New chemical structures and liver-protective activity of the diterpenoids from Callicarpa rubella

• Published in: Fitoterapia 2023-03, Vol.165, p.105394, Article 105394
• Main Authors: Chen, Ping, Huang, Yimin, Zhang, Xueer, Zhao, Zhongxiang, Sun, Zhanghua, Cui, Hui, Lin, Chaozhan, Peng, Guangtian, Wu, Aizhi, Zhu, Chenchen
• Format: Article
• Language: English
• Subjects: Callicarpa rubella; Diterpenoids; Liver protective activity; X-ray structure
• ISSN: 0367-326X
• DOI: 10.1016/j.fitote.2022.105394

Callicarpa rubella is a characteristic folk herb in the genus Callicarpa, and has abundant ethnobotanical usage as indigenous medicine in Lingnan area of P. R. China. However, the phytochemical and pharmacological properties of C. rubella was rarely investigated. Now, three new diterpenoids, named rubellapene A–C (1–3), along with five known analogues (4–8), were isolated from C. rubella. Their structures were determined by spectroscopic methods, quantum chemical electronic circular dichroism calculations and single-crystal X-ray diffraction analysis. Notably, the norditerpenoids C18 of clerodane type (rubellapene B) was rarely found in the genus Callicarpa. The liver protective effects of all of the isolates (1–8) were evaluated by the changes of cell viability and transaminase content of AST and ALT in H2O2-induced BRL cells. Compound 1, 3–8 exhibited that potent liver protective effects at different levels. [Display omitted] •Three new diterpenoids, rubellapene A–C (1-3), were isolated from the leaves and twigs of Callicarpa rubella.•The norditerpenoids C18 of clerodane type (rubellapene B) was rarely found in the genus Callicarpa.•Rubellapene A exhibited that potent liver protective effects in H2O2-induced BRL cells.