Neuroprotective diterpenes from the fruiting body of Antrodia camphorata.

Three new compounds, 19-hydroxylabda-8(17)-en-16,15-olide (1), 3beta,19-dihydroxylabda-8(17),11E-dien-16,15-olide (2), and 13-epi-3beta,19-dihydroxylabda-8(17),11E-dien-16,15-olide (3), together with four known compounds, 19-hydroxylabda-8(17),13-dien-16,15-olide (4), 14-deoxy-11,12-didehydroandrographolide (5), 14-deoxyandrographolide, and pinusolidic acid, were isolated from the fruiting bodies of Antrodia camphorata. The structures of compounds 1-3 were elucidated by the analysis of their spectroscopic data. The in vitro neuroprotective activity of all compounds was evaluated, and compounds 1-5 protected neurons from Abeta damage by 39.2, 35.0, 36.7, 30.6, and 27.0%, respectively, at concentrations between 5 and 20 microM.