Kember Mejía

Palm communities in wetland forest ecosystems of Peruvian Amazonia.

Kahn, F. and Mejia, K., 1990. Palm communities in wetland forest ecosystems of Peruvian Amazonia. For. Ecol. Manage., 33/34 169-179. Palm surveys in most representative wetland forest ecosystems were carried out in the lower Ucayali and upper Huallaga River valleys, in the lowland and Andean piedmont regions of Peruvian Amazonia, respectively. These ecosystems are characterized by the species association, density, and vertical distribution of their palm communities. Palms may form almost monospecific stands, e.g., Mauritia flexuosa swamps (aguajal), or multispecific communities, e.g., the seasonal swamp forests in upland valleys (bosque de quebrada) which are dominated by Euterpeprecatoria, Jessenia bataua, Mauritia flexuosa, and Socratea exorrhiza, and the forests on periodically flooded alluvial soils (restinga) dominated by some species of the genera Astrocaryum, Phytelephas, and Scheelea. Palm diversity is very low in the forests which are periodically flooded by blackwater streams (tahuampa); palm density, however, is often high with a characteristic patchy distribution due to clustered species.

Species richness and density of palms in terra firme forests of Amazonia

The characteristics of the palm community in Amazonian terra firme forests are defined from three inventories carried out in the lower Tocantins (east), the lower Rio Negro (center), and the lower Ucayali (west) valleys. At all sites, most of the palms are small, understory species; the palm community is mainly under 10 m in height (99.8 to 99.9%); and adult arborescent palms occur at very low densities. Species richness and diversity are dearly higher in the western and central forests. The difference in density seen in the latter sites reflects a difference in dominant life forms. Spatial occupation of the understory by palms is almost complete at both sites: in the western forest by a large number of small axes from rhizomatous species, and in the central forest by a lower density of subterranean-trunked palms with larger leaves.

Antiprotozoal activity of medicinal plants used by Iquitos-Nauta road communities in Loreto (Peru)

ETHNOPHARMACOLOGICAL RELEVANCE In the Peruvian Amazon, the use of medicinal plants is a common practice. However, there is few documented information about the practical aspects of their use and few scientific validation. The starting point for this work was a set of interviews of people living in rural communities from the Peruvian Amazon about their uses of plants. Protozoan diseases are a public health issue in the Amazonian communities, who partly cope with it by using traditional remedies. Validation of these traditional practices contributes to public health care efficiency and may help identify new antiprotozoal compounds. AIMS OF STUDY to inventory and validate the use of medicinal plants by rural people of Loreto region. MATERIALS AND METHODS Rural mestizos were interviewed about traditional medication of parasite infections with medicinal plants. Ethnopharmacological surveys were undertaken in two villages along Iquitos-Nauta road (Loreto region, Peru), namely 13 de Febrero and El Dorado communities. Forty-six plants were collected according to their traditional use for the treatment of parasitic diseases, 50 ethanolic extracts (different parts for some of the plants) were tested in vitro on Plasmodium falciparum (3D7 sensitive strain and W2 chloroquine resistant strain), Leishmania donovani LV9 strain and Trypanosoma brucei gambiense. Cytotoxic assessment (HUVEC cells) of the active extracts was performed. Two of the most active plants were submitted to preliminary bioguided fractionation to ascertain and explore their activities. RESULTS From the initial plants list, 10 were found to be active on P. falciparum, 15 on L. donovani and 2 on the three parasites. The ethanolic extract from Costus curvibracteatus (Costaceae) leaves and Grias neuberthii (Lecythidaceae) bark showed strong in vitro activity on P. falciparum (sensitive and resistant strain) and L. donovani and moderate activity on T. brucei gambiense. CONCLUSIONS The Amazonian forest communities in Peru represents a source of knowledge on the use of medicinal plants. In this work, several extracts with antiprotozoal activity were identified. This work contributes to validate some traditional uses and opens subsequent investigations on active compounds isolation and identification.

Profiling of Hura crepitans L. latex by ultra-high-performance liquid chromatography/atmospheric pressure chemical ionisation linear ion trap Orbitrap mass spectrometry

INTRODUCTION The phytochemistry of the latex of Hura crepitans L. (Euphorbiaceae), a widespread tree in the Amazonian forest having many uses, is little known. Only huratoxin, a daphnane diterpene orthoester, has been described despite the high pharmacological potential of this kind of compounds. Glucosphingolipids (cerebrosides) are also known to be distributed in Euphorbiaceae latexes. OBJECTIVE To tentatively identify daphnanes diterpenes and cerebrosides in the latex of H. crepitans. METHODS An ethanolic extract of the lyophilised latex of H. crepitans was analysed by ultra-high-performance liquid chromatography (UHPLC) coupled with positive and negative atmospheric pressure chemical ionisation high-resolution mass spectrometry (APCI-HRMS) method using a quadrupole/linear ion trap/Orbitrap (LTQ-Orbitrap). Tandem mass spectrometry (MS/MS) spectra were recorded by two different fragmentation modes: collision induced dissociation (CID) and higher-energy collisional dissociation (HCD). RESULTS The analysis of CID- and HCD-MS/MS spectra allowed to propose fragmentation patterns for daphnane esters and cerebrosides and highlight diagnostic ions in positive and negative ion modes. A total of 34 compounds including 24 daphnane esters and 10 cerebrosides have been tentatively annotated. Among them, 17 daphnane diterpenes bearing one or two acyl chains are new compounds and the cerebrosides are described in the genus Hura for the first time. CONCLUSION This study revealed the chemical constituents of the latex of H. crepitans and particularly its richness and chemical diversity in daphnane diterpenes, more frequently encountered in the species of Thymelaeaceae.