Protocatechuic Acid Research Articles

Consumption of Plant-Derived Phenolic Acids Modulates Hunger and Satiety Responses Due to Chemical Interactions with Enteroendocrine Mediators

Energy-dense foods are commonly rich in fat and simple sugars and poor in dietary fiber and micronutrients; regularly consuming them decreases the concentration and/or effect of anorexigenic hormones and may increase that of orexigenic ones, thereby decreasing satiety. In contrast, plant-derived phenolic-rich foods exert positive effects on satiety. In silico, in vitro, and in vivo investigations on some of most representative phenolic acids like chlorogenic acid (CGA), gallic acid (GA), ferulic acid (FA), and protocatechuic acid (PCA) have shown that they are able to modulate various hunger and satiety processes; however, there are few studies that show how their chemical structure contributes to achieve such effects. The objective of this review is to summarize how these phenolic acids can favorably modulate hormones and other satiety mediators, with emphasis on the chemical interactions exerted between the core of these compounds and their biological targets. The evidence suggests that they form interactions with certain hormones, their receptors, and/or enzymes involved in regulating hunger and satiety, which are attributed to their chemical structure (such as the position of hydroxyl groups). Further research is needed to continue understanding these molecular mechanisms of action and to utilize the knowledge in the development of health-promoting foods.

Phenolic Metabolites Protocatechuic Acid and Vanillic Acid Improve Nitric Oxide Bioavailability via the Akt-eNOS Pathway in Response to TNF-α Induced Oxidative Stress and Inflammation in Endothelial Cells

Background/Objectives: Reduced nitric oxide (NO) bioavailability secondary to excess-superoxide-driven oxidative stress is central to endothelial dysfunction. Previous studies suggest that phenolic metabolites may improve NO bioavailability, yet limited research is available in response to an inflammatory mediator. Therefore, we assessed the effects of cyanidin-3-glucoside (C3G) and its phenolic metabolites protocatechuic acid (PCA) and vanillic acid (VA) on NO bioavailability in a TNF-α induced inflammatory environment. Methods: Primary human umbilical vein endothelial cells (HUVECs) were supplemented with either C3G, PCA, or VA at 1 μM for 24 h before being stimulated with TNF-α 20 ng/mL for an additional 24 h. Measurements included cell viability, apoptosis, reactive oxygen species (ROS), nitrite concentrations, and endothelial nitric oxide synthase (eNOS) and Akt at the mRNA and protein level. Results: Phenolic metabolites did not increase the eNOS expression or nitrite levels in the unstimulated environment; rather, the metabolites mediated NO bioavailability in response to TNF-α induced oxidative stress, with increased viability, eNOS mRNA, phosphorylation, and nitrite levels. Conclusions: Phenolic metabolites, in the presence of TNF-α, can improve NO bioavailability at physiologically relevant concentrations via the Akt-eNOS pathway. This demonstrates that the induction of inflammation is a prerequisite for phenolic metabolites to promote protective properties in endothelial cells by activating the Akt-eNOS pathway.

Unraveling the Impact of Aspergillus sojae—A Food-Grade Fungus—On Phytoalexins, Phenolic Acids, and the Antioxidant and Antidiabetic Activity of Different Legumes

Legumes are a rich source of polyphenolic compounds known for their ability to promote health. Under stress conditions, legumes have been shown to produce higher levels of secondary metabolites, as a defensive mechanism. Hence, the present study aimed to induce legume seeds (e.g., soybean, chickpea, green pea, and red kidney bean) by inoculating them with Aspergillus sojae (A. sojae) and to evaluate the extracts for phytoalexins, phenolics, and antioxidant, antiobesity, and antidiabetic potentials. The UPLC-DAD findings of A. sojae-induced legumes showed medicarpin and maackiain in chickpea, pisatin in green pea, glyceollin I-III in soybean, and kievitone and phaseollin in red kidney bean. All induced legumes exhibited a higher total polyphenol content compared to the non-induced ones. Among induced legumes, soybean exhibited a higher (4.85 mg GAE/g) polyphenol content. The UPLC-ESI-QTOF-MS/MS findings established that legumes contained substantial levels of protocatechuic acid, vanillic acid, ferulic acid, chlorogenic acid, coumaric acid, 4-hydroxybenzoic acid, and caffeic acid. The results of antioxidant assays revealed a significantly higher level of activity in induced red kidney bean and soybean, whereas the level of activity in non-induced legumes was markedly lower. Moreover, induced red kidney bean effectively inhibited α-glucosidase (87.2%) and α-amylase (63.90%) at 5 mg/mL. Additionally, the maximum lipase inhibitory effects were displayed by induced soybean (72.54%) at 20 mg/mL.

Carvacrol maintains antioxidant capacity in goji fruit by increasing the content of bioactive compounds

Fresh goji berries are prone to decay and spoilage, resulting in economic losses. We investigated the effects of carvacrol (CVR) on the natural disease incidence and quality of goji berries by fumigating with varying CVR concentrations (0.06, 0.12, and 0.24 μL/mL). The results showed that CVR treatment inhibited the natural decay of goji berries by enhancing their quality, color, and total soluble solids/titratable acidity ratio. Moreover, 0.12 μL/mL CVR was determined to be the optimal concentration, as it maintained the sensory quality (except for aroma) and inhibited the disease incidence and preliminary disease expansion of goji fruit inoculated with Alternaria alternata. The treated berries exhibited elevated total phenolic content, total flavonoid content, ascorbic acid, glutathione, melatonin, total chlorophyll, and carotenoid levels. Higher hydrophilic and lipophilic total antioxidant activities and free radical scavenging capacities were also observed in the treated berries. Targeted metabolomics showed that treatment with 0.12 μL/mL CVR increased the levels of four phenolic acids (caffeic acid, chlorogenic acid, ferulic acid, and protocatechuic acid) and two flavonoids (naringenin and quercetin) in goji berries, thereby activating the gene expression of the phenylpropanoid metabolic pathway. In summary, CVR treatment delayed fruit senescence and the decline in fruit quality, promoted the accumulation of bioactive compounds, and improved antioxidant capacity and disease resistance by activating the phenylpropanoid metabolic pathway.

Insights into the chili phytochemicals, bioactive components, and antioxidant activity of instant premixes (green and red chilies) and their reconstitution products

Chili fruits are a potential source of phytochemicals and nutrients for food and reconstituted products. Due to its high nutritional and bioactive components, the current study focused on developing chili instant food products employing hot-air drying method. The effect of the hot-air drying method on physicochemical properties, microbiological quality, retention of bioactive components, phytochemicals, antioxidant properties, and sensory quality of green and red chilies reconstitution products were investigated. HPLC quantification unveiled that fresh red chili product had retained the highest capsaicin (2703.14 µg/g) and dihydrocapsaicin (1518 µg/g) content on the 0th day. Furthermore, UPLC-MS confirmed the presence of eleven phenolic compounds such as gallic acid, chlorogenic acid, caffeic acid, syringic acid, p-coumaric acid, protocatechuic acid, trans-cinnamic acid, ferulic acid, catechin, rutin, and quercetin. Among all, ferulic acid (382.91 µg/g) was the most abundant phenolic compound in fresh green chili products, followed by trans-cinnamic acid (73.19 µg/g) in green chili reconstituted and catechin (65.66 µg/g) in green and red chili reconstituted products. The chili products retained reasonable amounts of bioactive components and antioxidants during storage without microbial growth. The correlation analysis revealed a significant correlation between capsaicinoids, phenolic compounds, and antioxidant properties, which are linearly related in green chili products. This study offers manufacturers a cost-effective technology for producing high-quality chili-reconstituted products rich in essential nutrients and health benefits.Graphical

Exploring the Medicinal Potential of Hyptis suaveolens (Lamiaceae): A Comprehensive Review of Phytochemicals, Pharmacological Properties, and Drug Development Prospects

Hyptis suaveolens is a widely well-known species of the Lamiaceae family. This plant is regarded as noxious exotic invasive weeds. It has medicinal and insecticidal properties and is used in traditional medicine to treat various illnesses. This review examines the potential utility of the understudied plant species H. suaveolens for future drug development and design, the existence of medicinally significant secondary metabolites, and their potential pharmacological and pharmacognostic importance . Search engines such as Science Direct, Google Scholar, Springer Link, PubMed, and Scopus were used to find data and information to write this paper. Alkaloids, essential oils, terpenoids, sterols, tannins, saponins, and flavonoids are only a few of the phytochemicals abundant in H. suaveolens that have therapeutic value . These bioactive compounds possess diaphoretic, analgesic, gastroprotective, antiviral, antimicrobial, anticancer, antispasmodic, antirheumatic, antibacterial, antiseptic, anti-inflammatory, and antiulcer properties. Among the polyphenolic substances found in high concentration in H. suaveolens are methyl rosamarinate, p-coumaric acid, p-hydroxybenzoic acid, vanillic acid, prodelphinidins, syringic acid, profisetinidins, protocatechuic acid, gentisic acid, caffeic acid, rosamarinic acid, and proanthocyanidins. In H. suaveolens, some terpenoid bioactive compounds such as ursolic acid, methyl suaveolate, suaveolic acid, beta-sitosterol, and suaveolol are available in different parts of the plant. Some essential compounds, such as Linoleic acid, Palmitic acid, and Oleic acid, are found in the seed oils of H. suaveolens. Pentacyclic triterpenoid and ursolic acid from H. suaveolens have been reported to have effective antiviral response s. The plant extract is used to prepare silver and copper nanoparticles for different biological activities. Due to these characteristics, the plant may be able to treat resistant and recently discovered bacterial and viral infections instead of conventional medications.

Advanced Bionic Technology Combining Online Electrochemistry-Mass Spectrometry and Offline Electrochemistry-Liquid Chromatography-Mass Spectrometry for Simulating and Characterizing Metabolic Processes of Bioactive phenolic acids in Natural Products.

The metabolism research of bioactive phenolic acids widely found in natural products is of great significance for elucidating pharmacologic mechanisms and screening lead compounds. However, it is time-consuming and vulnerable to interference to conduct the traditional metabolism approach by applying organisms or biomaterials. Herein, a bionic technology was established by combining online electrochemistry-mass spectrometry (EC-MS) with offline electrochemistry-liquid chromatography-mass spectrometry (EC-LC-MS) to investigate the oxidative transformation and metabolic processes of the active phenolic acids (including salvianolic acid A, caffeic acid, 3, 5-O-dicaffeoylquinic acid, ferulic acid, salvianic acid A, and protocatechuic acid). Phase I metabolism of the phenolic acids were simulated by applying a three-electrode controlled potential electrochemical reactor with a boron-doped diamond electrode, with glutathione mixed into the oxidative products simultaneously for obtaining the phase II metabolites. Finally, structural characterization of the simulated metabolites of the phenolic acids was achieved successfully, including hydroxylation, methylation, demethylation, decarboxylation, etc. It was revealed that the simulated metabolism process based on an electrochemical system was effective in yielding a wide variety of metabolites for these compounds, which was also compared with the metabolism results applying rat liver microsomes. Consequently, this bionic technology is expected to be a powerful tool to investigate the material basis for the efficacy of active ingredients of natural products.

Folic Acid - Based Hydrogels Co-assembled with Protocatechuic Acid for Enhanced Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) presents a significant therapeutic challenge due to the need for oral drug delivery systems that withstand acidic environment of stomach while effectively targeting intestinal inflammation. To address this issue, we created a novel hydrogel system based on a folic acid (FA)-dopamine (DA) conjugate, co-assembled with protocatechuic acid (PCA), to form F-DP hydrogels. These hydrogels demonstrated robust anti-gastric acid, mucosal adhesive, and injectable properties, enhancing their efficacy for targeted delivery. In DSS-induced colitis mouse models, treatment with F-DP hydrogels resulted in significant therapeutic improvements, including increased body weight, reduced disease activity index (DAI), and maintained colon length. Biochemical assays revealed that F-DP hydrogels significantly enhanced antioxidant enzyme activities (GSH and SOD) and reduced oxidative stress markers (NO and MDA). Histological assessments confirmed effective repair of the colonic mucosal barrier, restoration of tight junction protein ZO-1, and reduction of inflammatory lesions. Furthermore, immunofluorescence staining indicated that F-DP hydrogels facilitated macrophages polarization from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype, thereby reducing inflammation and promoting tissue repair. Our study demonstrates that F-DP hydrogels show significant potential for improving IBD treatment through enhanced gastric resistance, intestinal adhesion, and synergistic anti-inflammatory effects, warranting further investigation for clinical applications.

Valorization of Potato Peels (Solanum tuberosum) Using Infrared-Assisted Extraction: A Novel Sprouting Suppressant and Antibacterial Agent.

Recently, there has been a growing interest in reducing waste to promote environmental sustainability, with particular focus on agricultural by-products, especially fruits and vegetables. Potato, a widely used crop across various industries, generates a significant amount of peel waste. This study aims to valorize potato peels using water bath extraction (WBE) and infrared-assisted extraction (IRAE), both with distilled water as the solvent, followed by assessments of antioxidant, antibacterial, and anti-sprouting activities. Optimization using response surface methodology identified optimal extraction conditions for WBE (90 °C for 70 min) and IRAE (80 °C for 10 min), with both methods yielding 3.5 mg GAE/g DM in polyphenol content. IRAE demonstrated superior energy efficiency and enhanced antioxidant activity. The extracts exhibited antibacterial properties against both Gram-positive (Listeria monocytogenes) and Gram-negative bacteria (Proteus sp. and Salmonella sp.), with inhibition zones ranging from 10 to 14 mm. Furthermore, the potato peels extract showed significant anti-sprouting effects at room temperature, reducing both the number and size of sprouts compared with the control. HPLC analysis showed the presence of different phenolic compounds such as rutin, catechin, caffeic acid, protocatechuic acid, chlorogenic acid, p-coumaric acid, and gallic acid in one or both extracts. These findings suggest that potato peels extract holds potential for applications in the food industry as a natural preservative due to its antioxidant properties, as well as a sprout suppressant. The antibacterial activity of the extracts suggests their potential as a natural preservative as well, offering protection against both Gram-positive and Gram-negative bacteria that may be present in food.

The Profile of Phenolic Compounds Identified in Pitaya Fruits, Health Effects, and Food Applications: An Integrative Review.

This integrative review aimed to identify the phenolic compounds present in pitayas (dragon fruit). We employed a comprehensive search strategy, encompassing full-text articles published between 2013 and 2023 in Portuguese, English, and Spanish from databases indexed in ScienceDirect, Capes Periodics, Scielo, and PubMed. The study's selection was guided by the question, "What are the main phenolic compounds found in pitaya fruits?". After screening 601 papers, 57 met the inclusion criteria. The identified phytochemicals have been associated with a range of health benefits, including antioxidant, anti-inflammatory, and anxiolytic properties. Additionally, they exhibit promising applications in the management of cancer, diabetes, and obesity. These 57 studies encompassed various genera, including Hylocereus, Selenicereus, and Stenocereus. Notably, Hylocereus undatus and Hylocereus polyrhizus emerged as the most extensively characterized species regarding polyphenol content. Analysis revealed that flavonoids, particularly kaempferol and rutin, were the predominant phenolic class within the pulp and peel of these fruits. Additionally, hydroxycinnamic and benzoic acid derivatives, especially chlorogenic acid, caffeic, protocatechuic, synaptic, and ellagic acid, were frequently reported. Furthermore, betalains, specifically betacyanins, were identified, contributing to the characteristic purplish-red color of the pitaya peel and pulp. These betalains hold significant potential as natural colorants in the food industry. Therefore, the different pitayas have promising sources for the extraction of pigments for incorporation in the food industry. We recommend further studies investigate their potential as nutraceuticals.

Lignin valorization to bioplastics with an aromatic hub metabolite-based autoregulation system

Exploring microorganisms with downstream synthetic advantages in lignin valorization is an effective strategy to increase target product diversity and yield. This study ingeniously engineers the non-lignin-degrading bacterium Ralstonia eutropha H16 (also known as Cupriavidus necator H16) to convert lignin, a typically underutilized by-product of biorefinery, into valuable bioplastic polyhydroxybutyrate (PHB). The aromatic metabolism capacities of R. eutropha H16 for different lignin-derived aromatics (LDAs) are systematically characterized and complemented by integrating robust functional modules including O-demethylation, aromatic aldehyde metabolism and the mitigation of by-product inhibition. A pivotal discovery is the regulatory element PcaQ, which is highly responsive to the aromatic hub metabolite protocatechuic acid during lignin degradation. Based on the computer-aided design of PcaQ, we develop a hub metabolite-based autoregulation (HMA) system. This system can control the functional genes expression in response to heterologous LDAs and enhance metabolism efficiency. Multi-module genome integration and directed evolution further fortify the strain’s stability and lignin conversion capacities, leading to PHB production titer of 2.38 g/L using heterologous LDAs as sole carbon source. This work not only marks a leap in bioplastic production from lignin components but also provides a strategy to redesign the non-LDAs-degrading microbes for efficient lignin valorization.

Beneficial effect of Caesalpinia pulcherrima linn., on diabetic neuropathy, cognitive dysfunction and cardiac complications in streptozotocin-induced diabetic rats

Pharmacological relevanceCaesalpinia pulcherrima L. is used in Indian Traditional Medicinal system to treat Diabetes. AimThis study was carried out to evaluate the standardized alcoholic extract of Caesalpinia pulcherrima seed (CPS) in Streptozotocin (STZ)-induced diabetic neuropathic and cardiac complications in rodents. Materials and methodsHPLC finger printing profile of CPS was performed to identify the bioactive molecules. Two doses of CPS (100 & 200 mg/kg b.w.) was orally administered daily once for six weeks to streptozotocin (50 mg/kg, i.v.)-induced diabetic rats. Every week intervals hot & cold immersion tests were carried to know the effect of CPS on peripheral neuropathy. In addition, blood glucose, body weight, food and water intake were also monitored. At the end of the study, sciatic nerve conduction velocity, diabetic cardiomyopathy and diabetic cognitive parameters were evaluated. Furthermore, histopathological studies of sciatic nerve and aortic strip were also carried out. ResultsHPLC finger print experiment showed the presence of gallic acid and protocatechuic acid. Administration of CPS for six weeks significantly prevented the development of diabetic peripheral neuropathy (DPN), cardiomyopathy and cognitive dysfunction in diabetic rats. The CPS treated rats displayed prominent (P < 0.001) improvement in motor coordination, muscle grip, locomotor activity and memory in diabetic rats. CPS treatment restored elevated systolic, diastolic, mean arterial blood pressure (MABP), and heart rate to near normal in diabetic condition. These observed beneficial effects were well correlated and justified with histopathological studies. In addition, CPS treatment also exhibited significant (P < 0.001) reduction of loss in body weight, and reduce the water and feed intake throughout the study. ConclusionTaken together, the present study provided a good insight in the therapeutic efficacy of Caesalpinia pulcherrima seed extract in dealing with diabetic complications. The study also scientifically justifies the ethnomedicinal/traditional claims of the title plant.

Mechanistic Insights into the Antioxidant Potential of Sugarcane Vinegar Polyphenols: A Combined Approach of DPPH-UPLC-MS, Network Pharmacology and Molecular Docking.

This study investigated the antioxidant potential of sugarcane vinegar, an emerging functional food, by analyzing its polyphenols and underlying molecular mechanisms that intervene in oxidative stress. Using a 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) assay combined with UPLC-MS analysis, six key polyphenols were identified: chlorogenic acid, caffeic acid, ferulic acid, luteolin, protocatechuic acid, and syringic acid. These compounds showed a positive correlation with antioxidant capacity. In a simulated sugarcane vinegar environment, these polyphenols exhibited synergistic antioxidant effects, while in methanol, antagonistic interactions were predominant. Network pharmacology revealed five key polyphenols targeting 10 critical proteins involved in oxidative stress, including the PI3K-Akt and IL-17 signaling pathways. Molecular docking confirmed strong binding affinities between these polyphenols and core targets like PTGS2, STAT3, and GSK3B. This study establishes a reference for the antioxidant mechanisms of sugarcane vinegar and highlights its potential for developing functional products.

Polyphenolic Compounds in the Stems of Raspberry (Rubus idaeus) Growing Wild and Cultivated.

The stems of Rubus idaeus L., a byproduct of the fruit-food industry, are known sources of bioactive compounds. The main objective of this study was to investigate the composition of polyphenolic compounds in R. idaeus stems. Seven cultivated raspberry varieties, thirteen garden samples, including five well-known raspberry varieties, and thirteen wild raspberry samples from different locations in Estonia were analyzed. The HPLC-MS method detected 62 substances, of which 42 were identified, 12 were tentatively identified, and 8 compounds remained unknown. Protocatechuic acid pentoside was dominant in most varieties and in all garden and wild raspberry samples. Dihydroxybenzoic acid hexoside 1, p-coumaroyl quinic acid 1, quercetin 4'-glucuronide, and p-coumaric acid glycoside were found in significant quantities. Correlations among the contents of individual compounds were established. When studying the dynamics of polyphenolic compound accumulation in, for example, the GR1 sample over a year, it was found that, in raspberry stems, the largest amount of them accumulated in April and slightly less in January and October. Investigating the dependence of the accumulation of polyphenols on the parts of the stem, it was found that the upper parts have the highest phenolic contents. Therefore, it is recommended to harvest approximately the upper third of the stem.

Ultrasonic-Assisted Extraction and Antioxidant Evaluation of Resveratrol from Peanut Sprouts

The orthogonal array design method was used to optimize ultrasonic-assisted extraction of resveratrol from peanut sprouts. The results showed that the highest extraction yield of resveratrol using ultrasonic-assisted extraction could be up to 1.1%. The optimal extraction conditions were liquid to solid ratio of 30:1 (mL/g) and ethanol concentration of 80% (v/v) as solvent for 40 min at the temperature of 70 °C. AB-8 macroporous adsorption resin was used to purify the crude extract and the resveratrol content increased to 47.5% after one treatment run. The optimal adsorption parameters were initial concentrations in the sample solution of 2 mg/mL, a pH of 5.0, a flow rate of 2 mL/min, and a temperature of 25 °C. The optimal desorption parameters were 60% ethanol and a flow rate of 1 mL/min. The chemical composition of the peanut sprout’s resveratrol sample was investigated via HPLC, and the predominant constituents were found to be protocatechuic acid, catechins, caffeic acid, epicatechuic acid, resveratrol, and rutin. The antioxidant activities of the resveratrol were measured via the following different analytical methods: reducing power, 2,2-diphenyl-1-picrylhdrazyl (DPPH), hydroxyl radical-scavenger activity, superoxide radical-scavenger activity, the β-carotene bleaching test, and the scavenging nitrite test. The results indicated that the resveratrol in peanut sprouts have significant antioxidant activities and can be used as a source of potential antioxidant. And peanut sprout’s resveratrol has the potential and valuable application to be used as a new type of resveratrol resource. The finding of this study can provide some theoretical reference for the comprehensive utilization of peanut resources in the development of antioxidant health foods.

Synergistic wall digestion and cuproptosis against fungal infections using lywallzyme-induced self-assembly of metal-phenolic nanoflowers

Fungi are very common infectious pathogens, which may cause invasive and potentially life-threatening infections. However, the efficacy of antifungal medications remains limited. Herein, a Cu2+-phenolic nanoflower is designed to combat fungal infections by combining cuproptosis and cell wall digestion. Firstly, protocatechuic acid (PA)-Cu2+ (PC) nanopetals are prepared by coordination interaction. Lywallzyme (Lyw) is then added to induce the self-assembly of PC to form Lyw loaded PC (PCW) nanoflowers. PCW nanoflowers can effectively adhere to fungal surface and Lyw can digest fungal cell walls to facilitate Cu2+ to penetrate into fungal interior, thereby exerting a synergistic fungicidal effect. PCW nanoflowers exhibit excellent fungicidal activity even in protein-rich and high-salt conditions, where dissociative Cu2+ completely loses fungicidal activity. Transcriptome sequencing analysis reveals that PCW can lead to fungal cuproptosis. The in vivo fungicidal effect of PCW nanoflowers is confirmed on a murine skin fungal infection model and a murine fungal keratitis model.

Simultaneous Qualitative and Quantitative Analyses of 41 Constituents in Uvaria macrophylla Leaves Screen Antioxidant Quality-Markers Using Database-Affinity Ultra-High-Performance Liquid Chromatography with Quadrupole Orbitrap Tandem Mass Spectrometry.

To date, no study has focused on Uvaria macrophylla leaves with various traditional efficiencies. This paper therefore applied a database affinity ultra-high-performance liquid chromatography with quadrupole Orbitrap tandem mass spectrometry (UHPLC-Q-Orbitrap-MS/MS) strategy to analyze the lyophilized aqueous extract of U. macrophylla leaves. Through database comparison and MS fragment elucidation, this study has putatively identified 41 constituents belonging to flavonoid, phenolic acid, steroid, and saccharide natural product classifications. Significantly, four groups of isomers (liquiritigenin vs. isoliquiritigenin vs. pinocembrin; oroxylin A vs. wogonin vs. galangin 3-methyl ether; isoquercitrin vs. hyperoside; protocatechuic acid vs. 2,5-dihydroxybenzoic acid) have been successfully distinguished from each other. All of 41 constituents were then subjected to a quantitative analysis based on linear regression equation established by the above UHPLC-Q-Orbitrap-MS/MS strategy and an ABTS+•-scavenging antioxidant assay. Finally, the chemical content was multiplied by the corresponding ABTS+•-scavenging percentage to calculate the antioxidant contribution. It was shown that the chemical contents of 41 constituents varied from 0.003 ± 0.000 to 14.418 ± 1.041 mg/g, and gallic acid showed the highest antioxidant contribution. Gallic acid is considered as a suitable antioxidant quality-marker (Q-marker) of U. macrophylla leaves. These findings have scientific implications for the resource development and quality control of U. macrophylla leaves.

Protocatechuic acid grafted chitosan/oxidized glucomannan hydrogel with antimicrobial and anti-inflammatory effects for enhancing wound repair

Oxidative stress, inflammation, and bacterial infection are critical barriers to wound healing. In this work, a composite wound dressing was designed to promote wound healing and reduce complications. A hydrogel with antibacterial, anti-inflammatory, and antioxidant properties was prepared by crosslinking chitosan (CS) and oxidized konjac glucomannan with Mg2+. We named the prepared hydrogel CPO/Mg2+. The proposed hydrogel demonstrated a significant capacity for promoting wound healing. Experimental results indicate that the CPO/Mg2+ composite hydrogel exhibits a bacteriostatic rate of over 95 % against S. aureus and P. aeruginosa. Furthermore, CPO/Mg2+ reduced oxidative damage to L929 cells in an H2O2-induced ROS microenvironment and promoted the polarization of macrophage M2. In vivo full-thickness skin defect experiments revealed that the CPO/Mg2+ composite hydrogel enhances collagen deposition and angiogenesis, achieving a closure rate of over 95 % for infected wounds within 14 days. This novel composite hydrogel offers an effective strategy for the repair of infected wounds.

Pomegranate peel-derived activated carbon: An effective adsorbent for protocatechuic acid removal and environmental remediation

Pomegranate peel-derived activated carbon: An effective adsorbent for protocatechuic acid removal and environmental remediation

Research Progress on the Mechanisms of Protocatechuic Acid in the Treatment of Cognitive Impairment

Cognitive impairment (CI) is a type of mental health disorder that mainly affects cognitive abilities, such as learning, memory, perception, and problem-solving. Currently, in clinical practice, the treatment of cognitive impairment mainly focuses on the application of cholinesterase inhibitors and NMDA receptor antagonists; however, there is no specific and effective drug yet. Procatechuic acid (PCA) possesses various functions, including antibacterial, antiasthmatic, and expectorant effects. In recent years, it has received growing attention in the cognitive domain. Therefore, by summarizing the mechanisms of action of procatechuic acid in the treatment of cognitive impairment in this paper, it is found that procatechuic acid has multiple effects, such as regulating the expression of neuroprotective factors, inhibiting cell apoptosis, promoting the autophagy-lysosome pathway, suppressing oxidative stress damage, inhibiting inflammatory responses, improving synaptic plasticity dysfunction, inhibiting Aβ deposition, reducing APP hydrolysis, enhancing the cholinergic system, and inhibiting the excitotoxicity of neuronal cells. The involved signaling pathways include activating Pi3K-akt-mTor and inhibiting JNK, P38 MAPK, P38-ERK-JNK, SIRT1, and NF-κB/p53, etc. This paper aims to present the latest progress in research on procatechuic acid, including aspects such as its chemical properties, sources, pharmacokinetics, mechanisms for treating neurodegenerative diseases.