Unusual phenethylamine-containing alkaloids from Elaeocarpus tectorius

• Main Authors: Ezeoke, Margret Chinonso, Krishnan, Premanand, Sim, Dawn Su Yin, Lim, Siew Huah, Low, Yun Yee, Chong, Kam Weng, Lim, Kuan Hon
• Format: Article
• Published: Elsevier 2018
• Subjects: Q Science (General); QD Chemistry
• Online Access: http://eprints.um.edu.my/22099/; https://doi.org/10.1016/j.phytochem.2017.12.003

From the leaves of Elaeocarpus tectorius (Lour.) Poir. four previously undescribed phenethylamine-containing alkaloids were isolated, namely, tectoricine, possessing an unprecedented isoquinuclidinone ring system incorporating a phenethylamine moiety, tectoraline, representing a rare alkamide incorporating two phenethylamine moieties, and tectoramidines A and B, representing the first naturally occurring trimeric and dimeric phenethylamine alkaloids incorporating an amidine function. The structures of these alkaloids were established by detailed spectroscopic analysis. The absolute configuration of tectoricine was determined by comparison of the experimental and calculated ECD spectra. Plausible biosynthetic pathways to the four alkaloids are proposed.