Variation in emetine and cephaeline contents in roots of wild Ipecac (Psychotria ipecacuanha)

Ipecac (Psychotria ipecacuanha) is a perennial, medicinal herb that grows as clusters in the understory of humid, shady areas of the Atlantic Rain Forest of southeastern Brazil. This investigation followed the contents of emetine and cephaeline, the bioactive constituents, and assessed root attributes in roots that were sampled periodically from four clusters of Ipecac (VRB8, ITA1, ITA2, and ITA3) that were growing in natural conditions. HPLC analyses showed that the content of the two alkaloids underwent monthly fluctuations over one year period. The concentration of emetine, but not cephaeline, differed significantly among the four clusters. The highest mean content of emetine was found in VRB8 (1.44%), followed by ITA1 (1.14%), ITA2 (0.63%), and finally ITA3 (0.44%). The highest mean content of cephaeline was found in ITA2 and ITA3 (0.26%), although it was not significantly different from ITA1 and VRB8 contents (0.15%). Correlation analysis revealed that contents of emetine are significant (P < 0.01), but negatively correlated (−0.23) with that of cephaeline. Small sized roots characterized the low-emetine clusters ITA2 and ITA3, while the high-emetine clusters ITA1 and VRB8 consistently yielded larger roots. In these four clusters, emetine contents were correlated positively with fresh root weight, and with diameter and weight of the dried root. Conversely, cephaeline contents were negatively correlated with these three attributes.