Regulating the Selectivity of Nitrate Photoreduction for Purification or Ammonia Production by Cooperating Oxidative Half-Reactions.

The removal and conversion of nitrate (NO3-) from wastewater has become an important environmental and health topic. The NO3- can be reduced to nontoxic nitrogen (N2) for environmental remediation or ammonia (NH3) for recovery, in which the tailoring of the selectivity is greatly challenging. Here, by construction of the CuOx@TiO2 photocatalyst, the NO3- conversion efficiency is enhanced to ∼100%. Moreover, the precise regulation of selectivity to NH3 (∼100%) or N2 (92.67%) is accomplished by the synergy of cooperative redox reactions. It is identified that the selectivity of the NO3- photoreduction is determined by the combination of different oxidative reactions. The key roles of intermediates and reactive radicals are revealed by comprehensive in situ characterizations, providing direct evidence for the regulated selectivity of the NO3- photoreduction. Different active radicals are produced by the interaction of oxidative reactants and light-generated holes. Specifically, the introduction of CH3CHO as the oxidative reactant results in the generation of formate radicals, which drives selective NO3- reduction into N2 for its remediation. The alkyl radicals, contributed to by the (CH2OH)2 oxidation, facilitate the deep reduction of NO3- to NH3 for its upcycling. This work provides a technological basis for radical-directed NO3- reduction for its purification and resource recovery.

Promoting the efficiency and selectivity of NO3--to-NH3 reduction on Cu-O-Ti active sites via preferential glycol oxidation with holes.

The combined reductive and oxidative reaction is the essence of a solar-driven photoredox system. Unfortunately, most of these efforts focus on the specific half-reactions, and the key roles of complete photoredox reactions have been overlooked. Taking the nitrate reduction reaction (NO3-RR) as a typical multiple-electrons involved process, the selective reduction of the NO3- into ammonia (NH3) synthesis with high efficiency is still a grand challenge. Herein, a rational oxidative half-reaction is tailored to achieve the selective conversion of NO3- to NH3 on Cu-O-Ti active sites. Through the coupled NO3-RR with glycol oxidation reaction system, a superior NH3 photosynthesis rate of 16.04 ± 0.40 mmol gcat-1 h-1 with NO3- conversion ratio of 100% and almost 100% of NH3 selectivity is reached on Cu-O-Ti bimetallic oxide cluster-anchored TiO2 nanosheets (CuOx@TNS) catalyst. A combination of comprehensive in situ characterizations and theoretical calculations reveals the molecular mechanism of the synergistic interaction between NO3-RR and glycol oxidation pair on CuOx@TNS. The introduction of glycol accelerates the h+ consumption for the formation of alkoxy (•R) radicals to avoid the production of •OH radicals. The construction of Cu-O-Ti sites facilitates the preferential oxidation of glycol with h+ and enhances the production of e- to participate in NO3-RR. The efficiency and selectivity of NO3--to-NH3 synthesis are thus highly promoted on Cu-O-Ti active sites with the accelerated glycol oxidative half-reaction. This work upgrades the conventional half photocatalysis into a complete photoredox system, demonstrating the tremendous potential for the precise regulation of reaction pathway and product selectivity.

Xuanfei Baidu decoction in the treatment of coronavirus disease 2019 (COVID-19): Efficacy and potential mechanisms.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread worldwide and become a major global public health concern. Although novel investigational COVID-19 antiviral candidates such as the Pfizer agent PAXLOVID™, molnupiravir, baricitinib, remdesivir, and favipiravir are currently used to treat patients with COVID-19, there is still a critical need for the development of additional treatments, as the recommended therapeutic options are frequently ineffective against SARS-CoV-2. The efficacy and safety of vaccines remain uncertain, particularly with the emergence of several variants. All 10 versions of the National Health Commission's diagnosis and treatment guidelines for COVID-19 recommend using traditional Chinese medicine. Xuanfei Baidu Decoction (XFBD) is one of the "three Chinese medicines and three Chinese prescriptions" recommended for COVID-19. This review summarizes the clinical evidence and potential mechanisms of action of XFBD for COVID-19 treatment. With XFBD, patients with COVID-19 experience improved clinical symptoms, shorter hospital stay, prevention of the progression of their symptoms from mild to moderate and severe symptoms, and reduced mortality in critically ill patients. The mechanisms of action may be associated with its direct antiviral, anti-inflammatory, immunomodulatory, antioxidative, and antimicrobial properties. High-quality clinical and experimental studies are needed to further explore the clinical efficacy and underlying mechanisms of XFBD in COVID-19 treatment.

Continuous NO Upcycling into Ammonia Promoted by SO2 in Flue Gas: Poison Can Be a Gift.

Although ammonia (NH3) synthesis efficiency from the NO reduction reaction (NORR) is significantly promoted in recent years, one should note that NO is one of the major air pollutants in the flue gas. The limited NO conversion ratio is still the key challenge for the sustainable development of the NORR route, which potentially contributes more to contaminant emissions rather than its upcycling. Herein, we provide a simple but effective approach for continuous NO reduction into NH3, promoted by coexisting SO2 poison as a gift in the flue gas. It is significant to discover that SO2 plays a decisive role in elevating the capacity of NO absorption and reduction. A unique redox pair of SO2-NO is constructed, which contributes to the exceptionally high conversion ratio for both NO (97.59 ± 1.42%) and SO2 (99.24 ± 0.49%) in a continuous flow. The ultrahigh selectivity for both NO-to-NH3 upcycling (97.14 ± 0.55%) and SO2-to-SO42- purification (92.44 ± 0.71%) is achieved synchronously, demonstrating strong practicability for the value-added conversion of air contaminants. The molecular mechanism is revealed by comprehensive in situ technologies to identify the essential contribution of SO2 to NO upcycling. Besides, realistic practicality is realized by the efficient product recovery and resistance ability against various poisoning effects. The proposed strategy in this work not only achieves a milestone efficiency for NH3 synthesis from the NORR but also raises great concerns about contaminant resourcing in realistic conditions.

Efficient purification of a nitrate and chlorate mixture in water via photoredox activated intermediate coupling-decoupling pathway.

Nitrate (NO3-) is a widespread contaminant that threatens human health and ecological safety. Meanwhile, the disinfection byproducts chlorate (ClO3-) is generated inevitably in conventional wastewater treatment. Therefore, the contaminants mixture of NO3- and ClO3- are universal in common emission units. Photocatalysis technology is a feasible approach for the synergistic abatement of contaminant mixture, where matching suitable oxidation reactions is a potential strategy to improve the photocatalytic reduction reactions. Herein, formate (HCOOH) oxidation is introduced to facilitate the photocatalytic reduction of the NO3- and ClO3- mixture. As a result, high purification efficiency of NO3- and ClO3- mixture are achieved, evidenced by 84.6% e--dependent removal of the mixture at a reaction time of 30 min, with 94.5% N2 selectivity and 100% Cl- selectivity, respectively. Specifically, by the close combination of in-situ characterizations and theoretical calculations, the detailed reaction mechanism is revealed, in which the intermediate coupling-decoupling route from NO3- reduction and HCOOH oxidation is established by the chlorate-induced photoredox activation, leading to the significantly enhanced efficiency for the wastewater mixture purification. The practical application of this pathway is established for simulated wastewater to show its wide applicability. This work provides new insights into photoredox catalysis technology for its environmental application.

Beyond Purification: Highly Efficient and Selective Conversion of NO into Ammonia by Coupling Continuous Absorption and Photoreduction under Ambient Conditions.

Although the selective catalytic reduction technology has been confirmed to be effective for nitrogen oxide (NOx) removal, green and sustainable NOx re-utilization under ambient conditions is still a great challenge. Herein, we develop an on-site system by coupling the continuous chemical absorption and photocatalytic reduction of NO in simulated flue gas (CNO = 500 ppm, GHSV = 18,000 h-1), which accomplishes an exceptional NO conversion into value-added ammonia with competitive conversion efficiency (89.05 ± 0.71%), ammonia production selectivity (95.58 ± 0.95%), and ammonia recovery efficiency (>90%) under ambient conditions. The anti-poisoning capacities, including the resistance against factors of H2O, SO2, and alkali/alkaline/heavy metals, are also achieved, which presents strong environmental practicability for treating NOx in flue gas. In addition, the critical roles of corresponding chemical absorption and catalytic reduction components are also revealed by in situ characterizations. The emerging strategy herein not only achieves a milestone efficiency for sustainable NO purification but also opens a new route for contaminant resourcing in the near future of carbon neutrality.

In situ preparation of g-C3N4/polyaniline hybrid composites with enhanced visible-light photocatalytic performance.

The graphic carbon nitride/polyaniline (g-C3N4/PANI) hybrid composites were successfully synthesized by a facile in situ polymerization process under ice water bath. The photocatalytic activities of the g-C3N4/PANI composites were evaluated by using oxytetracycline (OTC) as model pollutants. The optimal g-C3N4/PANI composite (5%PANI: the g-C3N4/PANI hybrid with 5 wt.% of PANI) showed an enhancement degradation rate of 5-fold compared to that of conventional g-C3N4 under simulated-sunlight irradiation. In addition, the 5%PANI demonstrate significantly photocatalytic evolution H2 rate (163.2 µmol/(g⋅hr)) under the visible light irradiation. Furthermore, based on the results of optical performance and electrochemical testing, a possible mechanism was proposed, indicating that the incorporation of PANI into the traditional g-C3N4 can effectively tune the electronic structures, improve the photo-generated electrons-holes separation and enhance extensive absorption of visible light. Such a g-C3N4/PANI hybrid nanocomposites could be envisaged to possess great potentials in practical wastewater treatment and water splitting.

Discovery of the active compounds of Smilacis Glabrae Rhizoma by utilizing the relationship between the individual differences in blood drug concentration and the pharmacological effect in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: This study addresses the rapid discovery of the active compounds (the original constituents and/or metabolites) of a traditional Chinese drug, Smilacis Glabrae Rhizoma (SGR). AIM OF THE STUDY: The aim of this study was to develop a new method to find out the active compounds of traditional drugs in vivo. MATERIALS AND METHODS: A method was established to discover and identify the potential active compounds in drug-containing plasma from rats that were orally administered SGR extract, utilizing the relationship between the individual differences in blood drug concentrations in the rats and the resulting differences in pharmacological effect, and the method was denoted as the RID-PE method. For this method, we used high-performance liquid chromatography with a diode array detector combined with electrospray ionization ion trap time-of-flight multistage mass spectrometry (LC-MSn) to identify the compounds (the original constituents and metabolites) and to determine the peak areas of the compounds in drug-containing plasma following SGR treatment. The anti-inflammatory effect of SGR was evaluated using a carrageenan-induced inflammatory rat model. According to the percent inhibition of paw edema in each model rat (14 rats total) orally administered SGR extract, the plasma samples from the rats were sorted and divided into 7 groups. Each group consisted of two plasma samples, and their percent inhibition of paw edema were similar to each other. We performed an LC-MSn analysis on 3 plasma groups, which showed large differences in the inhibition rates, with percent inhibitions of 92.7%, 72.4% and 38.4%. The correlation coefficients (r) between the peak area of each compound and the pharmacological effect (inhibition ratio) of SGR in the three groups were analyzed using SPSS software. When the correlation coefficients of the compounds are greater than 0.8 (0.8 < r ≤1), these compounds are strongly and positively correlated with anti-inflammatory activity, making them potential anti-inflammatory active compounds. RESULTS: Fifty-eight potential anti-inflammatory compounds (0.8 < r ≤ 1) from SGR were discovered in model rat plasma using the RID-PE method, 47 of which were considered to be new potentially anti-inflammatory compounds. Among these compounds, four original constituents and 5 isomers of potential anti-inflammatory metabolites were validated to have significant anti-inflammatory effects, and they included astilbin, syringic acid, catechin, coumalic acid, resveratrol-3'-O-glucuronide (RG, isomer of M2 or M3), 3'-O-methyl-(+)-epicatechin-4'-O-glucuronide (CA-1, isomer of M16), 4'-O-methyl-(+)-epicatechin-3'-O-glucuronide (CA-2, isomer of M16), 4'-O-methyl-(+)-epicatechin-7-O-glucuronide (CA-3, isomer of M16) and 3'-O-methyl-(+)-epicatechin-7-O-glucuronide (CA-4, isomer of M16). In addition, four isomers (CA-1-CA-4) were reported to have anti-inflammatory effects for the first time, and CA-3 was a new compound. CONCLUSIONS: The RID-PE method can be used to discover and identify the active constituents and metabolites of SGR systematically and in vivo. Furthermore, these findings enhance our understanding of the metabolism and effective forms of SGR.

[Anti-inflammation effect of Jinlingzi San in rat metabonomics based on 1H-NMR and LC-MS technology].

To further explore the regulatory effect of Jinlingzi San on in vivo inflammatory mechanism during inflammatory treatment, this study adopted 1H-NMR and LC-MS technology to analyze differences in in vivo metabolites of carrageen-induce rat foot swelling model. Besides, biomarkers related to inflammation models of Jinlingzi San in SD rats were discovered to speculate the regulatory mechanism of Jinlingzi San in resisting carrageen-induce inflammation. Through the analysis of detection spectrum, we found 18 biomarkers of metabolites(citrate, pyruvate, malic acid, succinate, glutamate, lysine, tartrate, 2-oxobutyric acid, glycine, guanosine, 9-cis-retinoic acid, triphosphate, inosine 5'-diphosphate, inosine diphosphate, tripolyphosphate, inorganic triphosphate, glycerophosphocholine, 21-deoxycortisol). Relevant pathway analysis results were TCA cycle, pyruvate metabolism, glycine, serine and threonine metabolism, and dicarboxylic acid metabolism. From the metabolic network, we can see that the anti-inflammatory effect of Jinlingzi San can regulate citric acid, succinic acid and glycine content to resist oxygen free radical and reduce body damage by ROS, so as to down-regulate inflammatory factors generated from body tissues and resist inflammation.

[Subacute toxicity metabonomics of Jinlingzi powder based on LC-MS].

To further understand the metabolic characteristics of Jinlingzi powder toxicity effect in rats and explore the effect of Jinlingzi powder on unknown biological pathways in the treatment process. In this experiment, the effect of three doses of Jinlingzi powder decoction on rat liver and kidney was investigated to explore the characteristics and rules of Jinlingzi powder on in vivo metabonomic changes in rats. First, urine and serum samples of the rats were used for LC-MS analysis. Under the XCMS online analysis, 44 differential substances were found in the identification of metabolites. Finally, Metpa was used for metabolic pathways enrichment and analysis, and five related metabolic pathways were obtained: steroid hormone biosynthesis, tryptophan metabolism, pentose and glucuronate interconversions, ascorbate and aldarate metabolism, as well as glutathione metabolism. Metabolic network diagram showed that the toxicity-related pathways were mainly associated with lysine metabolism in living organisms, glucuronic acid conversion, and hormone metabolism, especially the metabolism imbalance of lysine and glutathione would result in the disorder of energy metabolism or oxidative stress regulation, and thus inducing the damage in rats. Subacute toxicity test results for three doses groups (low, middle and high doses) showed that, Jinlingzi powder with doses of 19.7 g•kg⁻¹ and 39.4 g•kg⁻¹ caused obvious toxic effect, indicating Jinlingzi powder could produce toxic effect in vivo in a dose-dependent manner, and cause irreversible damage to the body.

Metabonomic analysis of biochemical changes in the plasma and urine of carrageenan-induced rats after treatment with Yi-Guan-Jian decoction.

The urinary and plasma metabonomics method based on a Agilent-1200 LC system coupled to an Agilent-6410 mass spectrometry (HPLC-MS/MS) had been established to investigate the anti-inflammatory activity of Yi-Guan-Jian (YGJ) decoction and explore its potential anti-inflammatory mechanism. Rat acute inflammation was induced by subcutaneous injection of carrageenan in hind paws. Multivariate statistical approaches, such as principal component analysis (PCA), partial least-squares discriminant analysis (PLS-DA) and XCMS online software were used to distinguish normal control group (NG), model group (MG), aspirin-treated group (AG) and Yi-Guan-Jian decoction group (YGJ), aimed at finding out the potential biomarkers. There was a clear separation among the four groups in PCA model. Twenty-five potential biomarkers had been identified using PCA, PLS-DA and XCMS online software. Lastly, we had an enrichment for the related metabolic pathways and screened out the pathways that influence the organism a lot in MetPA, then five mainly metabolism: tryptophan metabolism, lipid metabolism, oxidative stress, glyoxylate and dicarboxylate metabolism, taurine and hypotaurine metabolism were found. In this study, YGJ showed good anti-inflammatory effects and it could suppress the changes of pathologic inflammatory cytokines of carrageenan-induced rat paw edema (CIE). There might be a correlation between these results and the regulation of the disturbed metabolites in urine and plasma. This study demonstrates that metabonomics is a powerful methodology to gain insight into the mechanisms of traditional Chinese medicine (TCM) formula in therapy.

[Nuclear magnetic resonance-based metabonomics for sedative and hypnotic effect of Banxia Houpo decoction].

Insomnia was a common disease, which might be correlated with γ-aminobutyric acid A (GABAA) receptor mechanism, cytokine regulatory mechanism, excitatory amino acid mechanism and hydroxytryptamine (5-HT) receptor mechanism, but the correlations between these independent mechanisms and pathological characterization were still unclear. To further explore the effect of Banxia Houpo decoction on known or unknown biological pathways during treatment of insomnia, the metabonomics method based on ¹H-NMR was developed for detecting the significant changes in metabolomics after the administration with Banxia Houpo decoction in pentobarbital sodium-induced rat sleeping experiment. Serum and urine samples were analyzed by ¹H-NMR. Principal component analysis (PCA) was carried out for endogenous small molecule metabolites in urine and serum. H-NMR spectroscopies and relevant metabolites were found and identified by Simca-p 17.0 (Umet-rics, Umea, Sweden) and Chenomx NMR Suite 7.1 (Chenomx, Inc., Edmonton, Alberta, Canada) software. The result suggests that Banxia Houpo decoction group and indiplon group had significant differences. The load diagram showed the biggest variation metabolites and intergroup significant differences among 10 metabolic substances. According to the experiment, Banxia Houpo decoction group and indiplon group can prolonge the sleeping time of pentobarbital sodium-induced sprague-dawley rats, with a synergistic effect. The significant changes of these biomarkers indicated that the Banxia Houpo decoction could aid sleep by adjusting the content of glutamine, creatine phosphate, 2-oxoglutarate, and reducing the activity of brain nerves.

Investigating the effectiveness of St John's wort herb as an antimicrobial agent against mycobacteria.

A persistent need exists for effective treatment agents for mycobacterial infections. This research investigated the effectiveness of the Hypericum perforatum herb (commonly known as St John's wort; SJW) in its growth inhibition of mycobacteria. A SJW extract was effective at inhibiting five nonpathogenic Mycobacterium isolates and Bacillus subtilis, but not Escherichia coli. Quantitative studies of concentration sensitivity to the SJW extract were performed with minimal bactericidal concentrations (MBC) ranging from 0.33 to 2.66 mg extract/mL. The SJW compounds hyperforin (Hfn), hypericin (Hpn), and pseudohypericin (Phn) were quantified in the extract using HPLC. The SJW extract solution of 133 mg extract/mL used in this study contained 2.3 mg Hfn/mL, 0.8 mg Hpn/mL, and 2.1 mg Phn/mL. Purified Hfn, Hpn, and Phn were tested for inhibitory activity against Mycobacterium JLS (M. JLS) at similar concentrations used in the crude extract. While Hfn was inhibitory at 46 µg/mL, none of the purified SJW constituents were bactericidal at concentrations corresponding to SJW treatments. Scanning electron microscopy (SEM) analysis of SJW-treated M. JLS cells showed changes in cell surface morphology.

Effect of lactose monolaurate on pathogenic and nonpathogenic bacteria.

The antimicrobial activities of sucrose monolaurate and a novel ester, lactose monolaurate (LML), were tested. Gram-positive bacteria were more susceptible than Gram-negative bacteria to both esters. The minimal bactericidal concentrations of LML were 5 to 9.5 mM for Listeria monocytogenes isolates and 0.2 to 2 mM for Mycobacterium isolates.