The bioassay-guided chemical investigation of the stems of Dendrobium fimbriatum Hook led to the isolation of seven first reported bibenzyl dimers with a linkage of a methylene moiety, fimbriadimerbi-benzyls A-G (1-7), together with a new dihydrophenanthrene derivative (S)-2,4,5,9-tetrahydroxy-9, 10-dihydrophenanthrene (8) and thirteen known compounds (9-21). The structure of the new compound was established by spectroscopic analysis. Biological evaluation of bibenzyl derivatives against five human cell lines indicated that seven of those compounds exhibited broad-spectrum and cytotoxic activities with IC50 values ranging from 2.2 to 21.2 mu M. Those rare bibenzyl dimers exhibited cytotoxic activities in vitro and the cytotoxicity decreased as the number of oxygen-containing groups in the structure decreases. (C) 2014 Elsevier Ltd. All rights reserved.
1.Anhui Univ Chinese Med, Hefei 230031, Peoples R China 2.Chinese Acad Sci, Kunming Inst Bot, State Key Lab Phytochem & Plant Resources West Ch, Kunming 650201, Peoples R China 3.Yunnan Agr Univ, Kunming 650201, Peoples R China 4.Med Univ Anhui, Affiliated Hosp 1, Dept Neurol, Hefei, Anhui, Peoples R China
Xu,Feng-Qing;Xu,Fang-Cheng;Hou,Bo;Fan,Wei-Wei;Zi,Cheng-Ting;Li,Yan;Dong,Fa-Wu;Liu,Yu-Qing;Sheng,Jun;Zuo,Zhi-Li;Hu,Jiang-Miao.Cytotoxic bibenzyl dimers from the stems of Dendrobium fimbriatum Hook,BIOORGANIC & MEDICINAL CHEMISTRY LETTERS,2014,51(5):297-304