The Bisbenzylisoquinolines

Bisbenzylisoquinolines have been classified into 26 types. The recent characterization of the new alkaloids tiliamosine and thalistyline brings this total to 28. These types can best be described by a numerical system obeying the following rules,  

The numbering system for a benzylisoquinoline half of a dimer is shown in structure 1 (see page 81). 

The symbols, f, and J indicate the shared oxygens of diaryl ethers, and are placed at the upper right of the appropriate numbers. 

Dauricine, daurinoline, dauricinoline, dauricoline, magnoline, berbamunine, espinine, espinidine, lindoldhamine, thalibrine, cuspidaline, grisabine 

Rodiasine, funiferine, ocotosine, tiliageine, phlebicine ocotine, dirosine 

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In addition to the foregoing benzylwoquinoline alkaloids all derived from Papauer spp, two other members of the group, coclaurine and iso-coclaurine are described in the bisbenzylisoquinoline group (p. 349) with which they are naturally associated. 

Fig. 10.3 Reaction catalyzed by the cytochrome P-450-dependent oxidase berbamunine synthase (CYP80A1). This enzyme creates a branchpoint in the (5)-reticuline biosynthetic pathway to form the bisbenzylisoquinoline alkaloids.

In the bisbenzylisoquinolines the size of the macrocyclic system affects the chemical shifts of some groupings of protons in a characteristic way. In certain conformations of the 21-membered ring in 5-7 ether linked systems the 2- and 6-substituents lie over aryl rings with a consequent shift to lower frequency. This is illustrated by the H NMR spectrum of thalictine [39] (38) which shows absorption for the 8-and 8 -protons to low frequency of the other aromatic protons. 

Although it is almost a cliche to point out the ever-accelerating pace of scientific development, since the last review on the bisbenzylisoquinoline alkaloids in... 

The format follows that of the earlier review. The subject of synthesis, however, which formerly constituted a separate chapter, is included in this work, and other coverage has been expanded, particularly in the areas of plant biochemistry and pharmacology. The tabulation of all known bisbenzylisoquinoline alkaloids has been revised and updated. A section listing other major review articles on these alkaloids is also included, and the reader may wish to consult some of these for extensive physical data. In keeping with the original purpose of this treatise, we have tried for a comprehensive overview, with strong emphasis on the specific chemistry of the bisbenzylisoquinoline alkaloids, rather than an exhaustively detailed presentation. 

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