Naphthalenes A and B, two new naphthalene derivatives from the fungus Phellinus igniarius.

Two new naphthalene derivatives, named naphthalene A (1) and naphthalene B (2), together with eight known compounds (3-10) were isolated from dichloromethane fraction of Phellinus igniarius. The structures of compounds were elucidated on the basis of spectroscopic analysis and absolute configurations were established based on electronic circular dichroism data. Compounds 9 and 10 exhibited moderate activity, increasing Glucose transporter 4 (GLUT-4) translocation by 1.62 and 1.87 folds, respectively.