Lignans from the bark extract of Pinus sylvestris L.

Abstract Three lignans were isolated from a bioactive fraction of the 70% aqueous acetone extract of the pine ( Pinus sylvestris L.) bark. Their structures were identified by high‐resolution positive ion EI mass spectrometry and NMR spectroscopy. The complete assignment of proton and carbon signals was achieved by 2D NMR experiments: HSQC, HMBC, DQF‐COSY and NOESY. Copyright © 2006 John Wiley & Sons, Ltd.