Erythroxylum in Focus: An Interdisciplinary Review of an Overlooked Genus.

The genus Erythroxylum contains species used by indigenous people of South America long before the domestication of plants. Two species, E. coca and E. novogranatense, have been utilized for thousands of years specifically for their tropane alkaloid content. While abuse of the narcotic cocaine has impacted society on many levels, these species and their wild relatives contain untapped resources for the benefit of mankind in the form of foods, pharmaceuticals, phytotherapeutic products, and other high-value plant-derived metabolites. In this review, we describe the current state of knowledge of members within the genus and the recent advances in the realm of molecular biology and biochemistry.

Chemosystematic identification of fifteen new cocaine-bearing Erythroxylum cultigens grown in Colombia for illicit cocaine production.

Colombian coca farmers have historically cultivated three varieties of coca for cocaine production (Erythroxylum novogranatense var. novogranatense, Erythroxylum novogranatense var. truxillense, and Erythroxylum coca var. ipadu). Within the past 13 years, 15 new cultigens of cocaine-bearing Erythroxylum have been propagated by Colombian coca farmers; each with differing physical characteristics, yet producing cocaine alkaloids at similar levels found in the historical and native varieties. Fifteen new cultigens were collected from throughout Colombia and propagated along with the three historical varieties within an experimental field in Colombia. Five plants/cultigen were randomly selected and examined for alkaloid content to determine their varietal characteristics when compared to the three known varieties. Ten cultigens gave classic Erythroxylum coca var. ipadu alkaloid profiles, four cultigens produced alkaloid profiles consistent with a hybridization of Erythroxylum novogranatense and Erythroxylum coca var. ipadu, while one cultigen gave heterogeneous alkaloid profiles that could not be characterized.

Edge effect and phenology in Erythroxylum tortuosum (Erythroxylaceae), a typical plant of the Brazilian Cerrado.

The edge of a forest fragment can be considered a zone of transition between the interior of the fragment and the surrounding habitat matrix. Plants along the edge are more exposed to disturbance and microclimate variation than interior plants, resulting in the so-called edge effect. In this study, we compared leaf area, fluctuating asymmetry and chemical (water, nitrogen and tannins) leaf traits between Erythroxylum tortuosum plants inhabiting the edge with those growing in the interior of a cerrado fragment in Brazil. We also describe the temporal variation in the vegetative and reproductive phenological events of E. tortuosum plants throughout the season. Nitrogen, leaf area and fluctuating asymmetry did not differ between the two plant groups. Young leaves of the edge plants had significantly higher levels of tannins and lower levels of water than those of interior plants. We suggest that differences in leaf chemical concentrations between edge and interior plants may occur due to factors such as light intensity, wind, temperature and leaf age rather than plant stress. With respect to plant phenology, most reproductive events occurred during the spring. Leaf buds and young leaves prevailed during the rainy season. In the dry season, however, the vegetative events decreased due to leaf senescence followed by leaf abscission.

Edge effect and phenology in Erythroxylum tortuosum (Erythroxylaceae), a typical plant of the Brazilian Cerrado / Efeito de borda e fenologia em Erythroxylum tortuosum Mart. (Erythroxylaceae), uma planta típica do Cerrado brasileiro

The edge of a forest fragment can be considered a zone of transition between the interior of the fragment and the surrounding habitat matrix. Plants along the edge are more exposed to disturbance and microclimate variation than interior plants, resulting in the so-called edge effect. In this study, we compared leaf area, fluctuating asymmetry and chemical (water, nitrogen and tannins) leaf traits between Erythroxylum tortuosum plants inhabiting the edge with those growing in the interior of a cerrado fragment in Brazil. We also describe the temporal variation in the vegetative and reproductive phenological events of E. tortuosum plants throughout the season. Nitrogen, leaf area and fluctuating asymmetry did not differ between the two plant groups. Young leaves of the edge plants had significantly higher levels of tannins and lower levels of water than those of interior plants. We suggest that differences in leaf chemical concentrations between edge and interior plants may occur due to factors such as light intensity, wind, temperature and leaf age rather than plant stress. With respect to plant phenology, most reproductive events occurred during the spring. Leaf buds and young leaves prevailed during the rainy season. In the dry season, however, the vegetative events decreased due to leaf senescence followed by leaf abscission.

A borda de um fragmento florestal pode ser considerada uma zona de transição entre o interior do fragmento e a matriz de habitat. As plantas localizadas na borda estão mais expostas a distúrbios e variações microclimáticas do que as plantas do interior, resultando no chamado efeito de borda. Neste estudo, a área foliar, a assimetria flutuante e os caracteres químicos das folhas (água, nitrogênio e taninos) foram comparados entre plantas de Erythroxylum tortuosum situadas na borda e no interior de um fragmento de cerrado brasileiro. A variação temporal de eventos fenológicos vegetativos e reprodutivos de E. tortuosum também foi investigada durante o período de estudo. Nitrogênio, área foliar e assimetria flutuante não diferiram entre os dois grupos de plantas. As folhas jovens das plantas localizadas na borda apresentaram, significativamente, níveis mais altos de taninos e menores níveis de água do que as plantas do interior. Sugere-se que as diferenças nos conteúdos químicos foliares entre as plantas da borda e do interior devem ter ocorrido em razão de fatores como intensidade luminosa, vento, temperatura e idade foliar e não por causa do nível de estresse da planta. Com relação à fenologia, a maioria dos eventos reprodutivos ocorreu durante a primavera. Os botões foliares e as folhas novas prevaleceram durante a estação chuvosa. No entanto, na estação seca, os eventos vegetativos decresceram por causa da senescência das folhas, seguida pela abscisão foliar.

Cocaine distribution in wild Erythroxylum species.

Cocaine distribution was studied in leaves of wild Erythroxylum species originating from Bolivia, Brazil, Ecuador, Paraguay, Peru, Mexico, USA, Venezuela and Mauritius. Among 51 species, 28 had never been phytochemically investigated before. Cocaine was efficiently and rapidly extracted with methanol, using focused microwaves at atmospheric pressure, and analysed without any further purification by capillary gas chromatography coupled to mass spectrometry. Cocaine was reported for the first time in 14 species. Erythroxylum laetevirens was the wild species with the highest cocaine content. Its qualitative chromatographic profile also revealed other characteristic tropane alkaloids. Finally, its cocaine content was compared to those of two cultivated coca plants as well as with a coca tea bag sample.

Inter- and intra-specific variation among five Erythroxylum taxa assessed by AFLP.

BACKGROUND: and Aims The four cultivated Erythroxylum taxa (E. coca var. coca, E. novogranatense var. novogranatense, E. coca var. ipadu and E. novogranatense var. truxillense) are indigenous to the Andean region of South America and have been cultivated for folk-medicine and, within the last century, for illicit cocaine production. The objective of this research was to assess the structure of genetic diversity within and among the four cultivated alkaloid-bearing taxa of Erythroxylum in the living collection at Beltsville Agricultural Research Center. METHODS: Amplified fragment length polymorphism (AFLP) fingerprinting was performed in 86 Erythroxylum accessions using a capillary genotyping system. Cluster analysis, multidimensional scaling (MDS) and analysis of molecular variance (AMOVA) were used to assess the pattern and level of genetic variation among and within the taxa. KEY RESULTS: A clear distinction was revealed between E. coca and E. novogranatense. At the intra-specific level, significant differentiation was observed between E. c. var. coca and E. c. var. ipadu, but the differentiation between E. n. var. novogranatense and E. n. var. truxillense was negligible. Erythroxylum c. var. ipadu had a significantly lower amount of diversity than the E. c. var. coca and is genetically different from the E. c. var. ipadu currently under cultivation in Colombia, South America. CONCLUSIONS: There is a heterogeneous genetic structure among the cultivated Erythroxylum taxa where E. coca and E. novogranatense are two independent species. Erythroxylum coca var. coca is most likely the ancestral taxon of E. c. var. ipadu and a founder effect may have occurred as E. c. var. ipadu moved from the eastern Andes in Peru and Bolivia into the lowland Amazonian basin. There is an indication of artificial hybridization in coca grown in Colombia.