Indolizidine, simple and quinolizidine alkaloids

This review describes structural diversity, structural identification and biological activity of simple indolizidine and quinolizidine alkaloids, and covers the period from 1994 to 1999. A review of stereoselective methods for the synthesis of indolizidines and quinolizidines will be pubUshed in this series in the near future. 

The first comprehensive survey of simple indolizidine and quinolizidine alkaloids in this treatise was presented in Volume 28, which was published in 1986... 

A major difficulty that arises fiom the diffuse nature of the topic is that simple indolizidine and quinolizidine alkaloids often occur in genera, families, orders, and classes that have merited clusters of their own in this series of volumes. An unfortunate consequence is that some themes introduced in the earlier review in Volume 28 have been selectively updated in the intervening years, wdiile others have rentained unsurveyed. This piecemeal coverage means that the present... 

The isolation, structural elucidation, and biological activity of the extraordinary metabolite indolizomycin (63) were described in the earlier review on simple indolizidine and quinolizidine alkaloids in Volume 28 of this series (7). The compound was obtained from a mutant Streptomyces strain bioengineered by protoplast fusion of two strains that do not normally produce antibiotics 54). It was reported to be exceedingly unstable, undergoing decomposition within a few hours under neutral conditions at room temperature. 

Porantherilidine (415), the only bicyclic member of a group of quinolizidine alkaloids from the Australian shrub Poranthera corymbosa, was described in the previous chapter on simple indolizidine and quinolizidine alkaloids in Volume 28 of this series (/). The related tricyclic alkaloid porantheiidine (416) is included here as an obvious carbinolamine derivative of the simple bicyclic system. 

Previous treatment of this topic may be found in the review on insect alkaloids by Numata and Ibuka in Volume 31 of this treatise (J), and in the general chapters on simple indolizidine and quinolizidine alkaloids in Volumes 28 and 44 (7,2). 

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