3,5-Disubstituted indolizidine myrmicarin

Two new 3,5-disubstituted indolizidines, (-)-myrmicarin 237A and (+)-myrmicarin 237B, Fig. (7), were isolated as the major components of the poison gland secretion of the afiican ant Myrmicaria eumenoides [22]. NMR data analysis ( H, COSY, COLOC and... 

Fig. (7). 3,5-Disubstituted indolizidines (-)-myrmicarin 237A and (+)-myrmicarin 237B [22]...

Despite their structural complexity, it appears that these compounds derive from fairly straightforward dimerization or trimerization of a simple 15-carbon precursor. Although their biosynthesis has not been investigated yet, it seems probable that unsaturated derivatives of myrmicarin 237 (81) such as the hypothetical 141 could represent an immediate precursor, which through a series of intra- and/or intermolecular condensation steps could give rise to myrmicarins 215A/B, 430A, 645, and 663. ° In fact, synthetic studies have shown that the 3,5-disubstituted indolizidine 145 is a suitable precursor for myrmicarin 217 (87). ° ... 

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