Euphonoids A−G, cytotoxic diterpenoids from Euphorbia fischeriana

• Published in: Phytochemistry (Oxford) Vol. 166; p. 112064
• Main Authors: Yan, Xue-Long, Zhang, Jun-Sheng, Huang, Jia-Luo, Zhang, Yao, Chen, Jia-Qi, Tang, Gui-Hua, Yin, Sheng
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 01.10.2019; Elsevier
• Subjects: Biochemistry & Molecular Biology; Cytotoxicity; Diterpenoids; Ent-abietanes; Euphorbia fischeriana (Euphorbiaceae); Life Sciences & Biomedicine; Plant Sciences; Science & Technology; Diterpenoids; Ent-abietanes; Cytotoxicity; Euphorbia fischeriana (Euphorbiaceae); FIJIAN PLANTS; CHEMISTRY; ROOTS; ENT-ABIETANE
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2019.112064

Seven previously undescribed polycyclic diterpenoids, euphonoids A−G, including four ent-abietanes, two ent-atisanes, and one ent-kaurene, along with 26 known analogues were isolated from the roots of Euphorbia fischeriana. The structures of the undescribed compounds were elucidated by spectroscopic analysis, ECD calculations, and single crystal X-ray diffraction. Besides, the structure of a previously reported ent-abietane diterpenoid, fischeriabietane A, was revised. All the isolates were screened for the cytotoxicities against five cancer cell lines. Euphonoid A, fischeriabietane A, 11-oxo-ebracteolatanolide B, caudicifolin, jolkinolide B, and methyl-8,11-3-dihydroxy-12-oxo-ent-abietadi-13,15(17)-ene-16-oate showed significant inhibitory activities against human prostate cancer C4-2B and C4-2B/ENZR cell lines, with IC50 values being less than 10 μM. The brief structure-activity relationships (SARs) of these diterpenoids were also discussed. Seven previously undescribed polycyclic diterpenoids along with 26 known analogues were isolated from the roots of Euphorbia fischeriana. Six compounds showed significant inhibitory activity against C4-2B and C4-2B/ENZR cell lines, with IC50 values being less than 10 μM. [Display omitted] •Seven previously undescribed diterpenoids were isolated from Euphorbia fischeriana.•Six compounds showed significant cytotoxicity against a panel of cancer cell lines.•The brief structure-activity relationships of these diterpenoids were discussed.