Cephaelis Ipecacuanha Research Articles

Risk of genetic vulnerability and aspects of the reproductive biology of Psychotria ipecacuanha (Rubiaceae), a threatened medicinal plant species of Brazilian forests

Risk of genetic vulnerability and aspects of the reproductive biology of Psychotria ipecacuanha (Rubiaceae), a threatened medicinal plant species of Brazilian forests

Effect of indolebutyric acid on in vitro root production of Psychotria ipecacuanha (Brot.) Stokes (Rubiaceae)

Psychotria ipecacuanha (Brot.) Stokes (Rubiaceae) é uma planta medicinal, conhecida como ipeca, que em suas raízes, são encontrados dois alcalóides de grande valor farmacológico (emetina e cefalina), usados no tratamento antidiarréico, amebicida, expectorante e antiinflamatório. O risco de extinção e a dificuldade do cultivo convencional da espécie, frente à grande demanda de mercado, fomentam estudos de métodos de cultivo que possibilitem a exploração econômica da mesma. Este trabalho apresenta dados sobre o desenvolvimento de protocolo de cultivo de raízes in vitro de P. ipecacuanha. Foram utilizadas folhas, segmentos nodais, internodais e raízes, que foram introduzidos em meios de cultura contendo diferentes concentrações (0,5; 1,0; 1,5; 2,0; 2,5 e 3,0 mg.L-1) de ácido indolbutírico. O melhor tratamento para a formação de raízes foi com a utilização de segmentos nodais, em meio de cultura contendo 2,5 e 3,0 mg.L-1 de AIB, que deram origem a 100% de formação de raízes, aos 60 dias de cultivo. Com relação ao número de raízes, o melhor resultado (13:1), foi obtido com a utilização de segmentos internodais em meio suplementado com 2,5 mg.L-1 de AIB e, o melhor comprimento de raízes foi obtido em segmentos radiculares desenvolvidos em 1,5 mg.L-1 de AIB (0,87cm por raiz).

In vitro propagation of Psychotria ipecacuanha (Brot.) Stokes under different concentrations of Indoleacetic Acid

Psychotria ipecacuanha, é uma planta medicinal nativa da América com a maior área de ocorrência no Estado de Mato Grosso - Brasil, críticamente ameaçada devido à sobreexploração das populações naturais. Devido à dificuldades na propagação convencional, o objetivo deste estudo foi a avaliação do efeito de diferentes concentrações do regulador de crescimento ácido indolacético (AIA) na propagação in vitro de P. ipecacuanha. Segmentos nodais foram cultivados em meio de Murashige e Skoog (MS) sem reguladores de crescimento (controle) e suplementado com quatro concentrações (0,05; 0,5; 1,5 e 2,0 mg.L-1) de AIA, em meios semi-sólidos. Após 60 dias de cultivo, segmentos nodais (n=30) cultivados em meio de Murashige & Skoog (MS) suplementado com 0,05 mg.L-1 de AIA produziram, em média, 4,56 segmentos nodais por explante, cujas plântulas foram aclimatizadas com sucesso, sem exibição de qualquer anomalia morfológica ou variação.

Diversity of Secondary Metabolites from Some Medicinal Plants and Cultivated Lichen Mycobionts

Studies on the structural determination, biosynthesis, and biological activities of secondary metabolites from natural sources are significant in the field of natural products chemistry. This review focuses on diverse secondary metabolites isolated from medicinal plants and cultivated mycobionts of lichens in our laboratory. Monoterpene-tetrahydroisoquinoline glycosides and alkaloids isolated from Cephaelis acuminata and Alangium lamarckii gave important information on the biosynthesis of ipecac alkaloids. A variety of glycosides linked with a secologanin unit and indole alkaloids were obtained from medicinal plants belonging to the families of Rubiaceae, Apocynaceae, and Loganiaceae. Plant species of the four genera Fraxinus, Syringa, Jasminum, and Ligustrum of the family Oleaceae were chemically investigated to provide several types of secoiridoid and iridoid glucosides. The biosynthetic pathway leading from protopine to benzophenanthridine alkaloids in suspension cell cultures of Eschscholtzia californica was elucidated. The structures and biological activities of the bisbenzylisoquinoline alkaloids of Stephania cepharantha and Nelumbo nucifera were also investigated. In addition, the mycobionts of lichens were cultivated to afford various types of metabolites that differ from the lichen substances of intact lichens but are structurally similar to fungal metabolites. The biosynthetic origins of some metabolites were also studied. These findings suggest that cultures of lichen mycobionts could be sources of new bioactive compounds and good systems for investigating secondary metabolism in lichens.

Cyclotides Isolated from an Ipecac Root Extract Antagonize the Corticotropin Releasing Factor Type 1 Receptor.

Cyclotides are plant derived, cystine-knot stabilized peptides characterized by their natural abundance, sequence variability and structural plasticity. They are abundantly expressed in Rubiaceae, Psychotrieae in particular. Previously the cyclotide kalata B7 was identified to modulate the human oxytocin and vasopressin G protein-coupled receptors (GPCRs), providing molecular validation of the plants’ uterotonic properties and further establishing cyclotides as valuable source for GPCR ligand design. In this study we screened a cyclotide extract derived from the root powder of the South American medicinal plant ipecac (Carapichea ipecacuanha) for its GPCR modulating activity of the corticotropin-releasing factor type 1 receptor (CRF1R). We identified and characterized seven novel cyclotides. One cyclotide, caripe 8, isolated from the most active fraction, was further analyzed and found to antagonize the CRF1R. A nanomolar concentration of this cyclotide (260 nM) reduced CRF potency by ∼4.5-fold. In contrast, caripe 8 did not inhibit forskolin-, or vasopressin-stimulated cAMP responses at the vasopressin V2 receptor, suggesting a CRF1R-specific mode-of-action. These results in conjunction with our previous findings establish cyclotides as modulators of both classes A and B GPCRs. Given the diversity of cyclotides, our data point to other cyclotide-GPCR interactions as potentially important sources of drug-like molecules.

Dynamics of Endogenous Indole-3-acetic Acid and Cytokinins During Adventitious Shoot Formation in Ipecac

For most plant species, auxins and cytokinins are added to the culture medium to induce adventitious shoot formation. In ipecac (Carapichea ipecacuanha (Brot.) L. Andersson), however, shoots form on internodal segments without phytohormone treatment. This creates an opportunity to analyze the dynamics of endogenous phytohormones during adventitious shoot formation. Ipecac is a medicinal plant whose root extract is used as an expectorant and emetic. We explored the relationships among adventitious shoot formation and levels of an auxin (indole-3-acetic acid) and four cytokinins in ipecac. Adventitious shoots that formed in the apical region of internodal segments were derived from epidermal cells. One of the shoots grew vigorously with a vascular bundle connected to that of the segment, and the others were suppressed in the outgrowth. When the biggest shoot was removed, another began to grow. During adventitious shoot formation, endogenous auxin accumulated in the basal region of segments, whereas cytokinins accumulated in the middle region. Thus, the distribution of auxin, not cytokinins, determined where adventitious shoots formed.

HERG Channel Blocking Ipecac Alkaloids Identified by Combined In Silico - In Vitro Screening.

Human ether-a-go-go-related gene channel blocking is associated with QT interval prolongation and increased risk of potentially fatal arrhythmias. As natural products keep increasing in popularity, there is an urgent need for studies assessing human ether-a-go-go-related gene channel-related cardiotoxic risks. We selected 49 plant species based on the results of a pharmacophore-based virtual screening campaign, in parallel with a literature data survey concerning highly consumed herbal medicines with reported cardiac liabilities. Lead-like enhanced extracts were prepared, an initial in vitro screening was performed at 100 µg/mL by voltage clamp on Xenopus oocytes, and five human ether-a-go-go-related gene channel blocking extracts were identified. In accordance to the six virtually predicted alkaloids, the root extract of Carapichea ipecacuanha inhibited human ether-a-go-go-related gene channel currents by 32.5 %. A phytochemical workflow resulted in the isolation and identification of five out of the six virtually predicted alkaloids. All isolates blocked human ether-a-go-go-related gene channel currents to different extents. The major ipecac constituents emetine (1) and cephaeline (2) showed IC50 values of 21.4 and 5.3 µM, respectively, measured by whole-cell patch clamp in HEK293 cells. This is the first report on human ether-a-go-go-related gene channel blockers from C. ipecacuanha. Its roots and rhizomes are used to produce different pharmacopeial ipecac preparations that are mainly used as emetics for poisoning treatment. Our findings raise further questions regarding the safety and over-the-counter appropriateness of these herbal products.

Biological activity of four plant oils, against the red palm weevil, Rhynchophorus ferrugineus (Oliver), (Coleoptera Curculionidae)

In the present study, four botanical oils of Melissa officinalis, Borago officinalis, Laurus nobilis and Carapichea ipecacuanha were tested against newly emerged adult males and females of the red palm weevil, Rhynchophorus ferrugineus (Oliver) for investigating their insecticidal activity, their effects on some bilogical aspects and morphogenetic abnormalities in the all stages.The results revealed that the males of Rhynchophorus ferrugineus were more susceptible to the four botanical oils than the females, followed by the immature larvae. The larvae showed different degrees of susceptibility to the four botanical oils, they showed the highest susceptibility to C. ipecacuanha and the lowest to B. officinalis oil at LC50 levels. Both adult males and females showed the highest susceptibility to C. ipecacuanha and the lowest to L. nobilis oil at LC50 levels. Also, the obtained results showed that the four tested oils disrupted some biological aspects of the tested insects. These oils markedly reduced male and female longevity, female fecundity and hatchability of the laid eggs. Morphogenetic abnormalities such as darkness of pupae, incomplete adult eclusion , dwarfism and crumpled wings and legs of adults appeared in the different stages of the insect as a result of treatment with the four tested oils.

Natural Plant Alkaloid (Emetine) Inhibits HIV-1 Replication by Interfering with Reverse Transcriptase Activity.

Ipecac alkaloids are secondary metabolites produced in the medicinal plant Psychotria ipecacuanha. Emetine is the main alkaloid of ipecac and one of the active compounds in syrup of Ipecac with emetic property. Here we evaluated emetine’s potential as an antiviral agent against Human Immunodeficiency Virus. We performed in vitro Reverse Transcriptase (RT) Assay and Natural Endogenous Reverse Transcriptase Activity Assay (NERT) to evaluate HIV RT inhibition. Emetine molecular docking on HIV-1 RT was also analyzed. Phenotypic assays were performed in non-lymphocytic and in Peripheral Blood Mononuclear Cells (PBMC) with HIV-1 wild-type and HIV-harboring RT-resistant mutation to Nucleoside Reverse Transcriptase Inhibitors (M184V). Our results showed that HIV-1 RT was blocked in the presence of emetine in both models: in vitro reactions with isolated HIV-1 RT and intravirion, measured by NERT. Emetine revealed a strong potential of inhibiting HIV-1 replication in both cellular models, reaching 80% of reduction in HIV-1 infection, with low cytotoxic effect. Emetine also blocked HIV-1 infection of RT M184V mutant. These results suggest that emetine is able to penetrate in intact HIV particles, and bind and block reverse transcription reaction, suggesting that it can be used as anti-HIV microbicide. Taken together, our findings provide additional pharmacological information on the potential therapeutic effects of emetine.

Morphoanatomy of Shoot-Bud Forming Root Systems of Poaia (Carapichea ipecacuanha(Brot.) L. Andersson) - Rubiaceae

Carapichea ipecacuanha is a sub-shrub species known as “poaia” or Ipecac, widely used as therapy for healing and amoebiasis, attributed to emetic alkaloids. This work was undertaken to describe the main aspects of the vegetative reproduction and ontogeny of root-derived adventitious buds. In nature, the regeneration of this species is essentially carried out from root sprouts. Variation on the stem external morphology was observed which encloses subterranean parts (straight or horizontal to soil) and aerial parts that, in general, bend to the soil surface, where adventitious roots are emitted from the internode.. Root fragments of C. ipecacuanha were placed in distilled water (with and without 8.9 µM 6-benzyladenine - BA) and in hydroponics medium with Hoagland solution (with and without 8.9 µM BA). Adventitious buds developed from the phellogen, whose cells divided in several planes, generating the neoformed meristemoids. The buds were formed asynchronously on the surface of roots that presented secondary growth. The bud vascular system was formed mainly by differentiating meristematic cells, and with a late development it was entirely connected to the root vascular system.

Glass beads in liquid media: an alternative matrix for in vitro root induction of Cephaelis ipecacuanha A. Richard

Cephaelis ipecacuanha shoots were rooted in different concentrations of auxins on solid Murashige and Skoog (Physiol Plant 15:473–497, 1962) media and liquid MS media with glass beads. Glass beads were used as an alternative source of support matrix in liquid culture media to replace agar. The highest rooting response was observed on liquid MS medium with glass beads containing 2 mg l−1 α-naphthalene acetic acid within 15–20 days. Shoot elongation was also found to be better compared to solid MS medium. Rooted shoots were successfully hardened and established in the soil. Hence, an easy, reliable and reproducible protocol was developed for in vitro rooting of Ipecac on liquid MS medium with glass beads, which is biologically inert and reusable.

Propagação da poaia (Psychotria ipecacuanha) em diferentes substratos e posicionamento das estacas

A poaia (Psychotria ipecacuanha), Rubiaceae, é importante espécie medicinal, nativa da América, com a maior área de ocorrência no estado de Mato Grosso, principalmente no município de Cáceres. O objetivo neste trabalho foi verificar o efeito de substratos, da posição de estacas de raiz, e de tipos de estacas na propagação de P. ipecacuanha. No primeiro experimento foram usadas estacas de raiz com 2 cm de comprimento no delineamento experimental de blocos ao acaso, no esquema de parcela subdividida 2 x 2, sendo duas posições (vertical e horizontal) e dois substratos (areia e espuma fenólica), com 15 repetições com 15 estacas cada. No segundo experimento introduzimos estacas basais e apicais da raiz e da parte aérea nos substratos areia, comercial para hortaliças, solo do ambiente natural da espécie e espuma fenólica. O delineamento experimental foi em blocos casualizados no esquema fatorial 4 x 4, com quatro repetições e cinco estacas por parcela. As variáveis analisadas foram diâmetro, comprimento, número de brotações e número de folhas por brotação. A produção de mudas de P. ipecacuanha pode ser feita com estacas de raiz de 2 cm de comprimento plantadas na posição horizontal ou estacas da parte aérea apical com duas gemas, plantadas na posição vertical e em substratos areia ou solo da área de ocorrência da espécie.

Cyclotide discovery in Gentianales revisited--identification and characterization of cyclic cystine-knot peptides and their phylogenetic distribution in Rubiaceae plants.

Cyclotides are a unique class of ribosomally synthesized cysteine-rich miniproteins characterized by a head-to-tail cyclized backbone and three conserved disulfide-bonds in a knotted arrangement. Originally they were discovered in the coffee-family plant Oldenlandia affinis (Rubiaceae) and have since been identified in several species of the violet, cucurbit, pea, potato, and grass families. However, the identification of novel cyclotide-containing plant species still is a major challenge due to the lack of a rapid and accurate analytical workflow in particular for large sampling numbers. As a consequence, their phylogeny in the plant kingdom remains unclear. To gain further insight into the distribution and evolution of plant cyclotides, we analyzed ∼300 species of >40 different families, with special emphasis on plants from the order Gentianales. For this purpose, we have developed a refined screening methodology combining chemical analysis of plant extracts and bioinformatic analysis of transcript databases. Using mass spectrometry and transcriptome-mining, we identified nine novel cyclotide-containing species and their related cyclotide precursor genes in the tribe Palicoureeae. The characterization of novel peptide sequences underlines the high variability and plasticity of the cyclotide framework, and a comparison of novel precursor proteins from Carapichea ipecacuanha illustrated their typical cyclotide gene architectures. Phylogenetic analysis of their distribution within the Psychotria alliance revealed cyclotides to be restricted to Palicourea, Margaritopsis, Notopleura, Carapichea, Chassalia, and Geophila. In line with previous reports, our findings confirm cyclotides to be one of the largest peptide families within the plant kingdom and suggest that their total number may exceed tens of thousands.

Hyphenation of optimized microfluidic sample preparation with nano liquid chromatography for faster and greener alkaloid analysis

A glass liquid–liquid extraction (LLE) microchip with three parallel 3.5cm long and 100μm wide interconnecting channels was optimized in terms of more environmentally friendly (greener) solvents and extraction efficiency. In addition, the optimized chip was successfully hyphenated with nano-liquid chromatography with ultraviolet and mass spectrometric detection (nanoLC–UV–MS) for on-line analysis. In this system, sample pretreatment, separation and detection are integrated, which significantly shortens the analysis time, saves labor and drastically reduces solvent consumption. Strychnine was used as model analyte to determine the extraction efficiency of the optimized 3-phase chip. Influence of organic solvent, pH of feed phase, type of alkaloid, and flow rates were investigated. The results demonstrated that the 3-phase chip nanoLC–UV/MS hyphenation combines rapid (∼25s) and efficient (extraction efficiency >90%) sample prep, with automated alkaloid analyses. The method was applied to real samples including Strychnos nux-vomica seeds, Cephaelis ipecacuanha roots, Atropa belladonna leaves, and Vinca minor leaves.

3-phase sample preparation chip hyphenated to nano-HPLC/ESI-MS for rapid miniaturised analysis of alkaloids

A 3-phase liquid-liquid extraction (LLE) chip was hyphenated with nano-HPLC/ESI-MS (Fig.). Thus the purification, separation and MS detection of alkaloids was accomplished on-line. The system is solvent-efficient with a nanoLC flow rate of 200 nL/min, and chip flow rate of 500 nL/min, sample-efficient (50-330 nL sample volume) and time-efficient (saving tedious off-line sample pretreatment steps. The transfer efficiency of strychnine was above 92% in 25sec). The analyses of alkaloids in Semen strychni, Cephaelis ipecacuanha, Atropa belladonna, Vinca minor, and Coptidis rhizome were successfully performed. The limits of detection (LODs) of the alkaloids are lower than with conventional HPLC/ESI-MS and nano-HPLC-DAD, i.e. 5ng/mL for emetine, palmatine, vincamine, strychnine and 10ng/mL for atropine.

Medical knowledge exchanges between Brazil and Portugal: An ethnopharmacological perspective

Ethnopharmacological relevanceLike many traditional medical systems found at Latin America, the very existence of a Brazilian traditional medical system is debated. Despite the absence of written material and organized knowledge, there is little doubt that Brazilians from all regions and all social classes recognize and access an estimated 4000 plant species with alleged therapeutic purposes as well as medicinal practices ranging from bone setting to spiritual healing. This “Brazilian folk medicine” is usually described as a rich mixture of African, European, and Indigenous medical traditions. Aim of the studyThis study questions this view, and argues it is both simplistic and Eurocentric. Materials and methodsBy scrutinizing the origins of the medical uses of Zingiberis officinale, Curcuma longa, Ruta officinalis, Cephaelis ipecacuanha, Pilocarpus pinnatifolius, and curare (Chondrodendron, Abuta and Curarea), we illustrate the intense circulation of materials during imperial times. We further discuss how these practices articulated with local medical knowledge, and exemplify some of the ways by which knowledge was produced, transformed, incorporated, and resignified over time. DiscussionThough not a systematic or comprehensive analysis of Brazilian folk medicine development, these selected examples show that, in opposition to usual simplistic descriptions, complex and convoluted manners of medicinal plant development occurred over time to compound both the Brazilian and European pharmaceutical armamentarium.

Poaia [Psychotria ipecacuanha (Brot.) Stoves]: aspectos da memória cultural dos poaieiros de Cáceres - Mato Grosso, Brasil

O Brasil está entre os principais exportadores de poaia [Psychotria ipecacuanha (Brot.) Stoves] seguido do Panamá e Costa Rica. A poaia brasileira apresenta alto valor farmacológico das raízes devido aos teores de emetina e cefalina. Este trabalho teve como objetivo descrever como as famílias de poaieiros mantém a memória cultural sobre a Psychotria ipecacuanha (Brot.) Stoves. As informações foram coletadas no município de Cáceres, Mato Grosso, através de entrevista estruturada e observação participante com 20 homens e 10 mulheres, de faixa etária de 45 a 86 anos. Foram citadas as formas de utilização na alimentação para animais, inseticida, carrapaticida, emético, contra diarréias, para alívio de dor de cabeça, contra malária, bronquite e dor no estômago. A raiz é a parte mais usada e a forma de preparo é tintura ou misturada ao fumo, ao vinho ou à cachaça. Poucos entrevistados passaram aos filhos o conhecimento sobre a P. ipecacuanha. A memória cultural sobre a P. ipecacuanha deve-se a vivência, extração e comercialização da planta, e por ouvir as conversas dos pais com amigos. A perda de conhecimento associado a poaia é causada pelo êxodo rural, destruição do habitat com o desmatamento e ocupação agrícola. A extinção da espécie na região contribui para a erosão cultural.

Iridoids as chemical markers of false ipecac (Ronabea emetica), a previously confused medicinal plant

Ethnopharmacological relevanceSeveral roots or rhizomes of rubiaceous species are reportedly used as the emetic and antiamoebic drug ipecac. True ipecac (Carapichea ipecacuanha) is chemically well characterized, in contrast to striated or false ipecac derived from the rhizomes of Ronabea emetica (syn. Psychotria emetica). Besides its previous use as substitute of ipecac, the latter species is applied in traditional medicine of Panama and fruits of its relative Ronabea latifolia are reported as curare additives from Colombia. Materials and methodsCompounds of Ronabea emetica were isolated using standard chromatographic techniques, and structurally characterized by NMR spectroscopy and mass spectrometry. Organ specific distribution in Ronabea emetica as well as in Ronabea latifolia was further assessed by comparative HPLC analysis. ResultsFour iridoid-glucosides, asperuloside (1), 6α-hydroxygeniposide (2), deacetylasperulosidic acid (3) and asperulosidic acid (4) were extracted from leaves of Ronabea emetica. Rhizomes, used in traditional medicine, were dominated by 3. HPLC profiles of Ronabea latifolia were largely corresponding. These results contrast to the general tendency of producing emetine-type and indole alkaloids in species of Psychotria and closely related genera and merit chemotaxonomic significance, characterizing the newly delimited genus Ronabea. ConclusionsThe aim of the work was to resolve the historic problem of adulteration of ipecac by establishing the chemical profile of Ronabea emetica, the false ipecac, as one of its less known sources. The paper demonstrates that different sources of ipecac can be distinguished by their phytochemistry, thus contributing to identifying adulterations of true ipecac.

Dopamine-iridoid alkaloids in Carapichea affinis (= Psychotria borucana) confirm close relationship to the vomiting root Ipecac

Broad-based HPLC-UV comparison of 57 methanolic crude extracts of the Psychotria complex (Rubiaceae), representing about 20 different species collected in Costa Rica, exhibited a clear chemical segregation of Psychotria borucana . In contrast to the more widespread tryptamine-iridoid alkaloids it deviated by an accumulation of dopamine-iridoid alkaloids. Similar to the South American vomiting root Ipecac, Psychotria ipecacuanha (= Cephaelis ipecacuanha ), cephaeline and emetine were found together with four related glycosides characterized by various N -acylations. Two glycosides were identified as the known N -acetates ipecoside and 6- O -methylipecoside, whereas the two others represent corresponding N - O -methylcaffeate derivatives from which borucoside was described as a new compound. Structure elucidation of all compounds was carried out by NMR- and MS-analyses supported by CSEARCH-NMR-database system. In addition to morphological characters and analyses of nucleotide sequence variation the chemical profile of P. borucana supported a recent taxonomic rearrangement where it has been grouped together with P. ipecacuanha in a separate genus Carapichea . ► HPLC-UV comparison of 57 methanolic crude extracts of 20 different Psychotria species from Costa Rica showed a clear chemical segregation of P. borucana . ► Instead of the more widespread tryptamine-iridoid alkaloids P.borucana deviates by an accumulation of dopamine-iridoid alkaloids. ► Together with morphological characters and DNA sequence data phytochemical results confirm the taxonomic rearrangement of P. borucana in a separate genus Carapichea together with C. ipecacuanha . ► Apart from the known aglyca cephaeline and emetine four related glycosides were isolated and identified from which borucoside was described as a new compound.

Evolution of the 5.8S nrDNA gene and internal transcribed spacers in Carapichea ipecacuanha (Rubiaceae) within a phylogeographic context

Nuclear ribosomal DNA (nrDNA) constitutes a multicopy gene family that is used widely to test evolutionary hypotheses across a broad range of organisms. It is presumed that, as a result of concerted evolution, tandem nrDNA repeats are homogeneous within species and different between species. We sampled 77 specimens of a disjunct species ( Carapichea ipecacuanha) from throughout its three geographic ranges and obtained 266 nrDNA sequences, of which 26 were obtained by direct sequencing and 240 by cloning of PCR products. Complementary sequence analyses, which included analyses of secondary structure stability, the pattern of base substitutions, GC content, and the presence of conserved motifs, were used to characterize the internal transcribed spacer (ITS) region (ITS1–5.8S nrDNA–ITS2). Our results showed that concerted evolution of the ITS region was incomplete in C. ipecacuanha, particularly in the Atlantic range. In the highly polymorphic populations of the Atlantic range, intraindividual variation was observed and involved 56 functional paralogs and 15 pseudogenes from two highly divergent ribogroups. The Amazonian range (with 12 functional paralogs) and the Central-American range (with five functional paralogs) were genetically depauperate and exhibited no pseudogenes. In the two latter ranges, almost complete homogenization of the ITS sequences had occurred. We argue that it is important to consider past evolutionary history when making inferences about the efficiency with which concerted evolution homogenizes tandem nrDNA repeats a single sequence.