Estudo morfológico comparativo das cascas e folhas de Stryphnodendron adstringens, S. polyphyllum e S. obovatum - Leguminosae

The genus Stryphnodendron (S.) belongs to the family Leguminosae, subfamily Mimosoideae, which includes mostly trees of tropical and subtropical South America. Extracts of the stem bark are used traditionally by the local population to treat leucorrhoea and diarrhoea, as anti-inflammatory and antiseptic agents (antimicrobial) and to promote blood clotting and wound healing, and in a few cases of gastric ulcers. A review of the literature presented a previous morpho-anatomical study only for S. adstringens (Mart.) Coville. The aim of the present work is to compare morpho-anatomically the stem bark and leaves of three species of Stryphnodendron, known popularly as barbatimão: S. adstringens, S. polyphyllum and S. obovatum, in order to help botanical identification and contribute to quality control. Macro- and microscopical evaluation of the stem barks revealed no significant differences among the species. Morphological analyses of the leaves revealed differences in size, coloration, and pubescence. The leaves of S. adstringens are the largest, glabrous, and concolor. The leaves of S. polyphyllum are smaller, pubescent, and discolor; whereas the leaves of S. obovatum are the same size as those of S. polyphyllum, however, they are glabrous, and discolor.

Few substitutions affect the bioluminescence spectra of Phrixotrix (Coleoptera: Phengodidae) luciferases: a site-directed mutagenesis survey

Phrixotrix (railroad worm) luciferases produce bioluminescence in the green and red regions of the spectrum, depending on the location of the lanterns, and are the only luciferases naturally producing red bioluminescence. Comparison of the luciferase sequences showed a set of substitutions that could be involved in bioluminescence colour determination: (a) unique substitutions in the red luciferase replacing otherwise invariant residues; (b) conserved basic residues in the green-yellow emitting luciferases; and (c) an additional R353 residue in red-emitting luciferase (Viviani et al., 1999). To investigate whether these sites have a functional role in bioluminescence colour determination, we performed a site-directed mutagenesis. Natural substitutions in the region 220-344 and residues in the putative luciferin-binding site were also investigated. With the exception of the previously identified substitution of R215 and T226 (Viviani et al., 2002), which display dramatic red-shift effects on the spectrum of green-yellow-emitting luciferases, only a few substitutions had a moderate effect on the spectrum of the green-emitting luciferase. In contrast, no single substitution affected the spectrum of the red-emitting luciferase. The results suggest that the identity of the active site residues is not so critical for determining red bioluminescence in PxRE luciferase. Rather, the conformation assumed during the emitting step could be critical to set up proper interactions with excited oxyluciferin. Copyright ©2007 John Wiley & Sons, Ltd.

Profile of Maytenus aquifolium action over free radicals and reactive oxygen species

Reactive oxygen species (ROS) and free radical species have been implicated in initiating, accompanying or causing many diseases in living organisms; there is thus, a continual need for antioxidants molecules to inactivate ROS/free radicals. Many studies of plants crude extracts have demonstrated free-radical scavenging and antioxidant action. Maytenus species have long been used, in several countries, as traditional medicines against gastric ulcers, dyspepsia and others gastric problems and for their anti-inflammatory properties. In this study, Maytenus aquifolium (Celastraceae) root bark ethanol extract was assessed for its ability to scavenge free radicals and reactive oxygen species. The results were expressed as percentage inhibition of the active species. The extract was efficient against studied reactive species: DPPH radical (obtained inhibition = 35.5 ± 1.3 %), ABTS.+ (IC50 = 0.0036 ± 0.0003 mg/mL), HOCl (IC50 = 0.002 ± 0.0001 mg/mL), O2 .- (obtained inhibition = 36.0 ± 2.1 %), and NO. (obtained inhibition = 18.3 ± 0.4 %). Uniterms Oxidant species Free radicals Maytenus aquifolium Oxidative damage.

Antimycobacterial activity of some Brazilian indigenous medicinal drinks

Tuberculosis (TB) is a very serious problem worldwide and the increasing number of multiple drugs resistant TB cases makes the search for new anti-TB drugs an urgent need. Indigenous knowledge about the use of native plants to treat illnesses has contributed to the discovery of new medicines. In this study, the antimycobacterial activity of seven medicinal drinks was assessed: Ananas sativus (hydroalcoholic fruit extract), Aristolochia triangularis (aqueous and hydroalcoholic leaf, root and stem extracts), Bromelia antiacantha (hydroalcoholic fruit extract), Stryphnodendron adstringens (hydroalcoholic bark extract), Tabebuia ovellanedae (hydroalcoholic bark extract), Vernonia polyanthes (hydroalcoholic root extract), all used by the Vanuíre indigenous community in the treatment of respiratory diseases. The activity was evaluated by using a time-to-kill assay, in which Mycobacterium tuberculosis H37Rv was cultured on Löwenstein-Jensen medium, after thirty minutes, one, three, six, twelve and twenty-four hours contact of the bacteria with each drink. Within half to one hour contact, the hydroalcoholic drinks of A. triangularis, S. adstringens, T. ovellanedae and V. polyanthes reduced the bacterial growth by 2 orders of magnitude in CFU/mL, and all bacterial growth was absent after three hours contact. In contrast, no mycobactericidal effect was detected in the aqueous extract of A. triangularis or in the hydroalcoholic beverages of A. sativus and B. antiacantha, even after twenty-four hours contact.

Bioprospecção de atividade antioxidante e antimicrobiana da casca de Stryphnodendron adstringens (Mart.) Coville (Leguminosae-Mimosoidae)

The aim of this work was to evaluate the class of secondary metabolites responsible for the antioxidant and antimicrobial activities of bark extracts of Stryphnodendron adstringens (Mart.) Coville (Leguminosae-Mimosoidae), a plant widely used in folk medicine in Brazil. Extracts of the bark were prepared with 50% ethanol, 70% ethanol, acetone:water (7:3, v/v) and chloroform. Antioxidant activity was prospected by spraying thin-layer chromatographs of the extracts with 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and measuring the DPPH radical scavenging capacity by spectrophotometry. Antibacterial activity was revealed by the agar diffusion method and bioautography. TLC spots assigned to tannins in the polar extracts showed antioxidant activity by DPPH radical scavenging and the chloroform extract showed the least scavenging activity. Antimicrobial activity was indicated by the bacterial growth inhibition haloes around polar extracts and bioautography showed activity in the TLC spots assigned to tannins. It was concluded that polar extracts of the bark of S. adstringens possessed antioxidant and antimicrobial activities which were due to secondary metabolite derived from the tannin class, which are the main constituent of these bark extracts, according to the literature.

Mitochondrial genome sequence of the Brazilian luminescent click beetle Pyrophorus divergens (Coleoptera: Elateridae): Mitochondrial genes utility to investigate the evolutionary history of Coleoptera and its bioluminescence

The Coleoptera order is the richest group among Metazoa, but its phylogenetics remains incompletely understood. Among Coleoptera, bioluminescence is found within the Elateroidea, but the evolution of this character remains a mystery. Mitochondrial DNA has been used extensively to reconstruct phylogenetic relationships, however, the evolution of a single gene does not always correspond to the species evolutionary history and the molecular marker choice is a key step in this type of analysis. To create a solid basis to better understand the evolutionary history of Coleoptera and its bioluminescence, we sequenced and comparatively analyzed the mitochondrial genome of the Brazilian luminescent click beetle Pyrophorus divergens (Coleoptera: Elateridae). © 2007 Elsevier B.V. All rights reserved.

The influence of the loop between residues 223-235 in beetle luciferase bioluminescence spectra: A solvent gate for the active site of pH-sensitive luciferases

Beetle luciferases emit a wide range of bioluminescence colors, ranging from green to red. Firefly luciferases can shift the spectrum to red in response to pH and temperature changes, whereas click beetle and railroadworm luciferases do not. Despite many studies on firefly luciferases, the origin of pH-sensitivity is far from being understood. Through comparative site-directed mutagenesis and modeling studies, using the pH-sensitive luciferases (Macrolampis and Cratomorphus distinctus fireflies) and the pH-insensitive luciferases (Pyrearinus termitilluminans, Phrixotrix viviani and Phrixotrix hirtus) cloned by our group, here we show that substitutions dramatically affecting bioluminescence colors in both groups of luciferases are clustered in the loop between residues 223-235 (Photinus pyralis sequence). The substitutions at positions 227, 228 and 229 (P. pyralis sequence) cause dramatic redshift and temporal shift in both groups of luciferases, indicating their involvement in labile interactions. Modeling studies showed that the residues Y227 and N229 are buried in the protein core, fixing the loop to other structural elements participating at the bottom of the luciferin binding site. Changes in pH and temperature (in firefly luciferases), as well as point mutations in this loop, may disrupt the interactions of these structural elements exposing the active site and modulating bioluminescence colors. © 2007 The Authors.

The structural origin and biological function of pH-sensitivity in firefly luciferases

Firefly luciferases are called pH-sensitive because their bioluminescence spectra display a typical red-shift at acidic pH, higher temperatures, and in the presence of heavy metal cations, whereas other beetle luciferases (click beetles and railroadworms) do not, and for this reason they are called pH-insensitive. Despite many studies on firefly luciferases, the origin of pH-sensitivity is far from being understood. This subject is revised in view of recent results. Some substitutions of amino-acid residues influencing pH-sensitivity in firefly luciferases have been identified. Sequence comparison, site-directed mutagenesis and modeling studies have shown a set of residues differing between pH-sensitive and pH-insensitive luciferases which affect bioluminescence colors. Some substitutions dramatically affecting bioluminescence colors in both groups of luciferases are clustered in the loop between residues 223-235 (Photinus pyralis sequence). A network of hydrogen bonds and salt bridges involving the residues N229-S284-E311-R337 was found to be important for affecting bioluminescence colors. It is suggested that these structural elements may affect the benzothiazolyl side of the luciferin-binding site affecting bioluminescence colors. Experimental evidence suggest that the residual red light emission in pH-sensitive luciferases could be a vestige that may have biological importance in some firefly species. Furthermore, the potential utility of pH-sensitivity for intracellular biosensing applications is considered. © The Royal Society of Chemistry and Owner Societies.

Clonagem do abacateiro variedade Duke 7 (Persea americana Mill.) por alporquia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Verificação da atividade antibacteriana de sabonete líquido contendo extrato glicólico de Dimorphandra mollis Benth.

Dimorphandra mollis Benth., Compositae, false barbatimão, has been used topically as a healing, astringent and antibacterial. In this study, antibacterial activity was verified on liquid soap containing glycolic extract of D. mollis (DGE) at different concentrations (8, 15 and 20%) and at different pH levels (6 and 8). Five soap formulations (F) were prepared: F1 - tryclosan (0.1%), F2 - DGE (8%), F3 - DGE (15%), F4 - DGE (20%) and F5 - without preservatives. Bark of D. mollis were dried in a circulating air oven and ground. The rude extracts were prepared by turbo extraction with ethanol. After screening, the extract were concentrated in rotating evaporator, lyophilized and resuspended in propileneglycol to obtain the glycolic extract. The antimicrobial activity was verified by diffusion in agar method, using cylinder in plate. Plates containing Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli were incubated at 37°C for 24 hours. After incubation, the results were analysed with a pachymeter, observing the bacterial grouth inhibition halo diameter. It was verified that the liquid soap containing tryclosan caused on inhibition of bacterial growth at both pH levels; the soaps without preservatives and containing DGE, independently of the concentration and pH levels used, did not present antibacterial activity.

Pyrearinus termitilluminans larval click beetle luciferase: Active site properties, structure and function relationships and comparison with other beetle luciferases

Several beetle luciferases have been cloned and sequenced. However, most studies on structure and function relationships and bioanalytical applications were done with firefly luciferases, which are pH sensitive. Several years ago we cloned Pyrearinus termitilluminans larval click beetle luciferase, which displays the most blue-shifted bioluminescence among beetle luciferases and is pH insensitive. This enzyme was expressed in E. coli, purified, and its properties investigated. This luciferase shows slower luminescence kinetics, KM values comparable to other beetle luciferases and high catalytic constant. Fluorescence studies with 8-anilino-1-naphtalene-sulfonic acid (1,8-ANS) and modeling studies suggest that the luciferin binding site of this luciferase is very hydrophobic, supporting the solvent and orientation polarizability effects as determining mechanisms for bioluminescence colors. Although pH insensitive in the range between pH 6-8, at pH 10 this luciferase displays a remarkable red-shift and broadening of the bioluminescence spectrum. Modeling studies suggest that the residue C312 may play an important role in bioluminescence color modulation. Compared to other beetle luciferases, Pyrearinus termitilluminans luciferase also displays higher thermostability and sustained luminescence in a bacterial cell environment, which makes this luciferase particularly suitable for in vivo cell analysis and bioimaging. © The Royal Society of Chemistry and Owner Societies 2009.

Controle de Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) em instalações para frangos de corte

Searching for a new alternative to A. diaperinus control, it was evaluated the action of Spinosad in two concentrations (250ppm, 400ppm) and two doses (0.05 L/m 2 and 0.1 L/m 2), applied in poultry broiler facilities naturally infested by this coleoptera. Assessments of the infestation were held in weekly intervals, during 49 days after treatment, using traps. The percentage of effectiveness were calculated from the results of the number of adults and/or larval stages in control and treated groups. Spinosad at the concentration of 250ppm, applied at a dose of 0.1L/m2, can be considered ineffective against these beetles, however the application of 400ppm at a dose of 0.1L/m2 showed high efficacy and short residual period. The dose of 0.1L/m 22 of Spinosad at the concentration of 400ppm demonstrated, between treatments, better effectiveness against coleopters, reaching efficacy of 100% against larvae of A. diaperinus, observed after the seventh day post-treatment.

Estimativas de parâmetros genéticos para caracteres quantitativos em progênies de polinização aberta de Eucalyptus urophylla

Eucalyptus urophylla S. T. Blake is outstanding for valuable wood production potential, adaptation plasticity for different environmental conditions, and for tolerance to canker. However, genetic improvement of this specie in Brazil depends on the existence of genetic variability in the introduced populations. The objective of this study was to investigate the genetic variation and gains in quantitative traits in a population established in 1992 in Selvíria - MS. The progeny trial was established in a partially balanced, 8 x 8 lattice design, with 64 families, collected at Anhembi Experimental Station (IPEF/ESALQ/USP). Each plot was made up of eight trees planted in a 3 × 3 m spacing. Significant among families genetic variations were observed in diameter at breast height (DBH), bark type, stem form, and survival. Estimates of average family heritability were high for all traits, ranging from 0.50 to 0.85. The simulated selection by using multi-effect index showed that under a varying number of plants per family. This method is the most indicated to maximize genetic gains (7.24%) and the effective population size (69.3). These results are a useful support for the transformation of this test into a seedling seed orchard and to become a source of vegetative material to build a clonal seed orchard.

Classificação Estrutural e Qualidade da Madeira do Clone GT 1 de Hevea brasiliensis Muell. Arg

Latex is the main product extracted from rubber trees (Hevea brasiliensis). In Brazil, at the end of the production cycle of latex, the wood of rubber tree is traditionally used for energy purposes, but several international studies have reported consolidated practices of adding value to it. The objective of this paper was to evaluate the quality of wood and classify it structurally based on its mechanical properties. Six 20-year-old trees of the clone GT 1 of rubber tree proceeding from Itajobi, State of Sao Paulo, Brazil were sampled. Reduced dimensions specimens in the radial direction of the wood were produced to evaluate the quality by compression parallel to the grain, static bending and Janka hardness tests. Two specimens, one from the lower log (since the ground up to breast height) and one from the higher log (from breast height up to 2.50 m) were produced for structural classification of the wood based on the characteristic strength in compression parallel to the grain (NBR 7190 norm, 1997). The wood was classified as C40 (fc0k ≥ 40 MPa) class. Results revealed that the strength was not statistically different in the radial direction (except for the Janka hardness), though tending to increase from pith to bark.

Predatory behavior of Canthon virens (Coleoptera: Scarabaeidae): A predator of leafcutter ants

We present a detailed description of the predatory behavior of the beetle Canthon virens Mannerheim, 1829, on the leafcutter ant Atta sp. We observed 51 acts of predation, which were also recorded on film and subjected to behavioral analysis. Canthon virens exhibited 28 behaviors while predating upon Atta sp. queens. Adult beetles search for queens while flying in a zigzag pattern, 15 to 20cm above the ground. After catching a queen, the predator stands on its back and starts cutting the queen cervix. Once the prey is decapitated, the predator rolls it until an insurmountable obstacle is reached. The distance from the site of predation to the obstacle can vary widely and is unpredictable. The beetle rolling the queen also buries it in a very peculiar way: first, it digs a small hole and pulls the queen inside, while another beetle is attached to the prey. The burial process takes many hours (up to 12) and may depend on the hardness of the soil and the presence of obstacles. In general, one or two beetles are found in a chamber with the queen after it is buried. They make the brood balls, which serve as food for the offspring. This study contributes to the knowledge of the predatory behavior of Canthon virens, a predator poorly studied in Brazil and widespread in the country. Copyright © 2012 Luiz Carlos Forti et al.