Piptadenia Stipulacea Research Articles

Volumetric and energy production assessment of wood in managed forest in the Brazilian arid biome

There is a growing demand for wood products from forests located in dry regions, which includes the Caatinga, a biome in Northeast Brazil. This study evaluates the relationship between volumetric production, energy potential, and the rotation cycle. Information was collected from forest stands in different stages of regeneration located in an arid region of Brazil. Based on the forest management plan, four fields were selected with post-logging ages of 9, 11, 13, and 16 years. This inventory recorded circumference at chest height, circumference at base height, total height, volume, stored energy, technical cutting age, and rainfall index. The results showed that the species that presented the most significant quantity of stems did not always correspond to those that obtained the most significant amount of biomass. The technical cutting age was determined at 16 years, aiming to maximize wood utilization. Regarding energy density, the 9-year-old field reached 7,281 kcal ha-1, the 11-year-old field obtained 14,448 kcal ha-1, the 13-year-old field recorded 41,526 kcal ha-1, and the 16-year-old field reached 98,190 kcal ha-1. The species that contributed most to energy accumulation included Mimosa tenuiflora with 3,740 kcal m–³, Piptadenia stipulacea with 3,271 kcal m-3, and Cenostigma pyramidale with 3,101 kcal m-3.

Distribution of thornless Mimosa tenuiflora, Piptadenia stipulacea and Cnidoscolus quercifolius in a seasonally dry tropical forest remnant

ABSTRACT The density and distribution of three tree species of local economic importance with, but sometimes without, thorns (Mimosa tenuiflora, Piptadenia stipulacea) or urticating hairs (Cnidoscolus quercifolius) thriving in native seasonally dry tropical forests, were assessed in a 43.5-hectare cattle-grazed caatinga remnant, located in Patos/Paraíba, Brazil. We recorded and georeferenced all the thorny and thornless regenerant plants (≥50 cm high and circumference at breast height (CBH) < 6 cm). We also recorded and georeferenced all the mature thorny and thornless trees (CBH ≥ 6 cm); in addition all the thornless mature trees and their respective nearest thorny mature plant were measured. Thornless M. tenuiflora, P. stipulacea and C. quercifolius totaled 560, 9 and 13 plants, respectively. The thornless plants formed groups and the mature ones showed height and CBH similar to their respective nearest mature thorny neighbor. Based on our data and on published data, we suggest management practices aiming at replacing thorny trees by thornless trees, including among others: the planting of 15 groups/ha of, respectively, 7, 2 and 2 thornless M. tenuiflora, P. stipulacea and C. quercifolius seedlings. Such a progressive replacement of the thorny trees by thornless trees would facilitate grazing and the management of the forest.

Toxicological evaluation and safety of the ethanol extract from leaves of Piptadenia stipulaceae

Piptadenia stipulacea is popularly known as “Jurema Branca” and is apply in empiric therapy as anti-inflammatory, analgesic, cells regenerator, antipyretic and astringent pectoral. The present work had as objective to carry out the toxicological analysis of the ethanol extract of the leaves of P. stipulacea. In vitro toxicity was performed according to the methodologies of osmotic fragility against sheep erythrocytes and genotoxicity by Allium cepa and in vivo toxicity according to the protocol of Organization for Economic Cooperation and Development (OECD 423). Erythrocyte osmotic fragility presented low levels of hemolysis both by the qualitative evaluation of the supernatant and by the hemolytic percentage result. In cytotoxic evaluation with Allium cepa, no chromosomal abnormalities or differences in the cell division process (interphase, prophase, anaphase metaphase and telophase) were identified between the control group and the groups submitted to the different concentrations of the ethanolic extract of the leaves of P. stipulaceae (50μg/mL, 500μg/mL and 1000μg/mL). The ethanolic extract of the leaves of P. stipulaceae can be considered of low acute toxicity, since it did not cause the death of treated animals at the dose of 2000 mg/kg, as recommended by OECD 423. The results obtained allow to proceed with additional tests of sub-acute and chronic toxicity, biological activities on specific organisms in order to define the low risk of this plant.

Potential for the use of coconut shell (Cocus nucifera) as an alternative fuel in the production of cassava flour

The production of cassava and tapioca flour are recognized as activities merged in family culture in the North and Northeast regions of Brazil, which demand the use of firewood to feed the furnaces in the flour mills. Due to the small number of studies on this theme, this work aims to evaluate the quality of woody species commonly used as solid fuels in the production of manioc flour in the state of Sergipe, namely: Poincianella pyramidalis (“catingueira”), Cronton sonderianus (“marmeleiro”) and Piptadenia stipulacea (white “jurema”), as well as coconut shells (Cocos nucifera), as an alternative to the use of woody species. Representative samples of the materials were analyzed for parameters: total extracts, lignin, holocellulose, volatile materials, fixed carbon, ashes, higher (HHV) and lower (LHV) heating values, in addition to thermogravimetric analysis. The data were analyzed in a completely randomized design, with four treatments and three replications. The species Piptadenia stipulacea and Cocos nucifera showed high contents of total extracts (18.14%; 29.81%), lignin (29.14%; 28.18%) and fixed carbon (28.22%; 29.62%), and lower contents of holocellulose (52.72%; 42.01%) and volatile materials (70.60%; 66.14%), respectively. The species with the lowest ash content were Croton sonderianus and Piptadenia stipulacea, and the species with the highest HHV and LHV were Piptadenia stipulacea and Croton sonderianus, respectively. Regarding to the thermogravimetric properties, Cocos nucifera behaved like the other biomasses, with ignition temperature slightly lower and peak temperature higher than those for the other species. Among the species analyzed, Piptadenia stipulacea and Cocos nucifera showed the best results as combustibles for cassava flour production. Hence, dried Cocos nucifera shells can properly replace the conventional firewood.

Potencial energético do carvão do Ziziphus joazeiro (Martius) e da Prosopis juliflora (Sw.) DC.

Visando determinar o potencial energético do carvão da Prosopis juliflora (Sw.) DC. e do Ziziphus joazeiro (Martius), o presente trabalho vem incrementar as informações sobre as espécies de ocorrência no semiárido brasileiro. Foram avaliados os parâmetros dendrométricos, tais como: altura total e comercial da árvore, diâmetro à altura do peito (DAP), o volume com casca e sem casca. Após as carbonizações da madeira, foram determinadas as características energéticas do carvão oriundo das espécies estudadas, tais como: poder calorífico superior, rendimento gravimétrico, densidade verdadeira e aparente, porosidade, rendimento em produto condensado, análise de química imediata (teor de materiais voláteis, cinzas e carbono fixo) e umidade, dos quais a Prosopis juliflora possui maiores valores, superando os do Ziziphus joazeiro e os das demais espécies arbóreas correlacionadas, tais como: Mimosa tenuiflora, Aspidosperma pyrifolium, Croton sonderianus, Piptadenia stipulacea, Amburana cearensis, Cemostigma bracteosum e Handroanthus impetiginosus. Ambas possuem um grande potencial para a produção de carvão vegetal, considerando os seus excelentes níveis de rendimento gravimétrico, carbono fixo e do poder calorífico.

Dormancy overcoming and germination test in Piptadenia stipulacea (Benth.) Ducke seeds

Piptadenia stipulacea (Benth.) Ducke presents slow and uneven germination due to integumentary dormancy. In addition, there are no standardized indications as to the temperature and substrate for conducting the germination test in the laboratory. Thus, the objective was to evaluate methods of dormancy overcoming, temperatures and substrates in the germination and vigor of P. stipulacea seeds. For this, two experiments were installed, the first one in a completely randomized design, with 4 replicates of 25 seeds and treatments to overcome dormancy were: immersion in water at 100 °C for 1; 2; 3; 4; 5 and 6 min; immersion in concentrated sulfuric acid (H2SO4 - 98% P.A) for 1; 4; 7; 10 and 13 min; scarification on sandpaper no 80; in the region opposite the micropyle and intact seeds. At 21 days after sowing, emergency, emergency speed index and mean emergency time were evaluated. In experiment II, the experimental design was completely randomized in a 4 x 6 factorial scheme, with four replicates of 25 seeds, using the substrates between sand, paper, paper roll and vermiculite at temperatures of 20; 25; 30; 35; 40 °C and alternated 20-30 °C, the variables analyzed were first count, germination, mean germination time and germination speed index. In order to overcome seed dormancy of P. stipulacea, it is recommended that the pre-germinating treatment be set in the region opposite to the micropyle, and to evaluate the germination and vigor of these seeds, the temperature of 30 °C and 20-30 °C can be used with the roller substrate of paper.

Diversity Of Rhizobia Isolated from Nodules of Indigenous Tree Legumes from the Brazilian Dry Forest

The diversity of rhizobial isolates in tropical dry forests (TDF) has been studied due to the great importance of finding new species of bacteria capable of fixing nitrogen in tree legumes. In the Brazilian TDF (caatinga), Leguminosae is the most important family of plants, so the knowledge of microbial communities that make symbioses with native plants can help in the understanding of the interaction plant-microorganisms, as well as in the optimization of biological processes that can improve the cultivation system in an area so rich and understudied. In this study was determined the characteristics of rhizobia isolated from nodules of Mimosa tenuiflora (Willd.) Poir., Piptadenia stipulacea (Benth.) Ducke and Mimosa caesalpiniifolia Benth, grown in soils collected under caatinga vegetation. The phenotypic and molecular characterization of the isolates, with use of fingerprint markers such as BOX, REP, ERIC and BOX-PCR were performed. Amplification technique by duplex PCR with the nifH and nodC genes was used for the authentication of isolates. The results showed that given the variation found in the amplification of the nifH and nodC genes, the duplex PCR technique can show false-positive results, as these genes have a very large polymorphism. The lack of knowledge of isolates that make symbioses with these plants further help to conclude that this authentication technique cannot yet be applied to all legume-nodulating isolates. Regarding the analyses made with fingerprint markers, it was observed that all were very efficient in the ability to distinguish species and that the greater the number of markers used, the safer the knowledge on the taxonomy and diversity of rhizobia.

Production of Piptadenia stipulacea (Benth.) Ducke seedlings irrigated with fish farming wastewater

ABSTRACT The objective of this study was to evaluate the growth of ‘jurema-branca’ seedlings (Piptadenia stipulacea (Benth.) Ducke.), irrigated with effluent from fish farming in order to meet the nutritional demand in the initial growth stage. The treatments consisted in the dilution of fish farming wastewater in different concentrations (0, 25, 50, 75 and 100%) with supply water. Seeds were sown in 0.9-L polyethylene bag containing a mixture of soil and manure. At 54 days after sowing the shoot length, stem diameter, height/diameter ratio, number of leaves, leaf area, unit leaf area, dry matter of stem, leaves, shoots, roots and total, chlorophyll content index and Dickson quality index were evaluated. The growth of ‘jurema-branca’ seedlings is favored by the dilution of 25% of fish farming wastewater in the supply water. Using up to 25% of the concentration of the fish farming effluent does not significantly affect the dry biomass accumulation in ‘jurema-branca’ seedlings, in relation to the control. The reuse of fish farming wastewater diluted at proportion of up to 25% is a viable alternative to meet the water demand in the production of forest seedlings.

Taninos: principal componente do extrato Piptadenia stipulacea (Benth) Ducke inibe o crescimento de cepas clínicas de Staphylococcus aureus de origem bovina

http://dx.doi.org/10.5007/2175-7925.2016v29n1p109Este estudo avalia a atividade antimicrobiana dos taninos presentes na casca do caule da Piptadenia stipulacea (Benth) sobre cepas de Staphylococcus aureus de origem bovina. A atividade antimicrobiana in vitro do tanino foi avaliada pela determinação da concentração mínima inibitória (CIM). Para determinar a CIM, os taninos foram dissolvidos de forma seriada em água destilada em concentrações variando entre 500 mg/mL e 0,976 mg/mL. Os ensaios foram realizados em triplicata. Os taninos inibiram o crescimento de S. aureus, apresentando valor de CIM de 31,25 mg/mL. Os resultados deste estudo são promissores, pois mostram a importância de avaliar novos compostos de origem natural no combate às infecções causadas por S. aureus. Novos estudos são necessários para confirmar a atividade in vivo e avaliar o mecanismo de ação do tanino isolado da casca do caule da Piptadenia stipulacea.

Efeitos da desertificação na composição de espécies do bioma Caatinga, Paraíba/Brasil

Desertification is recognized as the land degradation in arid, semiarid, and dry sub-humid zones, as a result from multiple anthropogenic impacts such as unsustainable natural resources management and land-use. In this context, the plant cover displays a crucial role due its capacity of soil protection against both terrestrial runoíFand high rates of rain infiltration. In Brazil, the desertification has reached mainly the Seasonally Dry Tropical Forest (STDF) biome, natively known as Caatinga, in which the major drivers are related to the historical severe deforestation and livestock expansion. In face of this alarming scenario, there is no or few information about direct effects driven by desertification, particularly those related to the floristic composition of aíFected areas or affected potentially areas. Herein, the aim was to assess the desertification eíFects on vegetation composition within three sites in the Brazilian semiarid zone. In order to ensure unbiased comparisons, the three sampling sites presented similar topographical, pedological and climate conditions, localized at distinctive municipality from Paraíba State, Northeastern region, Brazil. In each site, two contrasting situations were sampled, - desertified and non-desertified environments. These environments were previously selected though satellite images, using the NDVI technique, for identification of vegetation biomass level. In field, the floristic composition was surveyed by transect method, covering a patch of 50m x 4m delimitated with metric tape. In these perimeters, it was identified the specie and botanical family of each plant, richness (S) and abundance (N) of tree with DBH > 10 cm. Posteriorly, it was calculated the Shannon'sα diversity (H’) and Piellou's evenness (J’) by Primer β software (open access). Non-parametric univariate (U test) and multivariate (nMDS) analysis were performed to verify diíFerences in the vegetational variables (S, N, H’ and J’) and to demonstrate dissimilarities patterns (relative abundance) for the contrasting environments, respectively. In total, twenty-six plant species were identified, belonging to thirteen families. Of this set, seventeen species (65%) were exclusive of non-desertified areas and only two species were exclusive of desertified areas. U test showed that the both richness and diversity of plants species differed significantly between the two analyzed environments. Using a subset of 10 species most common in two environments, the nMDS discriminated three groups of plants: i) species associated to non-desertified areas (Anadenanthera columbrina, Bauhinia cheilantha and Tabebuia impetiginosa), ii) species related to desertified areas (Aspidosperma pyrifolium, Jatropha molissima, Mimosa tenuiflorã and Pilosocereusgouneleii) and iii) species with high density in both environments (Croton sonderianus, Piptadenia stipulacea e Poincianella pyramidalis). Dominant species in the non-desertified areas are restricted to the environments better preserved of Caatinga, which cannot to support strong degradation condition, whereas the species most common in the desertified areas are recognized as pioneer for the biome. Occurring to the two environments, such species harbors high capacity of settlement to the either impacted or preserved environments coupled to a strong resistance and resilience to disturbance (e.g. log and burn). Finally, the results obtained pointed out that the desertification triggered pervasive changes on the vegetational components (richness and diversity) and floristic composition of the Caatinga biome, suggesting also that human-induced disturbances were determinants to the establishment of the diíFerent environments.

Análise quantitativa da vegetação lenhosa da Caatinga em Teixeira, PB

&lt;p&gt;A cobertura vegetal da região semiárida do Nordeste brasileiro é compreendida pela caatinga, que é, em grande parte, determinada pelo clima e relevo. A região do município de Teixeira, PB apresenta uma cobertura vegetal de caatinga de porte e densidade diferente das encontradas na Depressão Sertaneja, motivada por maior umidade. O objetivo deste trabalho foi quantificar os remanescentes florestais do município de Teixeira, PB, por meio de técnicas de geoprocessamento e inventário florestal. Para o mapeamento da vegetação nativa, foram utilizadas imagens de satélites, referentes ao mês de novembro de 2008. Foi realizado inventário florestal com uso de amostragem por parcelas, selecionadas sistematicamente, em um total de 40 unidades amostrais com dimensões de 20 m x 20 m. Foi medida a altura e diâmetro a 1,30 m do solo (DAP) de todas as árvores com DAP ≥ 10 cm. Cada árvore foi identificada pelo seu nome popular e científico. A vegetação arbórea amostrada foi de 4.911 indivíduos, pertencentes a 46 espécies e 24 famílias, o que corresponde a 3.069 indivíduos ha-1. As espécies com maior valor de importância (VI) foram: &lt;em&gt;Croton blanchetianus, Mimosa tenuiflora &lt;/em&gt;e &lt;em&gt;Piptadenia stipulacea&lt;/em&gt;. As famílias que mais se destacaram foram Euphorbiaceae, Mimosaceae e Caesalpinaceae. O município de Teixeira apresenta áreas mais preservadas nas regiões serranas, de difícil acesso.&lt;/p&gt;

AVALIAÇÃO FÍSICO-QUÍMICA E ENERGÉTICA DA MADEIRA DAS ESPÉCIES &lt;i&gt;Piptadenia stipulacea &lt;/i&gt;(Benth.) Ducke E &lt;i&gt;Amburana cearensis&lt;/i&gt; (Allemao) A. C. Smith DE OCORRÊNCIA NO SEMIÁRIDO NORDESTINO BRASILEIRO

http://dx.doi.org/10.5902/1980509817474A Caatinga é um bioma exclusivamente brasileiro, que apresenta uma grande variedade de espécies da fauna e da flora, sendo uma boa parte destas endêmicas. Ao longo dos anos, a supressão da caatinga por ação antrópica vem reduzindo bastante esse bioma. Este fato se dá, principalmente, pelo uso do potencial energético de suas espécies vegetais sem a devida preocupação com a sustentabilidade do mesmo. Um melhor conhecimento do potencial energético das espécies vegetais da caatinga possibilita um manejo mais adequado. O objetivo deste trabalho foi avaliar o potencial energético e as características físico-químicas da madeira das espécies Amburana cearensis (Allemao) A. C. Smithe Piptadenia stipulacea (Benth.) Ducke. Foram abatidas cinco árvores de cada espécie, amostradas aleatoriamente no sítio São Bento, localizado no Município de Patos - PB. As árvores foram devidamente identificadas e transportadas para o Setor de Tecnologia de Produtos Florestais (STPF) da Universidade Federal de Campina Grande. De cada árvore, foram retirados discos pequenos (5 cm de espessura) a 0 (base), 25, 50, 75 e 100% da altura comercial do tronco (até 5 cm de diâmetro) e discos grandes (15 cm espessura), antes e após cada disco pequeno, os discos pequenos foram subdividido em quatro partes, em forma de cunha, passando pela medula. Duas cunhas opostas foram utilizadas para a determinação da densidade básica, e as restantes foram reservadas para a realização das análises físicas e químicas da madeira e os discos maiores foram destinados à realização das carbonizações. A densidade básica foi determinada de acordo com o método da balança hidrostática e para a determinação da densidade básica média de cada árvore utilizou-se como fator de ponderação o volume entre seções de cada disco. Após a secagem ao ar, as amostras destinadas às análises químicas foram transformadas em serragem e feitas determinações quantitativas de extrativos total, da lignina, das cinzas, e o teor de holocelulose foi estimado por diferença em relação à massa inicial [100% – (teor de extrativos totais + teor de lignina + teor de cinzas)]. As amostras destinadas às carbonizações foram transformadas em cavacos, e carbonizadas em forno elétrico (mufla) por 5h30min. Foram feitas determinações dos rendimentos dos produtos das carbonizações, e das propriedades físicas e químicas do carvão vegetal. Médias significativamente superiores a 1% de probabilidade de teor de lignina, teor de holocelulose, extrativos totais e de cinzas da madeira foram encontradas para as espécies Amburana cearensis Piptadenia stipulacea, sendo que esta última espécie apresentou maiores médias de teor de lignina e teor de holocelulose. O rendimento gravimétrico foi semelhante para ambas as espécies, enquanto o rendimento em líquido condensado foi significativamente superior para a Amburana cearensis. Em relação à qualidade do carvão, foram observados maiores valores de poder calorífico superior e carbono fixo para a Piptadenia stipulacea, enquanto a Amburana cearensis exibiu maiores teores de materiais voláteis e de cinzas.

Mechanisms underlying the relaxant effect of Galetin 3,6- dimethyl ether, from Piptadenia stipulacea (Benth.) Ducke, on guinea-pig trachea.

Galetin 3,6-dimethyl ether (FGAL), a flavonoid from the aerial parts of Piptadenia stipulacea (Benth.) Ducke, was found to exert a relaxant effect on carbachol (CCh)-pre-contracted guinea-pig trachea. Based on cumulative concentration-response curves to CCh, FGAL antagonized muscarinic receptors pseudo-irreversibly and noncompetitively, since it inhibited and shifted these curves towards higher concentrations in a nonparallel manner. In addition, FGAL was more potent in relaxing contractions induced by 18 mM as compared to 60 mM KCl (pD2 = 5:50 ±0:36 and 4.80 ±0.07, respectively), indicating the participation of K+ channels. In the presence of 10 mM tetraethylammonium (TEA+) chloride, a nonselective K+ channel blocker, the relaxant potency of FGAL was reduced (from pD2 = 5:12 ±0:07 to 4.87 ±0.02). Among several selective blockers of K+ channel subtypes, only apamin, an SKCa (small-conductance Ca2+-activated K+ channels) blocker, attenuated the relaxant potency of FGAL (pD2 = 4:85±0:06), suggesting SKCa activation. FGAL was equipotent in relaxing trachea contracted by 60 mM KCl (pD2 =4:80 ±0:07) or 10-6 M CCh (pD2 = 5:02 ±0:07), suggesting CaV (voltage-gated calcium channel), but not ROCs (receptor-operated calcium channels) participation. Furthermore, aminophylline-induced relaxation (pD2 = 4:12 ±0:06) was potentiated around 4-fold (pD2 = 4:80 ±0:44) in the presence of FGAL. Moreover, forskolininduced relaxation (pD2 = 6:51 ±0:06) was potentiated around 2.5-fold (pD2 = 6:90 ±0:05) by FGAL. Conversely, sodium nitroprusside-induced relaxation was unaffected, indicating that the AC/cAMP/PKA pathway, but not the NO pathway, may be modulated by the flavonoid. These results suggest that, in guinea-pig trachea, FGAL induces relaxation by pseudo-irreversible noncompetitive antagonism on muscarinic receptors, modulation of K+ and Ca2+ channels, as well as activation of the AC/cAMP/PKA pathway.

Piptadenia stipulacea (Benth.) Ducke Seed Germination in Response to Temperature, Light and Water Stress

The current study aimed to investigate the effects of the temperature, light, and water stress on Piptadenia stipulacea seed germination. It assessed germination percentage, speed and average germination time, root and stem length as well as the dry weight of seedlings subjected to the constant temperatures of 20°C, 25°C and 30°C and alternating temperatures from 20°C to 30°C. A 12-hour photoperiod was established in addition to the following light conditions: white, darkness, red and far red. The experimental design was completely randomized and four replicates of 25 seeds were performed for each treatment. Regarding water stress, seeds were subjected to osmotic potentials of 0, -0.2, -0.4, -0.6, -0.8, -1.0, and -1.2 MPa, at 30°C and 12 h light/12 h darkness photoperiods. After they were mixed, 100 seeds were randomly selected for biometric measurement and they were found to be uneven with respect to size and weight. P. stipulacea seeds germinated under all tested temperature and light conditions. Germination under water stress occurred up to -0.8 MPa. The conclusion is that there was no germination from -1.0 MPa. The seeds are light-indifferent and germinate at the constant temperatures of 20°C, 25°C and 30°C and alternating temperatures from 20°C to 30°C.

Microbial community biogeographic patterns in the rhizosphere of two Brazilian semi-arid leguminous trees

Arid environments are regular and well distributed over all continents and display drought characteristics whether full-time or seasonal. This study aims to characterize how the microbial communities of the rhizosphere of two leguminous trees from the Brazilian semi-arid biome the Caatinga are geographically and seasonally shaped, as well as the factors driving this variation. With that purpose, the soil rhizosphere from two leguminous trees (Mimosa tenuiflora and Piptadenia stipulacea (Benth.) Ducke) were sampled in two different seasons: rainy and drought at five different sites. Assessment of bacterial and archaeal communities occurred by T-RFLP analysis of 16S rRNA and archaeal amoA genes. By these means, it was observed that the seasons (wet and dry periods) are the factors that most influence the composition of the microbial community from both analyzed plants, except for the results obtained from the CCA applied to Archaeas. Furthermore, soil physical-chemical factors also had a significant influence on the community and indicated a geographical pattern of the bacterial community. It was not possible to observe significant modifications in the composition in relation to the plant species. We have seen that soil characteristics and rainfall were the factors that most influenced the microbial composition. Also, the bacterial community had a significant correlation with soil characteristics that indicates that these rhizosphere communities might be selected by environmental characteristics. Furthermore, the data suggest that climate plays a key role in structuring the microbial community of this biome.

How much nitrogen is fixed by biological symbiosis in tropical dry forests? 1. Trees and shrubs

Despite the recognized importance of the process, estimates of the amount of nitrogen fixed by biological symbiosis in tropical dry forests are almost nonexistent. We estimated the nitrogen fixed annually by the leaves of trees and shrubs at sites regenerating for 16 and 38 years and in an old-growth dry forest using 15N abundance methodology. The total leaf biomass (1,824–3,036 kg ha−1) and nitrogen contents (62–90 kg ha−1) did not differ among the areas. In all of the areas, most of the leaf biomass belonged to legume plants, but the proportion of the N2-fixing legumes decreased with increasing regeneration time. In the 16-year regenerating area, almost all of the N was in the leaves of the N-fixing Mimosa tenuiflora plants, but fixation was absent or very low as it was in the N-fixing species present in the 38-year regenerating area. In the old-growth Caatinga, all of the N-fixing species (M. tenuiflora, Piptadenia stipulacea and Anadenanthera colubrina) had large proportions (47–62 %) of their N derived from atmospheric N2, but the amount of fixed N (6 kg ha−1) was a small proportion of the total leaf N because these plant species were a small part of the vegetation. The total input of biologically fixed N to the old-growth forest was similar in magnitude to an estimate made for a humid tropical forest in Amazonia.

Abordagem fitoquímica, composição bromatológica e atividade antibacteriana de Mimosa tenuiflora (Wild) Poiret E Piptadenia stipulacea (Benth) Ducke

The need to find new efficient drugs to combat microbes has increased the search for new natural compounds with biological activities. In this work, phytochemical studies and microbiological analysis were carried out with the ethanol extracts of Mimosa tenuiflora (Wild) Poiret and Piptadenia stipulacea (Benth) Ducke on pathogenic bacteria strains. The bark powders of both species were submitted to bromatologic evaluation and the levels of dry matter, mineral matter, crude protein, neutral detergent fiber (NDF) and crude energy were determined. The results of the chemical search chemical showed the presence of tannins and other phenolic compounds as well as the presence of saponins in both extracts. The microbiologic evaluation of the extracts of both species showed that more than one part of the plants had antimicrobial activity. The bromatologic composition of the bark powder of Mimosa tenuiflora (Wild) Poiret and Piptadenia stipulacea (Benth) Ducke showed different contents for analyzed variables.

Spasmolytic effect of galetin 3,6-dimethyl ether, a flavonoid obtained from Piptadenia stipulacea (Benth) Ducke

Piptadenia stipulacea (Benth) Ducke is a tree of the Caatinga, in Northeast Brazil, popularly known as "Jurema-branca", "Jurema malícia-da-serra", "Carcará" and "Calumbi". In folk medicine, a decoction or tincture of its bark and leaves are used to treat wounds and as healing agents. Galetin 3,6-dimethyl ether (FGAL) is a flavonoid isolated from the aerial components of Piptadenia stipulacea (Benth) Ducke. We decided to investigate a possible FGAL spasmolytic effect on preparations of both the guinea pig ileum and trachea, the rat uterus and the male rat aorta. FGAL inhibited oxytocin (IC(50) = 2.2 ± 0.4 × 10(-5) M) and carbachol (CCh)-induced (IC(50) = 7.7 ± 1.3 × 10(-5) M) phasic contractions in the rat uterus, but was more effective in the inhibition of the oxytocin-induced contractions. In the guinea pig ileum, FGAL equipotently inhibited CCh (IC(50) = 2.8 ± 0.4 × 10(-5) M) and histamine-induced (IC(50) = 2.3 ± 0.5 × 10(-5) M) phasic contractions. FGAL equipotently and concentration-dependently relaxed guinea pig trachea preparations pre-contracted with CCh, both in the absence (EC(50) = 0.8 ± 0.1 × 10(-5) M) and presence (EC(50) = 1.0 ± 0.1 × 10(-5) M) of a functional epithelium. FGAL also relaxed preparations of the rat aorta pre-contracted with phenylephrine in both the absence (EC(50) = 5.0 ± 1.1 × 10(-6) M) and presence (EC(50) = 5.4 ± 1.2 × 10(-6) M) of a functional endothelium. FGAL shows a non-selective spasmolytic effect on each of the smooth muscle preparations we have tested, but with a greater effect on those from the rat aorta. The relaxant effect on preparations of both the guinea pig trachea and the rat aorta seems to not involve the epithelium or endothelium-derived relaxing factors.

Spasmolytic effect of galetin 3,6-dimethyl ether, a flavonoid obtained from Piptadenia stipulacea (Benth) Ducke

ErrataJ. Smooth Muscle Res. 45 (5): 123–134 (2011)Figure 1 and the legend to this figure, appeared in page 124 of this article, have to be corrected to those shown below.

The antinociceptive and anti-inflammatory activities of Piptadenia stipulacea Benth. (Fabaceae)

In this study, we attempted to identify the possible antinociceptive and anti-inflammatory actions of the aqueous phase, the ethyl acetate phase and one unknown flavonoid obtained from aerial parts of Piptadenia stipulacea, known in Brazil as "jurema-branca", "carcará" and "rasga-beiço". Aerial parts of Piptadenia stipulacea were used and after fractionation, the flavonoid FGAL was obtained. Experiments were conducted on Swiss mice using the acetic acid-induced writhing test, the hot plate test, the formalin-induced pain test and zymosan A-induced peritonitis test. The aqueous and ethyl acetate phases (p.o., 100mg/kg); and the flavonoid FGAL (p.o. and i.p. at 100 micromol/kg), reduced the nociception produced by acetic acid, by 49.92%, 54.62%, 38.97% and 64.79%, respectively. In vivo inhibition of nociception by the ethyl acetate phase (100mg/kg, p.o.) in the hot plate test was favorable, indicating that this fraction exhibited central activity. The ethyl acetate phase (100mg/kg, p.o.) reduced the formalin effects in both phases by 28.51% and 55.72%, respectively. Treatment with the aqueous phase (100mg/kg, p.o.) and FGAL (100 micromol/kg, i.p.) only protected the second phase by 69.76% and 68.78%, respectively. In addition, it was observed in the zymosan A-induced peritonitis test that the aqueous phase, the ethyl acetate phase and the FGAL exhibited anti-inflammatory activity, reducing significantly the number of recruit cells by 35.84%, 37.70% and FGAL (1), respectively. These data demonstrate that the FGAL elicits pronounced antinociceptive activity against several pain models. The actions of this flavonoid probably are due to antioxidative properties. However, pharmacological and chemical studies are continuing in order to characterize the mechanism(s) responsible for this antinociceptive action and also to identify other active substances present in Piptadenia stipulacea.