P-hydroxybenzoic Acid Research Articles

Dual microelectromembrane extraction as a tunable platform for the determination of antioxidant compounds with varied hydrophobicity in oral bioaccessibility assays of food commodities: a proof of concept.

An automatic millifluidic dual microelectromembrane extraction (D-µEME) method as a front-end to HPLC-UV-Vis is herein proposed for the first time to facilitate thematrixclean-up of relatively polar polyphenolic acidic (PPA) antioxidants with a relatively broad range of lipophilicity (logP from -0.27 to 2.14) from simulated gastric extracts of oral bioaccessibility tests. The flow setup is amenable to handle microliter volumes of two distinct organic phases along with donor and acceptor phases unsupervised, conduct in-tube D-µEME in parallel without supporting membranes, and mix the two acceptor phases automatically prior to online HPLC-UV-Vis. The target antioxidants involve gallic acid, chlorogenic acid, 4-hydroxybenzoic acid, caffeic acid, and trans-cinnamic acid. Various solvents are explored to investigate their compatibility for simultaneous D-µEME, including 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, and 1-nonanol, as well as deep eutectic solvents, e.g., thymol/6-methyl coumarin, and ionic liquids as additives to alcohols. Notably, 1-pentanol and 1-octanol exhibit the best performances in extracting the most polar (gallic acid and chlorogenic acid) and the least polar analytes (trans-cinnamic acid), respectively, notwithstanding both solvents are amenable to retrieve analytes with medium hydrophobicity (4-hydroxybenzoic acid and caffeic acid). The effects of the voltage, the extraction time, and the sample ionic strength on the extraction recoveries are also investigated in detail. Under the selected D-µEME conditions, the overall linear ranges span from 1.25 to 80mg/L, with limits of detection ranging from 0.2 to 3.3mg/L. The flow-based D-µEME is resorted to oral bioaccessibility assays in the gastric phase of the target compounds from eggplant, blueberry, and coffee bean extracts, with relative extraction recoveries ranging from 71.5 to 133.5%.

Functional analysis of the PcCDPK5 gene in response to allelopathic substances on p-hydroxybenzoic acid (p-HBA) stress in patchouli.

Calcium-dependent protein kinase (CDPK) is an important mediator for Ca2 + signal recognition and transduction, playing a crucial role in plant stress response. Previous studies have shown that PcCDPK5 may be involved in the response of patchouli to p-hydroxybenzoic acid (p-HBA) stress. In this study, we further found that the subcellular localization of PcCDPK5 protein is in the cytoplasm, and its gene expression is closely related to continuous cropping (CC) and p-HBA stress. Under p-HBA stress, silencing the PcCDPK5 homologous gene in Nicotiana tabacum leads to decreased antioxidant enzyme activity and increased malondialdehyde (MDA) content, significantly accumulating reactive oxygen species (ROS) and affecting normal plant growth. On the contrary, overexpression of PcCDPK5 can effectively alleviate the damage caused by p-HBA stress to plant bodies. Through this research, the function of PcCDPK5 in response to p-HBA stress has been preliminarily analyzed, laying a theoretical foundation for alleviating CC obstacles in patchouli.

Antioxidant Properties of Brassica Rapa L. Seeds and Immunostimulant Effect on Immunity Broilers Cells (Gallus Gallus Domesticus)

Background: In the past few decades, researchers have focused on finding the benefits of natural substances derived from plants. Objective: This study aimed to evaluate the use of Brassica rapa seeds in poultry feed as an antioxidant and immunostimulant of host defenses. Methods: We prepared three extracts using ethanol, Ethyl Acetate, and water. Spectrophotometric methods determined the total phenolic and flavonoid content in the three extracts. Antioxidant activity was assessed using 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing/antioxidant power (FRAP), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radicals and β-Carotene bleaching methods. An assessment of their immunostimulant activities in vitro was performed on chicken immunity cell proliferation (splenocytes, thymocytes, and Bursa cells) and IgY production. Results: The total phenolic contents ranged from 462.5 to 794.8 mg /g of extract, the order of TPC was as follows: EtOAc > EtOH >Water. Flavonoid contents were, 63.7 mg in EtOH extract, 81.2 mg in EtOAc extract, and 108.7 mg/g Extract in aqueous extract. By DPPH, the IC50s of EtOH, EtOAc, and water, were 1.8μg/ml, 2.4μg/ml, and 1.5μg/ml, respectively. Using the Ferric- Reducing Antioxidant Power (FRAP), we remarked that the EtOH and EtOAc extracts have important antioxidant powers. The ABTS assay indicated that EtOH and water had the highest activities with IC50s of 0.19 and 0.07, respectively. Finally, by the β-carotene bleaching test, we observed that the IC50 of the EtOH, EtOAc, and water were 62.1 μg/mL; 72.7 μg/mL, and 45.8 μg/mL, respectively. The results obtained indicate that Brassica aqueous extract stimulates humoral immunity by stimulating splenocyte (B and T-lymphocytes) and Bursa cell (B-lymphocyte) proliferation by more than 200% of response vs control. In addition, the aqueous extract highly stimulated the function of bursa cells by 208% of the reaction. In the same conditions, we recorded a stimulation of cellular immunity mediated by thymocytes by an increase in cell proliferation (352.7% of response) implicated in virus protection. These extracts also possessed an antimicrobial effect against diverse microorganisms such as coliforms and Staphylococcus. The FT-IR spectrum indicated that the hydroxyl group (phenol), hydroxybenzoic acid family, carbohydrate molecules such as glucopyranose, a carbonyl ester group, hydrocarbon chains (alkyls groups)) were present. Conclusion: This result could have interesting applications in the poultry feed industry to enhance the performance of animal development.

Flavonoid and Phenolic Properties of Dried Seedless and Seeded Grape Cultivars (Vitis vinifera L.)

In raisin cultivation, seeded (cvs. Gök Üzüm and Eksi Kara), parthenocarpic (cv. Black Corinth), and stenospermocarpic (cvs. Black Kishmish and Sultani Çekirdeksiz) grape varieties are used. Very little is known about the metabolic properties of raisins derived from these cultivars. According to the existing literature, certain metabolites including flavonoids and phenolic acids were studied in different raisin varieties. In this study, anthocyanidin, flavonol, flavone, flavanone, catechin, hydroxycinnamic acid, and hydroxybenzoic acid contents of 5 different grape cultivars were examined. As a result of the study, it was determined that phenolic acid and flavonoid contents were found to be significantly different among all varieties. Flavonol, catechin, and anthocyanin concentrations were higher in the cv. Gök Üzüm compared to other cultivars. As a result, when compared to seedless varieties, raisin varieties with seeds had a higher concentration of flavonoid capacity. In contrast, higher levels of most phenolic acids were detected in raisins produced from seedless varieties than in raisins produced from seeded varieties.

Ferula communis leaf extract: antioxidant capacity, UHPLC–MS/MS analysis, and in vivo and in silico toxicity investigations

IntroductionFerula communis has demonstrated an abundance of pharmacological and antioxidative qualities.MethodsThis study investigates the antioxidant activity of F. communis leaf aqueous extract, total polyphenol and flavonoid concentrations, and ultra-high-performance liquid chromatography (UHPLC) composition and then evaluates the toxicity of the plant’s leaves in vitro and in silico. The major compound of the studied extract, namely, p-hydroxybenzoic acid, was chosen for a molecular docking technique to discover the inhibition mechanism toward antioxidant proteins. In addition, a detailed molecular dynamics simulation was carried out to examine the thermodynamic stability of the produced intermolecular interactions. The antioxidant capacity of the extracts of F. communis was evaluated using 2,2-diphenylpicryl hydroxyl (DPPH) radical and ferric reducing antioxidant power (FRAP) procedures. Acute toxicity was tested on albino mice at doses of 200, 300, and 400 mg/kg.ResultsThe results show that the polyphenol and flavonoid contents of the extract are significant (0.257 ± 0.003 mg Eq AG/mg and 0.32 ± 0.04 mg Eq Q/mg, respectively). The antioxidant activity illustrates that the extracts have notable activity in DPPH and FRAP assays. The toxicity study revealed that the mice’s behavior, body weight, and organ weights (liver and kidneys) were unaffected by Ferula communis leaf extract administration compared to controls. UHPLC–tandem mass spectrometry (MS/MS) analysis of the extract highlights the presence of 11 compounds, the most abundant of which is p-hydroxybenzoic acid, representing 53.65%. The predicted pharmacokinetic characteristics of absorption, distribution, metabolism, excretion, and toxicity (ADMET) attest to the well-absorbed nature of the isolated compounds, with human intestinal absorption (HIA) varying from 42% for arbutin (M3) to 100% for ursolic acid (M4).ConclusionIn conclusion, the leaves of Ferula communis are a good source of natural antioxidants and phenolic compounds. Thus, this study demonstrates that this plant has a wide range of applications, including natural food preservatives, pharmaceuticals, and cosmetics, as evidenced by ongoing research.

Development and Optimization of a Cost-Effective Electrochemical Immunosensor for Rapid COVID-19 Diagnosis

The coronavirus disease (COVID-19) pandemic has created an urgent need for rapid, accurate, and cost-effective diagnostic tools. In this study, an economical electrochemical immunosensor for the rapid diagnosis of COVID-19 was developed and optimized based on charge transfer resistance (Rct) values obtained by electrochemical impedance spectroscopy (EIS) from the interaction between antibodies (anti-SARS-CoV-2) immobilized as a bioreceptor and the virus (SARS-CoV-2). The sensor uses modified pencil graphite electrodes (PGE) coated with poly(4-hydroxybenzoic acid), anti-SARS-CoV-2, and silver nanoparticles. The immobilization of anti-SARS-CoV-2 antibodies was optimized at a concentration of 1:250 for 30 min, followed by blocking the surface with 0.01% bovine serum albumin for 10 min. The optimal conditions for virus detection in clinical samples were a 1:10 dilution with a response time of 20 min. The immunosensor responded linearly in the range of 0.2–2.5 × 106 particles/μL. From the relationship between the obtained signal and the concentration of the analyzed sample, the limit of detection (LOD) and limit of quantification (LOQ) obtained were 1.21 × 106 and 4.04 × 106 particles/μL, respectively. The device did not cross-react with other viruses, including Influenza A and B, HIV, and Vaccinia virus. The relative standard deviation (RSD) of the six immunosensors prepared using the shared-pool sample was 3.87. Decreases of 22.3% and 12.4% were observed in the response values of the ten immunosensors stored at 25 °C and 4.0 °C, respectively. The sensor provides timely and accurate results with high sensitivity and specificity, offering a cost-effective alternative to the existing diagnostic methods.

Metabolomic Insights into the Potential of Chestnut Biochar as a Functional Feed Ingredient

Biochar is potentially a functional ingredient in animal nutrition that offers health benefits such as detoxification, while also promoting environmental sustainability through carbon sequestration, emission reduction, and its circular production. However, the heterogeneity of commercially available biochar products requires a detailed assessment of their functional properties for applications in animal feed. This study evaluates chestnut biochar from morphological, chemical, and metabolomic perspectives and assesses its functional properties. Metabolomic analysis of a water extract using QTOF HPLC-MS/MS confirmed the presence of bioactive compounds, such as hydroxybenzoic and succinic acids, highlighting its potential as a functional feed ingredient. The chestnut biochar inhibited the growth of the pathogenic E. coli strains F18+ and F4+, with maximum inhibition rates of 15.8% and 28.6%, respectively, after three hours of incubation. The downregulation of genes associated with quorum sensing (MotA, FliA, FtsE, and HflX, involved in biofilm formation and cellular division) suggests that biochar interferes with several aspects of the pathogenic process. Importantly, biochar was not found to adversely affect beneficial probiotic bacteria, such as Lactiplantibacillus plantarum and Limosilactobacillus reuteri. These findings support the potential of chestnut biochar as a versatile ingredient for sustainable animal nutrition, thus promoting animal welfare while offering environmental benefits.

Identification of chemical constituents and absorbed components in rat serum of Ipomoea muricata (L.) Jacq. by UPLC-Q-exactive-MS

Ipomoea muricata (L.) Jacq. has anti-inflammatory, analgesic, haemostatic and antioxidant effects, but its pharmacological components are still unclear. This study comprehensively identified chemical constituents and absorbed components of I. muricata by UPLC-Q-Exactive-MS. The column temperature was 35 °C, and the injection volume was 2 μl. The mobile phase using a 0.1% formic acid as phase A and 0.1% formic acid of solution in methanol as phase B was adopted in positive ion mode. And the mobile phase using a 10 mM formic ammonia solution as phase A and 10 mM formic ammonia of solution in 95% methanol as phase B was adopted in negative ion mode. In this study, we identified 25 compounds from the alcoholic extract of I. muricata, including 11 organic acids, 5 coumarins, 2 flavonoids, 7 alkaloids and nitrogen-containing compounds. Nine absorbed components were identified from the serum of rats after administration, including adenosine, p-hydroxybenzoic acid, chlorogenic acid, dextroquinic acid, shikimic acid, caffeic acid, p-hydroxycinnamic acid, chrysin, and umbelliferone. UPLC-Q-Exactive-MS technique can quickly identify the chemical constituents and absorbed components in rat serum of I. muricata, and provide scientific basis for clarifying the pharmacodynamic material basis and optimising the quality control index of I. muricata.

Compounds Involved in the Invasive Characteristics of Lantana camara.

Lantana camara L. is native to tropical America and has naturalized in many other tropical, subtropical, and temperate regions in Asia, Africa, Oceania, North and South America, and Europe. L. camara infests diverse habitats with a wide range of climatic factors, and its population increases aggressively as one of the world's 100 worst invasive alien species. Its infestation reduces species diversity and abundance in the natural ecosystems and reduces agricultural production. The life history characteristics of L. camara, such as its high reproductive ability and high adaptive ability to various environmental conditions, may contribute to its ability to infest and increase its population. Possible evidence of the compounds involved in the defense functions of L. camara against natural enemies, such as herbivore mammals and insects, parasitic nematodes, pathogenic fungi and bacteria, and the allelochemicals involved in its allelopathy against neighboring competitive plant species, have accumulated in the literature over three decades. Lantadenes A and B, oleanonic acid, and icterogenin are highly toxic to herbivore mammals, and β-humulene, isoledene, α-copaene thymol, and hexadecanoic acid have high insecticidal activity. β-Caryophyllene and cis-3-hexen-1-ol may function as herbivore-induced plant volatiles which are involved in sending warning signals to undamaged tissues and the next plants of the same species. Farnesol and farnesal may interrupt insect juvenile hormone biosynthesis and cause abnormal metamorphosis of insects. Several triterpenes, such as lantanolic acid, lantoic acid, pomolic acid, camarin, lantacin, camarinin, ursolic acid, and oleanonic acid, have demonstrated nematocidal activity. Lantadene A, β-caryophyllene, germacrene-D, β-curcumene, eicosapentaenoic acid, and loliolide may possess antimicrobial activity. Allelochemicals, such as caffeic acid, ferulic acid, salicylic acid, α-resorcylic acid, p-hydroxybenzoic acid, vanillic acid, unbelliferone, and quercetin, including lantadenes A and B and β-caryophyllene, suppress the germination and growth of neighboring plant species. These compounds may be involved in the defense functions and allelopathy and may contribute to L. camara's ability to infest and to expand its population as an invasive plant species in new habitats. This is the first review to focus on how compounds enhance the invasive characteristics of L. camara.

In vivo Differential Effects of Extractable and Non-Extractable Phenolic Compounds from Grape Pomace on the Regulation of Obesity and Associated Metabolic Alterations.

Grape pomace (GP) is a by-product rich in phytochemicals, including extractable polyphenols (EPPs) and non-extractable polyphenols (NEPPs), which have distinct metabolic fates that may affect their biological activities. The benefits of GP have been reported in relation to obesity and its comorbidities, particularly when administered preventively focusing on EPPs. Therefore, the aim of this study was to investigate the effects of EPPs and NEPPs from GP as a treatment for obesity and its associated metabolic alterations. A previous comprehensive characterization of the selected GP revealed the most relevant individual compounds in the EPPs fraction (malvidin hexoside, (-)-epicatechin, quercetin, and procyanidin dimer B2 isomer II), as well as in the NEPPs fraction (hydroxybenzoic acid isomers I-II). The experiment was performed in obese rats with insulin resistance, treated for 8 weeks with EPPs or NEPPs grape pomace fractions (100mg/kg). After the intervention, the HFFD + EPP group showed a significantly lower weight gain (9.6%) and body mass index (9.7%) compared to the HFFD group. While liver triglyceride levels were only significantly reduced in the HFFD + NEPP group (47%) compared to the HFFD group. Neither treatment resulted in a reduction of insulin resistance. Therefore, the supplementation with grape pomace phenolic fractions to an animal model of obesity exerted differential beneficial effects on body weight and liver lipid accumulation, overall contributing to an amelioration of some the metabolic alterations present in obesity, although not to aspects such as glycemic homeostasis.

Investigating the antioxidant and anti-inflammatory potential of Nypa fruticans: a multifaceted approach to skin protection and aging

Reactive oxygen species (ROS) produced in the mitochondria of skin cells play a significant role in the degradation of the extracellular matrix and induction of inflammatory responses, both of which are major contributors to skin aging. Antioxidants that reduce ROS production and inhibit inflammatory skin lesions are considered beneficial for the treatment of inflammatory skin diseases and prevention of skin aging. In this study, we evaluated the potential of Nypa fruticans (NF), which is known for its antioxidant properties, to mitigate tumor necrosis factor-alpha (TNF-α)- and interferon-gamma (IFN-γ)-induced damage in normal human epidermal keratinocytes. The major active constituents identified in NF include protocatechuic acid, hydroxybenzoic acid, procyanidin B, catechin, and epicatechin. NF significantly suppressed the production of ROS, nitric oxide (NO), and prostaglandin E2 (PGE2), while also reducing the levels of inflammatory cytokines interleukin-6 (IL-6) and interleukin-1 beta (IL-1β), which were elevated by TNF-α/IFN-γ stimulation. Furthermore, NF restored the expression of key skin barrier-related proteins such as serine peptidase inhibitor kazal type 5 (SPINK5), collagen type I alpha 1 chain (COLIA1), loricrin (LOR), aquaporin-3 (AQP3), and filaggrin (FLG). Additionally, NF significantly upregulated the expression of hyaluronan synthase (HAS) -1 and − 2 and human β-defensin (HBD) -2 and − 3, which are important for skin hydration and innate immune defense. These findings underscore the potential therapeutic applications of Nypa fruticans (NF) in mitigating oxidative stress, inflammation, skin barrier dysfunction, dehydration, and microbial imbalances. By targeting multiple pathways implicated in skin aging, NF represents a promising comprehensive approach for preserving skin health and addressing age-related dermatological conditions. Moreover, NF holds significant potential not only to alleviate the manifestations of skin aging but also to provide a basis for the development of innovative dermatological therapies. Future investigations should aim to further elucidate the clinical applications of NF in dermatology to maximize its therapeutic benefits.

Unveiling the Phytochemical Diversity and Bioactivity of Astragalus melanophrurius: A First Report Integrating Experimental and In Silico Approaches.

Background: The genus Astragalus is renowned for its diverse bioactive potential, yet the chemical composition and biological properties of Astragalus melanophrurius remain inadequately explored. This study aimed to investigate the chemical profile, antioxidant capacity, and enzyme inhibitory activities of methanol extracts from various plant parts of A. melanophrurius. Methods: Methanol extracts were obtained from leaves, stems, flowers, roots, and aerial portions of A. melanophrurius. The chemical composition was determined using LC-ESI-MS/MS, focusing on key phytochemicals such as hyperoside, kaempferol, 4-hydroxybenzoic acid, and chlorogenic acid. Antioxidant activities were assessed via DPPH, ABTS, and FRAP assays, while enzyme inhibitory activities were evaluated against α-amylase and tyrosinase. In silico molecular docking analyses were conducted to explore the interactions between major compounds and target enzymes. Results: The leaf extract exhibited the highest total phenolic and flavonoid contents, correlating with superior antioxidant activities, achieving IC50 values of 16.55 mg/mL, 4.58 mg/mL, and 3.07 mg/mL in DPPH, ABTS, and FRAP assays, respectively. The root extract demonstrated notable α-amylase (IC50 = 2.99 mg/mL) and tyrosinase (IC50 = 1.34 mg/mL) inhibitory activities, suggesting potential applications in diabetes and hyperpigmentation management. Molecular docking revealed stable complexes of hyperoside and kaempferol with target enzymes, supporting their roles in observed bioactivities. Conclusions: This study highlights the bioactivity of A. melanophrurius extracts, particularly from leaves and roots, supporting their therapeutic potential. Future research should focus on isolating active compounds and conducting in vivo studies to confirm efficacy and elucidate mechanisms of action.

The microbiota of cork and yellow stain as a model for a new route for the synthesis of chlorophenols and chloroanisoles from the microbial degradation of suberin and/or lignin

BackgroundThe main application of cork is the production of stoppers for wine bottles. Cork sometimes contains 2,4,6-trichloroanisole, a compound that, at a concentration of ng/L, produces an unpleasant musty odor that destroys the organoleptic properties of wine and results in enormous economic losses for wineries and cork industries. Cork can exhibit a defect known as yellow stain, which is associated with high levels of 2,4,6-trichloroanisole. We describe how the microbiota of cork and yellow stain define a novel mechanism that explains the formation of chlorophenols and chloroanisoles (including 2,4,6-trichloroanisole) from p-hydroxybenzoate produced during lignin and/or suberin breakdown.ResultsElectron microscopy revealed that cork affected by yellow stain exhibited significant structural degradation. This deterioration was attributed to the presence of higher microbial populations compared to those found in standard cork. Cork microbiota is rich in filamentous fungi able to metabolize lignin. A metataxonomic analysis confirmed that yellow stain contained significantly greater populations of fungal species belonging to Absidia, Geomyces, Mortierella, Mucor, Penicillium, Pseudogymnoascus, Talaromyces, and Umbelopsis. It also contained significantly greater amounts of bacteria belonging to Enterobacterales, Streptosporangiales, Tepidisphaerales, Pseudomonas, and several members of Burkholderiaceae, particularly species of the Burkholderia-Caballeronia-Paraburkholderia group. The extraction of aromatic compounds from cork samples allowed the identification of several compounds typically observed following lignin depolymerization. Notably, p-hydroxybenzoic acid and phenol were detected. Two strains of the genus Streptomyces isolated from yellow stain were able to biotransform p-hydroxybenzoate into phenol in resting cell assays. Phenol could be efficiently chlorinated in vitro to produce 2,4,6-trichlorophenol by a fungal chloroperoxidase, an enzymatic activity commonly found in filamentous fungi isolated from cork. Finally, as has been widely demonstrated before, 2,4,6-trichlorophenol can be efficiently O-methylated to 2,4,6-trichloroanisole by many of fungi that inhabit cork.ConclusionsChlorophenols and chloroanisoles can be produced de novo in cork from p-hydroxybenzoate generated by the microbial biodegradation of lignin and/or suberin through the participation of different types of microorganisms present in cork. The natural origin of these compounds, which are of great interest for the chlorine cycle and represent a new source of environmental contamination that differs from that caused by human activity, is described.BmZYZKVv9XTmg3g6suYKG9Video

Development of Homogeneous Carboxylation of Phenolates via Kolbe-Schmitt Reaction.

In this study, the homogeneous carboxylation of potassium, sodium, and lithium phenolates in DMSO solution at 100 °C by the Kolbe-Schmitt reaction was investigated. The impact of water, phenolate concentration, and cation nature on the yield of products and reaction selectivity was demonstrated. Based on the patterns observed, it was concluded that a complex cluster mechanism governs the carboxylation reaction in the solution. The use of a homogeneous reaction medium allowed for convenient testing of various additives to assess their impact on the reaction. Basic additives such as sodium salts of mesitol, tert-butylcalix[4]arene, sodium isopropyl, and tert-butyl cabonates were found to enhance the reaction, increasing the yield of hydroxybenzoic acids by 20% (to 61.6%). The main product in the DMSO solution was identified as 4-hydroxybenzoic acid, in contrast to the classical Kolbe-Schmitt method which typically yields 2-hydroxybenzoic (salicylic) acid. The use of 13C NMR spectroscopy enabled the observation of a "carbonate complex" in the solution for the first time, with the carbonate carbon displaying a chemical shift value of 142 ppm, an unusual finding for stable carbonates, and located between the signals of free dissolved CO2 and carboxylate derivatives.

The measurement of phenols with graphitic carbon fiber microelectrodes and fast-scan cyclic voltammetry

A phenol contains a six-membered, conjugated, aromatic ring bound to a hydroxyl group. These molecules are important in biomedical studies, aromatic food preparation, and petroleum engineering. Traditionally, phenols have been measured with several analytical techniques such as UV-VIS spectroscopy, fluorescence, liquid chromatography, and mass spectrometry. These assays provide for relatively high sensitivity and selectivity measurements, but they suffer from relatively low spatiotemporal resolution, low biocompatibility, long analysis time, high cost, and complex sample treatment. Recently, electrochemistry has served as a viable alternative to the measurement of phenols. In this study, we utilized carbon fiber microelectrodes (CFMEs) with fast-scan cyclic voltammetry for the sensitive and selective measurement of phenols. We tested four common phenolic compounds: phenol, 2-methylaminophenol (2-MAP), 4-methylaminophenol (4-MAP), and 3-hydroxybenzoic acid (3-HBA). We found that phenol, 2-MAP, 4-MAP, and 3-HBA were all partially adsorption and diffusion controlled to the surface of the CFMEs and that all four molecules could be detected with repeated injections. Structural differences led to varied sensitivities amongst the four phenols, and we were able to co-detect and differentiate the phenols in complex solutions with dopamine and serotonin. Lastly, we measured the phenols in simulated urine with a high percent recovery. These assays demonstrate enhanced electrochemical measurement of phenols, which will create more effective diagnostics for these complex molecules to help elucidate their mechanistic properties and ultimate significance in a biological context.

Syntheses, crystal structure, Hirshfeld Surface Analyzes of cocrystals and salt of a flexible imidazole tethered naphthalenediimide with some organic acids.

One salt and three cocrystals of 2,7-bis(3-(1H-imidazol-1-yl)propyl)benzo[lmn][3,8]phenanthroline-1,3,6,8(2H,7H)-tetraone (L) have been synthesized and reported. 3-Nitro benzoic acid (3NBA) forms salt with L and 4-Nitro benzoic acid (4NBA), 4-Hydroxy benzoic acid (4HBA) and 4-Amino benzoic acid (4ABA) forms cocrystals with L. L forms 1:1 salt with 3-NBA and 1:1 cocrystal with 4-NBA, 4-HBA and 4-ABA respectively. All the complexes were formed in a warm solvent condition. The solid-state structures were determined by single crystal X-ray diffraction method. Salt 1, exhibit zig zag tetrameric water cluster in the solid-state structure. Various types of supramolecular interactions such as OH…O, CH…O, π…π, and CH…π were observed in the x-ray structures and all these interactions guide the formation of 3D supramolecular architecture in the solid-state of all the complexes. Besides these, the 2D-fingerprint (2D-FP) and Hirshfeld surface analysis (HSA) computations were served to prove the 2D-network packed crystal lattice interactions.

Analysis of the antioxidant efficacy substances in fermented black mulberry juice and their preventive effects on oxidative stress in C2C12 cells.

This study evaluated the in vitro antioxidant activity and bioactive compound content of mixed-strain lactic acid bacteria-fermented black mulberry juice (FBMJ) and its protective effects against oxidative stress using physicochemical experiments and a cellular oxidative stress model. We also performed preliminary analyses of polysaccharide structures in FBMJ and identified the dynamic changes in the phenolic profiles of FBMJ during the fermentation process. The results indicated that FBMJ polyphenols can improve cell vitality and prevent H2O2-induced oxidative stress by reducing intracellular reactive oxygen species concentrations and regulating mitochondrial membrane potential. Metabolomic analysis proposed transformation pathways for FBMJ polyphenols, including the biotransformation of specific phenolic acids, such as hydroxycinnamic and hydroxybenzoic acids, and the degradation of rutin and anthocyanins. These findings will help explain why fermentation enhances the bioactivity of black mulberry juice by elucidating the biotransformation of polyphenolic compounds during fermentation.

CHEMICAL CONSTITUENTS OF Amburana acreana Ducke A. C. Sm. LEAVES

This study aimed to isolate, purify and characterize secondary metabolites present in Amburana acreana leaves, native to the state of Rondônia, using classical chromatographic methods and 1D, 2D nuclear magnetic resonance spectroscopy. From the hydroethanolic leaves extract of A. acreana, p-hydroxybenzoic acid, vanillic acid, coumarin, campesterol 3-β-D-glucoside and amburoside B, all known compounds, were identified. To the best of our knowledge, this is the first report of isolation and chemical characterization of secondary metabolites in A. acreana. In addition, in vitro assays indicated that amburoside B does not have inhibitory potential on the growth of gram-negative bacteria. The presence of these compounds suggests that, thus far, amburosides (A and B) could be chemotaxonomic markers of the genus Amburana.

High-efficiency biodegradation of crude oil and p-hydroxybenzoic acid by Acinetobacter haemolyticus JS-1: Integrated characterization and genomic analysis

High-efficiency biodegradation of crude oil and p-hydroxybenzoic acid by Acinetobacter haemolyticus JS-1: Integrated characterization and genomic analysis

Coffee and Cocoa By-Products as Valuable Sources of Bioactive Compounds: The Influence of Ethanol on Extraction.

Cocoa and coffee are two of the world's most important crops. Therefore, their by-products are generated in large quantities. This work proposes a simple method for the valorization of these residues by obtaining phenolic compounds and melanoidins by solid-liquid extraction using different hydroalcoholic solutions as extracting solvents (0, 25, 50, 75, 100% ethanol). Extracts of both by-products presented the highest antioxidant capacity and total phenolic and melanoidin content when using 50-75% ethanol in the solvent. Among all the extracts, those obtained from spent coffee grounds at 75% ethanol showed the highest concentrations of total phenolic compounds (13.5 ± 1.3 mmol gallic acid equivalents/g dry matter) and melanoidins (244.4 ± 20.1 mg/g dry matter). Moreover, the sun protection factor values of the coffee extracts obtained with 50 and 75% of ethanol as extraction solvent (7.8 ± 0.9 and 8.5 ± 0.7, respectively) showed their potential for use in the cosmetic sector. The most important phenolic compounds identified in the coffee by-products extracts were phenolic acids, and most of them were found in higher concentration in extracts obtained with lower percentages of ethanol (0-25%). Protocatechuic acid was the most abundant phenolic in cocoa extracts, with concentrations ranging from 18.49 ± 2.29 to 235.35 ± 5.55 µg/g dry matter, followed by 4-hydroxybenzoic acid, (-)-epicatechin and (+)-catechin. Esculetin was found in both coffee and cocoa extracts, which had not been reported to date in these residues. In summary, the use of 75% ethanol as an extraction solvent seems a good strategy to obtain extracts rich in phenolic compounds from food by-products rich in melanoidins, such as coffee and cocoa by-products. The high antioxidant potential of these extracts makes them of great interest for the cosmetic and nutraceutical industries.