Highly modified cephalotane-type diterpenoids from Cephalotaxus fortunei var. alpina and C. sinensis

• Published in: Phytochemistry (Oxford) 2024-05, Vol.221, p.114038-114038, Article 114038
• Main Authors: Ge, Zhan-Peng, Xu, Jin-Biao, Zhao, Peng, Xiang, Mai, Zhou, Yu, Lin, Ze-Min, Zuo, Jian-Ping, Zhao, Jin-Xin, Yue, Jian-Min
• Format: Article
• Language: English
• Subjects: Ceforloids A–F; Cephalotane; Cephalotaxaceae; Cephalotaxus fortunei var. alpina; Cephalotaxus sinensis; Diterpenoids; Immunosuppressive activity
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2024.114038

Cephalotanes are a rare class of diterpenoids occurring exclusively in Cephalotaxus plants. The intriguing structures and promising biological activities for this unique compound class prompt us to investigate C. fortunei var. alpina and C. sinensis, leading to the isolation of six undescribed cephalotane-type diterpenoids and/or norditerpenoids, ceforloids A–F (1–6). Their structures were elucidated by comprehensive analysis of spectroscopic data, including ECD and single-crystal X-ray diffraction studies, as well as quantum chemical calculations. Compound 1 possesses an unprecedented norditerpenoid skeleton featuring an unusual acetophenone moiety, and originated putatively from a disparate biogenetic pathway. Compounds 4 and 5 incorporate a unique 12,13-p-hydroxybenzylidene acetal motif. Compound 6 is a rare cephalotane-type diterpenoid glycoside. Immunosuppressive assays showed that compounds 2 and 6 exhibited mild suppressive activity against the activated T and B lymphocytes proliferation. These findings not only expanded the structural diversity of this small group of diterpenoids, but also explored their potential as novel structures for the development of immunosuppressive agents. Ceforloids A–F, six undescribed cephalotane-type diterpenoids, were isolated from two Cephalotaxus plants. Ceforloid A (1) possesses an unprecedented norditerpenoid skeleton featuring an atypical acetophenone moiety. [Display omitted] •Six undescribed cephalotane diterpenoids were isolated from two Cephalotaxus plants.•Ceforloid A possesses a new norditerpenoid skeleton incorporating an atypical acetophenone moiety.•Ceforloids D and E incorporate a rare 12,13-p-hydroxybenzylidene acetal motif.•Ceforloids B and F exhibited mild immunosuppressive activity.