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•Lignins from sugarcane bagasse are renewable templates to obtain colloidal lignin nanoparticles.•The obtained colloidal lignin nanoparticles stabilize Pickering emulsion systems.•The ...lignin nanoparticles properties were determined by the synthesis method applied.
Lignin nanoparticles has gained interest in recent years in a wide range of applications due to its unique properties compared to the microsized material. Furthermore, lignin is obtained from lignocellulosic biomass processing and it is still considered a poorly exploited macromolecule due to the heterogeneous nature and low solubility in aqueous medium. This study focus on the comparison between two ways environmentally friendly of obtaining colloidal lignin nanoparticles (LNPs), considering minimal processing steps and employing lignins derived from two sugarcane bagasse pretreatments (alkaline and organosolv). Raw lignins and LNPs were characterized by different techniques such as scanning electron microscopy (SEM), zeta potential, dynamic light scattering (DLS), small-angle X-ray scattering (SAXS) and antioxidant assay in order to evaluate the changes in its morphological, chemical and antioxidant properties. The results showed the formation of spherical-like nanoparticles which sizes were determined by the synthesis method. LNPs obtained from alkaline lignin showed an average diameter varying from 115 to 300 nm, while LNPs obtained from organosolv lignin ranged from 270 to 680 nm, as determined by DLS. All LNPs in aqueous suspension had a zeta potential ranging from −25 to −35 mV, which is considered stable for colloidal systems. The thermal stability properties of micro to nanosized lignins were preserved. The antioxidant capacity against the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical was improved for alkaline-LNPs compared to the raw lignin (IC30 = 12 and 9.9 μg mL−1, respectively), and worsened for organosolv-LNPs compared to the raw lignin (IC30 = 11.4 and 15 μg mL−1, respectively). Furthermore, LNPs were tested as stabilizing agents of Pickering emulsions, used as encapsulation agents of curcumin, a polyphenol with a wide range of pharmacological applications. Organosolv-LNPs were seen to be the most efficient stabilizer, retaining 73% of curcumin in its encapsulated form after 96 h. Therefore, this study demonstrated the potential of nanostructured lignins for bio-based field, and also highlights the influence factors for the choice of methodology and raw lignins over the properties resulted of LNPs.
Ferulic acid is a phenolic acid widely distributed in the plant kingdom. It presents a wide range of potential therapeutic effects useful in the treatments of cancer, diabetes, lung and ...cardiovascular diseases, as well as hepatic, neuro and photoprotective effects and antimicrobial and anti-inflammatory activities. Overall, the pharmaceutical potential of ferulic acid can be attributed to its ability to scavenge free radicals. However, recent studies have revealed that ferulic acid presents pharmacological properties beyond those related to its antioxidant activity, such as the ability to competitively inhibit HMG-CoA reductase and activate glucokinase, contributing to reduce hypercholesterolemia and hyperglycemia, respectively. The present review addresses ferulic acid dietary sources, the pharmacokinetic profile, antioxidant action mechanisms and therapeutic effects in the treatment and prevention of various diseases, in order to provide a basis for understanding its mechanisms of action as well as its pharmaceutical potential.
O ácido ferúlico é um ácido fenólico amplamente distribuído no reino vegetal. Ele apresenta uma ampla gama de potenciais efeitos terapêuticos utéis no tratamento do câncer, diabetes, doenças pulmonares e cardiovasculares, bem como efeitos hepáticos, neuro e fotoprotetores, atividades antimicrobianas e anti-inflamatórias. O potencial farmacêutico do ácido ferúlico pode ser atribuído à sua capacidade em sequestrar radicais livres. No entanto, estudos recentes revelaram que o ácido ferúlico apresenta propriedades farmacológicas, além da sua atividade antioxidante, como a capacidade de inibir competitivamente a HMG-CoA redutase e ativar a glucoquinase, contribuindo para reduzir a hipercolesterolemia e hiperglicemia, respectivamente. A presente revisão aborda as fontes dietéticas de ácido ferúlico, o perfil farmacocinético, os mecanismos de ação como antioxidante e efeitos terapêuticos no tratamento e prevenção de várias doenças, de modo a proporcionar uma base para a compreensão dos seus mecanismos de ação, bem como os seus potenciais farmacêuticos.
Laccase production in saline conditions is still poorly studied. The aim of the present study was to investigate the production of laccase in two different types of bioreactors by the marine-derived ...basidiomycete Peniophora sp. CBMAI 1063. The highest laccase activity and productivity were obtained in the Stirred Tank (ST) bioreactor, while the highest biomass concentration in Air-lift (AL) bioreactor. The main laccase produced was purified by ion exchange and size exclusion chromatography and appeared to be monomeric with molecular weight of approximately 55 kDa. The optimum oxidation activity was obtained at pH 5.0. The thermal stability of the enzyme ranged from 30 to 50 °C (120 min). The Far-UV Circular Dichroism revealed the presence of high β-sheet and low α-helical conformation in the protein structure. Additional experiments carried out in flask scale showed that the marine-derived fungus was able to produce laccase only in the presence of artificial seawater and copper sulfate. Results from the present study confirmed the fungal adaptation to marine conditions and its potential for being used in saline environments and/or processes.
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