Compounds 1 – 4 and 6 – 8 showed the inhibitory activity against α-glucosidase with the IC 50 of 0.99, 3.11, 4.53, 18.77, 2.98, 5.16, and 8.34 μM, respectively. Kinetic analysis of α-glucosidase indicated that compounds 1 and 2 inhibited the activity of α-glucosidase in a noncompetitive fashion with a Ki value of 0.02 and 0.21 μM, respectively. In antioxidant evaluation, compounds 1 and 4 showed weak DPPH scavenging activity (EC 50 = 82.50 and 161.75 μM) and weak reducing ability (EC 50 = 193.57 and 152.94 μM). The current research supports the potential use of mushroom-derived p -terphenyl derivatives for the treatment of diabetes. [ABSTRACT FROM AUTHOR]

Two new 2H-pyranones and two new isocoumarin derivatives, maculanslines A-D (1–4), together with seven known compounds (5–11), were isolated from the plant pathogenic fungus Leptosphaena maculans. Their planar structures and absolute configuration were elucidated by comprehensive spectroscopic techniques including high-resolution electrospray ionization mass spectrum, 1D and 2D nuclear magnetic resonance, as well as electronic circular dichroism. All 11 compounds were tested for their inhibitory activity against α-glucosidase. Compound 1 showed moderate inhibitory activity against α-glucosidase with IC50 of 74.35 μM. [ABSTRACT FROM AUTHOR]