-
Journal of the Science of Food and... Jul 2024The Cosmos sulphureus Cav. plant is studied for its high polyphenolic content with antioxidant properties. Its flowers, rich in phenolic acids, flavonoids, and tannins,...
BACKGROUND
The Cosmos sulphureus Cav. plant is studied for its high polyphenolic content with antioxidant properties. Its flowers, rich in phenolic acids, flavonoids, and tannins, hold promise as antioxidants in food preservation. The inclusion of these compounds in chickpea-based coatings with a previously studied preservative effect would be an excellent option as a food preservation method and microencapsulation addresses challenges like dispersion and degradation of polyphenols in the coating. The objective of this research was to evaluate the in vitro antioxidant activity of Cosmos sulphureus leaves, seed, and flower extracts and explore the protective effects of chickpea-based coatings containing microcapsules of flower polyphenolic extract on the chemical quality of stored roasted sunflower seeds during storage.
RESULTS
The ethanolic leaf extract exhibited the highest antiradical activity, followed by the aqueous flower extract. After a storage period of 15 days, at 40 °C, the chickpea-based coatings effectively delayed lipid oxidation in the roasted sunflowers seeds, and the inclusion of polyphenolic microcapsules with 0.01% extract (SMC 0.01%) in the coating significantly improved the protective effect. By day 15 of storage, SMC 0.01% showed comparable peroxide value, conjugated dienes, and linoleic acid content to samples containing the synthetic antioxidant BHT (butylated hydroxytoluene). Samples that only contained chickpea-based coating and coating with polyphenolic microcapsules with 0.005% extract exhibited significantly greater reduction in fatty acid content compared to the 0.01% SMC treatment.
CONCLUSION
The chickpea-based coating with polyphenolic microcapsules demonstrated antioxidant activity akin to synthetic BHT, offering a promising biopackaging solution for lipid-rich foods like roasted sunflower seeds. © 2024 Society of Chemical Industry.
PubMed: 38958470
DOI: 10.1002/jsfa.13715 -
Chemistry & Biodiversity Jul 2024A versatile and efficient chemo selective synthesis of 4-aryl-3-formyl-2H-chromenes (AFC) was undertaken using Pd-catalyzed cross-coupling conditions. The key oxidative...
Pd(II)-Catalyzed Site-Selective Cross Coupling Reaction: Synthesis of Highly Fluorescent Aryl-Formyl-Chromenes and its Iminoantipyrine Analogues as Selective AChE Inhibitors.
A versatile and efficient chemo selective synthesis of 4-aryl-3-formyl-2H-chromenes (AFC) was undertaken using Pd-catalyzed cross-coupling conditions. The key oxidative transmetalation was successfully applied to a significant range of substitutions on the chromene moiety and aryl ring in Ar(BOH), accommodating both electron-rich and electron-deficient groups. These π-extended scaffolds exhibited green-yellow fluorescence with a large Stokes shift and high quantum yield. Measurement of photophysical properties revealed that the compound with methoxy substitution in the chromene ring, 3t, caused a significant bathochromic shift. The AFCs obtained from this method can be transformed into biologically active 4-aryl-3-iminoantipyrine-2H-chromenes (AAC) through functionalization of the formyl chromenes. The AFCs and AACs with methoxy substitutions (3t and 4e) were docked against AChE inhibition, and compound 4e had the lowest binding energy of -11.20 kcal/mol. DFT calculations performed on representative compounds revealed that compound 4e is more reactive than 3t, which is in accordance with the docking studies.
PubMed: 38958461
DOI: 10.1002/cbdv.202400719 -
MSphere Jul 2024McKenzie Lehman works in the field of bacterial pathogenesis and metabolism. In this mSphere of Influence article, she reflects on how three papers entitled "Glycolytic...
McKenzie Lehman works in the field of bacterial pathogenesis and metabolism. In this mSphere of Influence article, she reflects on how three papers entitled "Glycolytic dependency of high-level nitric oxide resistance and virulence in by N. P. Vitko, N. A. Spahich, and A. R. Richardson (mBio 6:e00045-15, 2015, https://doi.org/10.1128/mbio.00045-15), "The cystine transporters TcyABC and TcyP facilitate nutrient sulfur acquisition during infection" by J. M. Lensmire, J. P. Dodson, B. Y. Hsueh, M. R. Wischer, et al. (Infect Immun 88:e00690-19, 2020, https://doi.org/10.1128/iai.00690-19), and "The second messenger c-di-AMP inhibits the osmolyte uptake system OpuC in " by C. F. Schuster, L. E. Bellows, T. Tosi, I. Campeotto, et al. (Sci Signal 16:ra81, 2016, https://doi.org/10.1126/scisignal.aaf7279) impacted her work on bacterial metabolism and pathogenesis.
PubMed: 38958458
DOI: 10.1128/msphere.00239-24 -
Environmental Science & Technology Jul 2024Effective synthesis and application of single-atom catalysts on supports lacking enough defects remain a significant challenge in environmental catalysis. Herein, we...
Effective synthesis and application of single-atom catalysts on supports lacking enough defects remain a significant challenge in environmental catalysis. Herein, we present a universal defect-enrichment strategy to increase the surface defects of CeO-based supports through H reduction pretreatment. The Pt catalysts supported by defective CeO-based supports, including CeO, CeZrO, and CeO/AlO (CA), exhibit much higher Pt dispersion and CO oxidation activity upon reduction activation compared to their counterpart catalysts without defect enrichment. Specifically, Pt is present as embedded single atoms on the CA support with enriched surface defects (CA-HD) based on which the highly active catalyst showing embedded Pt clusters (Pt) with the bottom layer of Pt atoms substituting the Ce cations in the CeO surface lattice can be obtained through reduction activation. Embedded Pt can better facilitate CO adsorption and promote O activation at Pt-CeO interfaces, thereby contributing to the superior low-temperature CO oxidation activity of the Pt/CA-HD catalyst after activation.
PubMed: 38958431
DOI: 10.1021/acs.est.4c03078 -
ACS Applied Materials & Interfaces Jul 2024MnO/polypyrrole (PPy) composite films were deposited on fluorine-doped tin oxide (FTO) conductive glasses by a two-step wet-chemical method, including electrochemical...
MnO/polypyrrole (PPy) composite films were deposited on fluorine-doped tin oxide (FTO) conductive glasses by a two-step wet-chemical method, including electrochemical deposition and chemical bath deposition (CBD). The porous MnO films were first grown on FTO glasses by an electrodeposition method. Second, polypyrrole nanoparticles were polymerized by the oxidation-reduction reaction between MnO and pyrrole, using the presynthesized MnO as the skeleton. Then, MnO/PPy composite films with coral-like structures were obtained. The electrochemical and electrochromic (EC) properties of the prepared films were investigated. The results show that, compared to the single MnO or PPy film, the MnO/PPy composite film has a larger optical modulation (67.3% at a wavelength of 900 nm), faster response times (4 s for coloration and 3 s for bleaching), and a higher coloration efficiency (218.16 cm·C). The high coloration efficiency attests to the exceptional performance of the composite film in converting electrical signals into vivid color changes. The electrochemical stability test results show that the composite film maintains a stable EC performance after 200 coloration/bleaching cycles. The coral-like structures of the composite film are responsible for the better EC properties.
PubMed: 38958414
DOI: 10.1021/acsami.4c05669 -
Acta Physiologica (Oxford, England) Jul 2024How the cerebral metabolic rates of oxygen and glucose utilization (CMRO and CMR, respectively) are affected by alterations in arterial PCO (PaCO) is equivocal and...
AIM
How the cerebral metabolic rates of oxygen and glucose utilization (CMRO and CMR, respectively) are affected by alterations in arterial PCO (PaCO) is equivocal and therefore was the primary question of this study.
METHODS
This retrospective analysis involved pooled data from four separate studies, involving 41 healthy adults (35 males/6 females). Participants completed stepwise steady-state alterations in PaCO ranging between 30 and 60 mmHg. The CMRO and CMR were assessed via the Fick approach (CBF × arterial-internal jugular venous difference of oxygen or glucose content, respectively) utilizing duplex ultrasound of the internal carotid artery and vertebral artery to calculate cerebral blood flow (CBF).
RESULTS
The CMRO was altered by 0.5 mL × min (95% CI: -0.6 to -0.3) per mmHg change in PaCO (p < 0.001) which corresponded to a 9.8% (95% CI: -13.2 to -6.5) change in CMRO with a 9 mmHg change in PaCO (inclusive of hypo- and hypercapnia). The CMR was reduced by 7.7% (95% CI: -15.4 to -0.08, p = 0.045; i.e., reduction in net glucose uptake) and the oxidative glucose index (ratio of oxygen to glucose uptake) was reduced by 5.6% (95% CI: -11.2 to 0.06, p = 0.049) with a + 9 mmHg increase in PaCO.
CONCLUSION
Collectively, the CMRO is altered by approximately 1% per mmHg change in PaCO. Further, glucose is incompletely oxidized during hypercapnia, indicating reductions in CMRO are either met by compensatory increases in nonoxidative glucose metabolism or explained by a reduction in total energy production.
PubMed: 38958262
DOI: 10.1111/apha.14197 -
Advanced Science (Weinheim,... Jul 2024Nickel cobalt oxides (NCOs) are promising, non-precious oxygen evolution reaction (OER) electrocatalysts. However, the stoichiometry-dependent electrochemical behavior...
Nickel cobalt oxides (NCOs) are promising, non-precious oxygen evolution reaction (OER) electrocatalysts. However, the stoichiometry-dependent electrochemical behavior makes it crucial to understand the structure-OER relationship. In this work, NCO thin film model systems are prepared using atomic layer deposition. In-depth film characterization shows the phase transition from Ni-rich rock-salt films to Co-rich spinel films. Electrochemical analysis in 1 m KOH reveals a synergistic effect between Co and Ni with optimal performance for the 30 at.% Co film after 500 CV cycles. Electrochemical activation correlates with film composition, specifically increasing activation is observed for more Ni-rich films as its bulk transitions to the active (oxy)hydroxide phase. In parallel to this transition, the electrochemical surface area (ECSA) increases up to a factor 8. Using an original approach, the changes in ECSA are decoupled from intrinsic OER activity, leading to the conclusion that 70 at.% Co spinel phase NCO films are intrinsically the most active. The studies point to a chemical composition dependent OER mechanism: Co-rich spinel films show instantly high activities, while the more sustainable Ni-rich rock-salt films require extended activation to increase the ECSA and OER performance. The results highlight the added value of working with model systems to disclose structure-performance mechanisms.
PubMed: 38958233
DOI: 10.1002/advs.202405188 -
Angewandte Chemie (International Ed. in... Jul 2024Enantioselective transformation of ubiquitous C(sp3)-H bonds into three-dimensional chiral scaffolds is of longstanding interest to synthetic chemists. Herein, an...
Enantioselective transformation of ubiquitous C(sp3)-H bonds into three-dimensional chiral scaffolds is of longstanding interest to synthetic chemists. Herein, an asymmetric paired electrolysis enables a highly efficient and sustainable approach to the enantioselective alkylation of sulfonylimines via C(sp3)-H functionalization. In this protocol, anodic oxidation for benzylic radical formation and Lewis acid-catalyzed sulfonylimine reduction on the cathode were seamlessly cross-coupled (up to 88% yield). Enantioenriched chiral amines containing a tetrasubstituted carbon stereocenter are accessed with high enantioselectivity (up to 96% ee). Mechanistic studies suggest that the amine generated in situ could serve as a base to deprotonate phenols and decrease the oxidation potential of the reaction, allowing phenols with lower potentials to be preferentially oxidized.
PubMed: 38958225
DOI: 10.1002/anie.202409222 -
ACS Applied Materials & Interfaces Jul 2024Tissue-engineered heart valve (TEHV) has emerged as a prospective alternative to conventional valve prostheses. The decellularized heart valve (DHV) represents a...
Tissue-engineered heart valve (TEHV) has emerged as a prospective alternative to conventional valve prostheses. The decellularized heart valve (DHV) represents a promising TEHV scaffold that preserves the natural three-dimensional structure and retains essential biological activity. However, the limited mechanical strength, fast degradation, poor hemocompatibility, and lack of endothelialization of DHV restrict its clinical use, which is necessary for ensuring its long-term durability. Herein, we used oxidized chondroitin sulfate (ChS), one of the main components of the extracellular matrix with various biological activities, to cross-link DHV to overcome the above problems. In addition, the ChS-adipic dihydrazide was used to react with residual aldehyde groups, thus preventing potential calcification. The results indicated notable enhancements in mechanical properties and resilience against elastase and collagenase degradation as well as the ability to withstand extended periods of storage without compromising the structural integrity of valve scaffolds. Additionally, the newly cross-linked valves exhibited favorable hemocompatibility and , thereby demonstrating exceptional biocompatibility. Furthermore, the scaffolds exhibited traits of gradual degradation and resistance to calcification through a rat subcutaneous implantation model. In the rat abdominal aorta implantation model, the scaffolds demonstrated favorable endothelialization, commendable patency, and a diminished pro-inflammatory response. As a result, the newly constructed DHV scaffold offers a compelling alternative to traditional valve prostheses, which potentially advances the field of TEHV.
PubMed: 38958205
DOI: 10.1021/acsami.4c03171 -
Journal of the American Chemical Society Jul 2024Water microdroplets promote unusual chemical reactions at the air-water interface. However, the interfacial structure of water microdroplets and its potential influence...
Water microdroplets promote unusual chemical reactions at the air-water interface. However, the interfacial structure of water microdroplets and its potential influence on chemical processes are still enigmatic. Here, we present evidence of in-droplet fractionation of water isotopologues. Employing a sonic spray, we atomized the heavy water (DO, 99.9 atom % D) solution of three classes of organic compounds (basic, acidic, and neutral). The analytes were predominantly desorbed from the resulting droplet surface in protonated form rather than deuterated form, as detected by mass spectrometry. This result remained unaltered upon adding formic acid- (DCOOD) to the droplet. Monitoring Dakin oxidation of benzaldehyde at the surface of binary microdroplets composed of 1:1 (/) DO/HO revealed the preferred formation of phenolate-O over phenolate-O. Atmospheric pressure chemical ionization mass spectrometric analysis of the vapor composition in the sprayed aerosol revealed the preferential evaporation of lighter water isotopologue impurities from the surface of heavy water microdroplets. These results indicate the enrichment of lighter water isotopologue impurities (HOD/HO) on the surface of heavy water microdroplets, implying possible future developments for water isotopologue fractionation using microdroplets.
PubMed: 38958201
DOI: 10.1021/jacs.4c03315