Edson Paula Nunes

Purification and characterization of a lectin from seeds of Vatairea macrocarpa Duke.

A lectin from Vatairea macrocarpa Duke seeds (VML) was isolated using affinity chromatography on a guar gum column. The lectin, a glycoprotein without erythrocyte specificity, displays specificity to galactose and some derivatives. On SDS-polyacrylamide gels, V. macrocarpa seed lectin is composed of two major high-Mr bands of 34 and 32 kDa and two minor low-Mr bands of 22 and 13 kDa. N-Terminal sequencing showed that the 34, 32, and 13 kDa products possess identical N-terminal sequence, which display best similarity with the N-terminal portion of Robinia pseudoacacia lectins (RPL). On the other hand, the N-terminal sequence of the 22 kDa band can be aligned with an internal sequence of RPL starting at residue 149 of the cDNA-derived sequence. These data indicate that, like other leguminous lectins, VML is made up of a mixture of one-chain 30-35 kDa glycoforms and of 22 and 13 kDa endogenous C- and N-terminal fragments. Size-exclusion chromatography indicated that, at neutral pH, VML is predominantly a dimeric (70 kDa) protein, although tetramers (115 kDa) and larger aggregates (300 kDa) were also present.

Purification and physicochemical characterization of a cotyledonary lectin from Luetzelburgia auriculata.

A lectin was purified from the cotyledons of Luetzelburgia auriculata (Fr. All) Ducke by affinity chromatography on agarose-N-acetyl-D-galactosamine. The lectin is a potent agglutinin for rabbit erythrocytes, reacts with human red cells, but is inactive against cow, sheep, and goat erythrocytes. Hemagglutination of rabbit erythrocytes was inhibited by either 0.39 mM N-acetyl-neuraminic acid or N-acetyl-D-galactosamin, 12.5 mM D-lactose or D-melibiose, 50 mM D-galactose or raffinose. Its hemagglutinating activity was lost at 80 degrees C, 5 min, and the activation energy required for denaturation was 104.75 kJ mol(-1). Chromatography on Sephadex G-100, at pH 7.6, showed that at this hydrogenic ionic concentration the native lectin was a homotetramer (123.5 kDa). By denaturing SDS-PAGE, LAA seemed to be composed of a mixture of 29 and 15 kDa polypeptide subunits. At acidic and basic pHs it assumed different conformations, as demonstrated by exclusion chromatography on Superdex 200 HR 10/30. The N-terminal sequence of the 29 kDa band was SEVVSFSFTKFNPNQKDII and the 15 kDa band contained a mixture of SEVVSFSFTKFNPNQKDII and KFNQIVAVEEDTDXESQPQ sequences, indicating that these bands may represent full-length and its endogenous fragments, respectively. The lectin is a glycoprotein having 3.2% neutral carbohydrate, with a pI of 5.8, containing high levels of Asp+Asn and Glu+Gln and hydroxy amino acids, and low amount or absence of sulfur amino acids. Its absorption spectrum showed a maximum at 280 nm and a epsilon (1%) x (1cm) of 5.2. Its CD spectrum was characterized by minima near 228 nm, maxima near 196 nm and a negative to positive crossover at 210 nm. The secondary structure content was 6% alpha-helix, 8% parallel beta-sheet, 38% antiparallel beta-sheet, 17% beta-turn, 31% unordered and others contribution, and 1% RMS (root mean square). In the fluorescence spectroscopy, excitation of the lectin solution at 280 nm gave an emission spectrum in the 285-445 nm range. The wavelength maximum emission was in 334.5 nm, typical for tryptophan residues buried inside the protein.

Chemical Composition and Larvicidal Activity of the Essential Oils of Cordia leucomalloides and Cordia curassavica from the Northeast of Brazil

Os oleos essenciais das folhas de Cordia leucomalloides e Cordia curassavica foram obtidos por hidrodestilacao e suas composicoes quimicas determinadas por uma combinacao de CG-EM e CG-DIC. Como resultado, vinte e tres componentes foram identificados em ambos os oleos, representando 98,6 e 91,2% da composicao volatil. O oleo essencial de C. leucomalloides foi caracterizado por uma alta percentagem de sesquiterpenos (90,6%), sendo d-cadineno (17,4%), (E)-cariofileno (15,7%), biciclogermacreno (12,5%) e germacreno D (11,2%) os majoritarios. Por outro lado, o oleo de C. curassavica mostrou proporcoes similares de monoterpenos (47,3%) e sesquitepenos (43,9%), entre os quais a-pineno (20,5%), b-pineno (13,1%), (E)-cariofileno (12,4%) e biciclogermacreno (13,8%) foram os compostos predominantes. O potencial larvicida dos dois oleos foi avaliado contra larvas no terceiro estagio do mosquito Aedes aegypti. Os resultados mostraram que ambos os oleos apresentaram atividade biologica significativa, particularmente o oleo essencial de C. leucomalloides, o qual foi capaz de matar 98,7% das larvas numa concentracao de 100 ppm.

Leaf essential oils of four Piper species from the State of Ceará - Northeast of Brazil

Os oleos essenciais obtidos por hidrodestilacao das folhas de quatro especies de Piper (P. arboreum, P. crassinervium, P. dilatatum and P. tuberculatum), coletadas no estado do Ceara, foram analisados por CG-EM. Os rendimentos dos oleos, calculados sobre o peso do material fresco, variaram entre 0,03 - 0,11% (p/p). Os oleos foram caracterizados pela presenca de mono- e sesquiterpenos, exceto o oleo de P. arboreum, no qual foram identificados apenas sesquiterpenos. b-Elemeno (0,58-3,03%), (E)-cariofileno (2,71-37,78%), germacreno D (3,43-11,81%), biciclogermacreno (2,83-25,07%) e d-cadineno (0,52-2,44%) foram detectados em todas as amostras analisadas. Os monoterpenos majoritarios identificados foram a-pineno (11,27%), b-pineno (20,01%), 1,8-cineol (10,81%) e linalol (28,61%) para P. crassinervium, e a-felandreno (22,53%) e D-3-careno (10,20%) para P. dilatatum. Biciclogermacreno (25,03 e 25,07%) para P. arboreum e P. dilatatum, (E)-nerolidol (11,12%) para P. arboreum, germacreno D (11,81%) para P. tuberculatum e (E)-cariofileno (10,26 e 37,78%) para P. dilatatum e P. tuberculatum, foram os principais sesquiterpenos. Este trabalho descreve, pela primeira vez, a composicao quimica dos oleos essenciais de P. crassinervium e P. tuberculatum.

Florística e formas de vida ao longo de um gradiente topográfico no centro-oeste do estado do Ceará, Brasil

To test whether the flora is organized in discrete or continuous units along a topographic gradient, three physiognomies were assessed on different soil classes in a semi-arid region of northeastern Brazil: caatinga (xeric shrubland) at altitudes from 300 to 500 m, deciduous forest at altitudes from 500 to 700 m and carrasco (deciduous shrubland) at 700 m. In each physiognomy a species inventory was carried out, and plants were classified according to life- and growth-forms. Species richness was higher in the deciduous forest (250) than in the carrasco (136) and caatinga (137). The caatinga shared only a few species with the carrasco (6 species) and the deciduous forest (18 species). The highest species overlap was between the deciduous forest and the carrasco (62 species). One hundred and four species occurred only in the caatinga, 161 only in the deciduous forest and 59 only in the carrasco. Woody species predominated in physiognomies on sedimentary soils with latosol and arenosol: 124 species occurred in the deciduous forest and 68 in the carrasco. In the caatinga on crystalline basement relief with predominance of planosol, herbs showed the highest species richness (69). Comparing the biological spectrum of Brazilian plant life-forms, the caatinga stood out with higher proportion of therophytes and chamaephytes. Considering the flora of the three phytophysiognomies studied here, we can affirm that the caatinga is a discrete floristic unit.

Constituintes químicos voláteis das folhas e galhos de Zanthoxylum syncarpum Tull.

The essential oils of the leaves and twigs from Zanthoxylum syncarpum Tull. were examined by GC/MS and GC-FID. Variation in the oil composition relative to the harvesting time was also described. The major components in the leaves oils were limonene (23.1-47.3%) and myrcene (4.8-10.8%). In the oils of twigs, the main components were ar-curcumene (12.8-18.1%), E-β-farnesene (9.1-9.7%) and β-caryophyllene (9.2-9.3%). This paper describes for the first time the composition of the essential oil of the twigs from Z. syncarpum.

Abietane diterpenes from Hyptis platanifolia

Das raizes de Hyptis platanifolia foram isolados tres novos diterpenos abietanos 19-oxo-inuroyleanol, 11,14-di-hidroxi-12-metoxi-7-oxo-8,11,13-abietatrien-19,20 b-olideo and 19,20-epoxi-12-metoxi-11,14,19-tri-hidroxi-7-oxo-8,11,13-abietatrieno, em adicao ao inuroyleanol e a coulterona. Investigacao das partes aereas forneceu a mistura de esteroides estigmasterol e b-sitosterol, e os triterpenos acido betulinico e acido ursolico. A caracterizacao estrutural dos compostos foi estabelecida com base em metodos espectroscopicos, principalmente RMN uni e bidimensional, e comparacao com dados da literatura.

Volatile Constituentes from Leaves of Vernonia chalybaea Mart. and Eupatorium ballotaefolium H.B.K.

Abstract The essential oils from leaves of Vernonia chalybaea and Eupatorium ballotaefolium were analyzed by GC/MS. The oil obtained from V. chalybaea was characterized by the presence of β-pinene (30.6%), β-caryophyllene (12.1%), whereas the oil of E. ballotaefolium was characterized by limonene (15.3%) and (E)-β-ocimene (10.5%) as the major constituents.

Phylogenetic relationships within Chamaecrista sect. Xerocalyx (Leguminosae, Caesalpinioideae) inferred from the cpDNA trnE-trnT intergenic spacer and nrDNA ITS sequences.

Chamaecrista belongs to subtribe Cassiinae (Caesalpinioideae), and it comprises over 330 species, divided into six sections. The section Xerocalyx has been subjected to a profound taxonomic shuffling over the years. Therefore, we conducted a phylogenetic analysis using a cpDNA trnE-trnT intergenic spacer and nrDNA ITS/5.8S sequences from Cassiinae taxa, in an attempt to elucidate the relationships within this section from Chamaecrista. The tree topology was congruent between the two data sets studied in which the monophyly of the genus Chamaecrista was strongly supported. Our analyses reinforce that new sectional boundaries must be defined in the Chamaecrista genus, especially the inclusion of sections Caliciopsis and Xerocalyx in sect. Chamaecrista, considered here paraphyletic. The section Xerocalyx was strongly supported as monophyletic; however, the current data did not show C. ramosa (microphyllous) and C. desvauxii (macrophyllous) and their respective varieties in distinct clades, suggesting that speciation events are still ongoing in these specimens.

Essential Oil Composition From Leaves and Fruits of Piper divaricatum G. Mey.

Abstract The chemical composition of the essential oils from leaves and fruits of Piper divaricatum G. Mey., collected in August 2005 and September 2006, was analyzed by GC/MS and GC-FID. Twenty-six components, representing more than 94.0% of the chemical compositions of the oils, were identified. Both oils showed higher concentrations of monoterpenoids, particularly the oils from leaves (74.2–81.1%). The oils showed some compositional similarities but the fruit oil could be easily distinguished from the leaf oil by the exclusive presence of α-phellandrene (4.6–10.0%) and significant content of β-caryophyllene (9.0–11.4%). The major constituents of the leaf oils were linalool (23.4–29.7%), β-pinene (19.9–25.3%) and α-pinene (9.0–18.8%), while the fruit oils contained β-pinene (18.0–12.0%), α-pinene (6.3–17.6%) and β-caryophyllene (9.0–11.4%) as prevalent compounds.