Ipecac alkaloids biosynthesis

Nomura, T. and T. M. Kutchan, Three new 0-methyltransferases are sufficient for all 0-methylation reactions of ipecac alkaloid biosynthesis in root culture of Psychotria ipecacuanha. J. Biol Chem., 2010. 285(10) p. 7722-38. 

Battersby, a. R., N. G. Lewis, and J. M. Tippett, The basic glucosides related to the biosynthesis of indole and ipecac alkaloids, Tetrahedron Lett., 4849-4852 (1978). 

The biosynthesis of the Ipecac alkaloids as illustrated for cephae-llne (XVII) and Ipecoslde (XVIII) involves geranlol (I) and loganln (II) for the non-tyramine derived portion, apparently in a manner similar to the indole alkaloids. 

Ipecac alkaloids are derived from the amino acid tyrosine and the monoterpene secologanin and are therefore termed terpenoid-isoquinoline alkaloids. They occur in the eudicot families Alangiaceae and Rubiaceae. Two species, Psychotria ipecacuanha (Rubiaceae) and Alangium lamarckii (Alangiaceae), have been investigated in detail with respect to their metabolites and biosynthesis of their alkaloids (Fujii and Ohba, 1998). Roots and rhizomes of P. ipecacuanha are the source of cephaeline and emetine (Fig. 9), two compounds with emetic, expectorant, and amebicidal properties. 

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... 

Scheme 1. Biosynthesis of ipecac, Alangium, and indole alkaloids C9-C10 unit portion.

The alkaloid contents of adventitious shoots in liquid medium were quantified by HPLC, Fig. (20). They produced alkaloids, especially cephaeline (0.4 - 0.6% dry weight), and there was no obvious difference in alkaloid contents among different concentrations of BA. This result indicates that ipecac shoots, formed on intemodal segments, have the capabilities of alkaloid biosynthesis. 

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