Abstract
The major benzophenanthridine alkaloid chelidonine (14) is shown to be biosynthesised in Chelidonium majus plants from (S)-reticuline (2)via(S)-scoulerine (4) and (S)-stylopine (7), and evidence consistent with a dihydroisoquinoline intermediate [e.g.(11)] is presented. Similar though less extensive evidence is provided for the same pathway to the aromatic systems, e.g. sanguinarine (13). Protopine (10) is shown to be formed in vivo from (S)-scoulerine (4) and (S)-stylopine (7). Studies have been made of the late biosynthetic stages beyond scoulerine and stylopine and the role of isocorypalmine (6) and canadine (21) in the biosynthesis of narcotine (3) and berberine in the opium poppy has been investigated.The results from 3H labelling at four different sites in the various precursors limit the possible mechanisms which can be considered for the enzymic transformations revealed by this research. Unexpected increases in 3H : 14C ratio (up to 20%) are discussed.Extensive degradations of the labelled alkaloids have been carried out to establish quantitatively the level of radioactivity at the multiple sites. The syntheses for the many specifically labelled substances used in this study are described.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the Chemical Society, Perkin Transactions 1
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
