Search Results (50)

Methylglyoxal (MGO) is a highly reactive a-dicarbonyl compound produced in foods and endogenously in humans and constitutes a predominant precursor of advanced glycation end products that contribute to the pathology of several diseases, including diabetes and neurodegenerative diseases. In this study, the efficiency of pyrogallol, gallic acid, ethyl, and propyl gallate in trapping MGO was investigated at pH 6.5 to 8.0. Pyrogallol was the most efficient MGO-trapping agent, followed by gallic acid, whereas the alkyl gallates were notably less efficient, particularly at slightly acidic and neutral pH. The increase of pH from slightly acidic to alkaline enhanced the MGO-trapping efficiency of all compounds, albeit to a different extent that correlated inversely to the pK_a of the most acidic -OH phenolic group, demonstrating the contribution of the deprotonated forms of the phenolic compounds in the enhanced reactivity towards MGO. The reaction products of pyrogallol, identified as the most efficient compound in MGO-trapping, were analyzed and characterized by liquid chromatography-mass spectrometry (LC-MS). Both mono-MGO and di-MGO conjugated adducts of pyrogallol were detected, with the mono-MGO adduct being dominant solely at acidic pH and the di-MGO pyrogallol adducts becoming prevalent at neutral and alkaline pH. Therefore, the pH was determined as a main factor that controls the reaction pathways of the phenolic compounds with MGO. Full article

Cyclodextrins (CDs) have been widely employed as natural host molecules to form inclusion complexes with bioactive molecules such as antioxidants. Their particular spatial configuration, in the form of truncated cones formed through α(1–4) ether linkages of glucopyranose units, makes them very appropriate for the formation of host–guest complexes, modifying their physicochemical properties and their location in multiphasic systems. Here, we investigated the effects of 2-hydroxypropyl-β-cyclodextrin (HPCD) on the efficiency of a series of gallic acid derivatives (propyl (PG), butyl (BG), octyl (OG), and lauryl (LG) gallates) in inhibiting the oxidation of soybean oil-in-water emulsions. For this purpose, we investigated the effects of HPCD on both the kinetics of lipid oxidation and the distribution of antioxidants in the same intact emulsions. The results show that in an aqueous solution, the antioxidants form 1:1 inclusion complexes with HPCD, with inclusion constants ranging from 383 M⁻¹ (PG) to 1946 M⁻¹ (OG). The results also show that the addition of HPCD to emulsions containing antioxidants does not lead to significant changes in their antioxidant effectiveness, with their efficiency being similar to that when no HPCD molecules are present. The results are interpreted in terms of the blocking effect exerted by the Tween 20 molecules, which act as effective guest competitors capable of removing the antioxidants from the HPCD cavity. The Tween 20 surfactant molecules need to be employed to stabilize the emulsions kinetically. This blocking effect, as a primary consequence, indicates that the interfacial concentration of the antioxidants, which is the region where the inhibition reaction takes place, remains constant; thus, their efficiency is not altered. Full article

Triboelectric nanogenerators (TENGs), as an emerging energy harvesting device, can efficiently convert the weak mechanical energy in the environment into electrical energy, demonstrating significant potential in self-powered systems. In this study, polyvinylidene fluoride (PVDF) nanofiber films mixed with a small amount of n-propyl gallate (PG) were prepared by using the electrospinning technique, and TENGs were fabricated based on these films. Unexpectedly, experimental results showed that PG (with 0.5–2.5 wt%) did not affect the β phase of the PVDF. However, the TENG based on PVDF/PG composite nanofiber film with 1 wt% PG (PG1-TENG) exhibited large output values of 334 V, 4.36 μA, and 78.4 nC for output voltage, current, and transferred charge, respectively, with a power density of 5.27 W/m², which highlights ~60% improvement in output voltage over pristine PVDF-TENG. This observation was attributed to the unique charge regulation ability of PG, without altering PVDF’s β phase. Furthermore, application potential of PG1-TENG was demonstrated by powering up an LCD calculator and 480 LEDs. Full article

Walnuts, which are rich in unsaturated fatty acids (UFAs), are highly susceptible to oxidation during storage, leading to quality degradation. Consequently, antioxidant technologies for the oxidative stability of walnuts have garnered significant attention. The addition of antioxidants remains the most cost-effective and efficient method currently available, with synergistic effects enhancing the efficacy of mixed antioxidant combinations compared to single antioxidants. In this study, four lipophilic antioxidants—tert-butylhydroquinone (TBHQ), butylated hydroxytoluene (BHT), dilauryl thiodipropionate (DLTP), and propyl gallate (PG)—were paired with four hydrophilic antioxidants—rosemary extract (RE), phytic acid (PA), tea polyphenols (TPs), and sodium ascorbate (SA)—resulting in 16 experimental groups to investigate synergistic effects. The effects of water-soluble and fat-soluble antioxidant combinations on walnut oxidation were systematically evaluated through peroxide value, acid value, thiobarbituric acid reactive substances, and DPPH radical scavenging capacities. Additionally, fatty acid composition analysis was employed to assess the preservation of beneficial UFAs. Mechanistic insights were obtained via thermogravimetric analysis and electron paramagnetic resonance spectroscopy. Notably, two combinations, 0.03% TBHQ + 0.03% TPs (w/w) and 0.03% DLTP + 0.03% SA (w/w), exhibited good oxidative stability of walnut kernels. These formulations demonstrated superior antioxidant performance and effectively inhibited oxidative pathways while maintaining UFA integrity, demonstrating their potential as advanced preservation strategies for lipid-rich foods. Full article

Biodegradable polyesters serve as matrices in pharmaceutical applications for the controlled release of therapeutic agents. These polymers are essential in the advancement of drug delivery systems (DDSs) that facilitate the gradual drug release over a predetermined duration. Therefore, this study introduces the novel use of a diethyl zinc/propyl gallate catalytic system to synthesize glycolide/ε-caprolactone copolymers (PGCL) for subsequent biomedical applications. A total of twenty-four biodegradable copolymeric matrices, characterized by a highly random microstructure and an average molecular weight (M_n) ranging from approximately 27 to 62 kDa, were synthesized and analyzed. The resulting copolymer samples underwent Neutral Red Uptake (NRU) and Umu tests, revealing no signs of cyto- or genotoxicity. Furthermore, a hemolysis assay was conducted on selected samples, indicating their suitability for intravenous administration. Finally, a release study of paclitaxel (PACL) from one of the synthesized matrices demonstrated a sustained and highly controlled drug release profile, following first-order kinetics and the Fickian diffusion mechanism. Full article

This experimental study investigates the critical role and impact of additive concentration in enhancing the tribological performance of castor oil as a biolubricant for agricultural tractor engines. Friction and wear are major contributors to reduced engine efficiency, highlighting the need for effective lubrication strategies. While biolubricants like castor oil offer environmental benefits, they often require additives to achieve optimal performance. However, the concentration of these additives is crucial, as an imbalance can negatively impact the lubrication system, leading to a higher coefficient of friction, increased wear, and reduced engine efficiency and lifespan. This study examines the effects of varying concentrations of a mixture of propyl gallate (PG) and ionic liquid (IL) additives on the tribological performance of castor oil. The tribological behaviour of lubricated top compression piston ring and cylinder liner samples was evaluated under simulated engine conditions using a Bruker UMT Tribolab test rig, in accordance with the ASTM G181 standard. The experimental results revealed an influence of additive concentration on the coefficient of friction and wear behaviour. This emphasises the importance of optimising additive formulations to minimise engine wear and friction. Notably, a 0.5% volume concentration of the additive mixture led to a remarkable 34.8% reduction in the average coefficient of friction (COF) and a lower wear rate. Full article

Bio-preservation strategies for sustainable food and dairy products are some of the most in-demand techniques that expand shelf life and meet consumer requirements. The purpose of this study is to produce high quality, sensory-acceptable labneh cheese with a prolonged shelf life and sustainable preservation. Ethanolic extract of clove flower buds was applied during the manufacturing of labneh as a bio-preserving agent. The effect of the sprayed-clove extract on the chemical composition, microbiological composition, texture profile, antioxidant capabilities, aromatic compounds, and sensory properties of the labneh cheese were determined. Phytochemical profiling showed chaulmoogric acid, trans-cinnamic acid, propyl gallate, and sinapine as major constituents in clove extract. Antimicrobial inhibitory potential was estimated against both foodborne pathogens and food spoilage microorganisms. Clove extract showed a promising inhibitory effect against fungi recording 1 mg/mL maximally. Labneh samples with clove extract contained the highest records of antioxidant activity in addition to having no record of any fungal growth after 60 days. It is also distinguished by its eugenol, β-Caryophyllene, and acetyleugeno as aroma compound content. All spray-treated samples achieved the highest scores in sensory properties during the storage period. It can be concluded that clove extract, when sprayed on the surface of labneh cheese, produced an antifungal effect in a smart and economic way which boosted the shelf life, quality, enhanced nutritional value, and the antioxidant capacity of labneh cheese. Full article

Terminalia bellirica (Gaertn) Roxb. and Terminalia chebula Retz. are significant botanicals in ancient Ayurvedic medicine. They are renowned for their therapeutic properties, notably in addressing gastrointestinal (GI) diseases. These plants have undergone thorough examination related to their antibacterial, anti-inflammatory, and antioxidant properties, which make them highly efficient natural treatments for controlling gastrointestinal infections. The current research demonstrated the antibacterial efficacy of fruit extracts of Terminalia bellirica and Terminalia chebula against Bacillus cereus, Shigella sonnei, Shigella flexneri, and Salmonella typhimurium. We performed disc diffusion and liquid microdilution experiments to evaluate the antibacterial efficacy. All extracts of Terminalia bellirica and Terminalia chebula showed good antibacterial effects against B. cereus and S. flexneri. The minimum inhibitory concentration (MIC) values ranged from 94 µg/mL to 556 µg/mL. The methanolic extracts from both plants also showed noteworthy antibacterial activity against S. sonnei and S. typhimurium, with MIC values of 755 µg/mL for both. Fractional inhibitory concentration studies revealed additive interactions between some conventional antibiotics and the plant extracts when used concurrently. Liquid chromatography–mass spectrometry (LC-MS) analyses revealed that the T. bellirica and T. chebula extracts contained various tannins including methyl gallate, propyl gallate, gallic acid, and ellagic acid. Lethality assays conducted using Artemia franciscana Kellogg nauplii indicated that all the plant extracts are non-toxic. The antibacterial properties and absence of toxicity in T. bellirica and T. chebula fruit extracts indicate their potential for antibiotic development, warranting additional mechanistic and phytochemical studies. Full article

The current energy scenario requires the use of alternatives for petrol-based products. In this context, the role of biodiesel and biolubricants can be promising, offering multiple advantages but also some challenges like their low oxidation stability. The use of antioxidants can offset this disadvantage, improving the general performance of these products during storage or usage. The aim of this work was to assess the combined and separate use of two different antioxidants (propyl gallate, PG, and tert-butylhydroquinone, TBHQ) on biodiesel and biolubricant based on waste cooking oil (WCO), carrying out a thorough characterization of these products and quantification of antioxidants through voltammetry techniques. Thus, the innovation of this work consists in the use of combined antioxidants and its simultaneous quality assessment and quantification. As a result, the combined use of antioxidants did not offer a synergistic effect, and the use of PG at low concentrations (300 ppm) is recommended in the case of WCO biolubricant. Voltammetry was a suitable and fast method to quantify both PG and TBHQ. Full article

Antimicrobial resistance (AMR) has arisen due to antibiotic overuse and misuse. Antibiotic resistance renders standard treatments less effective, making it difficult to control some infections, thereby increasing morbidity and mortality. Medicinal plants are attracting increased interest as antibiotics lose efficacy. This study evaluates the antibacterial activity of solvent extracts prepared using Terminalia bellirica and Terminalia chebula fruit against six bacterial pathogens using disc diffusion and broth microdilution assays. The aqueous and methanol extracts of T. bellirica and T. chebula showed substantial zones of inhibition (ZOIs) against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA). The activity against those bacteria was strong, with minimum inhibitory concentrations (MIC) ranging from 94 µg/mL to 392 µg/mL. Additionally, the T. bellirica methanolic extract showed noteworthy antibacterial activity against Escherichia coli and an extended spectrum β-lactamase (ESBL) E. coli strain (MIC values of 755 µg/mL for both). The aqueous T. bellirica and T. chebula extracts also inhibited Klebsiella pneumoniae growth (MIC values of 784 µg/mL and 556 µg/mL, respectively). The corresponding methanolic extracts also inhibited ESBL K. pneumoniae growth (MIC values of 755 µg/mL and 1509 µg/mL, respectively). Eighteen additive interactions were observed when extracts were combined with reference antibiotics. Strong antagonism occurred when any of the extracts were mixed with polymyxin B. Liquid chromatography-mass spectroscopy (LC-MS) analysis of the extracts revealed several interesting flavonoids and tannins, including 6-galloylglucose, 1,2,6-trigalloyl-β-D-glucopyranose, 6-O-[(2E)-3-phenyl-2-propenoyl]-1-O-(3,4,5-trihydroxybenzoyl)-β-D-glucopyranose, propyl gallate, methyl gallate, sanguiin H4, hamamelitannin, pyrogallol, gallic acid, ellagic acid, chebulic acid, and chebuloside II. All extracts were nontoxic in brine shrimp assays. This lack of toxicity, combined with their antibacterial activities, suggests that these plant species may be promising sources of antibacterial compound(s) that warrant further study. Full article

In this study, molecules of propyl gallate (PG) and polyethylene glycol methacrylate (PEGMA) were covalently bonded via a transesterification reaction and subsequently grafted onto polyvinylidene fluoride substrates using a homogeneous radiation grafting technique. The enhancement of the membranes’ hydrophilicity with the increment of the grafting rate was corroborated by scanning electron microscopy imaging and measurements of the water contact angle. At a grafting degree of 10.1% and after a duration of 4 min, the water contact angle could decrease to as low as 40.1°. Cyclic flux testing demonstrated that the membranes modified in this manner consistently achieved a flux recovery rate exceeding 90% across varying degrees of grafting, indicating robust anti-fouling capabilities. Furthermore, these modified membranes exhibited significant antioxidant ability while maintaining antifouling performance over 30 days. The ability of the modified membranes to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS⁺) free radicals remained nearly unchanged after being stored in pure water for 30 days, and the flux recovery rate remained above 95% after immersion in sodium hypochlorite solution for 30 days. Among the tested membranes, the PVDF-g-PEGMAG modified membrane with a grafting degree of 7.2% showed the best antioxidant effect. Full article

Breaded chicken coated in whey protein isolate (WPI) has been shown to reduce oil absorption during batch frying. What is not known is how this is affected by repeated fryings and whether antioxidant-rich oil will enhance this effect. The objective of this research was to determine how successive daily frying of WPI-coated breaded chicken in antioxidant-rich oil affects oil quality and oil inhibition, moisture retention, color, and texture of the breaded chicken. Chicken fritters with and without a 10% WPI post-breading dip were fried successively for 6 h per day over five days in oil without antioxidant or with either 1000 ppm rosemary extract or propyl gallate. The control oil became spent at 12 h of frying (>24% TPM, <50% DEGLEV). During this time, the oils treated with antioxidants were significantly less spent, and the WPI-treated fritters fried in these oils exhibited 22–49% less lipid; retained 10–18% more moisture; and became darker, less red, and less yellow (lower L*, a*, and b* values) compared to the un-dipped fritters fried in the control oil. These results suggest that the presence of antioxidants in the frying oil mitigated some of the degradative changes in the oil during frying but likely did not play a major role in moisture retention or inhibition of oil absorption. Full article

Oral delivery of peptides and biological molecules promises significant benefits to patients as an alternative to daily injections, but the development of these formulations is challenging due to their low bioavailability and high pharmacokinetic variability. Our earlier work focused on the discovery of MEDI7219, a stabilized, lipidated, glucagon-like peptide 1 agonist peptide, and the selection of sodium chenodeoxycholate (Na CDC) and propyl gallate (PG) as permeation enhancer combinations. We hereby describe the development of the MEDI7219 tablet formulations and composition optimization via in vivo studies in dogs. We designed the MEDI7219 immediate-release tablets with the permeation enhancers Na CDC and PG. Immediate-release tablets were coated with an enteric coating that dissolves at pH ≥ 5.5 to target the upper duodenal region of the gastrointestinal tract and sustained-release tablets with a Carbopol bioadhesive polymer were coated with an enteric coating that dissolves at pH ≥ 7.0 to provide a longer presence at the absorption site in the gastrointestinal tract. In addition to immediate- and enteric-coated formulations, we also tested a proprietary delayed release erodible barrier layer tablet (OralogiK^TM) to deliver the payload to the target site in the gastrointestinal tract. The design of tablet dosage forms based on the optimization of formulations resulted in up to 10.1% absolute oral bioavailability in dogs with variability as low as 26% for MEDI7219, paving the way for its clinical development. Full article

Voltammetric sensors based on CeO₂, SnO_2, CeO₂·Fe₂O₃ nanoparticles (NPs) and MnO₂ nanorods (NRs) were developed for the quantification of various organic substances. Surfactant media were applied as dispersive agents for metal oxide nanomaterials, providing a high stability of the dispersions after sonication and a decrease in the NPs’ size, as well as the preconcentration of the target analytes at the sensor surface due to the hydrophobic interactions between the surfactant and the analyte molecules. Natural phenolics (quercetin, rutin, gallic acid, taxifolin, eugenol, vanillin, and hesperidin), propyl gallate, α-lipoic acid, and synthetic food colorants (tartrazine, brilliant blue FCF, and sudan I) were studied as analytes. The effect of the nature and concentration of the surfactant on the target analyte response was evaluated. Cationic surfactants (cetylpyridinium (CPB) or cetyltriphenylphosphonium bromides (CTPPB)) showed the best effect for the majority of the analytes. Wide linear dynamic ranges and low detection limits were obtained and were improved vs. reported to date. The simultaneous quantification of tartrazine and brilliant blue FCF was achieved with a high selectivity. The practical applicability of the sensors was shown on the real samples and was validated by comparison to independent methods. Full article

Sesamol (SM) is a potent natural antioxidant that can quench free radicals and modulate the cholinergic system in the brain, thereby ameliorating memory and cognitive impairment in Alzheimer’s disease patients. Moreover, the total antioxidant capacity can be amplified by synergistic interactions between different antioxidants. Here, we constructed a ternary heterojunction graphitic carbon nitride/cupric sulfide/titanium dioxide (g-C₃N₄/CuS/TiO₂) photoelectrochemical (PEC) sensor for the quantification of SM and its synergistic interactions with other antioxidants. Crucially, the Schottky barrier in ternary semiconductors considerably enhances electron transfer. The PEC sensor showed a wide linear range for SM detection, ranging from 2 to 1277 μmol L⁻¹, and had a limit of detection of 1.8 μmol L⁻¹. Remarkably, this sensing platform could evaluate the synergism between SM and five typical lipid-soluble antioxidants: tert-butyl hydroquinone, vitamin E, butyl hydroxyanisole, propyl gallate, and butylated hydroxytoluene. Owing to its low redox potential, SM could reduce antioxidant radicals and promote their regeneration, which increased the overall antioxidant performance. The g-C₃N₄/CuS/TiO₂ PEC sensor exhibited high sensitivity, satisfactory selectivity, and stability, and was successfully applied for SM determination in both soybean and peanut oils. The findings of this study provide guidance for the development of nutritional foods, nutrition analysis, and the treatment of diseases caused by free radicals. Full article