Discovery of four modified classes of triterpenoids delineated a metabolic cascade: compound characterization and biomimetic synthesis

• Published in: Chemical science (Cambridge) Vol. 12; no. 28; pp. 9831 - 9838
• Main Authors: Zhou, Bin, Gao, Xin-Hua, Zhang, Min-Min, Zheng, Cheng-Yu, Liu, Hong-Chun, Yue, Jian-Min
• Format: Journal Article
• Language: English
• Published: CAMBRIDGE Royal Soc Chemistry 21.07.2021; Royal Society of Chemistry; The Royal Society of Chemistry
• Subjects: Biomimetic materials; Chemistry; Chemistry, Multidisciplinary; Crystallography; Data acquisition; Physical Sciences; Science & Technology; Tumors; ROUTE; DICHAPETALIN; ACID; STRUCTURAL ELUCIDATION; FURANS; MEDICINAL-PLANTS; CONSTITUENTS
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d1sc02710g

Chemical studies on Dichapetalum gelonioides have afforded 18 highly modified complex triterpenoids belonging to four compound classes as defined by the newly adapted functional motifs associated with the A ring of the molecules. Their structures were determined by solid data acquired by diverse methods. The biosynthetic pathway for the four compound classes was rationalized via cascade modifications involving diverse chemical events. The subsequent biomimetic syntheses afforded all the desired products, including compounds 16 and 19 that were not obtained in our purification, which validated the proposed biosynthetic pathway. Besides, some compounds exhibited strong cytotoxic activities, especially 2 and 4 showed nanomolar potency against the NAMALWA tumor cell line, and a gross structure-activity relationship (SAR) of these compounds against the tested tumor cell lines was delineated. Characterization of four classes of highly modified triterpenoids from Dichapetalum gelonioides sheds light on an unprecedented biosynthetic cascade, which was validated by the subsequent biomimetic syntheses. Moreover, some isolates exhibited nanomolar cytotoxic activities.