Bisbenzylisoquinolines, occurrence

Several biosynthetic proposals have been advanced, based on patterns of occurrence, known in vitro reactivity of bisbenzylisoquinoline alkaloids, and mechanistic analogy. Although unconfirmed (e.g., by isotopic labeling), these theories point the way toward further research. 

Previous volumes of this treatise have addressed the occurrence, chemistry, and pharmacology of the major structural types of alkaloids found in Guatteria. Nevertheless, of the 20 bisbenzylisoquinolines described to date as Guatteria constituents, only 2 are discussed in the chapter by Cava et al. (1), and only... 

Biogenetic significance is attached to the fact that benzylisoquinoline alkaloids occur in the plant with bisbenzylisoquinoline alkaloids. Examples of such occurrence are thalifendlerine with hernandezine in Thalictrum fendleri (Auth. ) and magnoflorine with thalicarpine in Thalictrum dasycarpum Fisch. and Ball. In each case the simpler alkaloid may well be the precursor of the bisbenzylisoquinoline alkaloid. 

It can be concluded that the alkaloids of this type are fundamentally of two groups the nortenuipine (7-demethyltenuipine) type and the tenuipine type, each with differing stereochemistry. The C(I2)/C(13) methylenedioxy group in these alkaloids is unusual in its occurrence, particularly within the bisbenzylisoquinoline alkaloids. The alkaloids of this group are restricted to the genus Daphnandra (Monimiaceae). 

MP Cava, KT Buck, and KL Stuart in The Alkaloids. Vol. 16. pp. 249, The Bisbenzylisoquinoline Alkaloids — Occurrence, Structure and Pharmacology, RHF Manske, Ed., Academic Press, New York (1977). 

Volume 14 of this series presents three interesting reviews of research on alkaloids. Chapter I, by Paul L. Schiff, Jr. is a monumental effort, presenting a selective, comprehensive tabular review of research on the bisbenzylisoquinoline alkaloids, with an analysis of the respective alkaloid types. The chapter should serve as a very useful tool for the bench research scientist who is involved in the isolation and elucidation of structures of bisbenzylisoquinoline alkaloids. Moreover, the data in these tables provides the botanical distribution and occurrence (family, genus, species) of the various classes of these alkaloids. The alkaloids are also categorized by their molecular weights and structural types. 

Table 2. Occurrence of bisbenzylisoquinolines and bisbenzyltetra-hydroisoquinolines in Annonaceae until 1981.

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