RESUMO
This work proposes the pyrolysis of the cassava plant shoot system biomass and a comprehensive chemical characterization of the resulting bio-oil. The highest yields of liquid products were obtained at 600 °C, with 12.6 % bio-oil (organic fraction), which presented the lowest total acid number of 65.7 mg KOH g-1. The bio-oil produced at 500 °C exhibited the highest total phenolic content of approximately 41 % GAE, confirmed by GC/MS analysis (33.8 % of the total area). FT-Orbitrap MS analysis found hundreds of oxygenated constituents in the bio-oils, belonging to the O2-7 classes, as well as nitrogen compounds from the Ny and OxNy classes. Higher pyrolysis temperatures resulted in more oxygenated phenolics (O4-7) undergoing secondary degradation and deoxygenation reactions, generating O2-3 compounds. Additional classes affected were O3-5N2-3, while O1-2N1 presented more stable compounds. These findings show that cassava bio-oils are promising sources of renewable chemicals.
Assuntos
Manihot , Oxigênio , Brotos de Planta , Pirólise , Manihot/química , Brotos de Planta/química , Oxigênio/metabolismo , Nitrogênio , Biocombustíveis , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectrometria de Massas/métodos , Compostos de Nitrogênio/química , Óleos de Plantas , PolifenóisRESUMO
The development of engineered nanomaterials has been considered a promising strategy to control oral infections. In this study, silver-embedded carbon nitrides (Ag@g-CN) were synthesized and tested against Candida albicans, investigating their antifungal action and biocompatibility in animal cells. Ag@g-CN was synthesized by a simple one-pot thermal polymerization technique and characterized by various analytical techniques. X-ray diffraction (XRD) analysis revealed slight alterations in the crystal structure of g-CN upon the incorporation of Ag. Fourier transform infrared (FT-IR) spectroscopy confirmed the presence of Ag-N bonds, indicating successful silver incorporation and potential interactions with g-CN's amino groups. UV-vis spectroscopy demonstrated a red shift in the absorption edge of Ag@g-CN compared with g-CN, attributed to the surface plasmon resonance effect of silver nanoparticles. Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) confirmed the 2D layered sheet like morphology of both materials. The Ag 3d peaks found in X-ray photoelectron spectroscopy (XPS) confirmed the presence of metallic Ag0 nanoparticles in Ag@g-CN. The Ag@g-CN materials exhibited high antifungal activity against reference and oral clinical strains of C. albicans, with minimal inhibitory concentration (MIC) ranges between 16-256 µg/mL. The mechanism of Ag@g-CN on C. albicans was attributed to the disruption of the membrane integrity and disturbance of the biofilm. In addition, the Ag@g-CN material showed good biocompatibility in the fibroblastic cell line and in Galleria mellonella, with no apparent cytotoxicity observed at a concentration up to 1000 µg/mL. These findings demonstrate the potential of the Ag@g-CN material as an effective and safe antifungal agent for the treatment of oral fungal infections.
Assuntos
Antifúngicos , Candida albicans , Nanopartículas Metálicas , Prata , Candida albicans/efeitos dos fármacos , Prata/química , Prata/farmacologia , Antifúngicos/farmacologia , Antifúngicos/química , Antifúngicos/síntese química , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Animais , Testes de Sensibilidade Microbiana , Compostos de Nitrogênio/química , Compostos de Nitrogênio/farmacologia , Compostos de Nitrogênio/toxicidade , Camundongos , NitrilasRESUMO
The objective of our study was to evaluate the effect of the use of legume (Arachis pintoi) or nitrogen fertilization on animal performance, characteristics of carcass and meat, and fatty acids profile of crossbred steers on Megathyrsus maximus cv. Aruana pasture, overseeded with temperate grasses. The experimental design was completely randomized, with three treatments and three replicates. The experiment was carried out from June to October (127 d). The treatments were: Low-N: 100 kg of N/ha; Medium-N: 200 kg of N/ha; and Legume: Arachis pintoi + 100 kg of N/ha. The pasture with higher nitrogen fertilization (N200) showed a more significant forage mass yield. The mixed grass with legumes presented a higher concentration of saturated fatty acids and saturated:unsaturated ratio in the meat. However, the grass pastures resulted in a higher content of unsaturated fatty acids in the meat. The other pasture variables, and characteristics of carcass and meat were not influenced by the treatments. The increase in nitrogen fertilization, from 100 to 200 kg/ha, and Arachis pintoi mixed with Aruana grass pasture overseeded with black oat and ryegrass does not affect the daily weight gain and the carcass and meat characteristics of the steers. The grass-legume mixture decreases the total concentration of unsaturated fatty acids in meat without influencing the concentration of polyunsaturated fatty acids.(AU)
Assuntos
Animais , Bovinos/fisiologia , Compostagem/métodos , Pastagens , Ingestão de Alimentos/fisiologia , Compostos de Nitrogênio/química , Poaceae/fisiologia , Fabaceae/químicaRESUMO
Aim: With the increasing abuse of antibacterial drugs, multidrug-resistant bacteria have become a burden on human health and the healthcare system. To find alternative compounds effective against hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA), novel derivatives of ocotillol were synthesized. Methods & Results: Ocotillol derivatives with polycyclic nitrogen-containing groups were synthesized and evaluated for in vitro antibacterial activity. Compounds 36-39 exhibited potent antibacterial activity against HA-MRSA, with MIC = 8-64 µg/ml. Additionally, a combination of compound 37 and the commercially available antibiotic kanamycin showed synergistic inhibitory effects, with a fractional inhibitory concentration index of ≤0.375. Conclusion: Compound 37 has a strong inhibitory effect, and this derivative has potential for use as a pharmacological tool to explore antibacterial mechanisms.
Assuntos
Antibacterianos/farmacologia , Desenho de Fármacos , Ginsenosídeos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Compostos de Nitrogênio/farmacologia , Compostos Policíclicos/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Ginsenosídeos/síntese química , Ginsenosídeos/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Compostos de Nitrogênio/química , Compostos Policíclicos/químicaRESUMO
This article aims to determine the adequate pasture height and the nitrogen dose at the beginning of the deferral period for Urochloa brizantha cv. Marandu (Marandu palisade grass). Two pasture heights (15 and 30 cm) and four nitrogen doses (0, 40, 80, and 120 kg ha-1) were evaluated in a completely randomized factorial (4x2) design with three replications. A linear increase in the number of vegetative tillers was observed with the application of nitrogen in the 15-cm deferred pasture. The lengths of stem and leaf blades of tillers increased linearly with the application of nitrogen. The weight of the vegetative tillers was greater in the 30-cm deferred pasture, compared to the 15-cm one when the pasture was fertilized with 0 and 40 kg ha-1 of N. The nitrogen fertilization linearly increased the weight of both the vegetative tillers in the 15-cm deferred pastures and the reproductive tillers in the 30-cm deferred pastures. The recommendation is that Marandu palisade grass be deferred with 15 cm and fertilized with 80 kg ha-1 of N at the beginning of the deferment period.
Assuntos
Brachiaria/química , Compostos de Nitrogênio/análise , Compostos de Nitrogênio/química , Pastagens/análise , Pastagens/métodos , CompostagemRESUMO
This article aims to determine the adequate pasture height and the nitrogen dose at the beginning of the deferral period for Urochloa brizantha cv. Marandu (Marandu palisade grass). Two pasture heights (15 and 30 cm) and four nitrogen doses (0, 40, 80, and 120 kg ha-1) were evaluated in a completely randomized factorial (4x2) design with three replications. A linear increase in the number of vegetative tillers was observed with the application of nitrogen in the 15-cm deferred pasture. The lengths of stem and leaf blades of tillers increased linearly with the application of nitrogen. The weight of the vegetative tillers was greater in the 30-cm deferred pasture, compared to the 15-cm one when the pasture was fertilized with 0 and 40 kg ha-1 of N. The nitrogen fertilization linearly increased the weight of both the vegetative tillers in the 15-cm deferred pastures and the reproductive tillers in the 30-cm deferred pastures. The recommendation is that Marandu palisade grass be deferred with 15 cm and fertilized with 80 kg ha-1 of N at the beginning of the deferment period.(AU)
Assuntos
Pastagens/análise , Pastagens/métodos , Compostos de Nitrogênio/análise , Compostos de Nitrogênio/química , Brachiaria/química , CompostagemRESUMO
The Achillea millefolium L. is a perennial herb with important antibacterial, antifungal, anti-inflammatory, antitumoral, and antioxidant properties. This research aimed to investigate the effect of shading (75%; black net) and nitrogen fertilization (0, 75 and 150 kg urea ha-1) on the nitrogen metabolism, essential oil yield and antimicrobial activity of A.millefolium at vegetative- and reproductive-stage. The evaluated parameters varied depending on the organ and the phenological stage of the plant considered. Overall, our findings indicated that shading decreased nitrogen assimilation. Decreased activities of nitrate reductase and glutamine synthetase were observed on shaded plants during reproductive and vegetative stages, respectively. Nitrate and total amino acid levels increased in shaded plants at the vegetative stage. Regarding nitrogen supply, the improved nitrogen metabolism and essential oil yield values were accompanied by intermediate concentrations of urea (75 kg ha-1). Plants fertilized with 75 kg urea ha-1 produced the highest amino acids concentration (vegetative stage), ammonium concentration (vegetative stage) and essential oil yield (reproductive stage). Shading or nitrogen supply did not influence the microbial activity of A. millefolium essential oil.However, the essential oil of leaves and flowers were highly effective against fungi and bacteria, especially gram-positive bacteria. In conclusion, the current study showed that full light and 75 kg urea ha-1 enhanced the nitrogen metabolism of A. millefolium in both vegetative and reproductive stages.
Assuntos
Achillea/metabolismo , Achillea/microbiologia , Achillea/química , Compostagem , Compostos de Nitrogênio/metabolismo , Compostos de Nitrogênio/química , Anti-Infecciosos , Técnica Histológica de SombreamentoRESUMO
The Achillea millefolium L. is a perennial herb with important antibacterial, antifungal, anti-inflammatory, antitumoral, and antioxidant properties. This research aimed to investigate the effect of shading (75%; black net) and nitrogen fertilization (0, 75 and 150 kg urea ha-1) on the nitrogen metabolism, essential oil yield and antimicrobial activity of A.millefolium at vegetative- and reproductive-stage. The evaluated parameters varied depending on the organ and the phenological stage of the plant considered. Overall, our findings indicated that shading decreased nitrogen assimilation. Decreased activities of nitrate reductase and glutamine synthetase were observed on shaded plants during reproductive and vegetative stages, respectively. Nitrate and total amino acid levels increased in shaded plants at the vegetative stage. Regarding nitrogen supply, the improved nitrogen metabolism and essential oil yield values were accompanied by intermediate concentrations of urea (75 kg ha-1). Plants fertilized with 75 kg urea ha-1 produced the highest amino acids concentration (vegetative stage), ammonium concentration (vegetative stage) and essential oil yield (reproductive stage). Shading or nitrogen supply did not influence the microbial activity of A. millefolium essential oil.However, the essential oil of leaves and flowers were highly effective against fungi and bacteria, especially gram-positive bacteria. In conclusion, the current study showed that full light and 75 kg urea ha-1 enhanced the nitrogen metabolism of A. millefolium in both vegetative and reproductive stages.(AU)
Assuntos
Compostagem , Compostos de Nitrogênio/química , Compostos de Nitrogênio/metabolismo , Achillea/química , Achillea/metabolismo , Achillea/microbiologia , Anti-Infecciosos , Técnica Histológica de SombreamentoRESUMO
Phenolic and nitrogenous compounds from different styles craft beers were identified by high performance liquid chromatography and mass spectrometry in order to stratify beer samples according to their style. For this, an exploratory assessment relying on Linear Discriminant Analysis was performed. Fifty-seven phenolic compounds were reported and twelve of them were found for the first time in beer: benzoic acids, 2,4-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, dimethoxybenzoic acid; phenolic acid conjugates, 3-p-coumaroylquinic acid, 4-p-coumaroylquinic acid, 3-feruloylquinic acid, 4-feruloylquinic acid, 5-feruloylquinic acid; flavonoids, taxifolin hexoside, quercetin dihexoside, apigenin-6,8-dipentoside, and isofraxidin hexoside. Additionally, 11 nitrogenous compounds belonging to the phenolamide class were found. Two discriminant functions were generated and allowed a satisfactory separation among all beer styles. 3-Caffeoylquinic acid, 3-p-coumaroylquinic acid, 4-p-coumaroylquinic acid, 5-caffeoylquinic acid, coumaric acid, kaempferol-3-O-rutinoside, proanthocyanidin B dimer III and proanthocyanidin B dimer V were the compounds that showed the highest capacity of discriminate the beer styles (IPA, Lager and Weiss).
Assuntos
Cerveja/análise , Análise de Alimentos/métodos , Compostos de Nitrogênio/análise , Fenóis/análise , Ácido Clorogênico/análise , Cromatografia Líquida de Alta Pressão/métodos , Flavonoides/análise , Hidroxibenzoatos/análise , Peso Molecular , Compostos de Nitrogênio/química , Fenóis/química , Ácido Quínico/análogos & derivados , Ácido Quínico/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodosRESUMO
Highly photoresponsive semiconductor photocatalysis for energy and environmental applications require judicious choice and optimization of semiconductor interfaces for wide spectral capabilities. This work aims at rational designing of highly active SrTiO3/g-C3N4 junctions bridged with Ag/Fe3O4 nanoparticles for utilizing Z-scheme transfer and surface plasmon resonance effect of Ag augmented by iron oxide. The SrTiO3/(Ag/Fe3O4)/g-C3N4 (SFC) catalyst was employed for photocatalytic hydrogen production and photodegradation of levofloxacin (LFC; 20 mg/L) under UV, visible, near infra-red, and natural solar light exhibiting high performance. Under visible light (<780 nm), SFC-3 sample (30 wt % g-C3N4 and 3% Ag/Fe3O4) shows a H2 evolution of 2008 µmol g-1 h-1 which is â¼14 times that of bare g-C3N4. In addition, 99.3% removal of LFC was degraded in 90 min under visible light with retention of activity under sun. The inherent topological properties, complete, higher charge separation, and reduced recombination allowed this catalyst for a high photocatalytic response which was proved by UV-diffuse reflectance spectroscopy, photoluminescence, electrochemical impedance spectroscopy, and photocurrent response measurements. Scavenging experiments and electron spin resonance analysis reveal that the mechanism shifts from a dual charge transfer in case of binary junction to essential Z-scheme with incorporation of Ag/Fe3O4. Both â¢O2- and â¢OH are main active radicals in visible light, whereas â¢O2- majorly participate under UV. The synergistic effect of SrTiO3, g-C3N4, and plasmon resonance of Ag/Fe3O4 not only improves light response and reduce recombination but also enhances the redox-ability of charge carriers. A H2 production mechanism and LFC degradation pathway (degradation, defluorination, and hydrolysis) has been predicted. This work paves a way for development of photocatalysts working in practical conditions for pollution and energy issues.