Search Results (18)

Butylated hydroxyanisole (BHA), a synthetic phenolic antioxidant (SPA), is now widely present in natural waters. To improve the degradation efficiency of BHA and reduce product toxicity, a combination of peroxymonosulfate (PMS) and Ferrate(VI) (Fe(VI)) was used in this study. We systematically investigated the reaction kinetics, mechanism and product toxicity in the degradation of BHA through the combined use of PMS and Fe(VI). The results showed that PMS and Fe(VI) have synergistic effects on the degradation of BHA. The effects of operational factors, including PMS dosage, pH and coexisting ions (Cl⁻, SO₄²⁻, HCO₃⁻, K⁺, NH₄⁺ and Mg²⁺), and different water matrices were investigated through a series of kinetic experiments. When T = 25 °C, the initial pH was 8.0, the initial BHA concentration was 100 μM, the initial concentration ratio of [PMS]₀:[Fe(VI)]₀:[BHA]₀ was 100:1:1 and the degradation rate could reach 92.4% within 30 min. Through liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) identification, it was determined that the oxidation pathway of BHA caused by PMS/Fe(VI) mainly includes hydroxylation, ring-opening and coupling reactions. Density functional theory (DFT) calculations indicated that ^•OH was most likely to attack BHA and generate hydroxylated products. The comprehensive comparison of product toxicity results showed that the PMS/Fe(VI) system can effectively reduce the environmental risk of a reaction. This study contributes to the development of PMS/Fe(VI) for water treatment applications. Full article

Litsea cubeba is a characteristic woody oil resource in Hunan. As a solid waste of woody oil resources, Litsea cubeba kernels are rich in Litsea cubeba kernel oil with a carbon chain length of C10–12 fatty acid. In this work, aliphatic hydroxamic acids (AHAs) with carbon chain lengths of C10–12 were prepared from Litsea cubeba kernel oil via methylation and hydroximation reactions. The adsorption and hydrophobicity mechanism of AHA towards wolframite was explored by contact angle, zeta potential, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The flotation results demonstrated that AHA was a superior collector than the traditional collector such as benzoyl hydroxamic acid (BHA). Zeta potential and contact angle results have shown that AHA was adsorbed on the surface of the Fe(III)-activated wolframite in its anionic form, which significantly improved the surface hydrophobicity of wolframite. FTIR and XPS revealed that AHA was chemically adsorbed on the surface of Fe(III)-activated wolframite in the form of a five-member ring, which made the hydrophobic chain reach into the solution, come in contact with bubbles, and achieve flotation separation. Full article

Color is a major feature that strongly influences the consumer’s perception, selection, and acceptance of various foods. An improved understanding regarding bio-safety protocols, health welfare, and the nutritional importance of food colorants has shifted the attention of the scientific community toward natural pigments to replace their toxic synthetic counterparts. However, owing to safety and toxicity concerns, incorporating natural colorants directly from viable sources into plant-based meat (PBM) has many limitations. Nonetheless, over time, safe and cheap extraction techniques have been developed to extract the purified form of coloring agents from raw materials to be incorporated into PBM products. Subsequently, extracted anthocyanin has displayed compounds like Delphinidin-3-mono glucoside (D3G) at 3.1 min and Petunidin-3-mono glucoside (P3G) at 5.1 277, 515, and 546 nm at chromatographic lambda. Fe-pheophytin was successfully generated from chlorophyll through the ion exchange method. Likewise, the optical density (OD) of synthesized leghemoglobin (LegH) indicated that pBHA bacteria grow more rigorously containing ampicillin with a dilution factor of 10 after 1 h of inoculation. The potential LegH sequence was identified at 2500 bp through gel electrophoresis. The color coordinates and absorbance level of natural pigments showed significant differences (p < 0.05) with the control. The development of coloring agents originating from natural sources for PBM can be considered advantageous compared to animal myoglobin in terms of health and functionality. Therefore, the purpose of this study was to produce natural coloring agents for PBM by extracting and developing chlorophyll from spinach, extracting anthocyanins from black beans, and inserting recombinant plasmids into microorganisms to produce LegH. Full article

Zivzik pomegranate (Punica granatum) has recently sparked considerable interest due to its nutritional and antioxidant properties. To evaluate the antioxidant capacities of P. granatum juice, ethanol (EEZP), and water (WEZP) extracts from peel and seed, the antioxidant methods of 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid radical (ABTS^•+) scavenging, 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH^•) scavenging, Fe³⁺-2,4,6-tris(2-pyridyl)-S-triazine (TPTZ) reducing, Fe³⁺ reducing, and Cu²⁺ reducing methods were used. The antioxidant capacities of samples were compared with the most commonly used synthetic antioxidants, i.e., BHA, BHT, α-tocopherol, and Trolox. In terms of setting an example, the IC₅₀ values of EEZP for ABTS^•+ and DPPH^• scavenging activities were found to be lower than standards, at 5.9 and 16.1 μg/mL, respectively. The phenolic and flavonoid contents in EEZP peel were 59.7 mg GAE/g and 88.0 mg QE/g, respectively. Inhibition of α-glycosidase, α-amylase, acetylcholinesterase, and human carbonic anhydrase II (hCA II) enzymes was also investigated. EEZP demonstrated IC₅₀ values of 7.3 μg/mL against α-glycosidase, 317.7 μg/mL against α-amylase, 19.7 μg/mL against acetylcholinesterase (AChE), and 106.3 μg/mL against CA II enzymes. A total of 53 phenolic compounds were scanned, and 30 compounds were determined using LC-MS/MS. E. coli and S. aureus bacteria were resistant to all four antibiotics used as standards in hospitals. Full article

Propolis is a complex natural compound that honeybees obtain from plants and contributes to hive safety. It is rich in phenolic and flavonoid compounds, which contain antioxidant, antimicrobial, and anticancer properties. In this study, the chemical composition and antioxidant activities of propolis were investigated; ABTS^•+, DPPH^• and DMPD^•+ were prepared using radical scavenging antioxidant methods. The phenolic and flavonoid contents of propolis were 53 mg of gallic acid equivalent (GAE)/g and 170.164 mg of quercetin equivalent (QE)/g, respectively. The ferric ion (Fe³⁺) reduction, CUPRAC and FRAP reduction capacities were also studied. The antioxidant and reducing capacities of propolis were compared with those of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol and Trolox reference standards. The half maximal inhibition concentration (IC₅₀) values of propolis for ABTS^•+, DPPH^• and DMPD^•+ scavenging activities were found to be 8.15, 20.55 and 86.64 μg/mL, respectively. Propolis extract demonstrated IC₅₀ values of 3.7, 3.4 and 19.6 μg/mL against α-glycosidase, acetylcholinesterase (AChE) and carbonic anhydrase II (hCA II) enzyme, respectively. These enzymes’ inhibition was associated with diabetes, Alzheimer’s disease (AD) and glaucoma. The reducing power, antioxidant activity and enzyme inhibition capacity of propolis extract were comparable to those demonstrated by the standards. Twenty-eight phenolic compounds, including acacetin, caffeic acid, p-coumaric acid, naringenin, chrysin, quinic acid, quercetin, and ferulic acid, were determined by LC-MS/MS to be major organic compounds in propolis. The polyphenolic antioxidant-rich content of the ethanol extract of propolis appears to be a natural product that can be used in the treatment of diabetes, AD, glaucoma, epilepsy, and cancerous diseases. Full article

Three novel two-dimensional metalloporphyrin COFs (MPor−COF−366, M = Fe, Mn, Cu) were fabricated by changing the metal atoms in the center of the porphyrin framework. The physicochemical characteristics of MPor−COF−366 (M = Fe, Mn, Cu) composites were fully analyzed by diverse electron microscopy and spectroscopy. Under optimal conditions, experiments on determining butylated hydroxy anisole (BHA) at FePor−COF−366/GCE were conducted using differential pulse voltammetry (DPV). It is noted that the FePor−COF−366/GCE sensor showed excellent electrocatalytic performance in the electrochemical detection of BHA, compared with MnPor−COF−366/GCE and CuPor−COF−366/GCE. A linear relationship was obtained for 0.04–1000 μM concentration of BHA, with a low detection limit of 0.015 μM. Additionally, the designed sensor was successfully employed to detect BHA in practical samples, expanding the development of COF-based composites in electrochemical applications. Full article

Magnofluorine, a secondary metabolite commonly found in various plants, has pharmacological potential; however, its antioxidant and enzyme inhibition effects have not been investigated. We investigated the antioxidant potential of Magnofluorine using bioanalytical assays with 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•+), N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD^•+), and 1,1-diphenyl-2-picrylhydrazyl (DPPH^•) scavenging abilities and K₃[Fe(CN)₆] and Cu²⁺ reduction abilities. Further, we compared the effects of Magnofluorine and butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), α-Tocopherol, and Trolox as positive antioxidant controls. According to the analysis results, Magnofluorine removed 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals with an IC₅₀ value of 10.58 μg/mL. The IC₅₀ values of BHA, BHT, Trolox, and α-Tocopherol were 10.10 μg/mL, 25.95 μg/mL, 7.059 μg/mL, and 11.31 μg/mL, respectively. Our results indicated that the DPPH· scavenging effect of Magnofluorine was similar to that of BHA, close to that of Trolox, and better than that of BHT and α-tocopherol. The inhibition effect of Magnofluorine was examined against enzymes, such as acetylcholinesterase (AChE), α-glycosidase, butyrylcholinesterase (BChE), and human carbonic anhydrase II (hCA II), which are linked to global disorders, such as diabetes, Alzheimer’s disease (AD), and glaucoma. Magnofluorine inhibited these metabolic enzymes with Ki values of 10.251.94, 5.991.79, 25.411.10, and 30.563.36 nM, respectively. Thus, Magnofluorine, which has been proven to be an antioxidant, antidiabetic, and anticholinergic in our study, can treat glaucoma. In addition, molecular docking was performed to understand the interactions between Magnofluorine and target enzymes BChE (D: 6T9P), hCA II (A:3HS4), AChE (B:4EY7), and α-glycosidase (C:5NN8). The results suggest that Magnofluorine may be an important compound in the transition from natural sources to industrial applications, especially new drugs. Full article

Scheelite associated with calcium-containing minerals such as calcite and fluorite is difficult to separate by flotation because of the Ca ions contained in the mineral lattices, which cause scheelite to have similar surface properties and floatability to gangue minerals. Traditional collectors such as oleic acid need to add a large amount of sodium silicate as gangue inhibitors, which causes difficulties for the settlement of tailings. In addition, the use of benzohydroxamic acid (BHA), which needs the addition of Pb(NO₃)₂ as the scheelite activator, can also cause environmental pollution. In this paper, Fe-BHA, a new collector containing the iron complex, was studied to investigate its flotation ability of scheelite, as well as its BHA/FeCl₃ ratio on scheelite flotations. In the single mineral flotations, the Fe-BHA showed a significant difference in the flotation recoveries of scheelite and calcite, with a scheelite recovery of 77.03% at pH 8.0 and calcite recovery of 16.69% at the same pH. The results of the roughing tests of Xianglushan actual ore showed that the scheelite with Fe-BHA (500 g/t BHA and 200 g/t FeCl₃) and 40 g/t oleic acid as collectors obtained satisfactory flotation results with a WO₃ grade of 1.56% and WO₃ recovery of 65.52%, which were much higher than those of scheelite with BHA or oleic acid as the collector, but there was still a gap with those of scheelite using Pb(NO₃)₂ as activation and BHA as the collector. The UV-Vis curves of the Fe-BHA with different BHA/FeCl₃ ratios indicated that the Fe-BHA chelates might have several different structural forms, and the single mineral tests of the BHA/FeCl₃ ratios showed that when the molar ratio of benzohydroxamic acid to FeCl₃ was about 1.2:1, the best scheelite flotation result was obtained in this test. In addition, the XPS analyses proved that the adsorption of the Fe-BHA on the scheelite surface occurred, and by fitting the peaks of Ca 2p and O 1s of scheelite, it was found that the mechanism of the Fe-BHA acting on the Ca sites of the scheelite surface was through the removal of H₂O from the Ca-OH of scheelite and Fe-OH from Fe-BHA to form Fe-O-H. Full article

The type of polymeric condensed tannins from plum fruit (Prunus salicina) (PCT), the degree of polymerization and the distribution of polymers were characterized by MALDI-TOF MS and NMR spectroscopy. The metal-binding capacity of PCT with five metal ions (Cu²⁺, Zn²⁺, Al³⁺, Fe²⁺, and Fe³⁺) was characterized by a fluorescence quenching method. The results demonstrated the following: epicatechin was the basic unit occurring in PCT, and A-type and B-type linkages were the most common between the structural units of the polymers. The PCT have a strong antioxidant activity, which is comparable with that of the synthetic antioxidant BHA. The quenching mechanism of the PCT’s fluorescence intensity by Zn²⁺, Cu²⁺, and Al³⁺ was different from that of Fe³⁺ and Fe²⁺. Fe³⁺, Al³⁺ and Fe²⁺ had much higher affinities for the PCT than Zn²⁺ and Cu²⁺. A simple UV-Vis spectra method was developed to determine the protein-precipitating capacity of tannins. Bovine serum albumin (BSA) was effectively precipitated by tannins isolated from plum fruits, Chinese gallnut, sorghum grain, and Platycarya strobilacea at pH values between 4.5 and 5.0. A statistically significant linear relationship (p < 0.0001 or p < 0.0003) existed between the amount of tannin–protein complex formed and the amount of tannins added to the reaction mixture. The slopes of these lines indicated the protein-precipitating capacity of tannins. Full article

Thiophosphate compounds have attracted much attention in coordination chemistry, but their deep adsorption mechanism remains underexplored as flotation collectors. The flotation performance and adsorption mechanism of a novel (dibutoxy-thiophosphorylsulfanyl)-acetic acid (CDDP) chelating collector on azurite surfaces were studied by micro-flotation tests, zeta potential measurements, and Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscopy (FE-SEM) analysis. The micro-flotation results indicated that CDDP exhibited superior collecting performances to direct flotation recovery of azurite and floated over 91.44% of azurite at pH 7. For sodium isopentyl xanthate (NaIX) and Benzohydroxamic acid (BHA) collectors, the addition of Na₂S still did not show good collection performance. The results of zeta potential, FTIR, XPS and FE-SEM measurements, all confirmed that CDDP showed a better affinity to azurite surfaces than NaIX and BHA. Furthermore, XPS and FE-SEM provided obvious evidence that CDDP could easily react with Cu²⁺ sites on azurite surfaces. Using the density functional theory (DFT) method, the collection capacity of azurite was CDDP > BHA > NaIX, which exactly matched the micro-flotation results. In addition, this study provided an atomic-scale understanding of the structure–property relationship of CDDP as chelating agents for copper mineral flotation. Full article

The sustainable utilization of different food waste and other products is one of the challenges of the European Green Course. Buckwheat has major potential as a food ingredient; however, processing buckwheat into food products generates a large amount of solid waste that needs to be sustainably disposed of. The by-products that come from the processing of the buckwheat contain high contents of carbon and hydrogen and can be used as raw materials for the production of granular biofuels. This work proposes and explores the potential of a different route of buckwheat husk ash utilization. Chemical analysis of the buckwheat husk ash (BHA) and uncleaned buckwheat husks (UBH) showed significant amounts of primary and secondary nutrients (0.28 ± 0.06%–5.84 ± 0.43% P₂O₅; 4.56 ± 0.46%–38.63 ± 1.82% K₂O; 0.09 ± 0.01%–12.18 ± 0.38% CaO and 0.47 ± 0.08%–3.56 ± 0.18% MgO) as well as micronutrients (Zn, Mn, Cu, and Fe) and carbon (29.53 ± 0.50%–54.35 ± 0.58% C). It has been determined that granular biofertilizers can be produced by using drum granulators from the mixture of raw materials in an 80–20% BHA, 20–80% UBH, and 10% polyvinyl acetate (PVA) solution. However, when more than 20% of the UBH is present in the raw material mixture, the humidity of granules is high (more than 6%), and bulk density is low (less than 450 kg/m³). The pH values of 10% solution of the produced granules range from 12.0 to 9.7; thus, the fertilizers can act as a liming agent, which can be recommended for acid soils. This suggests a potential for a cradle-to-cradle type of regenerative engineering process design, where the end product of buckwheat processing—buckwheat husk ash and untreated buckwheat husks—can be returned back to the soil to replenish the nutrients, resulting in an overall sustainable process. Full article

In this study, the antioxidant and antiradical properties of some phyto lignans (nordihydroguaiaretic acid, secoisolariciresinol, secoisolariciresinol diglycoside, and α-(-)-conidendrin) and mammalian lignans (enterodiol and enterolactone) were examined by different antioxidant assays. For this purpose, radical scavenging activities of phyto and mammalian lignans were realized by 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) radical (ABTS^•+) scavenging assay and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging assay. Additionally, the reducing ability of phyto and mammalian lignans were evaluated by cupric ions (Cu²⁺) reducing (CUPRAC) ability, and ferric ions (Fe³⁺) and [Fe³⁺-(TPTZ)2]³⁺ complex reducing (FRAP) abilities. Also, half maximal inhibitory concentration (IC₅₀) values were determined and reported for DPPH^• and ABTS^•+ scavenging influences of all of the lignan molecules. The absorbances of the lignans were found in the range of 0.150–2.320 for Fe³⁺ reducing, in the range of 0.040–2.090 for Cu²⁺ reducing, and in the range of 0.360–1.810 for the FRAP assay. On the other hand, the IC₅₀ values of phyto and mammalian lignans were determined in the ranges of 6.601–932.167 µg/mL for DPPH^• scavenging and 13.007–27.829 µg/mL for ABTS^•+ scavenging. In all of the used bioanalytical methods, phyto lignans, as secondary metabolites in plants, demonstrated considerably higher antioxidant activity compared to that of mammalian lignans. In addition, it was observed that enterodiol and enterolactone exhibited relatively weaker antioxidant activities when compared to phyto lignans or standard antioxidants, including butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), Trolox, and α-tocopherol. Full article

Lithium, sodium, potassium, rubidium and caesium salts of 5-O-caffeoylquinic acid (chlorogenic acid, 5-CQA) were synthesized and described by FT-IR (infrared spectroscopy), FT-Raman (Raman spectroscopy), UV (UV absorption spectroscopy), ¹H (400.15 MHz), ¹³C (100.63 MHz) NMR (nuclear magnetic resonance spectroscopy). The quantum–chemical calculations at the B3LYP/6-311++G** level were done in order to obtain the optimal structures, IR spectra, NBO (natural bond orbital) atomic charges, HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) orbitals and chemical reactivity parameters for 5-CQA and Li, Na and K 5-CQAs (chlorogenates). The DPPH (α, α-diphenyl-β-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) assays were used for the preliminary estimation of the antioxidant properties of alkali metal chlorogenates and chlorogenic acid. In the DPPH assay the EC₅₀ parameter were equal to 7.39 μM for 5-CQA and was in the range of 4.50–5.89 μM for salts. The FRAP values for two different concentrations (5 and 2.5 μM) of the studied compounds were respectively 114.22 and 72.53 μM Fe²⁺ for 5-CQA, whereas for salts they were 106.92–141.13 and 78.93–132.00 μM Fe²⁺. The 5-CQA and its alkali metal salts possess higher antioxidant properties than commonly applied antioxidants (BHA, BHT, l-ascorbic acid). The pro-oxidant action of these compounds on trolox oxidation was studied in the range of their concentration 0.05–0.35 μM. The lipophilicity (logk_w) of chlorogenates and chlorogenic acid was determined by RP-HPLC (reverse phase—high performance liquid chromatography) using five different columns (C8, PHE (phenyl), CN (cyano), C18, IAM (immobilized artificial membrane)). The compounds were screened for their in vitro antibacterial activity against E. coli, Bacillus sp., Staphylococcus sp., Streptococcus pyogenes and antifungal activity against Candida sp. The 5-CQA possessed lower antibacterial (minimal inhibitory concentration, MIC = 7.06 mM) and antifungal (MIC = 14.11 mM) properties than its alkali metal salts (MIC values: 6.46–2.63 mM and 12.91–5.27mM, respectively). The synthesized chlorogenates possessed better antioxidant, lipophilic, antimicrobial as well as lower pro-oxidant properties than the ligand alone. Moreover, a systematic change of the activity of alkali metal salts along the series Li→Cs suggests that there are correlations between the studied biological properties. The type of metal cation in the carboxylate group of chlorogenate is crucial for the activity of studied compounds. Full article

Vaccinium myrtillus (bilberry) leaf is traditionally used in southeastern Europe for the treatment of diabetes. In the present study, the ability of bilberry leaf extracts to inhibit carbohydrate-hydrolyzing enzymes and restore glutathione concentration in Hep G2 cells subjected to glucose-induced oxidative stress was investigated. A comprehensive analysis of the antioxidant activity of two bilberry leaf extracts was performed. The aqueous extract showed excellent total antioxidant and chelating activity. Its antioxidant activity in the β-carotene-linoleic acid assay was very good, reaching the activity of the antioxidant standard BHA (93.4 ± 2.3% vs. 95.1 ± 2.4%, respectively). The hydroethanolic extract (ethanol/H₂O, 8:2, v/v), on the other hand, was a better radical scavenger and Fe²⁺ reducing agent. Furthermore, the aqueous extract was able to efficiently increase glutathione concentration in Hep G2 cells subjected to glucose-induced oxidative stress and restore it to the levels observed in non-hyperglycaemic cells. The hydroethanolic extract strongly inhibited α-glucosidase, with the IC₅₀ statistically equal to the antidiabetic drug acarbose (0.29 ± 0.02 mg/mL vs. 0.50 ± 0.01 mg/mL, respectively). Phytochemical analysis revealed the presence of quercetin and kaemferol derivatives, as well as chlorogenic and p-coumaric acid. The study results indicate that V. myrtillus leaf may have promising properties as a supporting therapy for diabetes. Full article

The identification and quantification of the phenolic contents of methanolic extracts of three Salvia L. species namely S. brachyantha (Bordz.) Pobed, S. aethiopis L., and S. microstegia Boiss. and Bal. were evaluated using reverse phase high performance liquid chromatography, UV adsorption, and mass spectrometry (RP-HPLC/MS). In order to determine the antioxidant capacity of these species, cupric ions (Cu²⁺) reducing assay (CUPRAC) and ferric ions (Fe³⁺) reducing assay (FRAP) were performed to screen the reducing capacity and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay was employed for evaluation of the radical scavenging activity for both solvents. In further investigation, the antimicrobial activities of Salvia species were tested using the disc diffusion method against three Gram-positive and four Gram-negative microbial species, as well as three fungi species. The results showed that there is a total of 18 detectable phenols, the most abundant of which was kaempferol in S. microstegia and rosmarinic acids in S. brachyantha and S aethiopis. The other major phenols were found to be apigenin, luteolin, p-coumaric acid, and chlorogenic acid. All species tested showed moderate and lower antioxidant activity than standard antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and ascorbic acid. The ethanolic extracts of Salvia species revealed a wide range of antimicrobial activity. S. brachyantha and S. microstegia showed the highest antimicrobial activities against B. subtilis, whereas S. aethiopis was more effective on Y. lipolytica. None of the extracts showed anti-fungal activity against S. cerevisiae. Thus these species could be valuable due to their bioactive compounds. Full article