HSQC-based small molecule accurate recognition technology discovery of diverse cytotoxic sesquiterpenoids from Elephantopus tomentosus L. and structural revision of molephantins A and B

• Published in: Phytochemistry (Oxford) 2023-02, Vol.206, p.113562-113562, Article 113562
• Main Authors: Bai, Ming, Xu, Wei, Zhang, Xin, Li, Qian, Du, Ning-Ning, Liu, De-Feng, Yao, Guo-Dong, Lin, Bin, Song, Shao-Jiang, Huang, Xiao-Xiao
• Format: Article
• Language: English
• Subjects: Antineoplastic Agents - pharmacology; Asteraceae; Asteraceae - chemistry; Elephantopus tomentosus L; Molecular Structure; Plants; Sesquiterpenes - chemistry; Sesquiterpenoids; Small molecule accurate recognition technology; Structural revision
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2022.113562

Elephantopus tomentosus L. is a perennial herb taxonomically belonging to the family Asteraceae, which has been used as a folk medicine for the treatment of hepatobiliary diseases. Sesquiterpenoids from this plant have broad biological activities, including anti-tumor, anti-inflammatory, and antibacterial effects. In this study, fifteen structurally diverse sesquiterpenoids comprised 11 germacrane-type and 4 eudesmane-type sesquiterpenoids were prioritized to isolated from Elephantopus tomentosus L. based on the HSQC-based Small Molecule Accurate Recognition Technology (SMART) strategy. Among them, ten sesquiterpenoids were previously unreported, and their structures were elucidated by spectroscopic data, computational methods, single-crystal X-ray diffraction crystallographic data or electronic circular dichroism calculations. In addition, the structures of two known sesquiterpenoids, molephantin A and B, which were reported to possess E-geometry for the Δ1(10) double bond, were revised by reanalyzing their spectroscopic and X-ray crystallographic data. Some sesquiterpenoids exhibited significant cytotoxic activities against Hep3B and HepG2 cell lines. Structurally diverse sesquiterpenoids were prioritized to isolated from Elephantopus tomentosus by SMART, and the structures of two previously reported sesquiterpenoids were revised. [Display omitted] •Fifteen sesquiterpenoids were prioritized to isolated from Elephantopus tomentosus by SMART.•Structures were determined by NMR, X-ray, and calculate ECD.•The structures of two previously reported sesquiterpenoids were revised.•The cytotoxicity against Hep3B and HepG2 cell lines were evaluated.