Woodfordin D and oenothein A, trimeric hydrolyzable tannins of macro-ring structure with antitumor activity.

@article{Yoshida1991WoodfordinDA,
  title={Woodfordin D and oenothein A, trimeric hydrolyzable tannins of macro-ring structure with antitumor activity.},
  author={Takashi Yoshida and T Chou and Makoto Matsuda and Tadashi Yasuhara and Kazufumi Yazaki and Tsutomu Hatano and Atsuko Nitta and Takuro Okuda},
  journal={Chemical & pharmaceutical bulletin},
  year={1991},
  volume={39 5},
  pages={1157-62}
}
Two new antitumor trimeric hydrolyzable tannins, woodfordin D (5) and oenothein A (13), were isolated from the dried flowers of Woodfordia fruticosa, and their macrocyclic structures, which have a novel constituent unit (woodfordinoyl group) connecting the monomers, have been elucidated on the basis of spectral and chemical evidence. Oenothein A (13) was also isolated from the leaves of Oenothera biennis.