Heterodimeric ent-Kauranoids from Isodon tenuifolius
journal contributionposted on 26.11.2014 by Jian-Hong Yang, Wei-Guang Wang, Xue Du, Fei He, Hai-Bo Zhang, Xiao-Nian Li, Yan Li, Jian-Xin Pu, Han-Dong Sun
Any type of content formally published in an academic journal, usually following a peer-review process.
Thirteen new heterodimeric ent-kauranoids, bistenuifolins A–M (1–13), were isolated from the aerial parts of Isodon tenuifolius. The constituent units of compounds 1–6 were linked by a six-membered dihydropyran ring, while those of compounds 7–11 were joined by a rare single carbon–carbon bond (C-16→C-17′). The constituent units of 12 and 13 were linked via an unusual cyclobutane moiety. The structures of these metabolites were established via spectrometric analyses, and the absolute configurations of 1 and 4 were defined by single-crystal X-ray diffraction. Selected compounds were evaluated for their cytotoxicity against a small panel of human tumor cell lines; bistenuifolin B (2) exhibited weak inhibitory effects.