Absolute stereostructures of novel norcadinane- and trinoreudesmane-type sesquiterpenes with nitric oxide production inhibitory activity from Alpinia oxyphylla

Novel 14- norcadinane-type sesquiterpenes. oxyphyllenodiols A and B, and 11,12,13-trinoreudesmane-type sesquiterpenes. oxyphyllenones A and B, were isolated from the methanolic extract of kernels of Alpinia oxiphylla. The absolute stereostructures of these norsesquiterpenes were determined on the basis of physicochemical and chemical evidence. In addition, oxyphyllenodiol A and oxyphyllenone A were found to inhibit the NO production in lipopolysuccharide-activated macrophages. (C) 2001 Elsevier Science Ltd. All rights reserved.