SESQUILIGNANS AND LIGNANS FROM TSUGA-HETEROPHYLLA

Two epimeric sesquilignans and two lignans were isolated from the sapw ood of Tsuga heterophylla (western hemlock, Pinaceae). By spectroscopi c analyses their structures were deduced to be (8R,8'R,7'R,8''S,7''R)- 7'-hydroxylappaol E and (8R,8'R,7'R,8''S,7''S)-epi-7'-hydroxylappaol E , and (8'R,7'S)-8-hydroxy-alpha-conidendrin and (8'R,7'S)-8-hydroxy-al pha-conidendric acid ester. Their presence in several samples of weste rn hemlock sapwood was confirmed by quantitative analyses. Copyright ( C) 1997 Elsevier Science Ltd.