Himatanthus bracteatus-Composed In Situ Polymerizable Hydrogel for Wound Healing.

The Himatanthus genus presents anti-inflammatory, antioxidant activities, suggesting potential wound-healing properties. This study aimed to develop and analyze the wound-healing properties of a photopolymerizable gelatin-based hydrogel (GelMA) containing an ethanolic extract of Himatanthus bracteatus in a murine model. The extract was obtained under high pressure conditions, incorporated (2%) into the GelMA (GelMA-HB), and physically characterized. The anti-inflammatory activity of the extract was assessed using a carrageenan-induced pleurisy model and the GelMA-HB scarring properties in a wound-healing assay. The extract reduced IL-1ß and TNF-α levels (48.5 ± 6.7 and 64.1 ± 4.9 pg/mL) compared to the vehicle (94.4 ± 2.3 pg/mL and 106.3 ± 5.7 pg/mL; p < 0.001). GelMA-HB depicted significantly lower swelling and increased resistance to mechanical compression compared to GelMA (p < 0.05). GelMA-HB accelerated wound closure over the time course of the experiment (p < 0.05) and promoted a significantly greater peak of myofibroblast differentiation (36.1 ± 6.6 cells) and microvascular density (23.1 ± 0.7 microvessels) on day 7 in comparison to GelMA (31.9 ± 5.3 cells and 20.2 ± 0.6 microvessels) and the control (25.8 ± 4.6 cells and 17.5 ± 0.5 microvessels) (p < 0.05). In conclusion, GelMA-HB improved wound healing in rodents, probably by modulating the inflammatory response and myofibroblastic and microvascular differentiation.

Influence of seasonality on the physicochemical properties of Moringa oleifera Lam. Seed oil and their oleochemical potential.

The effect of abiotic factors, such as weather and climate can alter the properties of vegetable oils. In this work, the effects of the refining process and pre-drying of Moringa oleifera Lam. seeds collected in the dry and rainy seasons (seasonality) were evaluated on the characteristics of the extracted oils. The refined and crude dry season oils had lower acidity and moisture content than the dry and raw rainy season oils. Oleic acid (C18:1) showed the highest concentration in the different Moringa oils studied. The results suggest that dry season oils are more suitable for application as feedstocks in the cosmetic, food, medicinal and pharmaceutical industries. Furthermore, refining proved to be efficient in removing free fatty acids and in lightening the oil.

Oleochemistry potential from Brazil northeastern exotic plants.

Caatinga is a Brazilian semi-arid ecosystem that stands out for presenting unique environmental characteristics with a dry, spiny and deciduous shrub/forest vegetation with several species that can be renewable oil sources with potential applicability in oleochemical and nutrition. Caatinga oilseeds have a high content of unsaturated fatty acids, phytosterols and sterols, and this composition is related to its nutritional potential. The present review summarizes the knowledge on the oil contents and fatty acid profiles of seeds from six representatives caatinga species. It was observed that plants species like Caju (Anacardium occidentale L.), Favela (Cnidoscolus quercifolius Pohl), Licuri (Syagrus coronata (Mart.) Becc.), Pinhão-bravo (Jatropha mollissima Pohl Baill), Pequi (Caryocar brasiliense Camb) and Oiticica (Licania rígida Benth) contains approximately 33.1, 33.5, 49.2, 18.3, 70.16 and 57.0% w/w of oil, respectively, on a dry weight basis. Their fatty acid profiles are mostly saturated for Licuri oil, with a high content of lauric acid (up to 40%) and unsaturated for Favela, Pinhão-bravo, Cashew nut, Pequi and Oiticica oils. Oiticica oil shows a high concentration of unusual conjugated polyunsaturated fatty acids, like α-Eleostearic and Licanic acid with 16.90 and 43.20% w/w, respectively.

Surface crystallization of ionic liquid crystals.

The evidence for surface crystallization in ionic liquids is scarce. The existing reports seem to be contradictory as for its driving forces, since in the two compounds investigated in the literature, the contribution of coloumbic and van der Waals forces is very different. In this work 1-dodecyl-3-methylimidazolium tetrafluoroborate was studied and its surface crystallization characterized by surface tension, ellipsometry and optical microscopy. The results obtained seem to reconcile previous observations, and it was further shown, using the same techniques, that this phenomenon is prevalent in other ionic liquids. MD simulation results illustrate the different possibilities of organization, providing reasonable models to rationalize the experimental observations.

Influence of magnetic field on barium sulfate incrustation from aqueous solutions.

The formation of scales in the petroleum industry, such as those composed of calcium and barium sulfates, may reduce productivity since these sediments can partially or totally obstruct the pipes. The mitigation of these inorganic precipitates can be accomplished by using scale inhibitors or by non-intrusive physical technologies. Here, we investigated the influence of magnetic field on the incrustations of barium sulfate by analyzing the concentration of barium and sulfate ions, the solution flow rate, the capillary tube geometry, and the magnetic field intensity in a homemade experimental unit supported on the monitoring of the dynamic differential pressure. The results show that the saline concentration and the flow rate of the solutions and the geometry of the capillary tube have a significant influence on the dynamics of barium sulfate incrustation. The presence of the magnetic field tends to prolong the induction time of the barium sulfate precipitation. A semi-empirical model was used to describe the effect of the studied variables on the barium sulfate incrustation behavior. The X-ray diffraction data of the precipitated particles analyzed using the Rietveld method suggest that the use of the magnetic field favor the formation of more crystalline particles and with smaller crystallite size than those formed in the absence of a magnetic field. Optical and scanning electron microscopy measurements also corroborate with these findings. The results from this study suggest that magnetic fields can be of interest in practical crystallization processes of barium sulfate and successfully applied to decrease the speed of barium sulfate incrustation in pipelines.

Antiproliferative Activity of Neem Leaf Extracts Obtained by a Sequential Pressurized Liquid Extraction.

Azadirachta indica A. Juss (neem) extracts have been used in pharmaceutical applications as antitumor agents, due to their terpenes and phenolic compounds. To obtain extracts from neem leaves with potential antiproliferative effect, a sequential process of pressurized liquid extraction was carried out in a fixed bed extractor at 25 °C and 100 bar, using hexane (SH), ethyl acetate (SEA), and ethanol (SE) as solvents. Extractions using only ethanol (EE) was also conducted to compare the characteristics of the fractionated extracts. The results obtained by liquid chromatography-electrospray ionization mass spectrometry suggested a higher concentration of terpenes in the SEA extract in comparison to SH, SE, and EE extracts. Therefore, antiproliferative activity showed that SEA extracts were the most efficient inhibitor to human tumor cells MCF-7, NCI-H460, HeLa, and HepG2. Hepatocellular cells were more resistant to SH, SEA, SE, and EE compared to breast, lung, hepatocellular, and cervical malignant cells. Neem fractioned extracts obtained in the present study seem to be more selective for malignant cells compared to the non-tumor cells.

Thermoliquefaction of palm oil fiber (Elaeis sp.) using supercritical ethanol.

Thermoliquefaction of palm oil fiber was investigated using supercritical ethanol as solvent. A semi-continuous laboratory scale unit was developed to investigate the effects of temperature (300-500°C), heating rate (10-30°C.min-1) and cracking time (10-30min) on the conversion of biomass in bio-oil. The main advantage of the proposed process is that a pure solvent is pumping through the reactor that contains the biomass, dispensing the use of biomass slurries. The yield of bio-oil ranged from 56% to 84%, depending on the experimental conditions. It was observed that an increase in working temperature led to an increase in the bio-oil production. Cracking time and heating rate variation had not shown a considerable effect on the conversion of biomass. The chemical profiles of bio-oil determined by GC/MS, indicate that at low temperature mainly sugar derivatives are produced, while at higher temperatures alcohols and phenolic are the majority compounds of the bio-oil.

Stability and structural changes of horseradish peroxidase: microwave versus conventional heating treatment.

Effects of conventional heating (CH) and microwave (MW) on the structure and activity of horseradish peroxidase (HRP) in buffer solution were studied. CH incubation between 30 and 45 °C increased activity of HRP, reaching 170% of residual activity (RA) after 4-6 h at 45 °C. CH treatment at 50 and 60 °C caused HRP inactivation: RA was 5.7 and 16.7% after 12 h, respectively. Secondary and tertiary HRP structural changes were analyzed by circular dichroism (CD) and intrinsic fluorescence emission, respectively. Under CH, activation of the enzyme was attributed to conformational changes in secondary and tertiary structures. MW treatment had significant effects on the residual activity of HRP. MW treatment at 45 °C/30W followed by CH treatment 45 °C regenerated the enzyme activity. The greatest loss in activity occurred at 60 °C/60 W/30 min (RA 16.9%); without recovery of the original activity. The inactivation of MW-treated HRP was related to the loss of tertiary structure, indicating changes around the tryptophan environment.

Kinetic modeling of solvent-free lipase-catalyzed partial hydrolysis of palm oil.

This work reports the experimental data and kinetic modeling of diacylglycerol (DAG) production from palm oil using a commercial immobilized lipase (Lipozyme RM IM) in a solvent-free medium. The experiments were performed in batch mode, at 55 °C and 400 rpm, and the effects of enzyme concentration (0.68-2.04 wt% related to the mass of substrates), initial water concentration (5-15 wt% related to the mass of oil), and reaction time were evaluated. A novel kinetic model is presented based on the ordered-sequential bi-bi mechanism considering hydrolysis and esterification steps, in which a correlation between water-in-oil solubility and surfactant molecules concentration in the oil allowed the model to describe the induction period in the beginning of the hydrolysis reaction. Moreover, mass transfer limitations related to the enzyme concentration in the system were also taken into account. The proposed model presented a very satisfactory agreement with the experimental data, thus allowing a better understanding of the reaction kinetics. The best conditions obtained for the product (partially hydrolyzed palm oil) in terms of DAG yield (35.91 wt%) were 2.87 wt% enzyme/substrate, 2.10 wt% water/oil, and 72 h of reaction.

Solid-state radical grafting reaction of glycidyl methacrylate and poly(4-methyl-1-pentene) in supercritical carbon dioxide: surface morphology and adhesion.

Solid-state radical grafting of glycidyl methacrylate (GMA) onto poly(4-methyl-1-pentene) (PMP) was performed using supercritical carbon dioxide (scCO(2)) impregnation technology. The polymer films were firstly impregnated in the scCO(2) phase with the GMA using benzoyl peroxide as thermal initiator. The grafting degree and surface morphology of the samples may be controlled by the following factors: time, temperature, and pressure of impregnation. A 2(3) factorial design to evaluate the main and interaction effects of such factors on the grafting of the PMP by GMA (grafting response) was elaborated from FTIR data. The superior and inferior limits of the levels were defined on basis of a P-x-y diagram for binary system CO(2)+GMA that provided the location of the transition curves of such a system. Better grafting response was obtained for pressure of 130 bar, temperature of 70°C and time of 7h. The PMP-g-GMA films exhibited a thermal profile similar to that of the unmodified polymer. Adhesion characteristics of polymer films are dependent on grafting degree of GMA.

Analysis of organic compounds of water-in-crude oil emulsions separated by microwave heating using comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry.

In this work the higher peak capacity and resolution of comprehensive two-dimensional gas chromatography (GCxGC) has been successfully applied, for the first time, to tentatively identify several polar organic compounds of organic extracts of aqueous phases resulting from microwave demulsification process of water-in-crude oil emulsions. Results have shown that higher temperatures and longer exposure time to microwave irradiation produced water phases with a wider variety of polar organic compounds. The microwave process showed to be suitable for the extraction of several polar compounds classes of petroleum. The proposed microwave extraction method and GCxGC identification of polar compounds of petroleum samples are of practical interest for the petrochemical industry due to corrosion and related problems associated with these polar compounds in refinery equipments. The GCxGC/time-of-flight MS technique shows to be very important in the total separation of different classes of compounds and allows the identification of many compounds in these classes.

Pressurized liquid extraction of mate tea leaves.

The objective of this work is to investigate the influence of process parameters on the pressurized liquid extraction (PLE) of Ilex paraguariensis leaves. A factorial 2(6-2) experimental design was employed using responses as the extraction yield and the chromatographic profile of the extracts. The extraction time, polarity of solvent, amount of sample, numbers of PLE cycles, flushing volume and extraction temperature were selected as independent variables (factors). Results obtained indicated that the solvent polarity was the most significant variable in the study, while the amount of sample and extraction temperature also showed significant effect. The other variables did not present significant influence in the yield of extraction. GC/MS analysis of the extract enabled the identification of saturated hydrocarbons, fatty acids, fatty acid methyl esters, phytosterols and theobromine in the extracts. Quantitative analysis of four compounds presented in the extracts (caffeine, phytol, vitamin E and squalene) was performed by the GC/MS in the SIM mode.

Extraction of grape seed oil using compressed carbon dioxide and propane: extraction yields and characterization of free glycerol compounds.

The main objective of this work was to compare the extraction of grape seed oil with compressed carbon dioxide and propane on the extraction yields and chemical characteristics of free glycerol compounds. The experiments were performed in a laboratory scale unit in the temperature range of 30 to 60 degrees C and pressures from 60 to 254 bar. The results showed that propane is a more suitable solvent for grape seed oil extraction than carbon dioxide, as higher extractions yields and a very fast kinetic of extraction were achieved with this solvent. In relation to compressed carbon dioxide extractions, both temperature and density presented a very pronounced and positive effect on the extraction yield. The oils extracted were analyzed qualitatively and quantitatively with regard to the free glycerol compounds, mainly fatty acids, ethyl, and methyl esters. The results showed that these compounds are present in low concentration in vegetable oil (<3%) and that, in general, samples extracted with propane present a smaller amount of peaks of free glycerol compounds in the oil than samples extracted with carbon dioxide.

Semi-volatile compounds variation among Brazilian populations of Ilex paraguariensis St. Hil

The use of compressed carbon towards extracting semi-volatile compounds present in maté leaves (Ilex paraguariensis St. Hil.) is due to the growing interest in mate constituents to develop new products in the cosmetic, pharmaceutical and food industries. The objective of this work was to assess the chemical distribution of semi-volatile compounds in 20 native populations of maté collected all over Brazil. The extracts of bulk samples (30 plants) of each population were obtained by the high-pressure carbon dioxide extraction technique, and analyzed by GC/MSD. The quantification of compounds (caffeine, theobromine, phytol, squalene, vitamin E, eicosane, pentatriacontane, and stigmasterol) showed significant variations within the different populations and compounds analyzed, which are not related to geographical origin or macroclimate characteristics. The results pointed out to the importance of genetic and local environmental factors on the chemical composition of this species.

A extração empregando dióxido de carbono a altas pressões em erva-mate (Ilex paraguariensis St. Hil.), tem sido justificada pelo crescente interesse desta matriz vegetal ou de parte de seus constituintes na formulação de novos produtos, tais como cosméticos e medicamentos, entre outros. Neste contexto, o objetivo do presente trabalho é avaliar a distribuição química de compostos semi-voláteis em 20 populações de erva-mate coletadas em toda área de distribuição desta espécie no Brasil. 30 plantas foram selecionadas para produzir a amostra de cada população. Os extratos de cada amostra foram obtidos por extração com dióxido de carbono a alta pressão e, posteriormente, foram analisados por CG/EM. A quantificação de alguns compostos semi-voláteis presentes nos extratos (cafeína, teobromina, fitol, esqualeno, vitamina E, eicosano, pentatriacontano e stigmasterol), apresentaram variações significativas entre as concentrações dos diferentes compostos analisados nas diferentes populações, os quais não estão relacionados com origem geográfica ou com características de macroclima. Os resultados apontam para a importância dos fatores genéticos e/ou fatores de microclima sobre a composição química desta espécie.

Oxidases from mate tea leaves (Ilex paraguariensis): extraction optimization and stability at low and high temperatures.

Mate (Ilex paraguariensis) is an important natural product in the economic and cultural context of Brazil. Peroxidase and polyphenol oxidase have been responsible for quality deterioration and browning in mate. The objective of this work was to investigate a methodology of extraction and enzymatic activity determination of oxidases present in mate tea leaves and to evaluate the oxidases stability. The effects of raw-material mass, buffer molar concentration, Triton X-100 addition, extraction pH, pH activity measurement, polyvinylpyrrolidone K90 addition, and centrifugation time were evaluated by the experimental planning methodology. The storage of the oxidases along 150 days at low temperatures showed that no significant difference was found at -4 and -80 degrees C but significant difference was observed when compared to 4 degrees C. The results showed that higher activities of oxidases are obtained at similar conditions. The exposition to high-temperatures and the variation of the time of exposition affected the enzymatic activity significantly.

Influence of drying methods and agronomic variables on the chemical composition of mate tea leaves (Ilex paraguariensis A. St.-Hil) obtained from high-pressure CO2 extraction.

The main objective of this work is to assess the influence of two drying methods (microwave and vacuum oven) and some agronomic variables (plant fertilization conditions and sunlight intensity) on the characteristics of mate tea (Ilex paraguariensis) leaves extracts obtained from high-pressure carbon dioxide extractions performed in the temperature range from 20 to 40 degrees C and from 100 to 250 bar. Samples of mate were collected in an experiment conducted under agronomic control at Ervateira Barão LTDA, Brazil. Chemical distribution of the extracts was evaluated by gas chromatography coupled with a mass spectrometer detector (GC/MS). In addition to extraction variables, results showed that both sample drying methods and agronomic conditions exert a pronounced influence on the extraction yield and on the chemical distribution of the extracts.

Influence of agronomic variables on the macronutrient and micronutrient contents and thermal behavior of mate tea leaves (Ilex paraguariensis).

The influence of agronomic variables (light intensity, age of leaves, and fertilization type) on the content of macronutrients and micronutrients (potassium, calcium, sodium, magnesium, manganese, iron, zinc, and copper) of tea leaves was assessed by acid digestion, followed by flame atomic absorption spectrometry (FAAS). The thermal behavior of mate tea leaves (Ilex paraguariensis) was also studied in this work. Samples of mate (Ilex paraguariensis) were collected in an experiment conducted under agronomic control at Erva-Mate Barão Commerce and Industry LTD (Brazil). The results showed that the mineral content in mate is affected by the agronomic variables investigated. In general, the content of mineral compounds analyzed is higher for younger leaves and for plants cultivated in shadow. Thermal analysis of samples indicated a similar behavior, with three typical steps of decomposition: loss of water, degradation of low-molecular weight compounds, and degradation of residual materials.

The use of ultrasound in the extraction of Ilex paraguariensis leaves: a comparison with maceration.

The objective of this work is to discuss the main parameters that influence the sonication extraction of Ilex paraguariensis leaves. For this purpose, the extraction time, solvent polarity, solvent volume, sample mass and particle size were evaluated. Results showed that the main variable affecting the extraction process was the solvent polarity. Though in a less extent, temperature and extraction time also demonstrated to be important parameters, while the other variables did not present a significant influence on the extraction yield. The extracts at the optimized condition were compared with those obtained by maceration, in terms of mass yield and chemical composition. The major compounds identified in the extracts were caffeine and palmitic acid. Some saturated hydrocarbons such as fatty acids, fatty acid methyl esters, phytosterols, and theobromine were also identified in the fractions.

Microorganism screening for limonene bioconversion and correlation with RAPD markers.

The use of microorganisms for biotransformations of monoterpenes has stimulated the biotechnological market. Aiming at the highest efficiency in the process of strains screening, the application of molecular biology techniques have been proposed. Based on these aspects, the objective of this work was to select different strains able to convert limonene using fermentative process and random amplified polymorphic DNA (RAPD) markers. The results obtained in the fermentative screening, from 17 strains tested, pointed out that four microorganisms were able to convert limonene into oxygenated derivatives. The RAPD study showed a polymorphism of 96.02% and a similarity from 16.02 to 51.51%. Based on this it was possible to observe a high genetic diversity, even among strains of same species, concluding that the RAPD was not able to correlate the genetic characteristics of the microorganism with the results obtained from the biotransformation process.

Optimization of the sonication extraction method of Hibiscus tiliaceus L. flowers.

The influence of several experimental parameters on the ultrasonic extraction of Hibiscus tiliaceus L. flowers were investigated: extraction time, solvent polarity, sample amount, solvent volume and sample particle size. It was concluded that the most influential variables were extraction time and solvent polarity. The optimized procedure employed 5 g of ground flowers, 150 mL of methanol and 140 min of extraction. The extracts were fractionated using preparative silica columns and the resulting fractions were analyzed by GC/MS. Some saturated hydrocarbons, fatty acids, fatty acid methyl esters, phytosterols, and vitamin E were identified in the plant extracts.