Cocal Research Articles

Produção de lamelas em serra de fita horizontal múltipla para fabricação de piso engenheirado de madeira

Este trabalho teve como objetivo estudar a relacao da velocidade de avanco de um modelo de serra fita horizontal na qualidade final das lamelas de quatro especies de madeira utilizadas na producao de pisos engenheirados: jatoba (Hymenaea courbari L.), muiracatiara (Astronium lecointei), amendoim (Pterogyne nitens) e sucupira (Bowdichia nitida). Foram estudadas as distribuicoes das espessuras das lamelas com relacao a velocidade de avanco, considerando-se o tipo de madeira, a especificacao do controle de qualidade e a existencia de marcas na superficie. Os resultados mostraram que o amendoim apresentou maior aproveitamento na producao de lamelas, enquanto que o jatoba foi a especie que sofreu maior perda no processo de producao. A velocidade de avanco que apresentou os menores indices de desclassificacao de lamelas foi de 8 m/min, sendo a mais indicada para producao de lamelas.

Fungos Micorrízicos Arbusculares em Diferentes Coberturas Florestais em Vitória da Conquista, Bahia

Os fungos micorrizicos arbusculares (FMAs) sao organismos mutualistas obrigatorios, que facilitam a sobrevivencia e o desenvolvimento de plantas. Sao influenciados pela cobertura florestal e por outros fatores bioticos e abioticos. O objetivo deste trabalho foi avaliar a composicao e a diversidade dos FMAs em solo sob tres diferentes coberturas florestais, em Vitoria da Conquista-BA. O plantio de Madeira-nova apresentou maior abundância de esporos que o plantio de Eucalipto. O fragmento de Mata nativa apresentou um grande numero de especies quando comparado com os plantios, sendo seis exclusivas deste local e com potencial de apresentar uma maior diversidade. Os FMAs apresentaram diferencas marcantes de composicao e diversidade nas coberturas florestais avaliadas. A grande abundância de esporos e a homogeneidade amostral das especies no plantio de Madeira-nova sao fatores facilitadores para um futuro isolamento de FMAs.

Adequação da metodologia do teste de condutividade elétrica para sementes de Pterogyne nitens Tull.

Pterogyne nitens Tull. is a forest species belonging to the family Leguminosae Caesalpinoidea, recommended for replacement of degraded areas and greening of urban roads and highways. The electrical conductivity test is a test of seed vigor, whose measurement of exudates released during their driving reflects the integrity of the membrane system. The objective of this study was to adapt the methodology of electrical conductivity test for seeds of P. nitens. The seed dormancy overcome with concentrated sulfuric acid and then were subjected to accelerated aging test at 40 ° C for 0 (control), 24, 48 and 72 hours, determining the rate and speed of germination. Then, the electrical conductivity in seeds aged for 48 hours and witness was done, evaluating three quantities of seeds (25, 50 and 75), three volumes of distilled water (25, 50 and 75 mL) and three soaking (24, 48 and 72 hours) in the comparison of seed vigor for electrical conductivity. The experimental design was completely randomized with five replicates, and the mean aged seeds compared to the control by the Tukey test at 5% and electrical conductivity values correlated to the results of the germination test. The electrical conductivity test correlated with seed vigor subjected to artificial aging. Thus, the use of 50 seeds soaked in 50 ml distilled water for 24 hours is recommended to conduct the electrical conductivity in seeds of P. nitens.

Fast Screening for Antioxidant Properties of Flavonoids from Pterogyne nitens Using Electrochemical Methods

A fast, low-cost, convenient, and especially sensitive voltammetric screening approach for the study of the antioxidant properties of isoquercitrin and pedalitin from Pterogyne nitens is suggested in this work. These flavonoids were investigated for their redox properties using cyclic voltammetry in nonaqueous media using N,N-dimethylformamide and tetrabutylammonium tetrafluorborate as the supporting electrolyte, a glassy carbon working electrode, A6(see symbol in text)AgCI reference electrode, and Pt bare wire counter electrode. The comparative analysis of the activity of rutin has also been carried out. Moreover, combining HPLC with an electrochemical detector allowed qualitative and quantitative detection of micromolecules (e.g., isoquercitrin and pedalitin) that showed antioxidant activities. These results were then correlated to the inhibition of beta-carotene bleaching determined by TLC autographic assay and to structural features of the flavonoids.

Alterações fisiológicas e bioquímicas em sementes de Pterogyne nitens tull. Durante o envelhecimento artificial

O teste de envelhecimento acelerado é utilizado para avaliar o vigor e a qualidade de sementes. O presente trabalho teve como objetivo investigar e estabelecer relações entre a deterioração, alterações fisiológicas e atividade da enzima catalase, durante o envelhecimento artificial de sementes de Pterogyne nitens. Para tanto, sementes de P. nitens sem e com superação da dormência, por meio da aplicação de ácido sulfúrico concentrado (95-99%), durante 10 minutos, foram submetidas ao teste de envelhecimento acelerado, por 0, 24, 48 e 72 horas, determinando-se a percentagem de germinação, peroxidação de lipídios e atividade da enzima catalase. O envelhecimento artificial afetou significativamente a viabilidade e vigor das sementes, após prévia superação da dormência, observando-se decréscimo na germinação e na atividade da enzima catalase e aumento na peroxidação de lipídios, durante o envelhecimento. Nas sementes que não tiveram a dormência superada, não foi observada relação entre o envelhecimento artificial, alterações fisiológicas e atividade da enzima, de forma que a dormência atua como um mecanismo protetor do estresse oxidativo nas sementes.

Chemopreventive potential of natural products isolated from a alchornea glandulosa, pterogyne nitens and its semisynthetic analogs

AbstractINTRODUCTION: Chemoprevention involves the use of natural or synthetic substances to reduce the risk of developing cancer. Gallic acid was found to possess several pharmacological activities, such as anti-oxidant and anti-inflammatory. Guanidine alkaloids display a broad spectrum of biological activities and its cytotoxic effect were well investigated. OBJECTIVES: The present study evaluated the chemopreventive potential of natural products and its semi-synthetic analogs using quinone reductase (QR) induction, aromatase inhibition and the suppression of NFκB activity, which are well established strategies for screening compounds to cancer chemoprevention. METHODS: Gallic acid was isolated from Alchornea glandulosa, and alkyl gallates were prepared from the reaction of the corresponding alcohols with gallic acid or from the reaction with acetic anhydride. The guanidine alkaloids nitensidines A and B were isolated from Pterogyne nitens. All compounds were evaluated for QR induction using murine hepatoma cell line Hepa 1c1c7 and two mutant cell lines; for in vitro aromatase inhibition; and against TNFα-induced NFκB activation with stable transfected 293/NFκB-Luc human embryonic kidney cells. Compounds were tested at 20Bg/mL following 1:3 serial dilutions. RESULTS: No QR induction was observed at tested concentrations. Nitensidine A and B showed aromatase inhibition (IC50 18,3 ± 8,7 uM), but moderately cytotoxic to Hepa 1c1c7 cells (IC50 5,7 ± 0,6 uM). With IC50 values in a range of 10 to 50 μM, all the gallic acid esters mediated NFκB inhibitory activity. In addition, gallic acid mediated a modest cytotoxic effect, but none of the gallate esters affected cell viability at the tested concentrations. CONCLUSION: Based on these intracellular responses, we suggest that gallate esters are related to suppression of NFκB activation, which it could play a chemopreventive role in carcinogenesis.

Chemopreventive potential of natural products isolated from a alchornea glandulosa, pterogyne nitens and its semisynthetic analogs

Chemopreventive potential of natural products isolated from a alchornea glandulosa, pterogyne nitens and its semisynthetic analogs

Validation of quality tests for forest seed species

The Brazilian literature on seed germination testing of tropical forest species, although still insufficient, is extensive for species with economical potential. However, this information is still fragmented and often reported in scientific communications of modest circulation. In this summary, we present the results of a validation process for germination tests on Brazilian forest species, which had as a starting point the ample reviewing of current methods, besides exhaustive pre-testing in certified laboratories. Specific protocols were created for each species, including substrate, temperature, seed disinfection, breaking of dormancy, seedling classification and other information. These protocols were sent to research laboratories and accredited by the Ministry of Agriculture, together with seed lots of three distinct qualities. The presuppositions of normality of the residuals and homoscedasticity of the variations were previously tested and the completely randomized factorial design statistical model was applied to the normal seedlings of each species. After this analysis, germination test methods for seeds of Astronium fraxinifolium, Ceiba speciosa, Cybistax antisyphilitica, Enterolobium contortisiliquum, Guazuma ulmifolia, Lafoensia pacari, Mimosa caesalpiniaefolia, Peltophorum dubium, Pseudobombax tomentosum and Pterogyne nitens, all forest species of different Brazilian biomes, were considered to be validated.

Antimicrobial activity of Pterogyne nitens Tul., Fabaceae, against opportunistic fungi

As part of our ongoing research on antifungal agents from Brazilian flora, eight extracts and twelve fractions from Pterogyne nitens Tul., Fabaceae, were screened for antimicrobial activity against four opportunistic fungi species (Candida albicans, Candida krusei, Candida parapsilosis and Cryptococcus neoformans) using a broth microdilution method. The present investigation reveals that P. nitens extracts and fractions were more effective against C. krusei and C. parapsilosis than against C. neoformans. The growth of C. albicans was moderately affected by all tested extracts and fractions. The strongest effects were observed for n-butanol fractions from branches (MIC = 15.6 μg/mL) and roots (MIC = 31.2 μg/mL) against C. krusei. Additionally, the chromatographic fractionation of the n-butanol fraction from branches afforded four guanidine alkaloids; N-1,N-2,N-3-triisopentenylguanidine (1), described for the first time in the Fabaceae family, and nitensidines A-C (2-4), which showed moderate activity towards C. krusei (MIC = 62.5 μg/mL) and C. parapsilosis (MIC = 31.2 μg/mL).

Alkaloids extracted from Pterogyne nitens induce apoptosis in malignant breast cell line

In the present study, two alkaloids isolated from Pterogyne nitens, a plant native to Brazil, have been shown to induce apoptosis in human breast cancer cells. These compounds, pterogynine (PGN) and pterogynidine (PGD), were tested for their effect on a human infiltrating ductal carcinoma cell line (ZR-7531). The cell line was treated with each alkaloid at several concentrations. Time-dependence (with or without recuperation time) and concentration-dependence (in the range 0.25-10 mM) were investigated in cytotoxicity and apoptosis assays. The annexin assay indicated an apparently higher percentage of death by necrosis of malignant cells after 24 h exposure to both P. nitens extracts than the Hoechst assay. Thus, our results in the two tests demonstrated that the Hoechst assay can discriminate between late apoptotic cells and necrosis, whereas the flow cytometry-based annexin V assay cannot. We concluded that PGN and PGD have effective antineoplastic activity against human breast cancer cells in vitro, by inducing programmed cell death.

Alcohol extract of Pterogyne nitens leaves fails to reduce severity of streptozotocin-induced diabetes in rats.

Two constituents of Pterogyne nitens leaves, kaempferitrin, a diglycosylated flavonol, and galegin, a guanidine alkaloid, may be considered likely to exert an antidiabetic effect, on the basis of their chemical structures. Thus, experimentally diabetic rats were treated with P. nitens leaf extract, to observe the effects on biochemical and toxicological marker variables. Streptozotocin-diabetic rats (50 mg/kg body weight) were given ethanolic extract of the leaves (76 mg suspended in 0.5 mL of 10% aqueous glycerine per rat) (DP) by gavage, twice a day for 32 days. Diabetic controls were given 0.5 mL of 10% glycerine (DG), insulin (2.5 U in 0.3 mL s. c.) (DI) or 0.5 ml water (DW). Initial glycemia was 537.11 ± 10.35 mg/dL. Each week or fortnight after the treatment glucose, urea and protein contents were determined in the urine and glycemia and alkaline phosphatase activity in the serum. Except for proteinuria, the results for groups DP, DG and DW all differed significantly (p < 0.05) from those for group DI, which exhibited reduced values of all the other variables. The plant extract neither improved nor worsened the diabetic state of the rats; nor did it give rise to any hepato-biliary toxic effect.

Avaliação de defeitos no processo de fabricação de lamelas para pisos de madeira engenheirados com uso de ferramentas de controle de qualidade

Os defeitos das lamelas são responsáveis em grande parte pelo retrabalho, perdas e diminuição da qualidade do piso acabado. Esses defeitos geram aumento de custos de produção sendo um fator muito importante para o processo de fabricação de pisos de madeira. Este trabalho tem por objetivos classificar e quantificar os defeitos ocorrentes na produção de lamelas, buscar causas, propor soluções e melhorias através da aplicação de ferramentas de qualidade como: “Brainstorming", “ Diagrama de Pareto", “Diagrama de Ishikawa" e 5W2H . Foram amostrados 1598,47 m² de lamelas das seguintes espécies: Muiracatiara (Astronium lecointei Ducke), amendoim (Pterogyne nitens Tul), cabreúva (Myroxylon Balsamum Harms) e timborana (Pseudopiptadenia suaveolens Miq) com as seguintes dimensões: espessuras (2,5mm e 3,5mm), larguras (76,2mm, 82,5mm e 127mm), comprimentos (450mm a 1.200mm). O defeito mais freqüente encontrado na produção de lamelas foi a marca de serra (31%), seguido de corte da madeira feito pelo fornecedor (23%) e falta de instrução de trabalho (15%). As principais causas dos defeitos de marca de serra são devidas aos problemas de manutenção de serras da empresa fornecedora de madeira.

Tratamento crônico com extrato alcoólico de Pterogyne nitens não melhora parâmetros clássicos do diabetes experimental

Tem sido atribuido ao flavonoide kaempferitrina e ao alcaloide galegina efeito hipoglicemico. Folha de Pterogyne nitens, por conter tais compostos, poderia ser antidiabetica. Assim, avaliamos o efeito do tratamento com Pterogyne nitens a ratos diabeticos sobre niveis glicemicos e parâmetros fisiologicos. Ratos diabeticos (50 mg estreptozotocina/Kg peso) foram tratados durante 32 dias, 2 vezes ao dia, por gavagem com extrato etanolico de folhas de Pterogyne nitens (76 mg/0,5 mL glicerina 10% por rato) (DTPn). Grupos diabeticos controles foram tratados com: glicerina 10% (0,5 mL) (DTG), insulina (2,5 U/0,3 mL) (DTI) e agua (0,5 mL) (DTA). Semanalmente determinamos: peso corporal, ingestao hidrica e alimentar, volume urinario e nivel glicemico. Os resultados dos grupos DTPn, DTG e DTA foram diferentes do DTI para todos os parâmetros, ocorrendo ganho de peso corporal e reducao dos demais parâmetros no DTI. O grupo DTPn apresentou resultados semelhantes aos DTG e DTA. Atraves dos resultados apresentados no grupo DTI, constatamos que o modelo de estudo foi adequado. Tambem concluimos que o extrato vegetal e a glicerina nao melhoraram e nem exacerbaram o quadro diabetico. Resta a possibilidade da planta promover melhoria do diabetes com diferente: dose do extrato, via de administracao ou severidade do diabetes induzido.

AVALIAÇÃO MORFOLÓGICA DE MUDAS DE MADEIRA-NOVA (Pterogyne nitens Tull.) PRODUZIDAS EM TUBETES E SACOS PLÁSTICOS E DE SEU DESEMPENHO NO CAMPO

Avaliou-se a qualidade morfológica de mudas de madeira-nova (Pterogyne nitens) produzidas em sacos plásticos e tubetes, visando alcançar maior sobrevivência e desempenho inicial após o plantio. Estabeleceram-se 4 tratamentos: T1 - Tubete (50 cm3); T2 - Tubete (288 cm3); T3 - Saco plástico (577 cm3) e T4 - Saco plástico (2090 cm3). O experimento foi desenvolvido em duas etapas distintas. A primeira consistiu na produção e avaliação morfológica das mudas, visando a determinação das seguintes variáveis morfológicas: altura da parte aérea (H), diâmetro de colo (D), relação H/D e pesos de matéria fresca e seca das partes aérea, radicial e total. A segunda etapa foi desenvolvida no campo, com a finalidade de avaliar a sobrevivência das mudas nos três primeiros meses após o plantio e o seu desempenho, por meio da medição da altura e do diâmetro ao nível do solo. As mudas de madeira-nova produzidas em sacos plásticos (2090 cm3) apresentaram valores estatisticamente superiores em todas as fases de avaliação das variáveis morfológicas no viveiro e também de desempenho no campo, 24 meses após o plantio. As médias com valores mais baixos para todas as variáveis avaliadas em viveiro e campo foram observadas em mudas produzidas em tubetes de 50 cm3.

Avaliação de mutagenicidade e antimutagenicidade de diferentes frações de Pterogyne nitens (Leguminosae), utilizando ensaio de micronúcleo em Tradescantia pallida

Pterogyne nitens (Fabaceae-Caesalpinioideae) é uma árvore nativa da América do Sul, onde é empregada na medicina popular para o tratamento da ascaridíase. Recentemente, descrevemos o efeito mutagênico do extrato etanólico das folhas de P. nitens. Dessa forma, o presente estudo teve por objetivo aprofundar a avaliação do potencial mutagênico das frações isoladas das folhas de Pterogyne nitens, acetato de etila (AcOEt), n-butanólica (BuOH) e hidroalcóolica (HA). Quando o efeito mutagênico foi observado somente nas maiores concentrações testadas, o potencial antimutagênico também foi avaliado. Os ensaios mutagênicos e antimutagênicos foram realizados utilizando ensaio de micronúcleo em Trandescantia pallida. Na avaliação de mutagenicidade, observou-se o efeito nas frações AcOEt (0,460 mg/mL), BuOH (0,142, 0,285, 0,570 e 1,14 mg/mL) e HA (0,050, 0,100, 0,200 e 0,400 mg/mL). Considerando que o efeito mutagênico da fração AcOEt foi observado somente na concentração mais elevada (0,460 mg/mL), o potencial antimutagênico da mesma foi avaliado. As concentrações de 0,115 e 0,230 mg/mL da fração AcOEt demonstraram atividade antimutagênica. A partir dos resultados do presente estudo, conclui-se que determinadas frações de P. nitens apresentam mutagenicidade (BuOH e HA), enquanto a fração AcOEt apresentou efeito antimutagênico nas maiores concentrações. Esses resultados tornam o estudo da P. nitens bastante promissor, considerando que esta planta possui distribuição geográfica ampla e tem sido pouco estudada.

Cytotoxic Guanidine Alkaloids from Pterogyne nitens

As part of a bioprospecting program aimed at the discovery of potential anticancer drugs, two new guanidine-type alkaloids, nitensidines D and E (1, 2), and the known pterogynine (3), pterogynidine (4), and galegine (5), were isolated from the leaves of Pterogyne nitens. The structures of 1 and 2 were established on the basis of spectroscopic data interpretation. These compounds were tested against a small panel of human cancer cell lines. Compound 2 exhibited cytotoxicity for HL-60 (human myeloblastic leukemia) and SF-245 (human glioblastoma) cells.

Antioxidant properties of plant extracts: an EPR and DFT comparative study of the reaction with DPPH, TEMPOL and spin trap DMPO

This work presents a comparative study of the antioxidant activity of extracts from nine plant species belonging to the Brazilian flora - Swartzia langsdorffii, Machaerium villosum, Pterogyne nitens, Pera glabrata, Aegiphyla sellowiana, Copaifera langsdorffii, Chrysophyllum inornatum, Iryanthera juruensis, Didymopanax venosum - acting on the free-radicals DPPH (2,2-diphenyl-1-picrylhydrazyl) and TEMPOL (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy-1-oxyl) by electron paramagnetic resonance (EPR), and acting on the hydroxyl radical (OH•) by the spin-trapping technique generated by a Fenton reaction. Results showed that the extracts of Iryanthera juruensis and Chrysophyllum inornatum display the strongest antioxidant activities. The results of scavenging tests were clarified by computational calculations - density functional theory (DFT), local density approximation (LDA) with SIESTA code - indicating that the energy released in the reduction reaction of TEMPOL is less than DPPH. Due to its availability and cost DPPH is more often used in these tests than TEMPOL, however TEMPOL should be considered when studying processes dealing with smaller energies.

IDENTIFICATION OF TRITERPENES AND STEROLS FROM PTEROGYNE NITENS (FABACEAE-CAESALPINIOIDEAE) USING HIGH-RESOLUTION GAS CHROMATOGRAPHY

As part of our ongoing bioprospecting studies on secondary metabolites in plants of Cerrado and Atlantic Rain Forest of Sao Paulo State (Brazil), we describe the identification of triterpenes and sterols present in the hexane extracts and foliar epicuticular wax of Pterogyne nitens Tulasne (Fabaceae-Caesalpinioideae) using high resolution gas chromatography. Compounds detected in these extracts include β-amyrin (1), taraxerol acetate (2), lupenone (3), β-amyrenone (4), germanicone (5), campesterol (6), stigmasterol (7), and β-sitosterol (8). The method reported herein is shown to be a rapid, sensitive and reproducible tool for describing triterpenes and sterols present in non-polar extracts.

Free radical scavenging activity of Pterogyne nitens Tul . (Fabaceae)

As part of our ongoing research on antioxidant agents from Brazilian flora, twenty extracts and fractions obtained from Pterogyne nitens Tulasne (Fabaceae) were screened for free radical scavenging activity by using ABTS [2,2’-azinobis(3-ethylenebenzothiazoline-6-sulfonic acid)] and DPPH (2,2-diphenyl-1-picrylhydrazyl-hydrate) radicals colorimetric assay and
-carotene bleaching test. The strongest activity was found in ethyl acetate fraction from the stem barks, exhibiting IC50 values (in ig/ml) of 2.10 ± 0.1 and 10.2 ± 0.3 on ABTS•+ and DPPH•, respectively. Additionally, chromatographic fractionation of stem barks yielding myricetin, quercitrin and mirycetrin, three flavonols with remarkable antioxidant activity.

ChemInform Abstract: Flavonols from Pterogyne nitens and Their Evaluation as Myeloperoxidase Inhibitors.

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