Cytotoxic sesquiterpenoids from the leaves of Magnolia grandiflora

• Published in: Phytochemistry (Oxford) Vol. 155; pp. 182 - 190
• Main Authors: Ding, Lin-Fen, Su, Jia, Pan, Zheng-Hong, Zhang, Zhi-Jun, Li, Xiao-Nian, Song, Liu-Dong, Wu, Xing-De, Zhao, Qin-Shi
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 01.11.2018; Elsevier
• Subjects: Biochemistry & Molecular Biology; Cytotoxic activity; Life Sciences & Biomedicine; Magnolia grandiflora (Magnoliaceae); NF-κB transcriptional activity; Plant Sciences; Science & Technology; Sesquiterpenoids; NF-κB transcriptional activity; Magnolia grandiflora (Magnoliaceae); Sesquiterpenoids; Cytotoxic activity; NF-kappa B transcriptional activity; BIOMIMETIC TRANSFORMATIONS; LACTONES; PARTHENOLIDE; BARK; KOBUS; CONSTITUENTS; ALKALOIDS
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2018.08.006

Nine previously undescribed sesquiterpenoids, named magnograndins A-I, as well as fourteen known ones, were obtained from the 70% acetone extract of the leaves of Magnolia grandiflora. Their structures were ascertained based on the spectroscopic evidences. The assignment of the relative configuration of magnograndin A was further confirmed by single-crystal X-ray diffraction analysis. 1β,10α-Epoxyparthenolide, parthenolide, and micheliolide exhibited potent cytotoxic activity against MDA-MB-468, AGS, HCT116, Hela, and MDA-MB-231 human cancer cell lines with IC50 values ranging from 1.76 to 16.11 μM. 1β,10α-Epoxyparthenolide and micheliolide potently inhibited NF-κB transcriptional activity with IC50 of 13.92 and 8.95 μM, respectively. The expression levels of NF-κB downstream protein p65 and XIAP were clearly down-regulated in 1β,10α-epoxyparthenolide and micheliolide treated cells, which demonstrated the inhibition of NF-κB signaling pathway. Nine sesquiterpenoids, magnograndins A-I, along with fourteen known ones, were isolated from the leaves of Magnolia grandiflora. Eight sesquiterpenoids exhibited moderate cytotoxicity against five cancer cell lines, among which two compounds potently inhibited NF-κB transcriptional activity. [Display omitted] •Twenty-three sesquiterpenoids were isolated from the leaves of Magnolia grandiflora.•Nine previously undescribed sesquiterpenoids were characterized.•Eight compounds exhibited potent cytotoxicity against five cancer cell lines.•Two compounds potently inhibited NF-κB transcriptional activity.