The biosynthesis of roemerine, anonaine, and mecambrine

Abstract

ACCORDING to biogenetic theory1 roemerine (I11 ;( + )-roemerine, was incorporated. Since racemic R=Me, R'=H) and anonaine (111; R=R'=H) roemerine was used for dilution, a t least one step in should be derived in Nature from a benzyliso-biosynthetic sequence must be stereospecific. quinoline [as (I)] via a dienone [as (11)] and a (~)-[N-rnethyZ-~4C]N-Methylnorcoclaurine (I; R = corresponding dienol. Evidence for the first step Me, R'=R"=H) was also a good precursor for is available from studies on the biosynthesis of the roemerine. Herzig-Meyer demethylation of the dienone crotonosine.2 We now report investigations which support the complete biosynthetic sequence. (5)-Coclaurine (I; R = R " = H , R'=Me), (+)-

The potential of alkaloids in drug discovery

“…In this regard, one thinks of the classic efforts of Woodward in developing stereospecific syntheses of reserpine, and strychnine, among others (Bindra and Bindra, 1975), and the strategies of Barton for the formation of benzylisoquinoline-derived alkaloids through phenol oxidative coupling (Barton, 1963;Barton et al, 1966). In the area of drug development, many of the synthetic drugs that are available today have a phylogeny which can be traced to alkaloids such as papaverine or atropine (Foye, 1995).…”

Tritium-labelled alkaloids: Synthesis and applications

“…The aporphine alkaloids are tetracyclic benzyl isoquinoline derivatives, and scores of them exist as natural products with new ones being routinely identified. However, an exhaustive literature search located only two instances of naturally occurring aporphines being tritium labelled during biosynthetic studies by incorporating tritiated precursors and these were isocorydine and roemerine . However, because of their utility in dopaminergic investigations, we also devised methods to prepare the potent synthetic dopamine agonist derivatives [ 3 H]apomorphine ( 15 ) and [ 3 H] N ‐propylapomorphine ( 16 ) at high specific activity.…”

“…However, an exhaustive literature search located only two instances of naturally occurring aporphines being tritium labelled during biosynthetic studies by incorporating tritiated precursors and these were isocorydine 73 and roemerine. 74 However, because of their utility in dopaminergic investigations, we also devised methods to prepare the potent synthetic dopamine agonist derivatives [ 3 H]apomorphine (15) 75 and [ 3 H] N-propylapomorphine (16) 76 at high specific activity. Several hundred dopamine receptor publications have appeared to date using these two important radioligands.…”

Saldedines A and B, Dibromo Proaporphine Alkaloids from a Madagascan Tunicate

“…The biosynthesis of proaporphine alkaloids derives in nature from oxidative phenolic coupling of the benzylisoquinoline alkaloide . The benzylisoquinoline precursor was previously obtained only from the starfish Dermasterias imbricata …”

“…The biosynthesis of proaporphine alkaloids derives in nature from oxidative phenolic coupling of the benzylisoquinoline alkaloide. 7 The benzylisoquinoline precursor was previously obtained only from the starfish Dermasterias imbricata. 8 Saldedines A (1) and B (2) were both tested for toxicity to brine shrimp (Artemia salina) 9 and were found moderately active.…”