Comparative Biochemistry and Physiology Part B: Comparative Biochemistry, 1988
The biosynthesis of luciferin in larvae of the click beetle Pyrearinus termitilluminans has been ... more The biosynthesis of luciferin in larvae of the click beetle Pyrearinus termitilluminans has been studied by injection of ~4C-cystine (precursor) in their abdominal segments, followed by isolation and counting labelled luciferin. 2. Dose and time response were measured; the radiochemical yield of luciferin reached a plateau at 3% after 25 hours incorporation of labelled cystine. 3. The observed temporal response curve is similar to that previously described for fireflies using a benzothiazol derivative as luciferin precursor.
The assessment of human impacts on marine ecosystems is usually done by assessing changes in spec... more The assessment of human impacts on marine ecosystems is usually done by assessing changes in species diversity and abundance. Here, we add to this approach the assessment of primary and secondary metabolites from macroalgal communities in urban and protected areas in south Brazil and investigate whether the chemical diversity of marine macroalgae is affected by environmental changes, such as those caused by coastal urbanization, through the use of thin-layer chromatography. Additionally, we compare the chemical and biological diversity of macroalgal communities within urban and undeveloped sites along the southern Brazilian coast. Coastlines within protected areas had greater species richness and higher amounts of substances such as chlorophylls, carotenoids and lipids as well as a greater chemical diversity than coasts subjected to multiple stressors from urbanization. We conclude that the composition and abundance of primary and secondary metabolites provide useful additional information about the ecological status of coastal environments and improve our understanding of the effects of coastal biodiversity loss due to coastal urbanization.
... 1985). These appear as electron-dense bodies localized peripherally as cytoplasmic evagi-nati... more ... 1985). These appear as electron-dense bodies localized peripherally as cytoplasmic evagi-nations into the vacuole, enveloped by the vacuolar membrane (Nicolas et al. 1987a, b, 1991,Fritz et al. 1990). ... 1. ._! .. _-. ._ ErE _ - ЕЕ Er E Efc z lisi ~ ЕЕ ~~: ЕЕ iE ЕЕ Ut. ...
The release of superoxide anion (0;) by inflammatory macrophages, multinucleated giant cells, and... more The release of superoxide anion (0;) by inflammatory macrophages, multinucleated giant cells, and epithelioid cells, obtained by the insertion of round glass coverslips into the subcutaneous tissue of mice, was investigated. 0; was shown to be spontaneously released by cells on the surface of glass coverslips implanted up to 7 days, but not by cells obtained 14 or 21 days after coverslip implantation.
Leishmaniasis is a group of diseases that have limited and high toxic therapeutic options. Herein... more Leishmaniasis is a group of diseases that have limited and high toxic therapeutic options. Herein, we evaluated the antileishmanial potential and cytotoxicity of hexanic extract obtained from the Antarctic brown alga Ascoseira mirabilis using bioguided fractionation against Leishmania amazonensis and murine macrophages, which was fractionated by SPE, yielding seven fractions (F1-F7). The fraction F6 showed good anti-amastigote activity (IC 50 = 73. 4 ± 0.4 μg mL-1) and low cytotoxicity (CC 50 > 100 μg mL-1). Thus, in order to identify the bioactive constituent(s) of F6, the fraction was separated in a semipreparative HPLC, yielding four fractions (F6.1-F6.4). F6.2 was the most bioactive fraction (IC 50 = 66.5 ± 4.5 μg mL-1) and GC-MS analyses revealed that the compounds octadecane, propanoic acid, 1-monomyristin and azelaic acid correspond to 61% of its composition. These data show for the first time the antileishmanial potential of the Antarctic alga A. mirabilis.
Biochemical and Biophysical Research Communications, 1999
Leucyl aminopeptidase (LAP; EC 3.4.11.1) activity was purified from crude extracts of the marine ... more Leucyl aminopeptidase (LAP; EC 3.4.11.1) activity was purified from crude extracts of the marine unicellular algae Gonyaulax polyedra by a combination of hydrophobic interaction with phenyl sepharose, DEAE-cellulose, and mono-Q HR5/5 ion-exchange chromatography. The undenaturated protein has a molecular mass of about 110 kD and based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the enzyme appears to be composed of two possibly identical subunits of 55 kD. The identity of the protein was confirmed by a cross-reaction of the purified protein with an antibody raised against a commercial LAP. Biochemical characterization showed that the Gonyaulax enzyme was similar to most of the previously described LAPs. Gonyaulax LAP is a metalloenzyme since EDTA and 1,10-phenathroline significantly inhibited activity. Addition of the metal ions Zn 2؉ , Cu 2؉ inhibited 80% of LAP activity, suggesting they are not the natural cofactors of the enzyme. Other metals, such as Ca 2؉ , Co 2؉ , Mn 2؉ , or Mg 2؉ (concentrations up to 4 mM), caused no alteration in the total activity of Gonyaulax LAP.
The marine environment supports vast habitats with prodigious biodiversity comprising the largest... more The marine environment supports vast habitats with prodigious biodiversity comprising the largest source of unique bioactive compounds biosynthesized by macro and microorganisms, including seaweeds and their associated fungi. In this context, the interest in studying and characterizing marine natural products has increased in the last years. Among these metabolites, lipids and their derivatives play an important role in the metabolism of marine organisms and are sources of substances with therapeutic properties and biotechnological purposes. In this research, it was investigated the lipid amount present in the algae species Ascoseira mirabilis, Adenocystis utricularis, Desmarestia anceps, Phaeurus antarcticus and in their associated endophytic fungi Aspergillus flavus, Penicillium echinulatum, Microascus croci and Penicillium purpurogenum, respectively. This study was achieved by gas chromatography-mass spectrometry, using a standard methodology to analyze all of the components present in the eight organisms. Fatty acids (FAs) and sterols are among the lipids of the highest concentration in the studied algae and fungi. In general, phytol and fucosterol were the most abundant metabolites in all seaweed, while in endophytic fungi, the FAs (palmitic, linoleic, oleic and stearic acid) and ergosterol appeared in major concentrations. This work contributes to new chemical information on the underexploited biodiversity of macroalgae and endophytic fungi belonging to the Antarctic Peninsula and, furthermore, to increase the possibilities for the discovery of bioactive substances and apply it on biotechnological approaches.
This study represents the efforts of a network of researchers to characterise the large, floating... more This study represents the efforts of a network of researchers to characterise the large, floating Sargassum (Fucales, Phaeophyceae) biomass that had reached the Brazilian coast in 2014 and 2015. Material collected during these events was identified as Sargassum natans and S. fluitans using morphological characteristics; ITS2 sequences showed low divergence (0%-3%) with sequences of nine other Sargassum species. Several epiphytic macroalgae, invertebrates and fishes were associated with the floating Sargassum. Satellite images did not support the hypothesis of slicks moving south from the Sargasso Sea in the northern Atlantic Ocean. This strengthens the hypothesis that there is a matrix of pelagic Sargassum in the central Atlantic Ocean and that biomass accumulation should be considered a result of the combination of physicochemical seawater conditions and biological interactions. The biomass accumulation of the stranded Sargassum was estimated during four events, peaking in 98 kg m À2 wet weight on a beach on the Amazonian coast. The landing of huge Sargassum biomass represents a potential source of environmental stress, as it can lead to an increase in oxygen demand and eventually synthesise and release chemical compounds with allelopathic properties. On the other hand, these floating islands are a fundamental element of the biogeography and macroecology of tropical environments in the Atlantic Ocean, providing connectivity south/north and east/west among marine biodiversity from Atlantic reef environments. Studies concerning Sargassum effects on local communities are necessary for the proper management of this phenomenon.
This paper describes the preparation of silver nanoparticles (AgNPs) through an environmentally f... more This paper describes the preparation of silver nanoparticles (AgNPs) through an environmentally friendly route, using a disposable aqueous extract of seaweed as a reducing agent. The seaweeds used were Laurencia aldingensis and Laurenciella sp., and the AgNPs obtained from both algae were characterized by UV–vis spectroscopy, energy-dispersive X-ray (EDX), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and zeta potential measurements. Furthermore, cell viability assays were carried out to assess the cytotoxicity of these AgNPs on the P4 human foreskin fibroblast cell line, as well as on human uterine sarcoma (MES-SA) and the corresponding doxorubicin-resistant mutant MES-SA/Dx5 cells. High toxicity was observed in both of the tested cancer cell lines with very similar half maximal inhibitory concentration (IC50) values (1- to 4 μM range); however, no toxicity was observed in the P4 cells. The alternative synthetic method proposed in this work allows the use of renewable and disposable algae extracts, which leads to the preparation of AgNP with remarkable cytotoxicity against sarcoma tumor cells.
built a transgressive fiction, focusing the text on an audacious dialogue which shows the women r... more built a transgressive fiction, focusing the text on an audacious dialogue which shows the women ready to fight against all the archaic and traditional patriarchal values in the Portuguese society It will be discussed the following aspects: (i) the intertextuality with the letters supposedly written by the sister Mariana Alcoforado, (ii) analysis of epistolary gender discussion related to differences/equalities and, (iii) the complete emancipation and engagement political-social of Portuguese women.
ABSTRACT Carotenoids comprise one of the most widespread classes of pigments found in nature. Pol... more ABSTRACT Carotenoids comprise one of the most widespread classes of pigments found in nature. Polyene pigments from the dinoflagellate Gonyaulax polyedra were extracted every hour over a 24 hour period and the levels of beta-carotene during the day-phase were found to be twice as high as during the night-phase period. Using the thermal decomposition of 1,4-dimethylnaphthalene endoperoxide, the overall quenching ability of beta-carotene and G. polyedra carotenoids of singlet oxygen were found to be 2.04 x 10(9) M-1 s-1 and 4.75 x 10(9) M-1 s-1 respectively. Such a high quenching rate constant suggest a possible role for carotenoids as effective singlet oxygen quenchers in G. polyedra. The dose response curve for light-induced carotenoid synthesis shows a linear response up to 45 minutes of light exposure, after which night phase cells contain the same levels of beta-carotene as day-phase cells. Cells exposed to light pulses at different times during the night period display the highest beta-carotene induction in the middle of the night.
Amylase, cellulase, fl-giucosidase and trypsin are found in major amounts in the midgut lumen and... more Amylase, cellulase, fl-giucosidase and trypsin are found in major amounts in the midgut lumen and in regurgitated material, whereas aminopeptidase, ,~-glucosidase and trehalase occur mainly in the midgut tissue of Pyrearinus termitilluminans larvae. About 40% of the cell bound enzymes are membrane associated. Feeding seems to increase the luminal more than the cell-bound digestive enzymes. There is only one molecular species each of soluble aminopeptidase (M r 118,000), amylase (Mr 64,000), cellulase (Mr 58,000), ty-glucosidase (Mr 79,000), fl-glucosidase (Mr 110,000) and trehalase (Mr 110,000) in P. termitiiluminana midgut as judged by electrophoretic, isoelectric focusing and density-gradient centrifugation data. There are three trypsin activities resolved by electrophoresis and isoelectric focusing, and only one by centrifugation (Mr 39,000), suggesting that trypsin occurs as charged isomers. The pH optima of the digestive enzymes lie between 6 and 8.5, which agrees with the pH (7.3) value of the midgut contents. The data suggest that P. termitilluminans larvae regurgitate onto their prey their midgut contents which accomplishes initial digestion. Pre-liquefied material is then ingested by larvae and the intermediate and final digestion take place on the surface of the midgut cells. The adaptive features of the digestion of the P. termitilluminans larvae are thought to be derived characters evolved from a putative holometabolous vegetarian ancestor.
In order to survive in a highly competitive environment, freshwater or marine algae have to devel... more In order to survive in a highly competitive environment, freshwater or marine algae have to develop defense strategies that result in a tremendous diversity of compounds from different metabolic pathways. Recent trends in drug research from natural sources have shown that algae are promising organisms to furnish novel biochemically active compounds. The current review describes the main substances biosynthesized by algae with potential economic impact in food science, pharmaceutical industry and public health. Emphasis is given to fatty acids, steroids, carotenoids, polysaccharides, lectins, mycosporine-like amino acids, halogenated compounds, polyketides and toxins.
The capability of the mouse embryo to generate reactive oxygen species (ROS) was examined. Post-i... more The capability of the mouse embryo to generate reactive oxygen species (ROS) was examined. Post-implantation embryos were carefully harvested on Day 8 of pregnancy and the production of ROS was quantified using luminol-sensitized chemiluminescence. The embryos were stimulated with either phorbol myristate acetate (PMA) or all-trans-retinal (retinal) and the reaction kinetics were followed over 10 min. ROS secretion was directly proportional to the number of embryos and was suppressed 56% by superoxide dismutase (SOD), 25% by mannitol and as little as 16% by catalase. Embryos deprived of trophoblast showed no light emission suggesting that the source of ROS generation is the trophoblast. Dihydronicotinamide adenine dinucleotide (NADH)-dependent oxidase activity in the plasma membrane of the trophoblast surface was demonstrated by cytochemical methods. The release of ROS into the extracellular medium during the phagocytic process has been related to the cytolytic effect exhibited by t...
Comparative Biochemistry and Physiology Part B: Comparative Biochemistry, 1988
The biosynthesis of luciferin in larvae of the click beetle Pyrearinus termitilluminans has been ... more The biosynthesis of luciferin in larvae of the click beetle Pyrearinus termitilluminans has been studied by injection of ~4C-cystine (precursor) in their abdominal segments, followed by isolation and counting labelled luciferin. 2. Dose and time response were measured; the radiochemical yield of luciferin reached a plateau at 3% after 25 hours incorporation of labelled cystine. 3. The observed temporal response curve is similar to that previously described for fireflies using a benzothiazol derivative as luciferin precursor.
The assessment of human impacts on marine ecosystems is usually done by assessing changes in spec... more The assessment of human impacts on marine ecosystems is usually done by assessing changes in species diversity and abundance. Here, we add to this approach the assessment of primary and secondary metabolites from macroalgal communities in urban and protected areas in south Brazil and investigate whether the chemical diversity of marine macroalgae is affected by environmental changes, such as those caused by coastal urbanization, through the use of thin-layer chromatography. Additionally, we compare the chemical and biological diversity of macroalgal communities within urban and undeveloped sites along the southern Brazilian coast. Coastlines within protected areas had greater species richness and higher amounts of substances such as chlorophylls, carotenoids and lipids as well as a greater chemical diversity than coasts subjected to multiple stressors from urbanization. We conclude that the composition and abundance of primary and secondary metabolites provide useful additional information about the ecological status of coastal environments and improve our understanding of the effects of coastal biodiversity loss due to coastal urbanization.
... 1985). These appear as electron-dense bodies localized peripherally as cytoplasmic evagi-nati... more ... 1985). These appear as electron-dense bodies localized peripherally as cytoplasmic evagi-nations into the vacuole, enveloped by the vacuolar membrane (Nicolas et al. 1987a, b, 1991,Fritz et al. 1990). ... 1. ._! .. _-. ._ ErE _ - ЕЕ Er E Efc z lisi ~ ЕЕ ~~: ЕЕ iE ЕЕ Ut. ...
The release of superoxide anion (0;) by inflammatory macrophages, multinucleated giant cells, and... more The release of superoxide anion (0;) by inflammatory macrophages, multinucleated giant cells, and epithelioid cells, obtained by the insertion of round glass coverslips into the subcutaneous tissue of mice, was investigated. 0; was shown to be spontaneously released by cells on the surface of glass coverslips implanted up to 7 days, but not by cells obtained 14 or 21 days after coverslip implantation.
Leishmaniasis is a group of diseases that have limited and high toxic therapeutic options. Herein... more Leishmaniasis is a group of diseases that have limited and high toxic therapeutic options. Herein, we evaluated the antileishmanial potential and cytotoxicity of hexanic extract obtained from the Antarctic brown alga Ascoseira mirabilis using bioguided fractionation against Leishmania amazonensis and murine macrophages, which was fractionated by SPE, yielding seven fractions (F1-F7). The fraction F6 showed good anti-amastigote activity (IC 50 = 73. 4 ± 0.4 μg mL-1) and low cytotoxicity (CC 50 > 100 μg mL-1). Thus, in order to identify the bioactive constituent(s) of F6, the fraction was separated in a semipreparative HPLC, yielding four fractions (F6.1-F6.4). F6.2 was the most bioactive fraction (IC 50 = 66.5 ± 4.5 μg mL-1) and GC-MS analyses revealed that the compounds octadecane, propanoic acid, 1-monomyristin and azelaic acid correspond to 61% of its composition. These data show for the first time the antileishmanial potential of the Antarctic alga A. mirabilis.
Biochemical and Biophysical Research Communications, 1999
Leucyl aminopeptidase (LAP; EC 3.4.11.1) activity was purified from crude extracts of the marine ... more Leucyl aminopeptidase (LAP; EC 3.4.11.1) activity was purified from crude extracts of the marine unicellular algae Gonyaulax polyedra by a combination of hydrophobic interaction with phenyl sepharose, DEAE-cellulose, and mono-Q HR5/5 ion-exchange chromatography. The undenaturated protein has a molecular mass of about 110 kD and based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the enzyme appears to be composed of two possibly identical subunits of 55 kD. The identity of the protein was confirmed by a cross-reaction of the purified protein with an antibody raised against a commercial LAP. Biochemical characterization showed that the Gonyaulax enzyme was similar to most of the previously described LAPs. Gonyaulax LAP is a metalloenzyme since EDTA and 1,10-phenathroline significantly inhibited activity. Addition of the metal ions Zn 2؉ , Cu 2؉ inhibited 80% of LAP activity, suggesting they are not the natural cofactors of the enzyme. Other metals, such as Ca 2؉ , Co 2؉ , Mn 2؉ , or Mg 2؉ (concentrations up to 4 mM), caused no alteration in the total activity of Gonyaulax LAP.
The marine environment supports vast habitats with prodigious biodiversity comprising the largest... more The marine environment supports vast habitats with prodigious biodiversity comprising the largest source of unique bioactive compounds biosynthesized by macro and microorganisms, including seaweeds and their associated fungi. In this context, the interest in studying and characterizing marine natural products has increased in the last years. Among these metabolites, lipids and their derivatives play an important role in the metabolism of marine organisms and are sources of substances with therapeutic properties and biotechnological purposes. In this research, it was investigated the lipid amount present in the algae species Ascoseira mirabilis, Adenocystis utricularis, Desmarestia anceps, Phaeurus antarcticus and in their associated endophytic fungi Aspergillus flavus, Penicillium echinulatum, Microascus croci and Penicillium purpurogenum, respectively. This study was achieved by gas chromatography-mass spectrometry, using a standard methodology to analyze all of the components present in the eight organisms. Fatty acids (FAs) and sterols are among the lipids of the highest concentration in the studied algae and fungi. In general, phytol and fucosterol were the most abundant metabolites in all seaweed, while in endophytic fungi, the FAs (palmitic, linoleic, oleic and stearic acid) and ergosterol appeared in major concentrations. This work contributes to new chemical information on the underexploited biodiversity of macroalgae and endophytic fungi belonging to the Antarctic Peninsula and, furthermore, to increase the possibilities for the discovery of bioactive substances and apply it on biotechnological approaches.
This study represents the efforts of a network of researchers to characterise the large, floating... more This study represents the efforts of a network of researchers to characterise the large, floating Sargassum (Fucales, Phaeophyceae) biomass that had reached the Brazilian coast in 2014 and 2015. Material collected during these events was identified as Sargassum natans and S. fluitans using morphological characteristics; ITS2 sequences showed low divergence (0%-3%) with sequences of nine other Sargassum species. Several epiphytic macroalgae, invertebrates and fishes were associated with the floating Sargassum. Satellite images did not support the hypothesis of slicks moving south from the Sargasso Sea in the northern Atlantic Ocean. This strengthens the hypothesis that there is a matrix of pelagic Sargassum in the central Atlantic Ocean and that biomass accumulation should be considered a result of the combination of physicochemical seawater conditions and biological interactions. The biomass accumulation of the stranded Sargassum was estimated during four events, peaking in 98 kg m À2 wet weight on a beach on the Amazonian coast. The landing of huge Sargassum biomass represents a potential source of environmental stress, as it can lead to an increase in oxygen demand and eventually synthesise and release chemical compounds with allelopathic properties. On the other hand, these floating islands are a fundamental element of the biogeography and macroecology of tropical environments in the Atlantic Ocean, providing connectivity south/north and east/west among marine biodiversity from Atlantic reef environments. Studies concerning Sargassum effects on local communities are necessary for the proper management of this phenomenon.
This paper describes the preparation of silver nanoparticles (AgNPs) through an environmentally f... more This paper describes the preparation of silver nanoparticles (AgNPs) through an environmentally friendly route, using a disposable aqueous extract of seaweed as a reducing agent. The seaweeds used were Laurencia aldingensis and Laurenciella sp., and the AgNPs obtained from both algae were characterized by UV–vis spectroscopy, energy-dispersive X-ray (EDX), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and zeta potential measurements. Furthermore, cell viability assays were carried out to assess the cytotoxicity of these AgNPs on the P4 human foreskin fibroblast cell line, as well as on human uterine sarcoma (MES-SA) and the corresponding doxorubicin-resistant mutant MES-SA/Dx5 cells. High toxicity was observed in both of the tested cancer cell lines with very similar half maximal inhibitory concentration (IC50) values (1- to 4 μM range); however, no toxicity was observed in the P4 cells. The alternative synthetic method proposed in this work allows the use of renewable and disposable algae extracts, which leads to the preparation of AgNP with remarkable cytotoxicity against sarcoma tumor cells.
built a transgressive fiction, focusing the text on an audacious dialogue which shows the women r... more built a transgressive fiction, focusing the text on an audacious dialogue which shows the women ready to fight against all the archaic and traditional patriarchal values in the Portuguese society It will be discussed the following aspects: (i) the intertextuality with the letters supposedly written by the sister Mariana Alcoforado, (ii) analysis of epistolary gender discussion related to differences/equalities and, (iii) the complete emancipation and engagement political-social of Portuguese women.
ABSTRACT Carotenoids comprise one of the most widespread classes of pigments found in nature. Pol... more ABSTRACT Carotenoids comprise one of the most widespread classes of pigments found in nature. Polyene pigments from the dinoflagellate Gonyaulax polyedra were extracted every hour over a 24 hour period and the levels of beta-carotene during the day-phase were found to be twice as high as during the night-phase period. Using the thermal decomposition of 1,4-dimethylnaphthalene endoperoxide, the overall quenching ability of beta-carotene and G. polyedra carotenoids of singlet oxygen were found to be 2.04 x 10(9) M-1 s-1 and 4.75 x 10(9) M-1 s-1 respectively. Such a high quenching rate constant suggest a possible role for carotenoids as effective singlet oxygen quenchers in G. polyedra. The dose response curve for light-induced carotenoid synthesis shows a linear response up to 45 minutes of light exposure, after which night phase cells contain the same levels of beta-carotene as day-phase cells. Cells exposed to light pulses at different times during the night period display the highest beta-carotene induction in the middle of the night.
Amylase, cellulase, fl-giucosidase and trypsin are found in major amounts in the midgut lumen and... more Amylase, cellulase, fl-giucosidase and trypsin are found in major amounts in the midgut lumen and in regurgitated material, whereas aminopeptidase, ,~-glucosidase and trehalase occur mainly in the midgut tissue of Pyrearinus termitilluminans larvae. About 40% of the cell bound enzymes are membrane associated. Feeding seems to increase the luminal more than the cell-bound digestive enzymes. There is only one molecular species each of soluble aminopeptidase (M r 118,000), amylase (Mr 64,000), cellulase (Mr 58,000), ty-glucosidase (Mr 79,000), fl-glucosidase (Mr 110,000) and trehalase (Mr 110,000) in P. termitiiluminana midgut as judged by electrophoretic, isoelectric focusing and density-gradient centrifugation data. There are three trypsin activities resolved by electrophoresis and isoelectric focusing, and only one by centrifugation (Mr 39,000), suggesting that trypsin occurs as charged isomers. The pH optima of the digestive enzymes lie between 6 and 8.5, which agrees with the pH (7.3) value of the midgut contents. The data suggest that P. termitilluminans larvae regurgitate onto their prey their midgut contents which accomplishes initial digestion. Pre-liquefied material is then ingested by larvae and the intermediate and final digestion take place on the surface of the midgut cells. The adaptive features of the digestion of the P. termitilluminans larvae are thought to be derived characters evolved from a putative holometabolous vegetarian ancestor.
In order to survive in a highly competitive environment, freshwater or marine algae have to devel... more In order to survive in a highly competitive environment, freshwater or marine algae have to develop defense strategies that result in a tremendous diversity of compounds from different metabolic pathways. Recent trends in drug research from natural sources have shown that algae are promising organisms to furnish novel biochemically active compounds. The current review describes the main substances biosynthesized by algae with potential economic impact in food science, pharmaceutical industry and public health. Emphasis is given to fatty acids, steroids, carotenoids, polysaccharides, lectins, mycosporine-like amino acids, halogenated compounds, polyketides and toxins.
The capability of the mouse embryo to generate reactive oxygen species (ROS) was examined. Post-i... more The capability of the mouse embryo to generate reactive oxygen species (ROS) was examined. Post-implantation embryos were carefully harvested on Day 8 of pregnancy and the production of ROS was quantified using luminol-sensitized chemiluminescence. The embryos were stimulated with either phorbol myristate acetate (PMA) or all-trans-retinal (retinal) and the reaction kinetics were followed over 10 min. ROS secretion was directly proportional to the number of embryos and was suppressed 56% by superoxide dismutase (SOD), 25% by mannitol and as little as 16% by catalase. Embryos deprived of trophoblast showed no light emission suggesting that the source of ROS generation is the trophoblast. Dihydronicotinamide adenine dinucleotide (NADH)-dependent oxidase activity in the plasma membrane of the trophoblast surface was demonstrated by cytochemical methods. The release of ROS into the extracellular medium during the phagocytic process has been related to the cytolytic effect exhibited by t...
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