Tyrosine ipecac alkaloids

The amino acid tyrosine is a precursor of numerous alkaloids. The largest group is formed by the benzyhsoquinoline alkaloids. In addition, several other alkaloid classes originate from t5Tosine, for example, the Ipecac alkaloids and the Amarylhdaceae alkaloids. The benzyliso-quinoUnes, Ipecac- and Amarylhdaceae alkaloids will be reviewed. 

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. 

Tyrosine-derived alkaloids (ipecacuanha alkaloids or ipecac alkaloids) are found in dried rhizome and in the... 

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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