Atividade anticoagulante, antioxidante e antitumoral de heterofucanas da alga Dictyopteris delicatula (Lamouroux, 1809)

In the present study, six families of sulfated polysaccharides were obtained from seaweed Dictyopteris delicatula (Lamouroux, 1809) and their anticoagulant, antioxidant and antitumor activities were evaluated. All fractions showed anticoagulant activity on aPTT assay, but not on PT assay. Fractions also exhibited total antioxidant activity, superoxide radical scavenging capacity and ferric chelating property. Thus, six fractions (F0.5v, F0.7v, F1.0v, F1.3v, F1.5v e F2.0v) we obtained by proteolytic digestion, followed by acetone fractionation and molecular sieving on Sephadex G-100. Chemical analyses demonstrated that all polysaccharides contain heterofucans composed mainly of fucose, xylose, glucose, galactose, uronic acid, and sulfate. Any fractions changed the PT. However, all fractions were able on double the aPPT on a dose-dependent manner. The heterofucans F0.7v and F1.0v showed low anticoagulant activity while F1.5v presented the most prominent anticoagulant activity .When compared to Clexane®, a low molecular weight heparin, at same concentration F1.5v presented similar anticoagulant activity. The fucans F0.5v and F0.7v at 1.0 mg/mL showed high ferric chelating activity (~45%), whereas fucans F1.3v (0.5 mg/mL) showed considerable reducing power, about 53.2% of the activity of vitamin C. The fucan F1.5v presented the most prominent anticoagulant activity. The best antiproliferative activity was found with fucans F1.3v and F0.7v. However, F1.3v activity was much higher than F0.7v inhibiting almost 100% of HeLa cell proliferation. These fucans have been selected for further studies on structural characterization as well as in vivo experiments, which are already in progress

Increased hippocampal excitability and impaired spatial memory function in mice lacking VGLUT2 selectively in neurons defined by tyrosine hydroxylase promoter activity

Three populations of neurons expressing the vesicular glutamate transporter 2 (Vglut2) were recently described in the A10 area of the mouse midbrain, of which two populations were shown to express the gene encoding, the rate-limiting enzyme for catecholamine synthesis, tyrosine hydroxylase (TH).One of these populations (‘‘TH– Vglut2 Class1’’) also expressed the dopamine transporter (DAT) gene while one did not ("TH–Vglut2 Class2"), and the remaining population did not express TH at all ("TH-Vglut2-only"). TH is known to be expressed by a promoter which shows two phases of activation, a transient one early during embryonal development, and a later one which gives rise to stable endogenous expression of the TH gene. The transient phase is, however, not specific to catecholaminergic neurons, a feature taken to advantage here as it enabled Vglut2 gene targeting within all three A10 populations expressing this gene, thus creating a new conditional knockout. These knockout mice showed impairment in spatial memory function. Electrophysiological analyses revealed a profound alteration of oscillatory activity in the CA3 region of the hippocampus. In addition to identifying a novel role for Vglut2 in hippocampus function, this study points to the need for improved genetic tools for targeting of the diversity of subpopulations of the A10 area

Caracterização parcial e atividades farmacológicas do extrato rico em polissacarídeos sulfatatos da angiosperma marinha Halodule wrightii

Sulfated polysaccharides (PS) are biomolecules with a great biotechnological potential. There are few data about PS from high plants. In addition, pharmacological activities of PS from plants have not been carrying out. The aim of this work was extract PS from the angiosperm Halodule wrightii and study their anticoagulant and antioxidant activities. Histological analysis showed the presence of the PS manly in the roots. A polysaccharide-rich extract was obtained from H. wrightii by proteolysis followed by methanol and TCA precipitation. Chemical, infra-red analysis and agarose gel electrophoresis in 1.3 diaminopropane acetate buffer confirmed the presence of sulfated polysaccharides made by glucose, galactose, xylose and sulfate residues in the proportion 1: 0,9: 1: 1. In addition polyacrilamide electrophoresis have shown that extract is mainly compose by 11kDa sulfated polysaccharides. Pharmacological analysis have shown total antioxidant capacity (CAT) that resulted in 15,21 μg for equivalent of ascorbic acid, scavenging activity of the DPPH radical with 41,36 % of scavenging, activity of reducing power with the maximum of 0,290 nm (50 % of vitamin C activity) and scavenging activity superoxide radical (O2-) with a maximum of 32,23 %. Chelating activity of metal less than 4% and scavenging activity of the radical hydroxyl (OH-) less than 2%. Time of activated partial tromboplastin (aPTT) doubling the time of coagulation from 20μg of and protrombin time (PT) was not present. The data indicate that PS from Halodule wrightii could be considered for future applications in medicine, food production or cosmetic industry

Caracterização parcial e atividades farmacológicas do extrato rico em polissacarídeos sulfatados da angiosperma marinha Halodule wrightii

Sulfated polysaccharides (PS) are biomolecules with a great biotechnological potential. There are few data about PS from high plants. In addition, pharmacological activities of PS from plants have not been carrying out. The aim of this work was extract PS from the angiosperm Halodule wrightii and study their anticoagulant and antioxidant activities. Histological analysis showed the presence of the PS manly in the roots. A polysaccharide-rich extract was obtained from H. wrightii by proteolysis followed by methanol and TCA precipitation. Chemical, infra-red analysis and agarose gel electrophoresis in 1.3 diaminopropane acetate buffer confirmed the presence of sulfated polysaccharides made by glucose, galactose, xylose and sulfate residues in the proportion 1: 0,9: 1: 1. In addition polyacrilamide electrophoresis have shown that extract is mainly compose by 11kDa sulfated polysaccharides. Pharmacological analysis have shown total antioxidant capacity (CAT) that resulted in 15,21 μg for equivalent of ascorbic acid, scavenging activity of the DPPH radical with 41,36 % of scavenging, activity of reducing power with the maximum of 0,290 nm (50 % of vitamin C activity) and scavenging activity superoxide radical (O2-) with a maximum of 32,23 %. Chelating activity of metal less than 4% and scavenging activity of the radical hydroxyl (OH-) less than 2%. Time of activated partial tromboplastin (aPTT) doubling the time of coagulation from 20μg of and protrombin time (PT) was not present. The data indicate that PS from Halodule wrightii could be considered for future applications in medicine, food production or cosmetic industry

Estudo das interações polifenol-proteína e das reações de escurecimento não-enzimático para o processamento de cajuína

The cashew, a fruit from Brazilian Northeast is used to produce juice due to its flavor and vitamin C richness. However, its acceptance is limited due to its astringency. Cajuína is a derivate product appreciated by its characteristic flavor, freshness and lack of astringency, due to tannin removal. Cajuína is a light yellow beverage made from clarified cashew juice and sterilized after bottling. It differs from the integral and concentrated juice by the clarification and thermal treatment steps. Many problems such as haze and excessive browning could appear if these steps are not controlled. The objective of this work was divided into two stages with the aim to supply process information in order to obtain a good quality product with uniform characteristics (sensory and nutritional). Polyphenol-protein interaction was studied at the clarification step, which is an empirical process, to provide values on the amount of clarifying solution (gelatin) that must be added to achieve a complete juice clarification. Clarification essays were performed with juice dilutions of 1:2 and 1:10 and the effect of metabissulfite and tannic acid addition was evaluated. It was not possible to establish a clarification point. Metabissulfite did not influenced the clarification process however tannic acid addition displaced the clarification point, showing the difficulty visual monitoring of the process. Thermal treatment of clarified juice was studied at 88, 100, 111 e 121 °C. To evaluate the non-enzymatic browning, vitamin C, 5-hidroximetilfurfural (5-HMF) and sugar variation were correlated with color parameters (reflectance spectra, color difference and CIELAB). Kinetic models were obtained for reflectance spectra, ascorbic acid and 5-HMF. It was observed that 5-HMF introduction followed a first order kinetic rate at the beginning of the thermal treatment and a zero order kinetic at later process stages. An inverse correlation was observed between absorbance at 420 nm and ascorbic acid degradation, which indicates that ascorbic acid might be the principal factor on cajuína non-enzymatic browning. Constant sugar concentration showed that this parameter did not contribute directly to the nonenzymatic browning. Optimization techniques showed showed that to obtain a high vitamin C and a low 5-HMF content, the process must be done at 120 ºC. With the water-bath thermal treatment, the 90 °C temperature promoted a lower ascorbic acid degradation at the expense of a higher 5-HMF level

Desenvolvimento de tensoativos e sistemas microemulsionados para recuperação de petróleo

The high concentration of residual oil is one of the greatest problems found in petroleum mature fields. In these reservoirs, different enhanced oil recovery methods (EOR) can be used, highlighting the microemulsion injection. The microemulsion has showed to be efficient in petroleum recovery due to its ability to promote an efficient displacement of the petroleum, acting directly in the residual oil. In this way, this research has as objective the study of microemulsion systems obtained using a commercial surfactant (TP), determining microemulsion thermal stabilities and selecting points inside the pseudoternary phases diagram, evaluating its efficiencies and choosing the best system, that has the following composition: TP as surfactant (S), isopropyl alcohol as co-surfactant (C), kerosene as oil phase, water as aqueous phase, C/S ratio = 1, and 5% sodium p-toluenesulfonate as hydrotope; being observed the following parameters for the selection of the best pseudoternary phases diagram: C/S ratio, co-surfactant nature and addition of hydrotope to the system. The efficiency in petroleum recovery was obtained using two sandstone formation systems: Assu and Botucatu. The study of thermal stabilities showed that as the concentration of active matter in the system increased, the thermal stability also increased. The best thermal stability was obtained using point F (79.56 0C). The system that presented the best recovery percentile between the three selected (3) was composed by: 70% C/S, 2% kerosene and 28% water, with 94% of total recovery efficiency and 60% with microemulsion injection, using the Botucatu formation, that in a general way presented greater efficiencies as compared with the Assu one (81.3% of total recovery efficiency and 38.3% with microemulsion injection)

Secagem de misturas de polpa de frutas tropicais em leito de jorro

Drying of fruit pulps in spouted beds of inert particles has been indicated as a viable technique to produce fruit powders. Most of the processes employed to produce dried fruit pulps and juices, such as Foam Mat, encapsulation by co-crystallization and spray drying utilize adjuvant and additives (such as thickeners, coating materials, emulsifiers, acidulants, flavors and dyes), which is not always desirable. The fruit pulp composition exerts an important effect on the fruit powder production using a spouted bed. In the study by Medeiros (2001) it was concluded that lipids, starch and pectin contents play an important role on the process performance, enhancing the powder production; however, the drying of fruit pulps containing high content of reducing sugars (glucose and fructose) is practically unviable. This work has the objective of expanding the studies on drying of fruit pulps in spouted bed with aid of adjuvant (lipids, starch and pectin) aiming to enhance the dryer performance without jeopardizing the sensorial quality of the product. The optimum composition obtained by Medeiros (2001) was the basis for preparing the mixtures of pulps. The mixture formulations included pulps of mango (Mangifera indica), umbu (Spondias tuberosa) and red mombin (Spondia purpurea) with addition of cornstarch, pectin and lipids. Different products were used as lipids source: olive and Brazil nut oils, coconut milk, heavy milk, powder of palm fat and palm olein. First of all, experiments were conducted to define the best formulation of the fruit pulps mixture. This definition was based on the drying performance obtained for each mixture and on the sensorial characteristics of the dry powder. The mixture formulations were submitted to drying at fixed operating conditions of drying and atomizing air flow rate, load of inert particles, temperature and flow rate of the mixture. The best results were obtained with the compositions having powder of palm fat and palm olein in terms of the drying performance and sensorial analysis. Physical and physicochemical characteristics were determined for the dry powders obtained from the mixtures formulations. Solubility and reconstitution time as well as the properties of the product after reconstitution were also evaluated. According to these analyses, the powder from the mixtures formulations presented similar characteristics and compatible quality to those produced in other types of dryers. Considering that the palm olein is produced in Brazil and that it has been used in the food industry substituting the palm fat powder, further studies on drying performance were conducted with the composition that included the palm olein. A complete factorial design of experiments 23, with three repetitions at the central point was conducted to evaluate the effects of the air temperature, feeding flow rate and intermittence time on the responses related to the process performance (powder collection efficiency, material retained in the bed and angle of repose of the inert particles after the process) and to the product quality (mean moisture content, loss of vitamin C and solubility). Powder production was uniform for the majority of the experiments and the higher efficiency with lower retention in the bed (59.2% and 1.8g, respectively) were obtained for the air temperature of 80°C, mixture feed rate of 5ml/min in intervals of 10 min. The statistical analysis of the results showed that the process variables had individual or combined significant influences on the powder collection efficiency, material retention in the bed, powder moisture content and loss of vitamin C. At the experimental ranges of this work, the angle of repose and solubility were not influenced by the operating variables. From the results of the experimental design, statistical models were obtained for the powder moisture content and loss of vitamin C

Caracterização e aplicação de sistemas micelares e microemulsionados como inibidores de corrosão

Corrosion is an important phenomenon that frequently occurs in the oil industry, causing surface ablation, such as it happens on the internal surfaces of oil pipes. This work aims to obtain new systems to reduce this specific problem. The surfactants SDS, CTAB, and UNITOL L90 (in micellar and microemulsionated systems) were used as corrosion inhibitors. The systems were obtained using a C/S ratio of 2, butanol as cosorfactant, kerosene as oil phase and, as water phase, NaCl solutions of 0.5M with pH = 2, 4, and 7. Microemulsion regions were found both for direct and inverse micelles. SDS had the higher microemulsion region and the area was not dependent of pH. The study of micellization of these surfactans in the liquid-gas interface was carried out via the determination of CMC from surface tension measurements. Regarding microemulsionated systems, in the case of CTAB, CMC increased when pH was increased, being constant for SDS and UNITOL L90. Concerning micellar systems, increase in pH caused decrease and increase in CMC for SDC and CTAB, respectively. In the case of UNITOL L90, CMC was practically constant, but increased for pH = 4. The microemulsionated systems presented higher CMC values, except for UNITOL L90 L90. The negative values of free energy of micellization indicated that the process of adsorption was spontaneous. The results also indicated that, comparing microemulsionated to systems, adsorption was less spontaneous in the case of SDS and CTAB, while it did not change for UNITOL L90. SAXS experiments indicated that micelle geometry was spherical, existing also as halter and flat micelles, resuting in a better inght on the adsorption at the liquid-solid interface. Efficiency of corrosion inhibition as determined by electrochemical measurements, from corrosion currents calculated from Tafel extrapolation indicuting heat showed surfactants to be efficient even at low concentrations. Equilibrium isotherm data were fitted to the Freundlich model, indicating that surfactant adsorption occurs in the form of multilayers

Secagem de misturas de polpa de frutas tropicais em leito de jorro

Drying of fruit pulps in spouted beds of inert particles has been indicated as a viable technique to produce fruit powders. Most of the processes employed to produce dried fruit pulps and juices, such as Foam Mat, encapsulation by co-crystallization and spray drying utilize adjuvant and additives (such as thickeners, coating materials, emulsifiers, acidulants, flavors and dyes), which is not always desirable. The fruit pulp composition exerts an important effect on the fruit powder production using a spouted bed. In the study by Medeiros (2001) it was concluded that lipids, starch and pectin contents play an important role on the process performance, enhancing the powder production; however, the drying of fruit pulps containing high content of reducing sugars (glucose and fructose) is practically unviable. This work has the objective of expanding the studies on drying of fruit pulps in spouted bed with aid of adjuvant (lipids, starch and pectin) aiming to enhance the dryer performance without jeopardizing the sensorial quality of the product. The optimum composition obtained by Medeiros (2001) was the basis for preparing the mixtures of pulps. The mixture formulations included pulps of mango (Mangifera indica), umbu (Spondias tuberosa) and red mombin (Spondia purpurea) with addition of cornstarch, pectin and lipids. Different products were used as lipids source: olive and Brazil nut oils, coconut milk, heavy milk, powder of palm fat and palm olein. First of all, experiments were conducted to define the best formulation of the fruit pulps mixture. This definition was based on the drying performance obtained for each mixture and on the sensorial characteristics of the dry powder. The mixture formulations were submitted to drying at fixed operating conditions of drying and atomizing air flow rate, load of inert particles, temperature and flow rate of the mixture. The best results were obtained with the compositions having powder of palm fat and palm olein in terms of the drying performance and sensorial analysis. Physical and physicochemical characteristics were determined for the dry powders obtained from the mixtures formulations. Solubility and reconstitution time as well as the properties of the product after reconstitution were also evaluated. According to these analyses, the powder from the mixtures formulations presented similar characteristics and compatible quality to those produced in other types of dryers. Considering that the palm olein is produced in Brazil and that it has been used in the food industry substituting the palm fat powder, further studies on drying performance were conducted with the composition that included the palm olein. A complete factorial design of experiments 23, with three repetitions at the central point was conducted to evaluate the effects of the air temperature, feeding flow rate and intermittence time on the responses related to the process performance (powder collection efficiency, material retained in the bed and angle of repose of the inert particles after the process) and to the product quality (mean moisture content, loss of vitamin C and solubility). Powder production was uniform for the majority of the experiments and the higher efficiency with lower retention in the bed (59.2% and 1.8g, respectively) were obtained for the air temperature of 80°C, mixture feed rate of 5ml/min in intervals of 10 min. The statistical analysis of the results showed that the process variables had individual or combined significant influences on the powder collection efficiency, material retention in the bed, powder moisture content and loss of vitamin C. At the experimental ranges of this work, the angle of repose and solubility were not influenced by the operating variables. From the results of the experimental design, statistical models were obtained for the powder moisture content and loss of vitamin C

Increased hippocampal excitability and impaired spatial memory function in mice lacking VGLUT2 selectively in neurons defined by tyrosine hydroxylase promoter activity

Three populations of neurons expressing the vesicular glutamate transporter 2 (Vglut2) were recently described in the A10 area of the mouse midbrain, of which two populations were shown to express the gene encoding, the rate-limiting enzyme for catecholamine synthesis, tyrosine hydroxylase (TH).One of these populations (‘‘TH– Vglut2 Class1’’) also expressed the dopamine transporter (DAT) gene while one did not ("TH–Vglut2 Class2"), and the remaining population did not express TH at all ("TH-Vglut2-only"). TH is known to be expressed by a promoter which shows two phases of activation, a transient one early during embryonal development, and a later one which gives rise to stable endogenous expression of the TH gene. The transient phase is, however, not specific to catecholaminergic neurons, a feature taken to advantage here as it enabled Vglut2 gene targeting within all three A10 populations expressing this gene, thus creating a new conditional knockout. These knockout mice showed impairment in spatial memory function. Electrophysiological analyses revealed a profound alteration of oscillatory activity in the CA3 region of the hippocampus. In addition to identifying a novel role for Vglut2 in hippocampus function, this study points to the need for improved genetic tools for targeting of the diversity of subpopulations of the A10 area

Caracterização parcial e atividades farmacológicas do extrato rico em polissacarídeos sulfatatos da angiosperma marinha Halodule wrightii

Sulfated polysaccharides (PS) are biomolecules with a great biotechnological potential. There are few data about PS from high plants. In addition, pharmacological activities of PS from plants have not been carrying out. The aim of this work was extract PS from the angiosperm Halodule wrightii and study their anticoagulant and antioxidant activities. Histological analysis showed the presence of the PS manly in the roots. A polysaccharide-rich extract was obtained from H. wrightii by proteolysis followed by methanol and TCA precipitation. Chemical, infra-red analysis and agarose gel electrophoresis in 1.3 diaminopropane acetate buffer confirmed the presence of sulfated polysaccharides made by glucose, galactose, xylose and sulfate residues in the proportion 1: 0,9: 1: 1. In addition polyacrilamide electrophoresis have shown that extract is mainly compose by 11kDa sulfated polysaccharides. Pharmacological analysis have shown total antioxidant capacity (CAT) that resulted in 15,21 μg for equivalent of ascorbic acid, scavenging activity of the DPPH radical with 41,36 % of scavenging, activity of reducing power with the maximum of 0,290 nm (50 % of vitamin C activity) and scavenging activity superoxide radical (O2-) with a maximum of 32,23 %. Chelating activity of metal less than 4% and scavenging activity of the radical hydroxyl (OH-) less than 2%. Time of activated partial tromboplastin (aPTT) doubling the time of coagulation from 20μg of and protrombin time (PT) was not present. The data indicate that PS from Halodule wrightii could be considered for future applications in medicine, food production or cosmetic industry

Caracterização parcial e atividades farmacológicas do extrato rico em polissacarídeos sulfatados da angiosperma marinha Halodule wrightii

Sulfated polysaccharides (PS) are biomolecules with a great biotechnological potential. There are few data about PS from high plants. In addition, pharmacological activities of PS from plants have not been carrying out. The aim of this work was extract PS from the angiosperm Halodule wrightii and study their anticoagulant and antioxidant activities. Histological analysis showed the presence of the PS manly in the roots. A polysaccharide-rich extract was obtained from H. wrightii by proteolysis followed by methanol and TCA precipitation. Chemical, infra-red analysis and agarose gel electrophoresis in 1.3 diaminopropane acetate buffer confirmed the presence of sulfated polysaccharides made by glucose, galactose, xylose and sulfate residues in the proportion 1: 0,9: 1: 1. In addition polyacrilamide electrophoresis have shown that extract is mainly compose by 11kDa sulfated polysaccharides. Pharmacological analysis have shown total antioxidant capacity (CAT) that resulted in 15,21 μg for equivalent of ascorbic acid, scavenging activity of the DPPH radical with 41,36 % of scavenging, activity of reducing power with the maximum of 0,290 nm (50 % of vitamin C activity) and scavenging activity superoxide radical (O2-) with a maximum of 32,23 %. Chelating activity of metal less than 4% and scavenging activity of the radical hydroxyl (OH-) less than 2%. Time of activated partial tromboplastin (aPTT) doubling the time of coagulation from 20μg of and protrombin time (PT) was not present. The data indicate that PS from Halodule wrightii could be considered for future applications in medicine, food production or cosmetic industry