Polymer monoliths modified by using nanoparticles (NPs) integrate high NP specific surface area with different monolith surface chemistry and high porosity. As a result, they have extensive applications within different fields, whereas nanomaterial-functionalised porous polymer monoliths have elicited considerable interest from investigators. This study is aimed at fabricating organic polymer-based monoliths from polybutyl methacrylate-co-ethylenedimethacrylate (BuMA-co-EDMA) monoliths prior to immobilization of gold or silver metal on the pore surface of the monoliths using reducing reagent (extracts of lemon peels). This was intended to denote a sustainable technique of immobilizing nanoparticles that are advantageous over physical and chemical techniques because it is safe in terms of handling, readily available, environmentally friendly, and cheap. Two different methods were used in the study to effectively immobilize nanoparticles on monolithic components. The outcomes showed that soaking the monolith rod in the prepared nano solution directly and placing it within ovens at temperatures of 80°C constituted the most effective method. Characterisation of the fabricated monolith was undertaken using SEM/EDX analysis, UV-vis. spectra analysis, and visual observation. The SEM analysis showed that nanoparticles were extensively immobilised on the surface polymers. Another peak was attained through EDX analysis, thus confirming the Au atom existence at 2.83% alongside another peak that proved the Ag atom existence at 1.92%. The fabricated components were used as sorbents for purifying protein. The ideal performance was achieved using gold nanoparticles (GNPs) immobilised organic monolith that attained a greater pepsin extraction recovery compared to silver nanoparticles (SNPs) immobilised organic monoliths alongside bare organic-based monolith.
Abbreviations OMD, organic matter digestibility; TT, Tilley and Terry method; CM, pepsin-cellulase method; ME, metabolizable energy; WC, white clover; RC, red clover; LC, lucerne; BT, birdsfoot trefoil; KC, kura clover; RG, rotational grazing; CM-OMD, OMD based on pepsin-cellulase method; TTOMD, OMD based on Tilley and Terry method; ME CM , ME estimated by pepsin-cellulase method; ME TT , ME estimated by Tilley and Terry method; MAT, mean average temperature; AP, average precipitation. 1 Introduction With the genetic advancement of new cultivars, improvement in
AHyaluronic acid (HA) is part of the extracellular matrix of connective, epithelial and neural tissues, as well as the synovial fluid, skin, and cartilage. It is composed of repeating disaccharide units of D-glucuronic acid and N-acetyl glucosamine. Hyaluronic acid is used in abdominal surgery, ophthalmology, dermatology, rhinology; it is usable for the osteoarthritis treatment. The membranes of eggshell are a natural source of hyaluronic acid, collagen, glycosaminoglycan and collagenous proteins. In paper, we tested the possibility of extraction hyaluronic acid from the eggshell membranes by enzymatic hydrolysis. We identified optimal conditions of hydrolysis with trypsin at reaction temperature of 37 °C and pH 8; with pepsin at 40 °C and pH 3, as well as with papain at 60 °C and pH 7.5. The content of hyaluronic acid in samples was determined spectrophotometrically using the carbazole method. The experimental results showed a yield of ~ 4 -4.5 % hyaluronic acid per 1 g of dry eggshell membranes.
Increasing the potency of antihypertensive food-derived peptides is a critical and important step in the development of natural drugs for cardiovascular diseases prevention. We have proposed the egg-white protein precipitate (EWPP) obtained as a byproduct of cystatin and lysozyme isolation as a potential source of ACE-inhibitory peptides derived by pepsin digestion. The results indicated that hydrolysis of EWPP with pepsin produced the ACE inhibitory activity. During 3-h hydrolysis (DH: 38.3%), the IC50 value of EWPP hydrolysate was significantly increased and finally reached IC50=643.1 μg/mL. This hydrolysate was further fractionated by RP-HPLC. The peptide fraction exhibiting the highest ACE inhibitory activity was rechromatographed. Three peptide subfractions exhibiting ACE-inhibitory activities of 69.0, 25.0, and 37.6 μg/mL were further characterised. In each of them, mixtures of peptides with different molecular masses were observed.
treatment of tinea pedis. A placebo-controlled, double-blind study. Mycoses, 2000, 43, 197-202. Yamauchi K., Tomita M., Giehl T.J., Ellison R.T., Antibacterial activity of lactoferrin and a pepsin-derived lactoferrin peptide fragment. Inf. Immun., 1993, 61, 719-728. Ye X.Y., Wang H.X., Liu F., Ng T.B., Ribonuclease, cell-free translation-inhibitory and superoxide radical scavenging activities of the iron-binding protein lactoferrin from bovine milk. Int. J. Biochem. Cell. Biol., 2000, 32, 235-241. Yoo Y.C., Watanabe R., Koike Y., Mitobe M., Shimazaki K., Watanabe S
SE-HPLC-DAD Analysis of Flaxseed Lignan Macromolecule and its Hydrolysates
A lignan macromolecule (LM) was extracted from defatted flaxseeds using an ethanol-dioxan system (1:1, v/v) and purified using Amberlite column chromatography with water and methanol as mobile phases. The LM was subjected to chemical hydrolysis (base, acid, base & acid), as well as to enzymatic processing using pepsin, pancreatin, cellulase, and β-glucuronidase.
The study revealed that lignan macromolecule in flaxseed was not homogenous. The chemical hydrolysis as well as enzymatic treatment using β-glucuronidase and cellulase released low molecular phenolic compounds from the lignan macromolecule. The liberation of secoisolariciresinol (SECO) and free phenolic acids (p-coumaric and ferulic acids) from flaxseed lignan macromolecule as a result of the base and acid hydrolyses was noted. The application of pepsin and pancreatin did not change the composition of the lignan macromolecule.
Antioxidative Properties of Bee Pollen Extracts Examined by EPR Spectroscopy
Bee pollen is a valuable and highly recognized source of exogenous antioxidants. The aim of these studies was to determine the antioxidant capacity of three types of bee pollen extracts: ethanol extracts of bee pollen, pepsin extracts of bee pollen and ethanol extracts of pepsin-digested bee pollen. Their antioxidant properties were determined with the use of electron paramagnetic resonance (EPR) and their ability to quench DPPH free radicals was estimated. The EPR results showed that ethanol extracts of pepsin-digested bee pollen (EEPP) had the highest antioxidative effect and the highest free radical DPPH scavenging potential. The pepsin extracts of bee pollen (PEP) had the weakest antioxidant capacity. The ability to quench DPPH free radicals was also the weakest one for this extract. An average antioxidative effect was recorded for ethanol extracts of bee pollen (EEP).
Introduction: Gastric ulcer is one of the most common gastrointestinal diseases, therefore the constant interest for new treatments is due to adverse effects induced by current therapy. The restricted number of in vivo experimental models is a challenge for researchers. Objectives: Identifying the particularities of different types of experimentally induced gastric ulcer in laboratory animals to facilitate their choise for the study of new antiulcer drugs.
Material and method: A search in PubMed and Scopus using keywords ( “experimentally” AND “gastric ulcer” AND “rats/mice”) to include experimental studies with the description of local-induced changes. Review articles and in vitro studies were excluded.
Results and discussions: Experimental researches on new drugs for gastric ulcer use chemical or surgical methods to induce gastric lesions in rats. Non-steroidal anti-inflammatory drugs (NSAIDs) and acetic acid models to investigate antisecretory and cytoprotective effects; ethanol models evaluate cytoprotective and/or antioxidant effects; pylorus ligature models to evaluate the effects on the secretion of aggressive gastric factors (hydrochloric acid or pepsin). NSAIDs (indomethacin, acetylsalicylic acid or ibuprofen) inhibit cyclooxygenase activity, resulting from reduced mucus and bicarbonate secretion, decreased mucosal blood flow, alteration of microvascular structures, causing epithelial damage Ethanol enhances the proteolytic and hydrolytic action of hydrochloric acid and pepsin; in addition, stimulates the acid secretion and disruptes vascular endothelium. Pylorus ligature determines the accumulation of gastric acid resulting in gastric ulcers due to the autodigestion of the mucosa.
Conclusion: The knowledge of the mechanisms to induce experimental gastric ulcers is essential for choosing the model to evaluate new antiulcer agents.
Protein digestibility may be influenced by the presence of dietary fibre affecting the nutritional quality of a feed or food product. This study investigated the interplay between rapeseed (Brassica napus L.) protein and fibre constituents separated by industrially scalable pilot plant processing and recombined in mixed samples. Total dietary fibre (TDF) fractions were isolated from rapeseed hulls (TDF-RH) and purified rapeseed embryo fibres (TDF-RE). The effect of TDF sources on in vitro protein digestibility (IVPD) of a rapeseed protein concentrate rich in napin proteins (RP2) was assessed at three inclusion levels (200, 333, and 500 mg/g DM) using a sequential transient proteolysis by pepsin (1 h) and pancreatin (1 h). The IVPD of RP2 was dose-dependently decreased upon addition of hull fibres at all inclusion levels (8.9-26.6%; P<0.05), whereas the effect of embryo fibres was of a markedly lower magnitude and only significant at the medium to high levels (7.3-8.9%; P<0.05). These results demonstrated that TDF fractions obtained from rapeseed differentially affect the protein digestibility of rapeseed napin proteins depending on the fibre source and inclusion level.