Minquartia Research Articles

Triterpenes, steroids and phenolic isolated from Minquartia guianensis Aubl. (Coulaceae) and antibacterial activity

This work aimed to carry out a chemical study of Minquartia guianensis branches and leaves extracts (Coulaceae) and to evaluate their antibacterial potential. The collection of plant material was carried out at Reserva Ducke, Manaus, Amazonas. The plant material was dried, ground, and extracted with hexane (Hex) and methanol (MeOH). The extracts obtained were submitted to chromatographic analysis and showed characteristics mainly of terpenes and phenolics. The chemical fractionation of branches methanol extract allowed the isolation of the triterpenes: lupen-3-one, β-amyrone, lupeol, β-amyrin; the steroids: β-sitosterol and stigmasterol, and a phenolic derivative: methyl gallate. From the leaf’s methanol extract, the triterpene: taraxerol was identified. These same methanol extracts were active against gram-positive bacteria: Staphylococcus aureus and gram-negative bacteria: Aeromonas hydrophila and Pseudomonas fluorescens, with an inhibition percentage of 63 to 70%. Based on the results, this work contributed to the chemical and biological knowledge of the species M. guianensis, this being the first report of the substances: β-amyrin, β-amyrone and methyl gallate for the Coulaceae family.

Wood Nutrient-Water-Density Linkages Are Influenced by Both Species and Environment.

Tropical trees store a large amount of nutrients in their woody tissues, thus triggering the question of what the functional association of these elements with other wood traits is. Given the osmotic activity of mineral elements such as potassium, sodium, and calcium, these elements should be strong candidates in mediating the water storing capacity in tropical trees. We investigated the role of wood nutrients in facilitating wood water storage in trees by using branch samples from 48 tropical tree species in South America and examined their associations with wood density (ρ). Wood density varied from 316 kg/m3 in Peru plots, where the soil nutrient status is relatively higher, to 908 kg/m3 in Brazil plots, where the nutrient availability is lower. Phosphorus content in wood varied significantly between plots with lowest values found in French Guiana (1.2 mol/m3) and plots with highest values found in Peru (43.6 mol/m3). Conversely, potassium in woody tissues showed a significant cross-species variation with Minquartia guianensis in Brazil showing the lowest values (8.8 mol/m3) and with Neea divaricata in Peru having the highest values (114 mol/m3). We found that lower wood density trees store more water in their woody tissues with cations, especially potassium, having a positive association with water storage. Specific relationships between wood cation concentrations and stem water storage potential nevertheless depend on both species’ identity and growing location. Tropical trees with increased water storage capacity show lower wood density and have an increased reliance on cations to regulate this reservoir. Our study highlights that cations play a more important role in tropical tree water relations than has previously been thought, with potassium being particularly important.

Spatial distribution of six managed tree species is influenced by topography conditions in the Central Amazon

In tropical forests, the spatial distribution of trees may present random, uniform, or grouped patterns that can simultaneously be affected by site and species characteristics. In Central Amazon, topographic gradients and soil water levels drive differences in tree species distribution and in forest dynamics at local scales. Knowing this kind of information can be useful for a forest manager to plan harvesting operations considering the microhabitat preference of merchantable species to reduce the disturbances caused by logging activities. Thus, the spatial variation of tree species is an important information to be considered to support the planning process of forest logging. The present study aims to evaluate the spatial distribution pattern of six species and analyze the relationship between the topography and the population densities and stem size of those species. The study was carried out in a forest production compartment managed by a private company located in the municipality of Silves, state of Amazonas, Brazil. The spatial pattern of the six species was characterized by Ripley's K function. Spatial distribution of diameter at breast height (DBH) and tree density based on kernel incidence calculation were evaluated for topographic classes of slope, elevation, and distance from streams, which were mapped using geographic information systems (GIS). The means of DBH and density of each species were compared among topographic classes by ANOVA and Tukey's test. The results demonstrated the predominance of the aggregate distribution pattern for the six species up to 1105 m (p < 0.01). The tree species Minquartia guianensis Aubl., Protium puncticulatum J.F.Macbr, Manilkara elata (Allemão ex Miq.) Monach, and Caryocar glabrum Aubl. Pers showed an increase in the tree density as the distance from the streams and elevation increased, standing spatially incident on plateaus. Kernel densities of Dinizia excelsa Ducke and Goupia glabra Aubl. were higher closer to streams. The DBH averages followed similar trends of population density for M. guianensis, M. elata, and C. glabrum, and the opposite pattern for D. excelsa, which presented larger individuals in less densely populated areas. P. puncticulatum and G. glabra mean DBH distribution was not affected by the topographic variables analyzed. Topography-related variables showed effects on variations of density and tree size, suggesting that species may be spatially sensitive to the habitat variability available in the study area. In view of logging planning, spatial distribution must be considered in decisions related to cutting down trees and maintenance of remaining trees, especially because some species are more aggregated in smaller scales. Moreover, as topographic variations affect the spatial distribution of size and density, the timber yield will vary spatially in the area, bringing implications for planning logging intensities, roads, skid trails and forest operations. Finally, the procedures and information generated in this study can be reproduced and applied to other species and managed areas to support the planning toward minimizing impacts on the spatial structure of commercial species, as well as to increase the chances of future stock recovery of managed forests in the Amazon.

Sap flow rates of Minquartia guianensis in central Amazonia during the prolonged dry season of 2015–2016

Minquartia guianensis Aubl. is a slow-growing species with several uses. In the juvenile state, it is well-adapted to low light conditions of the forest understory. However, it is still unknown how climate variability affects transpiration of this species, particularly under drought stress. In this study, we aimed to assess the effect of climatic variability on sap flow rates (SFR). SFR and radial growth were measured in six trees (14‒50 cm diameter) in 2015 and 2016. Climate (precipitation, irradiance, relative humidity and temperature) and soil water content (SWC) data were also collected. SFR tended to increase in the dry season, with a negative relationship between SFR and SWC and precipitation (p < 0.001), while there was a positive association between radial growth and monthly precipitation (p = 0.004). Irradiance and temperature were the environmental factors more closely correlated with SFR during daytime (p < 0.001), whereas relative humidity and vapor pressure deficit were the most important factors at night (p < 0.001). Although negative SFR were sometimes recorded at night, the mean nocturnal sap flow was positive and across trees the nighttime sap flow accounted for 12.5% of the total daily sap flow. Increased transpiration during the dry season suggests that the root system of Minquartia was able to extract water from deep soil layers. These results widen our understanding of the ecophysiology of Amazonian trees under drought and provide further insight into the potential effect of the forecasted decline in precipitation in the Amazon region.

Salinity responses of inland and coastal neotropical trees species

Salinization of coastal lands by sea-level rise means that information on the response of tropical tree species to salinity is urgently required to effectively manage coastal systems under future climatic scenarios. While salinity represents a major selective abiotic stress, little is known about the underlying mechanisms determining salinity tolerance in tropical trees. We examined salinity responses in seedlings of eight neotropical tree species from Panama, including four coastal species (Sterculia apetala, Pithecellobium ungi-cati, Terminalia cattapa, and Thespesia populnea) and four inland species (Minquartia guianensis, Apeiba membranaceae, Ochroma pyramidale, and Ormosia macrocalyx). Three-month-old seedlings of each species were subjected to increasing concentrations of 80, 120, 200, and 300 mM of either NaCl or KCl, while controls were irrigated with tap water. Overall, growth parameters such as leaf area (LA), leaf area ratio (LAR), stem height (SH), total dry mass (TDM), and relative growth rates (RGR) were reduced for all species as salinity increased, regardless of salt treatment. However, species from coastal environments outperformed inland species at high salinity. For example, seedlings of coastal species growing in 300 mM of NaCl or KCl, corresponding to ~ 50% seawater, survived and maintained LA, SH, and TDM between 50 and 90% compared with control plants. In contrast, inland species showed reductions in RGR, LA, and SH of up to 100%, at 120 mM of either salt. At the foliar level, K+ accumulation remained similar under NaCl and KCl treatments, and almost all species, with the exception of Minquartia from inland forests, maintained foliar Na+ accumulation across treatments when compared to controls. While species from coastal environments maintained foliar Cl− under NaCl and KCl treatments, inland species such as Ochroma showed up 95% increase in foliar Cl−. Our results suggest that salinity tolerance among tropical trees is predetermined by habitat association and ultimately by the ability of species to manage toxicity associated to foliar Na+ and Cl−. While the ecological implications of sea-level rise in coastal vegetation require further examination, is foreseeable that adaptation strategies in tropical shorelines consider the use of coastal species (i.e., reforestation) as the best tool to ameliorate the impact of increased salinity.

Altitude and species identity drive leaf litter decomposition rates of ten species on a 2950 m altitudinal gradient in Neotropical rain forests

AbstractIdentifying the environmental factors controlling litter decomposition is key to understanding the magnitude and rates of nutrient cycling in tropical forests, and how they may be influenced by climate variability and environmental change. We carried out a leaf litter translocation experiment in mature rain forest over a 2,520 m altitudinal gradient in Costa Rica. Leaf litter decomposition rates (k) of ten tree species, two dominant species from each ecosystem, plus two standard species, were calculated over 540 days in four life zones. k was lowest in montane with 0.83 per year and lower montane forests with 2.21 per year. k did not differ between lowland and premontane forests at 3.12 per year, in spite of the 3℃ difference of mean annual temperature between these life zones. k varied fourfold among species. Species decomposition rates ranked as follows, and were predictably related to leaf economic spectrum traits of the species: Acalypha communis (standard, fast decomposer)» Hyeronima oblonga &gt; Alchornea latifolia, Quercus bumelioides, Jarava ichu (standard, slow decomposer)&gt; Minquartia guianensis &gt; Magnolia sororum &gt; Vochysia allenii &gt; Pourouma bicolor, Carapa guianensis. These two slowest‐decomposing species were native premontane and lowland forest dominants, respectively, with tough, low‐nutrient leaves. The ranking of species by k varied very little among life zones suggesting that decomposer organisms in very different ecosystems and environments react in similar ways to the litter quality in general. We conclude that while k decreases with temperature in rain forests on tropical mountains, bioclimatic zones defined as premontane may be “functionally lowland.” The effects of species identity on decomposition rates on tropical mountains are consistent and independent of environment for both standard and native species. Under climate change on these mountains, if moisture regimes do not change, decomposition rates will increase due to rising temperatures. Soil carbon storage may therefore decrease. Changes in the altitudinal distributions of currently dominant species will also affect this critically important biogeochemical process.

Male sexual enhancers from the Peruvian Amazon

Ethnopharmacological relevanceSelected Peruvian Amazon plants are macerated into sugar cane distillates to prepare alcoholic beverages used to improve male sexual performance. The tree bark from Campsiandra angustifolia Spruce ex Benth (Fabaceae), Swartzia polyphylla DC (Fabaceae), Minquartia guianensis Aubl. (Olacaceae) and Thynantus panurensis (Bureau) Sandwith (Bignoniaceae) usually are used as crude drugs in mixtures of several ingredients. Aim of studyDescribe the chemical composition of the most traded traditional male enhancer beverages, namely “Levántate Lazaro” and “Siete veces sin sacarla”, and their single crude drug constituents, as well as their inhibitory activity towards the enzyme phosphodiesterase-5. The presence of pro-sexual drugs such as Sildenafil® and derivatives was assessed in the samples. Materials and methodsSingle plant constituents and the preparation mixtures were purchased in the Mercado Belen (Iquitos, Peru). Chemical profiling was carried out by HPLC-DAD-ESI-MS/MS. The extracts were assessed for phosphodiesterase-5 inhibition. The occurrence of pro-sexual drugs was determined by HPLC-DAD-ESI-MS/MS. ResultsChemical profiling allowed the identification of condensed tannins as the main constituents of C. angustifolia and S. polyphylla, hydrolysable tannins for M. guianensis, and C-glycosides for T. panurensis. The traditional preparations showed similar composition compared to the crude drugs. At 200 µg/mL, the traditional preparation “Levántate Lázaro” and “Siete veces sin sacarla” inhibited the phosphodiesterase-5 by 49.88% and 27.90%, respectively. No adulterations with pro-sexual drugs were found in the samples. From the crude drugs, low effect was found for the extracts of S. polyphylla and T. panurensis and high activity for C. angustifolia which inhibited the enzyme by 89.37% and 81.32% at 200 and 100 µg/mL, respectively. ConclusionThe traditional preparations used to improve sexual performance in the Peruvian Amazon showed activity as phosphodiesterase-5 inhibitors. The most active ingredient of the traditional preparations was C. angustifolia, with some contribution from T. panurensis. These results encourage additional studies, including animal models to confirm the male enhancer effect of the preparations.

Ecuaciones alométricas para estimar tasas de crecimiento de Myroxylon balsamum, Minquartia guianensis y Otoba parvifolia en la Amazonía ecuatoriana

La evaluación del análisis de las tasas de crecimiento de las especies forestales Myroxylon balsamum (L.) Harms (Bálsamo) y Minquartia guianensis Aubl. (Guayacán negro) y Otoba parvifolia (Doncel) establecidas en rodales de investigación en la Estación Científica Jatun Sacha (ECJS), con una edad de 20 años, fue el motivo principal de esta investigación. De acuerdo a los resultados obtenidos se encontró que el Bálsamo necesita 59 años para alcanzar los 60 centímetros de Diámetro Mínimo de Corta (DMC), que está determinado por el Acuerdo Ministerial 039 del Ministerio del Ambiente, el Guayacán negro Huambula, necesita 69 años para llegar a los 40 centímetros de diámetro, mientras que el Doncel necesita 27 años para obtener 50 cm de diámetro.

Palikur traditional roundwood construction in eastern French Guiana: ethnobotanical and cultural perspectives

BackgroundPalikur Amerindians live in the eastern part of French Guiana which is undergoing deep-seated changes due to the geographical and economic opening of the region. So far, Palikur’s traditional ecological knowledge is poorly documented, apart from medicinal plants. The aim of this study was to document ethnobotanical practices related to traditional construction in the region.MethodsA combination of qualitative and quantitative methods was used. Thirty-nine Palikur men were interviewed in three localities (Saint-Georges de l’Oyapock, Regina and Trois-Palétuviers) between December 2013 and July 2014. Twenty-four inventories of wood species used in traditional buildings were conducted in the villages, as well as ethnobotanical walks in the neighboring forests, to complete data about usable species and to determine Linnaean names.ResultsAfter an ethnographic description of roundwood Palikur habitat, the in situ wood selection process of Palikur is precisely described.A total of 960 roundwood pieces were inventoried in situ according to Palikur taxonomy, of which 860 were beams and rafters, and 100 posts in 20 permanent and 4 temporary buildings. Twenty-seven folk species were identified. Sixty-three folk species used in construction were recorded during ethnobotanical walks. They correspond to 263 botanical species belonging to 25 families.Posts in permanent buildings were made of yawu (Minquartia guianensis) (51%) and wakap (Vouacapoua americana) (14%). Beams and rafters were made of wood from Annonaceae (79%) and Lecythidaceae (13%) families. The most frequently used species were kuukumwi priye (Oxandra asbeckii), kuukumwi seyne (Pseudoxandra cuspidata), and pukuu (Xylopia nitida and X. cayennensis).ConclusionsAlthough the Palikur’s relationship with their habitat is undergoing significant changes, knowledge about construction wood is still very much alive in the Oyapock basin. Many people continue to construct traditional buildings alongside modern houses, using a wide array of species described here for the first time, along with the techniques used.

Crescimento diamétrico e tempo de passagem de Minquartia guianensis após manejo na Floresta Nacional do Tapajós

Minquartia guianensis Aubl. (acariquara) ocorre nos estados do Acre, Amazonas, Roraima, Pará e Amapá, com grande procura de mercado e utilidade na região Amazônica. Seu principal uso é na construção civil, por apresentar alta durabilidade e reentrâncias em seu tronco, que a tornam de beleza singular e muito valorizada. A maioria das árvores utilizadas apresenta pequenos diâmetros, sendo este um fator crítico para seu manejo e comercialização. Portanto, objetivou-se avaliar o crescimento diamétrico e o ciclo de corte de M. guianensis, por meio da análise do tempo de passagem entre como classes diamétricas, no período de 31 anos, após uma exploração florestal, na Floresta Nacional do Tapajós, estado do Pará. Foram estabelecidos cinco tratamentos, e em cada um foram instaladas 12 parcelas permanentes de 0,25 ha, nas quais foram medidas todas as árvores com diâmetro a 1,30 m do solo (DAP) ≥ 5 cm, de 1981 a 2012. Como árvores com DAP ≤ 50 cm tem potencial para ser manejadas, em razão da diminuição do crescimento diamétrico a partir do DAP ≥ 50 cm. Esses resultados máfia de base para subsidiarhadas silviculturais sem manejo sustentável da espécie.

Stomatal conductance in Amazonian tree saplings in response to variations in the physical environment

In juvenile trees growing at the rainforest understory, light is the most limiting factor for growth. It has been assumed that stomata quickly respond to light irrespective of the physical conditions prevailing before leaf illumination. Nevertheless, so far this issue has not been addressed for saplings of Amazonian tree species. The aim of this study was to determine how stomatal conductance (g s) and photosynthetic parameters of Amazonian saplings respond to diurnal variation in the physical environment and to rainfall seasonality. Light-saturated net photosynthetic rate (P Nmax) and g s at light saturation (g smax) were measured in the dry (August) and rainy (January) season of 2008 in saplings of 10 Amazonian tree species (Minquartia guianensis, Myrcia paivae, Protium apiculatum, Guatteria olivacea, Unonopsis duckei, Rinorea guianensis, Dicypellium manausense, Eschweilera bracteosa, Gustavia elliptica, and Tapura amazonica). At the forest understory, variables of the physical environment were measured. Rainfall seasonality did not affect P Nmax and g smax, nor was the effect of species on P Nmax and g smax significant (p&gt;0.05). The g s and P Nmax increased as the forest understory became brighter and warmer; as a result, P Nmax and g smax were higher at midday than early in the morning or in the afternoon. However, contrary to expectations, neither changes in air vapor pressure deficit nor air CO2 concentration at the forest understory affected stomatal opening. More investigation is needed to elucidate the role of environmental factors in modulating stomatal movements in juvenile trees growing beneath the dense canopy of tropical rainforests.

Identificación de especies de árboles en peligro o amenazadas de Costa Rica basada en la anatomía de la madera y fluorescencia

A total of 45 native Costa Rican tree species are threatened or in danger of extinction, but the Convention on International Trade Endangered Species (CITES) includes only eight of these in its Appendices. However, the identification of other species based on their wood anatomy is limited. The present study objective was to describe and to compare wood anatomy and fluorescence activity in some endangered or threatened species of Costa Rica. A total of 45 (22 endangered and 23 threatened with extinction) wood samples of these species, from the xylaria of the Instituto Tecnológico de Costa Rica and the Forest Products Laboratory in Madison, Wisconsin, were examined. Surface fluorescence was positive in eight species, water extract fluorescence was positive in six species and ethanol extract fluorescence was positive in 24 species. Almost all species were diffuse porous except for occasional (Cedrela odorata, C. fissilis, Cordia gerascanthus) or regular (C. salvadorensis and C. tonduzii) semi-ring porosity. A dendritic vessel arrangement was found in Sideroxylon capari, and pores were solitary in Guaiacum sanctum and Vantanea barbourii. Vessel element length was shortest in Guaiacum sanctum and longest in Humiriastrum guianensis, Minquartia guianensis and Vantanea barbourii. Finally, anatomical information and fluorescence activity were utilized to construct an identification key of species, in which fluorescence is a feature used in identification.

Mesophyll conductance variations in response to diurnal environmental factors in Myrcia paivae and Minquartia guianensis in Central Amazonia

Mesophyll conductance (g m) is essential to determine accurate physiological parameters used to model photosynthesis in forest ecosystems. This study aimed to determine the effects of time of day on photosynthetic parameters, and to assess the effect of using either intercellular CO2 concentration (C i) or chloroplast CO2 concentration (C c), on maximum carboxylation velocity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), V cmax. We used Amazonian saplings of Myrcia paivae and Minquartia guianensis. Photosynthetic parameters were measured using an infrared gas analyzer (IRGA); g m was determined using both gas exchange and chlorophyll (Chl) a fluorescence and gas-exchange data alone. Leaf thickness (L T) and specific leaf area (SLA) were also measured. Air temperature, relative humidity or understory light did not correlate with g m and on average daily IRGA-fluorometer-determined g m was 0.04 mol(CO2) m−2 s−1 for M. paivae and 0.05 mol(CO2) m−2 s−1 for M. guianensis. Stomatal conductance (g s), g m, electron transport rate (J F), and light-saturated net photosynthetic rate (P Nmax) were lower in the afternoon than in the morning. However, no effect of time of day was observed on V cmax. L T and SLA did not affect any of the examined parameters. IRGA-determined g m was almost the double of the value obtained using the IRGA-fluorescence method. V cmax values determined using C c were about 25% higher than those obtained using C i, which highlighted the importance of using C c in V cmax calculation. Decline in P Nmax at the end of the afternoon reflected variations in g s and g m rather than changes in V cmax. Diurnal variation in g m appeared to be associated more with endogenous than with atmospheric factors.

Estudio de plantas medicinales usadas en la comunidad indígena Tikuna del alto Amazonas, Macedonia.

Entre Febrero del 2008 y Octubre del 2009, se realizó una investigación de plantas asociadas a las enfermedades más frecuentes en la Comunidad TIKUNA de Macedonia ubicada a 57 km de Leticia. Para realizar este estudio se aplicaron tres tipos de encuestas basadas en las “TRAMIL”. A a partir de estas, se establece como resultado el reporte de 115 plantas de valor de uso medicinal dentro de la Comunidad, y 308 remedios aplicados para la cura de diferentes enfermedades. Se presentó un listado que incluye: 109 géneros y 99 especies. Para cada una de las plantas medicinales se reporta el nombre vernáculo, nombre Tikuna, número de colección, familia taxonómica, usos tradicionales referidos, parte usada, propiedad medicinal, forma de preparación, administración, si la preparación en caso de ser combinada se hace con una planta o animal y si debe tener “dieta”2 o no. Cada planta reportada fue: fotografiada en campo, recolectada e identificada previamente en el SINCHI3 de Leticia, se calculó el nivel de uso significativo TRAMIL, valor de uso general, fitoetnoaloctoneidad y Fitoetnoendemicidad.Se concluye que las familias Arecaceae, Bignoniaceae y Rubiaceae y especies como el Yarumo (Cecropia sciadophylla) el Carambolo (Averrhoa carambola), la uña de gato (Uncaria tomentosa), el Acapu (Minquartia guianensis), la Lancetilla (Alternanthera brasiliana), y el Amacizo (Erythrina fusca) tienen un gran valor cultural dentro de la Comunidad. Asimismo, que el uso y aplicación de diferentes plantas que alivien dolencias es compartido por las etnias del Trapecio, pero la validez u orden de importancia de las plantas depende de la cosmología y cosmogonía particular de cada comunidad.

Growth and physiological changes in saplings of Minquartia guianensis and Swietenia macrophylla during acclimation to full sunlight

Low light availability under a forest canopy often limits plant growth; however, sudden increase in light intensity may induce photoinhibition of photosynthesis. The aim of this study was to evaluate the ecophysiological changes that occur in potted plants of Minquartia guianensis and Swietenia macrophylla during the acclimation process to full sunlight. We used six full-sun independent acclimation periods (30, 60, 90, 120, 150, and 180 days) and a control kept in the shade. Shading was obtained by placing plants under the canopy of a small forest. The Fv/Fm ratio, net photosynthetic rate (PN), the maximum carboxylation velocity of Rubisco (Vcmax), maximum electron transport rate (Jmax), specific leaf area (SLA), and growth were assessed at the end of each of the six acclimation periods. Plant exposure to full sunlight caused a sudden decrease in the Fv/Fm ratio (photoinhibition) particularly in Minquartia. Photooxidation (necrotic patches) of the leaf tissue was observed in upper leaves of Minquartia. The higher PN values were observed in Swietenia under full sun, about 12 μmol(CO2) m−2 s−1. Vcmax25 values were higher after 90 days of acclimation, about 14 μmol(CO2) m−2 s−1 for Minquartia, and 35 μmol(CO2) m−2 s−1 for Swietenia. At the end of a 180-d acclimation period Jmax25 was 35 μmol(electron) m−2 s−1 for Minquartia and 60 μmol(electron) m−2 s−1 for Swietenia. SLA was higher in Swietenia than in Minquartia. In Minquartia, monthly rate of leaf production per plant (MRLP) was positive (0.22 leaf month−1) after four months in the open. Whereas, in Swietenia MRLP was positive (0.56 leaf month−1) after an acclimation period of two months. After six months in the open, height growth rates were 3.5 and 28 mm month−1 for Minquartia and Swietenia, respectively. The greater acclimation capacity of Swietenia was associated to an enhanced photosynthetic plasticity under full sun. In Minquartia, transition to full-sun conditions and lack of physiological adjustment resulted in severe photoinhibition and loss of leaves.

Triterpenes from Minquartia guianensis (Olacaceae) and in vitro antimalarial activity

Minquartia guianensis, popularly known as acariquara, was phytochemically investigated. The following triterpenes were isolated from the dichloromethane extract of leaves: lupen-3-one (1), taraxer-3-one (2) and oleanolic acid (3). The dichloromethane extract of branches yielded the triterpene 3β-methoxy-lup-20(29)-ene (4). The chemical structures were characterized by NMR data. Plant extracts, substance 3, squalene (5) and taraxerol (6), (5 and 6 previously isolated), were evaluated by in vitro assay against chloroquine resistant Plasmodium falciparum. The dichloromethane extract of leaves and the three triterpenes assayed have shown partial activity. Thus, these results demonstrated that new potential antimalarial natural products can be found even in partially active extracts.

Antibacterial activity of Minquartia guianensis extracts and phytochemical evaluation.

The species Minquartia guianensis (Olacaceae) is found in the Amazon region and also in Nicaragua, Panama and Costa Rica. Indigenous people from Ecuador use the bark infusion for intestinal infections treatment caused by parasites, against muscular pain and cutaneous irritations. For this reason, the aim of this work was to evaluate the antibacterial activity of M. guianensis extracts over Gram-negative ( Shigella flexneri M90T, Salmonella choleraesuis 6958 , Escherichia coli E2348/69) and Gram-positive bacteria (Methicillin-Resistant Staphylococcus aureus 33591 , Methicillin-Sensible Staphylococcus aureus 25923, Bacillus cereus 9634 , Bacillus liquefaciens clinical isolated). These bacteria are diarrhea related, which causes several child death in tropical regions. The active extract is under fractionation (leaf DCM) and until now, four triterpene were isolated lupeol, taraxerol, lupenona and squalene, but it was not possible yet to assay the substances, because of their small amount.

Plants used by native Amazonian groups from the Nanay River (Peru) for the treatment of malaria

In order to evaluate the antimalarial potential of traditional remedies used in Peru, Indigenous and Mestizo populations from the river Nanay in Loreto were interviewed about traditional medication for the treatment of malaria. The survey took place on six villages and led to the collection of 59 plants. 35 hydro-alcoholic extractions were performed on the 21 most cited plants. The extracts were then tested for antiplasmodial activity in vitro on Plasmodium falciparum chloroquine resistant strain (FCR-3), and ferriprotoporphyrin inhibition test was also performed in order to assume pharmacological properties. Extracts from 9 plants on twenty-one tested (Abuta rufescens, Ayapana lanceolata, Capsiandra angustifolia, Citrus limon, Citrus paradise, Minquartia guianensis, Potalia resinífera, Scoparia dulcis, and Physalis angulata) displayed an interesting antiplasmodial activity (IC(50)<10 μg/ml) and 16 remedies were active on the ferriprotoporphyrin inhibition test. The results give scientific validation to the traditional medical knowledge of the Amerindian and Mestizo populations from Loreto and exhibit a source of potentially active plants.

Polymorphic microsatellite markers in the Neotropical forest tree Minquartia guianensis Aubl. (Olacaceae)

We present characteristics of eight microsatellite loci isolated from Minquartia guianensis Aubl (Olacaceae), an ecological and economically important forest tree species from Central and South America. Polymorphism was tested in two natural populations detecting 2 to 18 alleles per locus. The expected heterozygosities (HE) range from 0.313 to 0.903. Linkage disequilibrium was found only at two locus combination in one population. High exclusion probability was estimated. These markers turn to be useful for population genetics and gene flow studies in this threatened timber species from the Neotropics.

Assessment of anti-protozoal activity of plants traditionally used in Ecuador in the treatment of leishmaniasis

Aim of the Study For the assessment of the in vitro anti-protozoal potential of plants traditionally used in Ecuador in the treatment of leishmaniasis, a combined approach based on interviews with healers as well as a literature search was carried out. Materials and Methods From three regions of Ecuador, 256 local healers called “Agents of Traditional Medicine” (ATMs) were interviewed about their knowledge of the use of plants to treat and heal the illness recognized by the ATMs as leishmaniasis. From literature sources, 14 plants were identified as being used in the treatment of leishmaniasis. Subsequently, plant material was collected from a representative selection of 39 species. A total of 140 extracts were screened in vitro against Leishmania donovani, Plasmodium falciparum, Trypanosoma brucei rhodesiense and Trypanosoma cruzi. Additionally, these extracts were evaluated for their anti-microbial activities using five gram-positive and -negative bacteria as well as Candida albicans. Results and Conclusions The survey resulted in 431 use-records for 145 plant-taxa used for the treatment of leishmaniasis. The 10 most frequently reported taxa accounted for 37.7% of all records. In the case of leishmaniasis, activity was observed for Elephantopus mollis, Minquartia guianensis, Bocconia integrifolia, Gouania lupuloides, Scoparia dulcis, an as-yet-unidentified species of Piper and Brugmansia. For the leaves of M. guianensis and the twigs and bark of G. lupuloides a good selectivity index (SI) was found. IC 50 values and the SI of active plant extracts are presented.