Edson Teixeira - Academia.edu (original) (raw)

Papers by Edson Teixeira

Research paper thumbnail of Correlation between Enterococcus faecalis biofilms development stage and quantitative surface roughness using atomic force microscopy

Microscopy and Microanalysis, Apr 1, 2008

Biofilms are assemblages of microorganisms and their associated extracellular products at an inte... more Biofilms are assemblages of microorganisms and their associated extracellular products at an interface and typically with an abiotic or biotic surface. The study of the morphology of biofilms is important because they are associated with processes of biofouling, corrosion, catalysis, pollutant transformation, dental caries, drug resistance, and so forth. In the literature, biofilms have been examined by atomic force microscopy (AFM), which has proven to be a potent tool to study different aspects of the biofilm development ...

Research paper thumbnail of Casbane Diterpene as a Promising Natural Antimicrobial Agent against Biofilm-Associated Infections

Molecules, 2010

Abstract: Croton nepetaefolius is a native plant from northeastern Brazil that belongs to the Eup... more Abstract: Croton nepetaefolius is a native plant from northeastern Brazil that belongs to the Euphorbiaceae family. The biological action of this plant has been extensively explored, being the secondary metabolites responsible for its properties alkaloids, diterpenes, and triterpenes. This study ...

Research paper thumbnail of Antimicrobial activity and antibiotic synergy of a biphosphinic ruthenium complex against clinically relevant bacteria

Research paper thumbnail of Fruticulosin: A novel type 2 ribosome-inactivating protein from Abrus fruticulosus seeds that exhibits toxic and antileishmanial activity

Archives of Biochemistry and Biophysics

Research paper thumbnail of An unusual bidentate methionine ruthenium(II) complex: photo-uncaging and antimicrobial activity

JBIC Journal of Biological Inorganic Chemistry

Research paper thumbnail of Light-induced disruption of an acyl hydrazone link as a novel strategy for drug release and activation: isoniazid as a proof-of-concept case

Inorganic Chemistry Frontiers

Aldehydes and acyl hydrazines have been employed in a conjugation reaction that produces an acyl ... more Aldehydes and acyl hydrazines have been employed in a conjugation reaction that produces an acyl hydrazone bridge. A drawback to this linkage has been hydrolysis, which prevents its broader use...

Research paper thumbnail of Antimicrobial activity of the lupane triterpene 3β,6β,16β-trihydroxylup-20(29)-ene isolated from Combretum leprosum Mart

Journal of Medical Microbiology

Research paper thumbnail of Diterpenes isolated from Croton blanchetianus Baill: Potential compounds in prevention and control of the oral Streptococci biofilms

Industrial Crops and Products

Research paper thumbnail of A new mucin-binding lectin from the marine sponge Aplysina fulva (AFL) exhibits antibiofilm effects

Archives of Biochemistry and Biophysics

A new mucin-binding lectin (AFL) was isolated from the marine sponge Aplysina fulva. AFL was puri... more A new mucin-binding lectin (AFL) was isolated from the marine sponge Aplysina fulva. AFL was purified by affinity chromatography on Sepharose™ matrix. Its hemagglutinating activity was independent of divalent ions, and it was weakly inhibited by simple sugars. However, porcine stomach mucin was a powerful inhibitor. In SDS PAGE, piridylethylated AFL showed one band of approximately 16 kDa, whereas in the non-reducing conditions, AFL showed at least two bands of 30 and 70 kDa. Mass spectrometry MALDI-ToF analysis showed one major ion of 31,652 ± 5 Da, which corresponded to a dimer formed by subunits linked by disulfide bonds. The first fifteen amino acids of AFL were determined, and no sequence similarity was observed with any known protein. Internal sequences were obtained by mass spectrometry analysis of tryptic digestion of AFL spots. These peptides showed similarity with a lectin from marine sponge Aplysina lactuca. Secondary structure of AFL was predominantly formed by β-conformations, which were stable at variations of pH and temperature. AFL did not inhibit planktonic growth of Gram-positive and Gram-negative bacteria tested. However, the lectin did significantly reduce the biomass biofilm of the bacteria Staphylococcus aureus, S. epidermidis, and Escherichia coli.

Research paper thumbnail of Halilectin-3, a lectin from the marine sponge Haliclona caerulea, induces apoptosis and autophagy in human breast cancer MCF7 cells through caspase-9 pathway and LC3-II protein expression

Anti-cancer agents in medicinal chemistry, Nov 13, 2017

An ideal strategy for cancer treatment is the specific induction of tumor cell death, sparing nor... more An ideal strategy for cancer treatment is the specific induction of tumor cell death, sparing normal cells. Marine sponges are rich biological reservoirs of biomolecules, especially lectins, which have attracted considerable attention due to potential biological effect on human cells. Lectins are proteins that bind specific carbohydrate signatures and some gained further interest for their capacity to bind tumor associated carbohydrates antigens and induce tumor cell apoptosis. This study aimed to evaluate the antitumor potential of H3, a lectin, recently reported from marine sponge Haliclona caerulea on the human breast cancer cell line MCF7. H3 reduced MCF7 cell viability with an IC50 of 100 μg/ml, without a significant effect on normal cells. At 24h, H3 induced a significant arrest in the G1 cell cycle phase. Consistently, almost 50% of the cells were in early apoptosis and showed remarkable increased expression of caspase-9 (CASP 9). H3 impaired dramatically the adhesiveness of ...

Research paper thumbnail of Antibacterial activity of a new lectin isolated from the marine sponge Chondrilla caribensis

International journal of biological macromolecules, Jan 22, 2017

A new lectin from the marine sponge Chondrilla caribensis (CCL) was isolated by affinity chromato... more A new lectin from the marine sponge Chondrilla caribensis (CCL) was isolated by affinity chromatography in Sepharose 6B media. CCL is a homotetrameric protein formed by subunits of 15,445 ±2Da. The lectin showed affinity for disaccharides containing galactose and mucin. Mass spectrometric analysis revealed about 50% of amino acid sequence of CCL, which showed similarity with a lectin isolated from Aplysina lactuca. Secondary structure consisted of 10% α-helix, 74% β-sheet/β-turn and 16% coil, and this profile was unaltered in a broad range of pH and temperatures. CCL agglutinated Staphylococcus aureus, S epidermidis and Escherichia coli, and it was able to reduce biofilm biomass, but showed no inhibition of planktonic growth of these bacteria. CCL activity was inhibited by α-lactose, indicating that Carbohydrate Recognition Domain (CRD) of the lectin was involved in antibiofilm activity.

Research paper thumbnail of Structural characterization of two isolectins from the marine red alga Solieria filiformis (Kützing) P.W. Gabrielson and their anticancer effect on MCF-7 breast cancer cells

International journal of biological macromolecules, Jan 29, 2017

As described in the literature, Solieria filiformis lectin (SfL) from the marine red alga S. fili... more As described in the literature, Solieria filiformis lectin (SfL) from the marine red alga S. filiformis was found to have antinociceptive and anti-inflammatory effects. In this study, we characterized two SfL variants, SfL-1 and SfL-2, with molecular mass of 27,552Da and 27,985Da, respectively. The primary structures of SfL-1 and SfL-2 consist of four tandem-repeat protein domains with 67 amino acids each. SfL-1 and -2 showed high similarity to OAAH-family lectins. 3D structure prediction revealed that SfL-1 and -2 are composed of two β-barrel-like domains formed by five antiparallel β-strands, which are connected by a short peptide linker. Furthermore, the mixture of isoforms (SfLs) showed anticancer effect against MCF-7 cells. Specifically, SfLs inhibited 50% of viability in MCF-7 cells after treatment at 125μg.mL(-1), while the inhibition of Human Dermal Fibroblasts (HDF) was 34% with the same treatment. Finally, 24h after treatment, 25% of MCF-7 cells were in early apoptosis and...

Research paper thumbnail of Aryl-Substituted Ruthenium(II) Complexes: A Strategy for Enhanced Photocleavage and Efficient DNA Binding

Inorganic chemistry, Jan 7, 2017

Ruthenium polypyridine complexes have shown promise as agents for photodynamic therapy (PDT) and ... more Ruthenium polypyridine complexes have shown promise as agents for photodynamic therapy (PDT) and tools for molecular biology (chromophore-assisted light inactivation). To accomplish these tasks, it is important to have at least target selectivity and great reactive oxygen species (ROS) photogeneration: two properties that are not easily found in the same molecule. To prepare such new agents, we synthesized two new ruthenium complexes that combine an efficient DNA binding moiety (dppz ligand) together with naphthyl-modified (1) and anthracenyl-modified (2) bipyridine as a strong ROS generator bound to a ruthenium complex. The compounds were fully characterized and their photophysical and photochemical properties investigated. Compound 2 showed one of the highest quantum yields for singlet oxygen production ever reported (ΦΔ= 0.96), along with very high DNA binding (log Kb = 6.78). Such photochemical behavior could be ascribed to the lower triplet state involving the anthracenyl-modif...

Research paper thumbnail of Purification, Biochemical Characterization, and Amino Acid Sequence of a Novel Type of Lectin from Aplysia dactylomela Eggs with Antibacterial/Antibiofilm Potential

Marine biotechnology (New York, N.Y.), 2017

A new lectin from Aplysia dactylomela eggs (ADEL) was isolated by affinity chromatography on HCl-... more A new lectin from Aplysia dactylomela eggs (ADEL) was isolated by affinity chromatography on HCl-activated Sepharose™ media. Hemagglutination caused by ADEL was inhibited by several galactosides, mainly galacturonic acid (Ka = 6.05 × 10(6) M(-1)). The primary structure of ADEL consists of 217 residues, including 11 half-cystines involved in five intrachain and one interchain disulfide bond, resulting in a molecular mass of 57,228 ± 2 Da, as determined by matrix-assisted laser desorption/ionization time of flight mass spectrometry. ADEL showed high similarity with lectins isolated from Aplysia eggs, but not with other known lectins, indicating that these lectins could be grouped into a new family of animal lectins. Three glycosylation sites were found in its polypeptide backbone. Data from peptide-N-glycosidase F digestion and MS suggest that all oligosaccharides attached to ADEL are high in mannose. The secondary structure of ADEL is predominantly β-sheet, and its tertiary structure...

Research paper thumbnail of Isolation, biochemical characterization and antibiofilm effect of a lectin from the marine sponge Aplysina lactuca

International Journal of Biological Macromolecules, 2017

A new lectin was isolated from the marine sponge Aplysina lactuca (ALL) by combining ammonium sul... more A new lectin was isolated from the marine sponge Aplysina lactuca (ALL) by combining ammonium sulfate precipitation and affinity chromatography on guar gum matrix. ALL showed affinity for the disaccharides α-lactose, β-lactose and lactulose (Ka=12.5, 31.9 and 145.5M(-1), respectively), as well as the glycoprotein porcine stomach mucin. Its hemagglutinating activity was stable in neutral acid pH values and temperatures below 60°C. ALL is a dimeric protein formed by two covalently linked polypeptide chains. The average molecular mass, as determined by Electrospray Ionization Mass Spectrometry (ESI-MS), was 31,810±2Da. ESI-MS data also indicated the presence of three cysteines involved in one intrachain and one interchain disulfide bond. The partial amino acid sequence of ALL was determined by tandem mass spectrometry. Eight tryptic peptides presented similarity with lectin I isolated from Axinella polypoides. Its secondary structure is predominantly β-sheet, as indicated by circular dichroism (CD) spectroscopy. ALL agglutinated gram-positive and gram-negative bacterial cells, and it were able to significantly reduce the biomass of the bacterial biofilm tested at dose- dependent effect.

Research paper thumbnail of Miscellaneous Diterpenes from the Aerial Parts of Plectranthus ornatus Codd

Journal of the Brazilian Chemical Society, 2016

Five new diterpenes derivatives named as ornatin A, B, C, D and E, in addition to six known relat... more Five new diterpenes derivatives named as ornatin A, B, C, D and E, in addition to six known related diterpenes were isolated from the aerial parts of cultivated specimens of Plectranthus ornatus. The structures were elucidated using a combination of 1D/2D nuclear magnetic resonance (NMR) spectroscopy, high-resolution electrospray ionization mass spectrometry (HRESIMS) and comparison with published NMR data of analogous compounds. All isolated compounds were assayed against four human cancer cell lines, and Gram-positive and Gram-negative bacteria strains. None of them showed any cytotoxic activity, but ornatin C, D, E and three related diterpenes displayed marginal bactericidal or bacteriostatic effects against the Gram-positive strains.

Research paper thumbnail of Casbane diterpene as novel and natural antimicrobial agent against biofilm infections

Conference Handbook of the 4th International Conference Biofilms Iv Communities Bridging Disciplines, 2010

Croton nepetaefolius is a plant native from northeastern Brazil and belongs to Euphorbiaceae fami... more Croton nepetaefolius is a plant native from northeastern Brazil and belongs to Euphorbiaceae family. The essential oil of this plant is widely used in folk medicine from the treatment of gastrointestinal disorders to the use as an antiseptic agent, with an antifungal action scientifically proven. The action of this plant has been extensively explored by the scientific community, being the secondary metabolites, which are responsible for their properties, alkaloids, diterpenes, and triterpenes. The aim of this study was to evaluate the ability of the secondary metabolite, casbane diterpene (CD) (isolated of the species mentioned above), to inhibit microbial growth and biofilm formation of several clinical relevant species (about 15 species among bacteria and fungi). Minimal inhibitory concentration was assessed by the standard technique of microdilution and biofilm inhibition was tested using microtiter plates with biomass quantification by crystal violet staining method. It was found that the CD possessed biocidal and biostatic activity for the majority of the species screened, with the minimal concentration active between 125 and 500 mg/L. Moreover, CD anti-biofilm action was also observed for some of the species. In addition, it was noticed some biofilm formation inhibition even when the planktonic growth was not significantly affected. In conclusion it can be speculated that casbane diterpene shows potential to be a natural tool for the treatment of diseases caused by different infectious microorganisms.

Research paper thumbnail of Immunostimulatory activity of ConBr: a focus on splenocyte proliferation and proliferative cytokine secretion

Cell and Tissue Research, Oct 19, 2011

Lectins constitute a class of glycoproteins, which are capable of selectively and reversibly bind... more Lectins constitute a class of glycoproteins, which are capable of selectively and reversibly binding to carbohydrates, distinguishing small structural differences in complex oligosaccharides. Studies have shown that the binding of lectins to cell-surface carbohydrates can lead to various effects such as cellular proliferation, histamine release and cytokine production. Canavalia brasiliensis lectin (ConBr) is a (D-mannose) D-glucose lectin. In this study, murine splenocytes were cultured to determine the effect of ConBr on cell proliferation, nitric oxide (NO) release and cytokine secretion. In addition, cellular viability assays were performed to evaluate any mitogenic activity induced by this lectin. ConBr significantly increased cell proliferation with minimal cell damage. This lectin was able to induce an increased production of cytokines such as IL-2, IL-6 and IFN-γ and a decreased production of IL-10. The release of NO was also observed. The results of this study indicate that ConBr could potentially be used as an immunomodulator.

Research paper thumbnail of Dez anos de inclusão da Saúde Bucal na Estratégia Saúde da Família no Brasil: uma revisão da produção científica

Cadernos Esp, Aug 20, 2013

Research paper thumbnail of Compositional analysis of cashew (Anacardium occidentale L.) peduncle bagasse ash and its in vitro antifungal activity against Fusarium species

Revista Brasileira De Biociencias, Jun 20, 2011

I n stit u t o d e B io c i ê ncias U FRGS

Research paper thumbnail of Correlation between Enterococcus faecalis biofilms development stage and quantitative surface roughness using atomic force microscopy

Microscopy and Microanalysis, Apr 1, 2008

Biofilms are assemblages of microorganisms and their associated extracellular products at an inte... more Biofilms are assemblages of microorganisms and their associated extracellular products at an interface and typically with an abiotic or biotic surface. The study of the morphology of biofilms is important because they are associated with processes of biofouling, corrosion, catalysis, pollutant transformation, dental caries, drug resistance, and so forth. In the literature, biofilms have been examined by atomic force microscopy (AFM), which has proven to be a potent tool to study different aspects of the biofilm development ...

Research paper thumbnail of Casbane Diterpene as a Promising Natural Antimicrobial Agent against Biofilm-Associated Infections

Molecules, 2010

Abstract: Croton nepetaefolius is a native plant from northeastern Brazil that belongs to the Eup... more Abstract: Croton nepetaefolius is a native plant from northeastern Brazil that belongs to the Euphorbiaceae family. The biological action of this plant has been extensively explored, being the secondary metabolites responsible for its properties alkaloids, diterpenes, and triterpenes. This study ...

Research paper thumbnail of Antimicrobial activity and antibiotic synergy of a biphosphinic ruthenium complex against clinically relevant bacteria

Research paper thumbnail of Fruticulosin: A novel type 2 ribosome-inactivating protein from Abrus fruticulosus seeds that exhibits toxic and antileishmanial activity

Archives of Biochemistry and Biophysics

Research paper thumbnail of An unusual bidentate methionine ruthenium(II) complex: photo-uncaging and antimicrobial activity

JBIC Journal of Biological Inorganic Chemistry

Research paper thumbnail of Light-induced disruption of an acyl hydrazone link as a novel strategy for drug release and activation: isoniazid as a proof-of-concept case

Inorganic Chemistry Frontiers

Aldehydes and acyl hydrazines have been employed in a conjugation reaction that produces an acyl ... more Aldehydes and acyl hydrazines have been employed in a conjugation reaction that produces an acyl hydrazone bridge. A drawback to this linkage has been hydrolysis, which prevents its broader use...

Research paper thumbnail of Antimicrobial activity of the lupane triterpene 3β,6β,16β-trihydroxylup-20(29)-ene isolated from Combretum leprosum Mart

Journal of Medical Microbiology

Research paper thumbnail of Diterpenes isolated from Croton blanchetianus Baill: Potential compounds in prevention and control of the oral Streptococci biofilms

Industrial Crops and Products

Research paper thumbnail of A new mucin-binding lectin from the marine sponge Aplysina fulva (AFL) exhibits antibiofilm effects

Archives of Biochemistry and Biophysics

A new mucin-binding lectin (AFL) was isolated from the marine sponge Aplysina fulva. AFL was puri... more A new mucin-binding lectin (AFL) was isolated from the marine sponge Aplysina fulva. AFL was purified by affinity chromatography on Sepharose™ matrix. Its hemagglutinating activity was independent of divalent ions, and it was weakly inhibited by simple sugars. However, porcine stomach mucin was a powerful inhibitor. In SDS PAGE, piridylethylated AFL showed one band of approximately 16 kDa, whereas in the non-reducing conditions, AFL showed at least two bands of 30 and 70 kDa. Mass spectrometry MALDI-ToF analysis showed one major ion of 31,652 ± 5 Da, which corresponded to a dimer formed by subunits linked by disulfide bonds. The first fifteen amino acids of AFL were determined, and no sequence similarity was observed with any known protein. Internal sequences were obtained by mass spectrometry analysis of tryptic digestion of AFL spots. These peptides showed similarity with a lectin from marine sponge Aplysina lactuca. Secondary structure of AFL was predominantly formed by β-conformations, which were stable at variations of pH and temperature. AFL did not inhibit planktonic growth of Gram-positive and Gram-negative bacteria tested. However, the lectin did significantly reduce the biomass biofilm of the bacteria Staphylococcus aureus, S. epidermidis, and Escherichia coli.

Research paper thumbnail of Halilectin-3, a lectin from the marine sponge Haliclona caerulea, induces apoptosis and autophagy in human breast cancer MCF7 cells through caspase-9 pathway and LC3-II protein expression

Anti-cancer agents in medicinal chemistry, Nov 13, 2017

An ideal strategy for cancer treatment is the specific induction of tumor cell death, sparing nor... more An ideal strategy for cancer treatment is the specific induction of tumor cell death, sparing normal cells. Marine sponges are rich biological reservoirs of biomolecules, especially lectins, which have attracted considerable attention due to potential biological effect on human cells. Lectins are proteins that bind specific carbohydrate signatures and some gained further interest for their capacity to bind tumor associated carbohydrates antigens and induce tumor cell apoptosis. This study aimed to evaluate the antitumor potential of H3, a lectin, recently reported from marine sponge Haliclona caerulea on the human breast cancer cell line MCF7. H3 reduced MCF7 cell viability with an IC50 of 100 μg/ml, without a significant effect on normal cells. At 24h, H3 induced a significant arrest in the G1 cell cycle phase. Consistently, almost 50% of the cells were in early apoptosis and showed remarkable increased expression of caspase-9 (CASP 9). H3 impaired dramatically the adhesiveness of ...

Research paper thumbnail of Antibacterial activity of a new lectin isolated from the marine sponge Chondrilla caribensis

International journal of biological macromolecules, Jan 22, 2017

A new lectin from the marine sponge Chondrilla caribensis (CCL) was isolated by affinity chromato... more A new lectin from the marine sponge Chondrilla caribensis (CCL) was isolated by affinity chromatography in Sepharose 6B media. CCL is a homotetrameric protein formed by subunits of 15,445 ±2Da. The lectin showed affinity for disaccharides containing galactose and mucin. Mass spectrometric analysis revealed about 50% of amino acid sequence of CCL, which showed similarity with a lectin isolated from Aplysina lactuca. Secondary structure consisted of 10% α-helix, 74% β-sheet/β-turn and 16% coil, and this profile was unaltered in a broad range of pH and temperatures. CCL agglutinated Staphylococcus aureus, S epidermidis and Escherichia coli, and it was able to reduce biofilm biomass, but showed no inhibition of planktonic growth of these bacteria. CCL activity was inhibited by α-lactose, indicating that Carbohydrate Recognition Domain (CRD) of the lectin was involved in antibiofilm activity.

Research paper thumbnail of Structural characterization of two isolectins from the marine red alga Solieria filiformis (Kützing) P.W. Gabrielson and their anticancer effect on MCF-7 breast cancer cells

International journal of biological macromolecules, Jan 29, 2017

As described in the literature, Solieria filiformis lectin (SfL) from the marine red alga S. fili... more As described in the literature, Solieria filiformis lectin (SfL) from the marine red alga S. filiformis was found to have antinociceptive and anti-inflammatory effects. In this study, we characterized two SfL variants, SfL-1 and SfL-2, with molecular mass of 27,552Da and 27,985Da, respectively. The primary structures of SfL-1 and SfL-2 consist of four tandem-repeat protein domains with 67 amino acids each. SfL-1 and -2 showed high similarity to OAAH-family lectins. 3D structure prediction revealed that SfL-1 and -2 are composed of two β-barrel-like domains formed by five antiparallel β-strands, which are connected by a short peptide linker. Furthermore, the mixture of isoforms (SfLs) showed anticancer effect against MCF-7 cells. Specifically, SfLs inhibited 50% of viability in MCF-7 cells after treatment at 125μg.mL(-1), while the inhibition of Human Dermal Fibroblasts (HDF) was 34% with the same treatment. Finally, 24h after treatment, 25% of MCF-7 cells were in early apoptosis and...

Research paper thumbnail of Aryl-Substituted Ruthenium(II) Complexes: A Strategy for Enhanced Photocleavage and Efficient DNA Binding

Inorganic chemistry, Jan 7, 2017

Ruthenium polypyridine complexes have shown promise as agents for photodynamic therapy (PDT) and ... more Ruthenium polypyridine complexes have shown promise as agents for photodynamic therapy (PDT) and tools for molecular biology (chromophore-assisted light inactivation). To accomplish these tasks, it is important to have at least target selectivity and great reactive oxygen species (ROS) photogeneration: two properties that are not easily found in the same molecule. To prepare such new agents, we synthesized two new ruthenium complexes that combine an efficient DNA binding moiety (dppz ligand) together with naphthyl-modified (1) and anthracenyl-modified (2) bipyridine as a strong ROS generator bound to a ruthenium complex. The compounds were fully characterized and their photophysical and photochemical properties investigated. Compound 2 showed one of the highest quantum yields for singlet oxygen production ever reported (ΦΔ= 0.96), along with very high DNA binding (log Kb = 6.78). Such photochemical behavior could be ascribed to the lower triplet state involving the anthracenyl-modif...

Research paper thumbnail of Purification, Biochemical Characterization, and Amino Acid Sequence of a Novel Type of Lectin from Aplysia dactylomela Eggs with Antibacterial/Antibiofilm Potential

Marine biotechnology (New York, N.Y.), 2017

A new lectin from Aplysia dactylomela eggs (ADEL) was isolated by affinity chromatography on HCl-... more A new lectin from Aplysia dactylomela eggs (ADEL) was isolated by affinity chromatography on HCl-activated Sepharose™ media. Hemagglutination caused by ADEL was inhibited by several galactosides, mainly galacturonic acid (Ka = 6.05 × 10(6) M(-1)). The primary structure of ADEL consists of 217 residues, including 11 half-cystines involved in five intrachain and one interchain disulfide bond, resulting in a molecular mass of 57,228 ± 2 Da, as determined by matrix-assisted laser desorption/ionization time of flight mass spectrometry. ADEL showed high similarity with lectins isolated from Aplysia eggs, but not with other known lectins, indicating that these lectins could be grouped into a new family of animal lectins. Three glycosylation sites were found in its polypeptide backbone. Data from peptide-N-glycosidase F digestion and MS suggest that all oligosaccharides attached to ADEL are high in mannose. The secondary structure of ADEL is predominantly β-sheet, and its tertiary structure...

Research paper thumbnail of Isolation, biochemical characterization and antibiofilm effect of a lectin from the marine sponge Aplysina lactuca

International Journal of Biological Macromolecules, 2017

A new lectin was isolated from the marine sponge Aplysina lactuca (ALL) by combining ammonium sul... more A new lectin was isolated from the marine sponge Aplysina lactuca (ALL) by combining ammonium sulfate precipitation and affinity chromatography on guar gum matrix. ALL showed affinity for the disaccharides α-lactose, β-lactose and lactulose (Ka=12.5, 31.9 and 145.5M(-1), respectively), as well as the glycoprotein porcine stomach mucin. Its hemagglutinating activity was stable in neutral acid pH values and temperatures below 60°C. ALL is a dimeric protein formed by two covalently linked polypeptide chains. The average molecular mass, as determined by Electrospray Ionization Mass Spectrometry (ESI-MS), was 31,810±2Da. ESI-MS data also indicated the presence of three cysteines involved in one intrachain and one interchain disulfide bond. The partial amino acid sequence of ALL was determined by tandem mass spectrometry. Eight tryptic peptides presented similarity with lectin I isolated from Axinella polypoides. Its secondary structure is predominantly β-sheet, as indicated by circular dichroism (CD) spectroscopy. ALL agglutinated gram-positive and gram-negative bacterial cells, and it were able to significantly reduce the biomass of the bacterial biofilm tested at dose- dependent effect.

Research paper thumbnail of Miscellaneous Diterpenes from the Aerial Parts of Plectranthus ornatus Codd

Journal of the Brazilian Chemical Society, 2016

Five new diterpenes derivatives named as ornatin A, B, C, D and E, in addition to six known relat... more Five new diterpenes derivatives named as ornatin A, B, C, D and E, in addition to six known related diterpenes were isolated from the aerial parts of cultivated specimens of Plectranthus ornatus. The structures were elucidated using a combination of 1D/2D nuclear magnetic resonance (NMR) spectroscopy, high-resolution electrospray ionization mass spectrometry (HRESIMS) and comparison with published NMR data of analogous compounds. All isolated compounds were assayed against four human cancer cell lines, and Gram-positive and Gram-negative bacteria strains. None of them showed any cytotoxic activity, but ornatin C, D, E and three related diterpenes displayed marginal bactericidal or bacteriostatic effects against the Gram-positive strains.

Research paper thumbnail of Casbane diterpene as novel and natural antimicrobial agent against biofilm infections

Conference Handbook of the 4th International Conference Biofilms Iv Communities Bridging Disciplines, 2010

Croton nepetaefolius is a plant native from northeastern Brazil and belongs to Euphorbiaceae fami... more Croton nepetaefolius is a plant native from northeastern Brazil and belongs to Euphorbiaceae family. The essential oil of this plant is widely used in folk medicine from the treatment of gastrointestinal disorders to the use as an antiseptic agent, with an antifungal action scientifically proven. The action of this plant has been extensively explored by the scientific community, being the secondary metabolites, which are responsible for their properties, alkaloids, diterpenes, and triterpenes. The aim of this study was to evaluate the ability of the secondary metabolite, casbane diterpene (CD) (isolated of the species mentioned above), to inhibit microbial growth and biofilm formation of several clinical relevant species (about 15 species among bacteria and fungi). Minimal inhibitory concentration was assessed by the standard technique of microdilution and biofilm inhibition was tested using microtiter plates with biomass quantification by crystal violet staining method. It was found that the CD possessed biocidal and biostatic activity for the majority of the species screened, with the minimal concentration active between 125 and 500 mg/L. Moreover, CD anti-biofilm action was also observed for some of the species. In addition, it was noticed some biofilm formation inhibition even when the planktonic growth was not significantly affected. In conclusion it can be speculated that casbane diterpene shows potential to be a natural tool for the treatment of diseases caused by different infectious microorganisms.

Research paper thumbnail of Immunostimulatory activity of ConBr: a focus on splenocyte proliferation and proliferative cytokine secretion

Cell and Tissue Research, Oct 19, 2011

Lectins constitute a class of glycoproteins, which are capable of selectively and reversibly bind... more Lectins constitute a class of glycoproteins, which are capable of selectively and reversibly binding to carbohydrates, distinguishing small structural differences in complex oligosaccharides. Studies have shown that the binding of lectins to cell-surface carbohydrates can lead to various effects such as cellular proliferation, histamine release and cytokine production. Canavalia brasiliensis lectin (ConBr) is a (D-mannose) D-glucose lectin. In this study, murine splenocytes were cultured to determine the effect of ConBr on cell proliferation, nitric oxide (NO) release and cytokine secretion. In addition, cellular viability assays were performed to evaluate any mitogenic activity induced by this lectin. ConBr significantly increased cell proliferation with minimal cell damage. This lectin was able to induce an increased production of cytokines such as IL-2, IL-6 and IFN-γ and a decreased production of IL-10. The release of NO was also observed. The results of this study indicate that ConBr could potentially be used as an immunomodulator.

Research paper thumbnail of Dez anos de inclusão da Saúde Bucal na Estratégia Saúde da Família no Brasil: uma revisão da produção científica

Cadernos Esp, Aug 20, 2013

Research paper thumbnail of Compositional analysis of cashew (Anacardium occidentale L.) peduncle bagasse ash and its in vitro antifungal activity against Fusarium species

Revista Brasileira De Biociencias, Jun 20, 2011

I n stit u t o d e B io c i ê ncias U FRGS