Ipecac alkaloids ipecoside

The close biogenetic relationship of the ipecac and monoterpenoid indole alkaloids has already been reviewed in several places (3,5,117,287). In the case of the ipecac alkaloids, tracer experiments (288) have shown that labeled geraniol (146) and loganin (148) are incorporated by Cephaelis ipecacuanha into radioactive cephaeline (149) and ipecoside (150). Thus, the C9-C,0 units of the ipecac alkaloid and ipecoside, represented by thickened lines in formulas 149 and 150, are of monoterpenoid origin from geraniol (145), and loganin (147) acts as a precursor for both alkaloids. The incorporation of glycine into the C9 unit of cephaeline (2) in Cephaelis plants has also been reported (289). 

When the last review on the ipecac alkaloids and /3-carboline congeners (1) was prepared, the chemistries of (-)-ipecoside (7) and (-)-alangiside... 

Ipecac Alkaloids.— The stereochemistry of ipecoside (71) is known by X-ray analysis, and this has been confirmed. Feeding experiments in Cephaelis ipecacuanha have given results which demonstrate that it is not desacetylipecoside (72), as previously supposed cf. ref. 2), but desacetylisoipecoside (73), with the same stereochemistry at C-1 (= C-llb) as cephaeline (76) and emetine (75), which is the true precursor for these alkaloids. Similar results were obtained for cephaeline (76) in Alangium lamarckii On the other hand, desacetylipecoside (72), and not (73), is the precursor for ipecoside (71) (in C. ipecacu-... 

Battersby AR, Parry RJ (1971) Biosynthesis of the ipecac alkaloids and of ipecoside. J Chem Soc Chem Commun 901-902... 

Nagakura N, Hofle G, Coggiola D, Zenk MH (1978) The biosynthesis of the ipecac alkaloids and of ipecoside and alangiside. Planta Med 34 381-389... 

In the meantime, the formation of the main alkaloids in C. ipecacuanha under a variety of conditions has been extensively investigated emetine (1) in callus cultures (49) and under the effects of L-tyrosine supplementation (5t)) emetine (1) and cephaeline (2) in Panamanian ipecac (57), in Nicaraguan ipecac (52), in regenerates obtained by clonal propagation (53,54), in tissue cultures (55) and under the effects of exogenous feeding of shikimic acid and L-phenylalanine (55), in cell suspension and excised root cultures (57), in adventitious root cultures (58), and in callus cultures (56,59) and the effects of age and electrokinetic potential (60) ipecoside (7) in the roots (61) and the effect oi Azotobacter, leaf mold, and farmyard manure on alkaloid content (62). In addition, micropropagation systems for C. ipecacuanha have been developed (63-65). 

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