Pyrrole and Imidazole-Derived Alkaloids

A number of pyrrole- and imidazole-containing marine alkaloids have had inverse-detected 2D NMR experiments applied in the elucidation of their 

Naamidine-D. A number of 2-amino imidazole alkaloids were reported from the marine sponge Leucetta chagosensis (Carmely et al. 1989). An HMQC spectrum was utilized to establish direct proton-carbon shift correlations for naamidine-D (38), which was isolated in minute amount. 

Although the authors refer to establishing direct correlations, the Bax and Summers (1986) HMBC paper was referenced. 

Manzacidins A-C. A trio of novel pyrrole-derived alkaloids containing a tetrahydropyriniidine in their structures, manzacidins A-C, (41) were also 

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For the most part, five-membered ring alkaloids tend to make one think of pyrrole- and imidazole-derived alkaloids. There are, however, also alkaloids that fall into this class that are, for example, derived from 1,2,4-thiadiazoles, for example, 19, the characterization of which is discussed Section 7.1.8. 

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