Structural revision of Stemoburkilline from an E-alkene to a Z-alkene

• Main Authors: Kwankamol Sastraruji, Stephen G. Pyne, Alison T. Ung, Pitchaya Mungkornasawakul, Wilford Lie, Araya Jatisatienr
• Format: Journal
• Published: 2018
• Subjects: Biochemistry, Genetics and Molecular Biology; Chemistry; Medicine; Pharmacology, Toxicology and Pharmaceutics
• Online Access: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=62649115548&origin=inward; http://cmuir.cmu.ac.th/jspui/handle/6653943832/48900
• Institution: Chiang Mai University

Semisynthesis studies starting from (11Z)-1′,2′- didehydrostemofoline (4) indicated that the known Stemona alkaloid stemoburkilline is the Z-isomer and not the E-isomer as initially reported. The semisynthesis involved conversion of (11Z)-1′,2′- didehydrostemofoline (4) to 11(S),12(S)-dihydrostemofoline (3) followed by a stereoselective base-catalyzed ring-opening reaction to give (Z)-stemoburkilline (8). The same product was obtained using a similar synthetic protocol starting from isostemofoline (6) via a based-catalyzed ring-opening reaction of 11(S),12(R)-dihydrostemofoline (1). A re-examination of the crude root extracts of Stemona burkillii Prain and further NOE studies established stemoburkilline as the Z-isomer (8). © 2009 American Chemical Society and American Society of Pharmacognosy.