Bioabsorbable Polymeric Stent for the Treatment of Coarctation of the Aorta (CoA) in Children: A Methodology to Evaluate the Design and Mechanical Properties of PLA Polymer.

This study presents a methodology that combines experimental tests and the finite element method, which is able to analyse the influence of the geometry on the mechanical behaviour of stents made of bioabsorbable polymer PLA (PolyLactic Acid) during their expansion in the treatment of coarctation of the aorta (CoA). Tensile tests with standardized specimen samples were conducted to determine the properties of a 3D-printed PLA. A finite element model of a new stent prototype was generated from CAD files. A rigid cylinder simulating the expansion balloon was also created to simulate the stent opening performance. A tensile test with 3D-printed customized stent specimens was performed to validate the FE stent model. Stent performance was evaluated in terms of elastic return, recoil, and stress levels. The 3D-printed PLA presented an elastic modulus of 1.5 GPa and a yield strength of 30.6 MPa, lower than non-3D-printed PLA. It can also be inferred that crimping had little effect on stent circular recoil performance, as the difference between the two scenarios was on average 1.81%. For an expansion of diameters ranging from 12 mm to 15 mm, as the maximum opening diameter increases, the recoil levels decrease, ranging from 10 to 16.75% within the reported range. These results point out the importance of testing the 3D-printed PLA under the conditions of using it to access its material properties; the results also indicate that the crimping process could be disregarded in simulations to obtain fast results with lower computational cost and that new proposed stent geometry made of PLA might be suitable for use in CoA treatments-the approach that has not been applied before. The next steps will be to simulate the opening of an aorta vessel using this geometry.

Bioabsorbable polymeric Stent for the treatment of Coarctation of the Aorta (CoA) in children: A methodology to evaluate the design and mechanical properties of PLA polymer

This study presents a methodology that combines experimental tests and the finite element method, which is able to analyse the influence of the geometry on the mechanical behaviour of stents made of bioabsorbable polymer PLA (PolyLactic Acid) during their expansion in the treatment of coarctation of the aorta (CoA). Tensile tests with standardized specimen samples were conducted to determine the properties of a 3D-printed PLA. A finite element model of a new stent prototype was generated from CAD files. A rigid cylinder simulating the expansion balloon was also created to simulate the stent opening performance. A tensile test with 3D-printed customized stent specimens was performed to validate the FE stent model. Stent performance was evaluated in terms of elastic return, recoil, and stress levels. The 3D-printed PLA presented an elastic modulus of 1.5 GPa and a yield strength of 30.6 MPa, lower than non-3D-printed PLA. It can also be inferred that crimping had little effect on stent circular recoil performance, as the difference between the two scenarios was on average 1.81%. For an expansion of diameters ranging from 12 mm to 15 mm, as the maximum opening diameter increases, the recoil levels decrease, ranging from 10 to 16.75% within the reported range. These results point out the importance of testing the 3D-printed PLA under the conditions of using it to access its material properties; the results also indicate that the crimping process could be disregarded in simulations to obtain fast results with lower computational cost and that new proposed stent geometry made of PLA might be suitable for use in CoA treatments-the approach that has not been applied before. The next steps will be to simulate the opening of an aorta vessel using this geometry.

Nitrogen balance and microbial protein synthesis in dairy cows fed with peanut meal to replace soybean meal.

This research was carried out to evaluate the effect of replacing dietary soybean meal with peanut meal, on intake and digestibility, microbial protein synthesis, and nitrogen balance in lactating cows. Twelve crossbred Holstein × Gyr cows at 84 days in milk (DIM) were distributed in a triple 4 × 4 Latin square. The treatments consisted of increasing peanut meal levels (0, 330, 670, and 1000 g/kg dry matter basis) in replacement of soybean meal in the diet. Replacing soybean meal with peanut meal had no effect on the intake and digestibility of dry matter and nutrients. Nitrogen balance and percentage of retained were similar among treatments. Microbial nitrogen synthesis and microbial protein synthesis efficiency were similar among treatments. Thus, in regions where its cost is lower, peanut meal can totally replace soybean meal in dairy cow diets without affecting nitrogen balance and microbial protein synthesis.

Bio-based Substances From Compost as Reactant and Active Phase for Selective Capture of Cationic Pollutants From Waste Water.

Alumina porous monoliths were successfully fabricated using a simple and reproducible synthesis dispersing gamma alumina phase from commercial boehmite (GAB) in water containing water-soluble bio-based substances (BBSs) obtained from composted biowaste. The wet mixture obtained was shaped in form of small spheres and then dried and calcined at 500°C in order to burn the organic matter and obtain mesoporous monoliths. They were successively functionalized with BBSs in order to introduce BBS functional groups and obtain an efficient adsorbing system. Therefore, in this work, BBSs acted as template/binder for the production of monoliths and as functionalizing agent of the produced monoliths. The reference powders, deeply studied in a published article (Sadraei et al., 2019b), and the monoliths of GAB before and after functionalization were characterized by means of x-ray diffraction to evidence their crystal structure, Fourier transform infrared spectroscopy for evaluating the presence of BBSs on the supports, thermogravimetric analysis to measure the thermal stability of the materials and quantify the functionalizing BBS amount immobilized on the supports, nitrogen adsorption at 77 K for the investigation of the surface area and porosity of the systems, and zeta potential measurements to analyze the effect of BBS immobilization on the surface charge of the supports and to predict the type of interaction, which can be established with substrates. Finally, the systems were applied in removal of pollutants with different charge, polarity, and molecular structure, such as dyes (crystal violet and acid orange 7) and contaminants of emerging concern (carbamazepine and atenolol). Only the cationic dye CV is captured by the adsorbing material, and this allows envisaging a possible use of the functionalized monoliths for selective adsorption of cationic substrates.

Toxicity and Anti-promastigote Activity of Benzoxazinoid Analogs Against Leishmania (Viannia) braziliensis and Leishmania (Leishmania) infantum.

Purpose: Here, we aim to evaluate the antileishmanial activity of compounds with a benzoxazinoid (BX) skeleton, previously synthesized by our group, against Leishmania (Viannia) braziliensis and Leishmania (Leishmania) infantum promastigotes. Methods: Anti-promastigote activity, as well as cytotoxicity, were determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assays. The selectivity index (SI) for each compound was calculated using a ratio of the cytotoxicity of compounds and the geometric mean (GM) of antileishmanial concentrations to each species tested. The comparisons between groups were carried out using a t test or analysis of variance (one-way ANOVA). A P value of less than 0.05 was considered significant. Results: All the compounds tested were active, with IC50 falling between 92±6.19 µg/mL and 238±6.57 µg/mL for L. braziliensis, and 89±6.43 µg/mL and 188±3.58 µg/mL against L. infantum. Bex2, Bex3, Pyr1, Pyr2, and Pyr4 were compounds that showed activity similar to the drug Glucantime®, exhibited low cytotoxicity against splenic hamster cells (CC50 raging between >400 and 105.7±2.26 µg/mL) and had favorable selectivity indices (SI 1.12 to 3.96). Conclusion: The analogs in question are promising prototypes for the pharmaceutical development of novel, safer and more effective leishmanicidal agents.

Drug-induced anti-inflammatory response in A549 cells, as detected by Raman spectroscopy: a comparative analysis of the actions of dexamethasone and p-coumaric acid.

Corticosteroids are widely used as effective treatments for the control of chronic inflammatory diseases. However, because their long-term administration carries serious consequences, there is a need to investigate alternative therapies to reduce or even replace their use. In this regard, phenolic compounds have been presented as an alternative for the treatment of inflammatory diseases. p-Coumaric acid, a natural phenolic compound found throughout nature, exhibits antioxidative and anti-inflammatory properties. Herein, using a combination of Raman spectroscopy with principal component analysis and hierarchical cluster analysis, the inflammatory process induced by cigarette smoke extract (CSE) in epithelial cells treated with either a corticosteroid or p-coumaric acid was monitored in vitro. Our findings showed that p-coumaric acid had a significant anti-inflammatory effect in CSE-activated epithelial cells, and thus may be a useful alternative to corticosteroids for the treatment of airway inflammation in chronic obstructive pulmonary disease. In addition, multivariate analysis of the cell spectral data indicated that the mechanisms of action of the two drugs occur through different routes.

Influence of light and plant size on the reproduction and growth of small palm tree species: Comparing two methods for measuring canopy openness.

PREMISE OF THE STUDY: The reproduction and growth of large palms are influenced by many factors, including light and plant size, but few studies have examined smaller species (up to 2 m tall). We examined the effect of incident light and individual size on growth rates, the probability of reproduction, and the number of inflorescences of three small palm species and compared two methods for estimating canopy openness. METHODS: We measured canopy openness above the crowns of 132 adult plants and in the centers of 72 subplots (10 × 10 m) where individuals were sampled. We also recorded individual size and the number of leaves and inflorescences produced in two years. KEY RESULTS: Reproductive individuals of Butia paraguayensis tend to occur in illuminated microhabitats. Reproduction of Acrocomia emensis was correlated with stem diameter, but not with light. Reproduction was inversely related to individual size and light in Syagrus petraea, probably because this clonal palm invests heavily in sexual reproduction during its younger stages and clonal activity in older stages and may be adapted to the low-light conditions of the woodland understory. Growth was not predicted by light or individual size. Stronger correlations were found when incident light was measured directly above the crown, as opposed to the subplot center. CONCLUSIONS: The influences of light on reproduction are dependent on plant life histories, even among related and sympatric species. Light measurements directly above individual crowns provide better understanding of the reproductive effort rather than in subplot center.

Lettuce irrigated with contaminated water: Photosynthetic effects, antioxidative response and bioaccumulation of microcystin congeners.

The use of microcystins (MCs) contaminated water to irrigate crop plants represents a human health risk due to their bioaccumulation potential. In addition, MCs cause oxidative stress and negatively influence photosynthetic activities in plants. The present study was aimed at investigating the effect of MCs on photosynthetic parameters and antioxidative response of lettuce. Furthermore, the bioaccumulation factor (BAF) of total MCs, MC-LR and MC-RR in the vegetable after irrigation with contaminated water was determined. Lettuce crops were irrigated for 15 days with water containing cyanobacterial crude extracts (Microcystis aeruginosa) with MC-LR (0.0, 0.5, 2.0, 5.0 and 10.0 µg L(-1)), MC-RR (0.0, 0.15, 0.5, 1.5 and 3.0 µg L(-1)) and total MCs (0.0, 0.65, 2.5, 6.5 and 13.0 µg L(-1)). Increased net photosynthetic rate, stomatal conductance, leaf tissue transpiration and intercellular CO2 concentration were recorded in lettuce exposed to different MCs concentrations. Antioxidant response showed that glutathione S-transferase activity was down-regulated in the presence of MCs. On the other hand, superoxide dismutase, catalase and peroxidase activities were upregulated with increasing MCs concentrations. The bioaccumulation factor (BAF) of total MCs and MC-LR was highest at 6.50 and 5.00 µg L(-1), respectively, while for MC-RR, the highest BAF was recorded at 1.50 µg L(-1) concentration. The amount of total MCs, MC-LR and MC-RR bioacumulated in lettuce was highest at the highest exposure concentrations. However, at the lowest exposure concentration, there were no detectable levels of MC-LR, MC-RR and total MCs in lettuce. Thus, the bioaccumulation of MCs in lettuce varies according to the exposure concentration. In addition, the extent of physiological response of lettuce to the toxins relies on exposure concentrations.

Elevation as a barrier: genetic structure for an Atlantic rain forest tree (Bathysa australis) in the Serra do Mar mountain range, SE Brazil.

Distance and discrete geographic barriers play a role in isolating populations, as seed and pollen dispersal become limited. Nearby populations without any geographic barrier between them may also suffer from ecological isolation driven by habitat heterogeneity, which may promote divergence by local adaptation and drift. Likewise, elevation gradients may influence the genetic structure and diversity of populations, particularly those marginally distributed. Bathysa australis (Rubiaceae) is a widespread tree along the elevation gradient of the Serra do Mar, SE Brazil. This self-compatible species is pollinated by bees and wasps and has autochoric seeds, suggesting restricted gene dispersal. We investigated the distribution of genetic diversity in six B. australis populations at two extreme sites along an elevation gradient: a lowland site (80-216 m) and an upland site (1010-1100 m.a.s.l.). Nine microsatellite loci were used to test for genetic structure and to verify differences in genetic diversity between sites. We found a marked genetic structure on a scale as small as 6 km (F ST = 0.21), and two distinct clusters were identified, each corresponding to a site. Although B. australis is continuously distributed along the elevation gradient, we have not observed a gene flow between the extreme populations. This might be related to B. australis biological features and creates a potential scenario for adaptation to the different conditions imposed by the elevation gradient. We failed to find an isolation-by-distance pattern; although on the fine scale, all populations showed spatial autocorrelation until ∼10-20 m. Elevation difference was a relevant factor though, but we need further sampling effort to check its correlation with genetic distance. The lowland populations had a higher allelic richness and showed higher rare allele counts than the upland ones. The upland site may be more selective, eliminating rare alleles, as we did not find any evidence for bottleneck.

Variation in the population structure between a natural and a human-modified forest for a pioneer tropical tree species not restricted to large gaps.

The distribution of tree species in tropical forests is generally related to the occurrence of disturbances and shifts in the local environmental conditions such as light, temperature, and biotic factors. Thus, the distribution of pioneer tree species is expected to vary according to the gap characteristics and with human disturbances. We asked whether there was variation in the distribution of a pioneer species under different environmental conditions generated by natural disturbances, and between two forests with contrasting levels of human disturbance. To answer this question, we studied the distribution patterns and population persistence of the pioneer tree species Croton floribundus in the size and age gap range of a primary Brazilian forest. Additionally, we compared the plant density of two size-classes between a primary and an early successional human-disturbed forest. Croton floribundus was found to be widespread and equally distributed along the gap-size gradient in the primary forest. Overall density did not vary with gap size or age (F-ratio = 0.062, P = 0.941), and while juveniles were found to have a higher density in the early successional forest (P = 0.021), tree density was found to be similar between forests (P = 0.058). Our results indicate that the population structure of a pioneer tree species with long life span and a broad gap-size niche preference varied between natural and human-disturbed forests, but not with the level of natural disturbance. We believe this can be explained by the extreme environmental changes that occur after human disturbance. The ecological processes that affect the distribution of pioneer species in natural and human-modified forests may be similar, but our results suggest they act differently under the contrasting environmental conditions generated by natural and human disturbances.

Impact of forest fragment size on the population structure of three palm species (Arecaceae) in the Brazilian Atlantic rainforest.

The main threats to natural populations in terrestrial ecosystems have been widly recognized to be the habitat fragmentation and the exploitation of forest products. In this study, we compared the density of the populations and the structure of three tropical palm species, Astrocaryum aculeatissimum, Euterpe edulis and Geonoma schottiana. For this, we selected five forest fragments of different sizes (3 500ha, 2 400ha, 57ha, 21ha and 19ha) where palms were censused in nine 30 x 30m plots. We tracked the palms survival from 2005 to 2007, and recorded all new individuals encountered. Each individual was assigned in one of the five ontogenetic stages: seedling, infant, juvenile, immature and reproductive. The demographic structure of each palm species was analyzed and compared by a generalized linear model (GLM). The analysis was performed per palm species. The forest fragment area and the year of observation were explanatory variables, and the proportion of individuals in each ontogenetic class and palm density were response variables. The total number of individuals (from seedlings to reproductives, of all species) monitored was 6 450 in 2005, 7 268 in 2006, and 8 664 in 2007. The densities of two palm species were not influenced by the size of the fragment, but the population density of A. aculeatissimum was dependent on the size of the fragment: there were more individuals in the bigger than in the smaller forest fragments. The population structure of A. aculeatissimum, E. edulis, and G. schottiana was not altered in the smaller fragments, except the infants of G. schottiana. The main point to be drawn from the results found in this study is that the responses of density and population structure seem not to be dependent on fragment size, except for one species that resulted more abundant in bigger fragments.

Impact of forest fragment size on the population structure of three palm species (Arecaceae) in the Brazilian Atlantic Rainforest / Impacto del tamaño del fragmento de bosque en la estructura de la población de tres especies de palmas del Bosque Atlántico Brasileño

The main threats to natural populations in terrestrial ecosystems have been widly recognized to be the habitat fragmentation and the exploitation of forest products. In this study, we compared the density of the populations and the structure of three tropical palm species, Astrocaryum aculeatissimum, Euterpe edulis and Geonoma schottiana. For this, we selected five forest fragments of different sizes (3 500ha, 2 400ha, 57ha, 21ha and 19ha) where palms were censused in nine 30x30m plots. We tracked the palms survival from 2005 to 2007, and recorded all new individuals encountered. Each individual was assigned in one of the five ontogenetic stages: seedling, infant, juvenile, immature and reproductive. The demographic structure of each palm species was analyzed and compared by a generalized linear model (GLM). The analysis was performed per palm spe-cies. The forest fragment area and the year of observation were explanatory variables, and the proportion of individuals in each ontogenetic class and palm density were response variables. The total number of individuals (from seedlings to reproductives, of all species) monitored was 6 450 in 2005, 7 268 in 2006, and 8 664 in 2007. The densities of two palm species were not influenced by the size of the fragment, but the population density of A. aculeatissimum was dependent on the size of the fragment: there were more individuals in the bigger than in the smaller forest fragments. The population structure of A. aculeatissimum, E. edulis, and G. schottiana was not altered in the smaller fragments, except the infants of G. schottiana. The main point to be drawn from the results found in this study is that the responses of density and population structure seem not to be dependent on fragment size, except for one species that resulted more abundant in bigger fragments.

Uno de los principales riesgos que corren las poblaciones naturales de los ecosistemas terrestres es la fragmentación de hábitat y la explotación de los recursos forestales. Aquí hemos comparado la densidad de las poblaciones y el estado estructural de tres especies de palmeras, Astrocaryum aculeatissimum (Schott) Burret, Euterpe edulis Mart. y Geonoma schottiana Mart., en fragmentos de diferente tamaño. Las palmas fueron censadas en nueve cuadrantes de 30x30m en cinco fragmentos de bosque de diferente tamaño (3 500ha, 2 400ha, 57ha, 21ha y 19ha). Realizamos el seguimiento de la sobrevivencia de las palmas entre 2005-2007, y registramos todos los nuevos individuos encontrados. Cada individuo fue designado dentro de alguno de los siguientes cinco estadíos ontogenéticos: plántula, infantil, juvenil, inmaduro y reproductivo. La comparación de la estructura demográfica fue analizada usando Modelos Lineares Generalizados (GLM). Estos fueron utilizados para cada especie por separado, con el área del fragmento de bosque y el año como variables explicativas, así como proporción de individuos en cada estadío ontogenético y densidad de las palmeras como variables de respuesta. El número total de individuos monitoreado (desde semillas hasta adultos reproductivos, para todas las especies) fue 6 450 en 2005, 7 268 en 2006 y 8 664 en 2007. La densidad de población para dos especies de palmas no fue influenciada por el tamaño del fragmento, excepto para Astrocaryum aculeatissimum, cuya densidad dependió del tamaño del fragmento. Hubo más individuos en los fragmentos mayores que en los fragmentos menores. La estructura de la población de A. aculeatissimum, E. edulis y G. schottiana no se vio alterada en los fragmentos pequeños, excepto para G. schottiana en estado infante. El punto principal que se desprende de los resultados encontrados en este estudio es que la respuesta de la densidad y estructura de la población parece no ser dependiente del tamaño de fragmento, excepto para una especie que es más abundante en los fragmentos mayores.

The effect of management systems and ecosystem types on bark regeneration in Himatanthus drasticus (Apocynaceae): recommendations for sustainable harvesting.

Bark and exudates are widely commercialized non-timber forest products. However, the ecological impacts of the harvesting of these products have seldom been studied. The aim of this study is to investigate the relationship of tree resilience to harvesting intensity in Himatanthus drasticus, a tree that is highly exploited in the Brazilian savanna (Cerrado) for its medicinal latex. Although the traded product is the latex, the traditional harvesting systems involve the removal of the bark of the trees to allow exploitation. A 3-year experiment was conducted in two different Cerrado ecosystems (open savanna and savanna woodland). Trees were debarked at four debarking intensities to simulate the effects of traditional management systems. Measurements of bark growth were taken every 6 months, and quantitative and qualitative indexes of bark regeneration were obtained. The mortality of the debarked trees was low and could not be related to the intensity of harvesting. No signs of attack by fungi or insects were recorded. Compared with other species exploited for bark, H. drasticus is very resilient to harvesting; however, bark regeneration is relatively slow. In both analyzed ecosystems, the regeneration indexes showed higher values in the controls than in the treatments, indicating that 3 years is not sufficient for total recovery of the rhytidome. Bark regeneration occurred primarily by sheet growth and was more rapid in open savanna than in savanna woodland. No differences in the rate of bark recovery were found among management treatments. Based on the results, sustainable harvesting guidelines are suggested for the species.

Characterization of 10 microsatellite loci for Bathysa australis (Rubiaceae).

PREMISE OF THE STUDY: Bathysa australis is a common subcanopy tree from the Atlantic Forest that is pollinated by bees and wasps and produces autochoric seeds. This species exhibits great phenotypic plasticity along the elevational gradient of Serra do Mar in southeastern Brazil. We expect to assess the genetic diversity and gene flow between populations of this species along the elevational gradient. • METHODS AND RESULTS: We developed a microsatellite-enriched genomic library for B. australis, and 10 microsatellite loci were successfully amplified, ranging from one to 13 alleles per locus. The observed and expected heterozygosities ranged from 0.333 to 0.900 (average: 0.629) and 0.564 to 0.900 (average: 0.742), respectively. • CONCLUSIONS: These are the first microsatellite markers developed for the genus Bathysa and may be useful in other species of the Condamineeae tribe. These primers will be an important tool for studies of population ecology and conservation genetics.

Cytogenetics and characterization of microsatellite loci for a South American pioneer tree species, Croton floribundus.

Despite the recent advances in plant population genetic studies, the lack of information regarding pedigree, ploidy level, or mode of inheritance for many polyploids can compromise the analysis of the molecular data produced. The aim of this study was to examine both microsatellite and cytogenetic characteristics of the pioneer tree Croton floribundus Spreng. (Euphorbiaceae) to test for the occurrence of polyploidy in the species and to evaluate its implications for the appropriate use of SSR markers. Seven microsatellite markers were developed and screened for 62 individuals from a semi-deciduous tropical forest in Brazil. Chromosome number, meiotic behavior, and pollen viability were evaluated from male flower buds. All SSR loci were highly polymorphic. The number of bivalents observed in meiosis n = 56 (2n = 8× = 112) and the maximum number of alleles per individual (Ni = 8) demonstrated the occurrence of polyploidy in C. floribundus. The normal meiotic pairing and the high pollen viability suggested that C. floribundus is a regular and stable polyploid, most likely an allopolyploid. The combined SSR and cytogenetic data provided new evidence on the origin and evolution of the species as well as assured the accurate use of SSR loci for population genetic studies of the polyploid pioneer species.

Characterization of microsatellite loci in Himatanthus drasticus (Apocynaceae), a medicinal plant from the Brazilian savanna.

PREMISE OF THE STUDY: We developed a new set of microsatellite markers for studying the genome of the janaguba tree, Himatanthus drasticus (Mart.) Plumel, which is used in folk medicine in northeastern Brazil. These novel markers are being used to evaluate the effect of harvesting on the genetic structure and diversity of natural populations of this species. • METHODS AND RESULTS: Microsatellite loci were isolated from an enriched H. drasticus genomic library. Nine primer pairs successfully amplified polymorphic microsatellite regions, with an average of 8.5 alleles per locus. The average values of observed and expected heterozygosity were 0.456 and 0.601, respectively. • CONCLUSIONS: The microsatellite markers described here are valuable tools for population genetics studies of H. drasticus. The majority of the primers also amplified sequences in the genome of another species of the same genus. This new set of markers may be useful in designing a genetic conservation strategy and a sustainable management plan for the species.

Effect of 6 alpha,7 beta-dihydroxyvouacapan-17 beta-oic acid and its lactone derivatives on the growth of human cancer cells.

The furanditerpene 6 alpha,7 beta-dihydroxyvouacapan-17 beta-oic acid (1) is a natural product biosynthesized by some species from the genus Pterodon (Leguminosae). This secondary metabolite has multiple biological activities that include anti-inflammatory, analgesic, plant growth regulatory, anti-edematogenic, photosystem II inhibitory and photosynthesis uncoupler, and antifungal properties. However, few studies on the antiproliferative profile of compound 1 and/or its derivatives have been reported up to date. Here, we describe the isolation of compound 1 from hexane extract of P. polygalaeflorus fruits as well as the semisynthesis of three lactone derivatives: 6 alpha-hydroxyvouacapan-7 beta,17 beta-lactone (2), 6 alpha-acetoxyvouacapan-7 beta,17 beta-lactone (3), and 6-oxovouacapan-7 beta,17 beta-lactone (4). Additionally, antiproliferative activity of these compounds against nine human cancer cell lines was investigated. Our results revealed that 6 alpha-hydroxyvouacapan-7 beta,17 beta-lactone (2) was the most potent furanditerpene against all cancer cell lines studied. The presence of non-substituted hydroxyl group at C-6 and the presence of 7 beta,17 beta-lactone ring are important for the antiproliferative activity of these compounds.

Inhibition and uncoupling of photosynthetic electron transport by diterpene lactone amide derivatives.

Nine diterpene lactone amide derivatives 1-9 were synthesized from 6-oxovouacapan-7beta,17beta-lactone, which was obtained from 6alpha,7beta-dihydroxyvouacapan-17beta-oic acid isolated from Pterodon polygalaeflorus Benth., and tested for their activity on photosynthetic electron transport. Amide derivatives 3-5 behaved as electron transport chain inhibitors; they inhibited the photophosphorylation and uncoupled non-cyclic electron transport from water to methylviologen (MV). Furthermore, 4 and 5 enhanced the basal electron rate acting as uncouplers. Compound 6 behaved as an uncoupler; it enhanced the light-activated Mg2+-ATPase and basal electron flow, without affecting the uncoupled non-cyclic electron transport. Compounds 1-2 and 7-9 were less active or inactive. Compounds 3-5 did not affect photosystem I (PSI); they inhibited photosystem II (PSII) from water to 2,6-dichlorophenol indophenol (DCPIP). Compound 4 inhibited PSII from water to silicomolybdate (SiMo), but it had no effect on the reaction from diphenylcarbazide (DPC) to DCPIP indicating that its inhibition site was at the water splitting enzyme complex (OEC). Compounds 3 and 5 inhibited PSII from water to DCPIP without any effect from water to SiMo, therefore they inhibited the acceptor site of PSII. Chlorophyll a fluorescence kinetics confirmed the behaviour of 3-5.

A diterpene gamma-lactone derivative from Pterodon polygalaeflorus Benth. as a photosystem II inhibitor and uncoupler of photosynthesis.

6alpha,7beta-Dihydroxyvouacapan-17beta-oic acid (1) was isolated from Pterodon polygalaeflorus Benth. Modification of 1 yielded 6alpha-hydroxyvouacapan-7beta,17beta-lactone (2) and then 6-oxovouacapan-7beta,17beta-lactone (3). Photosynthesis inhibition by 3 was evaluated in spinach chloroplasts. The uncoupled non-cyclic electron transport rate and ATP synthesis were inhibited by 3, which behaved as a Hill reaction inhibitor. Furthermore, 3 acted as an uncoupler because it enhanced the basal and phosphorylating electron transport rate on thylakoids. This last property of 3 was corroborated when it was observed that it enhances the Mg2+-ATPase activity. In contrast, 3 did not affect photosystem I (PSI) activity. Analysis of the partial photosystem II (PSII) reactions from water to DCPIPOX and water to silicomolybdate allowed to locate the inhibition sites at the redox components of PSII. The OJIP test of the chlorophyll a fluorescence transient confirmed that the inhibition sites were 1.) the oxygen-evolving complex (OEC) and 2.) by the formation of silent centers in the non-QA reducing centers.

Leaf herbivory in Chrysophyllum gonocarpum (Sapotaceae) in the State Park Mata dos Godoy in Londrina, state of Paraná, Brazil - DOI: 10.4025/actascibiolsci.v27i3.1316 / Herbivoria foliar em Chrysophyllum gonocarpum (Sapotaceae) no Parque Estadual Mata dos Godoy, Londrina, Estado do Paraná, Brasil - DOI: 10.4025/actascibiolsci.v27i3.1316

The levels of leaf herbivory were studied in individuals of Chrysophyllum gonocarpum (Mart & Eichler) Engl. in sporadically flooded areas and unflood areas of the State Park Mata dos Godoy (23o27S, 51o15W ). The aim was to determine if herbivory affected the regeneration of this species. A relevant similarity was found in the average levels of herbivory among the sample sites and time. Only a small fraction of the sampled leaves presented considerable damage levels (removal of more than a third of the leaf area) and few individuals were intensely affected by herbivory. The herbivory did not influence the probability of death of the individuals nor affected their growth in high rates. Herbivory did not seem to be a limiting factor for Chrysophyllum gonocarpum regeneration in the State Park of Mata dos Godoy

Investigaram-se os níveis de herbivoria foliar em indivíduos de Chrysophyllum gonocarpum (Mart & Eichler) Engl. em sítios esporadicamente inundáveis e não inundáveis do Parque Estadual Mata dos Godoy (2327S, 5115W), visando a determinar se a herbivoria afetava a regeneração desta espécie. Observou-se marcante similaridade nos níveis médios de herbivoria entre os sítios amostrais e no tempo. Somente uma pequena fração de folhas amostradas apresentou níveis consideráveis de danos (remoção de mais de 1/3 do limbo) e poucos indivíduos foram intensamente herbivorados. A herbivoria não influenciou a probabilidade de morte dos indivíduos e não afetou suas taxas de crescimento em altura. Conclui-se que a herbivoria não foi um fator limitante para a regeneração de C. gonocarpum no Parque Estadual Mata dos Godoy