Neuroprotective naphthalene and flavan derivatives from Polygonum cuspidatum

Ten naphthalene derivatives including two unusual glycosides possessing a naphthalene-fused piceid via a [C8'-O-C6-C5-C7']-trans-dihydrofuran ring, two flavan derivatives, as well as sixteen known phenolic compounds, were isolated from Polygonum cuspidatum. The structures were determined by extensive NMR, MS, CD data, and chemical evidence. In the in vitro neuroprotective assays, at the concentration of 10 mu M, five of these compounds exhibited significant effects against PC12 cells injured by rotenone. (C) 2014 Elsevier Ltd. All rights reserved.