Μg mL-1 Research Articles

Benzenesulfonohydrazide-tethered non-fused and fused heterocycles as potential anti-mycobacterial agents targeting enoyl acyl carrier protein reductase (InhA) with antibiofilm activity.

Because resistant variants of the disease are always emerging, tuberculosis is a global issue that affects economies. New antitubercular medications should be developed, and this can be done by inhibiting druggable targets. Enoyl acyl carrier protein (ACP) reductase (InhA) is a crucial enzyme for the survival of Mycobacterium tuberculosis (MTB). In this study, a series of small molecules based on non-fused and fused heterocycles (pyridine, coumarin, quinoline, and indole) tethered with benzenesulfonohydrazide were prepared via an aza-Michael reaction exploiting a one-pot synthesis approach. The synthesized molecules (2-7) were evaluated for their activity against tubercle bacilli. Three analogues showed efficacy against tuberculosis, with compound 7 demonstrating a MIC value as low as 8 μg mL-1. Consequently, compounds 3 and 7 successfully hindered the growth of mycobacteria in human monocyte-derived macrophages (MDMs), demonstrating their ability to penetrate human professional phagocytes. Furthermore, they restricted the ability of mycobacteria to produce biofilms. In addition, the inhibitory effects of compounds 3 and 7 against InhA were assessed. Compound 7 exhibited the best efficacy, with an IC50 value of 0.91 μM. The findings showed that the sulfonamide and methyl ester's carbonyl functionalities were engaged in hydrogen bonding with the essential Ile194 and Tyr158 residues, respectively.

Improving design features and air bubble manipulation techniques for a single-step sandwich electrochemical ELISA incorporating commercial electrodes into capillary-flow driven immunoassay devices.

Integrating electrochemistry into capillary-flow driven immunoassay devices provides unique opportunities for quantitative point-of-care testing. Although custom electrodes can be inexpensive and are tunable, they require skilled fabrication. Here, we report the incorporation of a commercial electrode into a capillary-flow driven immunoassay (iceCaDI) device for a single end-user step sandwich electrochemical enzyme-linked immunosorbent assay (ELISA). The iceCaDI device is a pump-free portable microfluidic device with an integrated commercial screen-printed electrode and flow driven by capillary action. The iceCaDI device is composed of alternating polyester transparency film and double-sided adhesive film layers that are patterned with a laser cutter. This platform was designed to address known limitations of laminated device fabrication methods and operation. First, we developed a foldable laminated device fabrication using hinges for easy assembly and precise alignment. Second, reagent dispersing was achieved by incorporating a 1 mm wide arrow-shaped notch in the middle of the channel that trapped an air bubble and formed a baffle that facilitated reagent spreading to cover the detection area. Third, small vent holes were added to the top layer of the channels to prevent air bubbles from blocking flow. Finally, we fabricated a CRP immunosensor with a detection range of 0.625 to 10.0 μg mL-1 as a proof-of-concept to demonstrate an automatically driven sandwich electrochemical ELISA using the iceCaDI device. Three concentrations of CRP were successfully measured under flow conditions within 8 min. Our proposed device is a promising approach and a step forward in the development of point-of-care (POC) devices for techniques that traditionally require multiple user steps.

Quantitative assessment of daratumumab in serum via intact light chain measurement using liquid chromatography-high resolution mass spectrometry: a method suitable for therapeutic drug monitoring.

Daratumumab, a pivotal treatment for multiple myeloma, exhibits considerable inter-patient variability in pharmacological clinical outcomes, likely attributed to serum concentration that may underscore the need for its therapeutic drug monitoring. This study aims to develop and validate a straightforward analytical method for quantifying daratumumab in serum, focusing on intact light chain determination, using liquid chromatography high-resolution mass spectrometry. The sample preparation involved immunoglobulin enrichment using Melon gel followed by a reduction step to dissociate the light from the heavy chains of immunoglobulins. The latter were then separated using a MabPac RP 2.1 × 50 mm chromatographic column and the intact light chains were detected and quantified using a Q Exactive Orbitrap mass spectrometer operating in ESI-positive ion mode at 17 500 resolution. The method demonstrated excellent linearity (R2 > 0.992) across a serum concentration range of 100 to 2000 μg mL-1 and good precision and accuracy: intra- and interday relative errors ranged from -5.1% to 6.5%, with a relative standard deviation of less than 5.8%. Clinical suitability was confirmed by analyzing 80 clinical samples from multiple myeloma patients treated with 1800 mg of daratumumab. 99% of the samples fell within the analytical range with a mean daratumumab concentration evaluated before the next administration (Ctrough) of 398 μg mL-1. These findings highlighted that intact light chain monoclonal antibody quantification could be a valid and robust alternative to either immunoassays or to LC-MS/MS targeting peptides for measuring daratumumab in clinical samples, positioning it as a suitable method for therapeutic drug monitoring applications.

Facile synthesis of sulphur-doped carbon dots (S-CDs) using a hydrothermal method for the selective sensing of Cr6+ and Fe3+ ions: application to environmental water sample analysis.

In this work, we used a one-step hydrothermal method to synthesize blue-emission sulfur-doped carbon dots (S-CDs) using jaggery as a carbon precursor. The synthesized carbon quantum dots showed low toxicity, good water solubility, anti-interference properties, and stable fluorescence. When excited at 310 nm, the S-CDs produced bright emission with a quantum yield of 7.15% at 397 nm. The S-CDs exhibited selective and sensitive quenching responses with limits of detection (LODs) of 4.25 μg mL-1 and 3.15 μg mL-1 for variable concentrations of Cr6+ and Fe3+, respectively, accompanied by a consistent linear relationship between fluorescence intensity and these concentrations. Fluorescence lifetime measurements were used to investigate the fluorescence quenching mechanism, which supports the static type of quenching. Outstanding benefits of the developed S-CD based fluorescence probe include its low cost, excellent sensitivity and selectivity, and ease of use for the detection of Cr6+ and Fe3+ ions. The developed carbon dot based fluorescent probe was successfully used to detect Cr6+ and Fe3+ ions in real water samples with an excellent recovery ratio.

Atividade antioxidante e alterações ultraestruturais em Leishmania amazonensis induzidas por frações ricas em limonóides do óleo de andiroba

ABSTRACT In the Amazon region, andiroba (Carapa guianensis) oil is among the most used products by the local population due to its medicinal properties. Previously, our group described the leishmanicidal activity of three limonoid-rich fractions from andiroba oil. This work aimed to evaluate the antioxidant activity and ultrastructural changes in Leishmania amazonensis treated with these limonoid-rich fractions from andiroba oil: 6α,11β-diacetoxygedunin; 11β-hydroxygedunin; and a fraction with both 6α,11β-diacetoxygedunin +11β-hydroxygedunin. The antioxidant activity was evaluated by the DPPH method and ultrastructural changes were evaluated by transmission electron microscopy. The fraction with both 6α,11β-diacetoxygedunin + 11β-hydroxygedunin displayed the best antioxidant activity (IC50 330.35 ± 8.60 µg mL-1; p=0.0022) compared to the 6α,11β-diacetoxygedunin fraction. The three fractions induced structural changes to mitochondria and kinetoplasts of L. amazonensis, in addition to lipid bodies, vacuolization, and vesicles in the flagellar pocket, indicating that the limonoid-rich fractions from andiroba oil can induce structural damage to Leishmania.

Induction of autophagy-dependent and caspase- and microtubule-acetylation-independent cell death by phytochemical-stabilized gold nanopolygons in colorectal adenocarcinoma cells.

Collective functionalization of the phytochemicals of medicinal herbs on nanoparticles is emerging as a potential cancer therapeutic strategy. This study presents the facile synthesis of surface-functionalized gold nanoparticles using Bacopa monnieri (Brahmi; Bm) phytochemicals and their therapeutically relevant mechanism of action in the colorectal cancer cell line, HT29. The nanoparticles were characterized using UV-visible spectroscopy, TEM-EDAX, zeta potential analysis, TGA, FTIR and 1H NMR spectroscopy, and HR-LC-MS. The particles (Bm-GNPs) were of polygonal shape and were stable against aggregation. They entered the target cells and inhibited the viability and clonogenicity of the cells with eight times more antiproliferative efficacy (25 ± 1.5 μg mL-1) than Bm extract (Bm-EX). In vitro studies revealed that Bm-GNPs bind tubulin (a protein crucial in cell division and a target of anticancer drugs) and disrupt its helical structure without grossly altering its tertiary conformation. Like other antitubulin agents, Bm-GNPs induced G2/M arrest and ultimately killed the cells, as confirmed using flow cytometry analyses. ZVAD-FMK-mediated global pan-caspase inhibition and the apparent absence of cleaved caspase-3 in treated cells indicated that the death did not involve the classic apoptosis pathway. Cellular ultrastructure analyses, western immunoblots, and in situ immunofluorescence visualization of cellular microtubules revealed microtubule-acetylation-independent induction of autophagy as the facilitator of cell death. Together, the data indicate strong antiproliferative efficacy and a possible mechanism of action for these designer nanoparticles. Bm-GNPs, therefore, merit further investigations, including preclinical evaluations, for their therapeutic potential as inducers of non-apoptotic cell death.

Nanodrug delivery system constructed with dopamine-based functional molecules for efficient targeting of tumour cells.

In order to enhance the water solubility of chemotherapeutic drugs, improve their biodistribution and narrow therapeutic window, two molecules of PDAO and FA-DAO with acid-sensitive Schiff base structure were designed and synthesized based on dopamine linolenate (DAO) in this paper, and subsequently drug-loaded nanoparticles were prepared by simply mixing of them with curcumin (Cur) in aqueous solution. These nanoparticles can release a large amount of the drug in response to pH changes in the tumor microenvironment through passive targeting. The cumulative rate of drug release can reach up to 70% within 24 hours under pH = 5.0 conditions as a release medium. Furthermore, the drug-carrying nanoparticles achieve active targeting through folic acid (FA) on their surface, which further enhances targeting efficiency. The inhibitory effect of drug-loaded nanoparticles was nearly 8-fold enhanced than that of its loaded Active Pharmaceutical Ingredient (API) Cur on HepG2 cell lines at the administration concentration of 6.25 μg mL-1. In conclusion, the nanoparticles prepared in this work improved the aqueous solubility of the loaded drug Cur, where passive targeting provided by pH-responsiveness and active targeting provided by FA endowed the loaded drug Cur with highly efficient targeting of HepG2 cell lines.

Ionic Liquid-Catalyzed Multicomponent Synthesis of Isoxazole-5(4H)-ones: in vitro Activities and Principal Component Analysis

Heterocycles of the isoxazolone class stand out in the pharmaceutical field because they have numerous biological properties, such as antioxidant, antifungal and antibacterial properties. Thus, isoxazole derivatives have attracted the attention of organic researchers, and several procedures have been developed to obtain these compounds. The present study aimed to synthesize 17 derivatives of isoxazol-5(4H)-ones using a multicomponent reaction catalyzed by an acidic ionic liquid, which allowed yields from 20-96% of the products. To evaluate the bioactivity of the compounds, the synthesized derivatives were analyzed at various concentrations against bacteria and fungi; the derivatives, in general, showed a moderate activity of 125 μg mL-1 against the fungus Candida tropicalis (ATCC 13803) and four derivatives showed an inhibition of < 15.62 μg mL-1 for Gram-positive Staphylococcus epidermidis (ATCC 12228). Furthermore, the antioxidant potential of the derivatives was evaluated by measuring their ability to scavenge 2,2-diphenyl1-picryl-hydrazyl (DPPH) free radicals, resulting in a remarkable reduction percentage of up to 81.06%. To gain further insights into the structure-activity relationships, a principal component analysis was conducted to classify the compounds into active and inactive classes, providing a comprehensive understanding of their bioactivity profiles.

Exploring Cassia mimosoïdes as a promising natural source of steroids with potent anti-cancer, urease inhibition, and antimicrobial properties.

The genus Cassia is a rich source of physiologically active secondary metabolites, including a novel compound named 21-methylene-24-ethylidene lophenol, alongside 15 known compounds. These compounds were characterized using different spectroscopic techniques. They exhibited promising antimicrobial activity, particularly against bacteria causing gastrointestinal infections. Compound 1 showed strong anti-bacterial activity against H. pylori and S. aur with MIC values of 0.28 and 0.12 μg mL-1 respectively. The study investigated their impact on H. pylori, a contributor to ulcer development, by inhibiting the urease enzyme. Inhibiting urease can reduce H. pylori's pathogenic potential, evident from the fact that the compounds evaluated toward urease enzyme showed higher inhibitory activity (1.024 ± 0.43 <IC50 > 6.678±0.11 μM) compared to standard thiourea (IC50 = 18.61 ± 0.11 μM). Molecular docking studies confirmed their inhibitory action, with compound 7 notably outperforming thiourea in inhibiting urease (-6.95 kcal mol-1vs. -3.13 kcal mol-1). Additionally, these compounds showed positive effects on liver functioning, which H. pylori can impair. Compound 9 shows the best response against human HepG2 liver cancer cell lines i.e., % viability is 14.47% ± 0.69 and IC50 is 7.8 μM ± 0.21. These compounds hold potential as lead compounds for addressing gastrointestinal and liver disorders caused by H. pylori.

Two-photon excited luminescence of sulfur quantum dots for heavy metal ion detection.

Spectrally-resolved third-order nonlinear optical properties of water-dispersed sulfur quantum dots (SQDs) were investigated in the wavelength range from 740 nm to 820 nm with the two-photon excited emission technique using a tunable femtosecond laser system. The maximum value of the two-photon absorption (TPA) cross-section (σ2) for ∼5.4 nm size SQDs was found to be 185 GM (Goeppert-Mayer unit), while the two-photon brightness (σ2 × η) was found to be 1.5 GM at 780 nm, the wavelength being in the first biological transmittance window. The TPA properties are presented here as appropriate cross-sections normalized per molecular weight which enables meaningful comparison of the nonlinear factors of the studied quantum dots with those of various nanomaterials. The optimized TPA properties of these hydrophilic colloidal SQDs may be potentially useful for detection of Fe3+ metal ions. The experimentally determined limit of Fe3+ detection for both one- and two-photon regime was 10 μmol L-1 (0.6 μg mL-1). Förster resonance energy transfer between SQDs as donors and Fe3+ metal ions as acceptors was confirmed as one of the possible detection mechanisms using a time-correlated single photon counting technique.

Coating effect of renatured triple-helix lentinan on the morphology and antimicrobial activity of ZnO synthesized by hydrothermal method.

Polysaccharides are considered to be ideal green raw materials for enhancing biocompatibility and dispersion effects of nanoparticles. In this study, we coated and dispersed ZnO nanoparticles (NPs) using the denaturation-renaturation process of a triple helix glucan lentinan (LNT), induced by changes in pH value within the reaction system. Various ZnO/LNT composites with different particle sizes and crystal morphologies were prepared and characterized. The results demonstrated that renatured LNT (r-LNT) effectively encapsulated the {101̄0} crystal planes of ZnO, preventing crystal growth during the renaturation process and resulting in smaller, uniformly dispersed nanoparticles. Among the samples, ZnO/r-LNT-2 exhibited significantly higher antimicrobial activity, and it had a certain inhibitory effect on various plant pathogens. It also displayed the highest inhibitory effect against Candida albicans, with a minimum inhibitory concentration (MIC) of up to 8 μg mL-1. Consistently, ZnO/r-LNT-2 generated the highest amount of reactive oxygen species (ROS), thus exhibiting the most effective antimicrobial activity. However, excessive introduction of the dispersant LNT may reduce these activities. This study provides a foundation for further exploring the detailed mechanism of ROS generation catalyzed by ZnO and for harnessing the full potential of this type of antimicrobial agent.

An isocratic RP-HPLC-UV method for simultaneous quantification of tizanidine and lidocaine: application to in vitro release studies of a subcutaneous implant.

Implantable devices have been widely investigated to improve the treatment of multiple diseases. Even with low drug loadings, these devices can achieve effective delivery and increase patient compliance by minimizing potential side effects, consequently enhancing the quality of life of the patients. Moreover, multi-drug products are emerging in the pharmaceutical field, capable of treating more than one ailment concurrently. Therefore, a simple analytical method is essential for detecting and quantifying different analytes used in formulation development and evaluation. Here, we present, for the first time, an isocratic method for tizanidine hydrochloride (TZ) and lidocaine (LD) loaded into a subcutaneous implant, utilizing reversed-phase high-performance liquid chromatography (RP-HPLC) coupled with a UV detector. These implants have the potential to treat muscular spasticity while providing pain relief for several days after implantation. Chromatographic separation of the two drugs was accomplished using a C18 column, with a mobile phase consisting of 0.1% TFA in water and MeOH in a 58 : 42 ratio, flowing at 0.7 ml min-1. The method exhibited specificity and robustness, providing accurate and precise results. It displayed linearity within the range of 0.79 to 100 μg ml-1, with an R2 value of 1 for the simultaneous analysis of TZ and LD. The developed method demonstrated selectivity, offering limits of detection and quantification of 0.16 and 0.49 μg ml-1 for TZ, and 0.30 and 0.93 μg ml-1 for LD, respectively. Furthermore, the solution containing both TZ and LD proved stable under various storage conditions. While this study applied the method to assess an implant device, it has broader applicability for analysing and quantifying the in vitro drug release of TZ and LD from diverse dosage forms in preclinical settings.

Zeolitic imidazolate framework-8 encapsulated with Mo-based polyoxometalates as surfaces with antibacterial activity against Escherichia coli.

Bacterial infections represent a major global health concern, causing millions of deaths and a significant economic burden. The development of antibacterial nanoporous surfaces with potential mechano-bactericidal effects can revolutionize infection control practices. In this study, a hybrid material of zeolitic imidazolate framework-8 (ZIF-8) doped with phosphomolybdic acid (PMA) was synthesized and characterized by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and N2 sorption isotherms. PMA@ZIF-8 performance as an antibacterial agent against E. coli was superior to that of its individual constituents, suggesting a synergistic effect of PMA and ZIF-8. The incorporation of PMA into ZIF-8 significantly enhanced its antibacterial efficacy, as evidenced by a twofold reduction in MIC (375 μg mL-1 vs. 750 μg mL-1) and a 4.35 times increase in the bactericidal kinetics rate constant. The time-kill curve experiment revealed that PMA@ZIF-8 achieved a 3-log reduction within 7 hours, whereas ZIF-8 required 24 hours to reach the same level of reduction. The density functional theory (DFT) calculated bandgap of PMA@ZIF-8 was significantly less than that of ZIF-8. Also, PMA@ZIF-8 has caused the elimination of 56.72% of the thiol group as detected by Ellman's assay. Accordingly, PMA@ZIF-8 can be both computationally and experimentally demonstrated as an oxidative nanozyme. PMA@ZIF-8's surface topology revealed nanorod protrusions, suggesting a potential mechano-bactericidal effect, which was confirmed by live/dead assay on PMA@ZIF-8-coated glass. This study highlights the potential of the PMA@ZIF-8 hybrid as a highly effective antibacterial agent, holding promise for creating multifunctional antibacterial surfaces.

Evaluation of multi-target iridium(iii)-based metallodrugs in combating antimicrobial resistance and infections caused by Staphylococcus aureus.

The rapid emergence and spread of multidrug-resistant bacteria pose a serious challenge to human life and health, necessitating the development of novel antibacterial agents. Herein, to address this challenge, three iridium-based antibacterial agents were prepared and their antimicrobial activity were explored. Importantly, the three complexes all showed robust potency against S. aureus with MIC values in the range of 1.9-7.9 μg mL-1. Notably, the most active complex Ir3 also exhibited relative stability in mammalian fluids and a significant antibacterial effect on clinically isolated drug-resistant bacteria. Mechanism studies further demonstrated that the complex Ir3 can kill S. aureus by disrupting the integrity of the bacterial membrane and inducing ROS production. This multi-target advantage allows Ir3 to not only effectively combat bacterial resistance but also efficiently clear the bacterial biofilm. In addition, when used together, complex Ir3 could enhance the antibacterial potency of some clinical antibiotics against S. aureus. Moreover, both G. mellonella wax worms and mouse infection model demonstrated that Ir3 has low toxicity and robust anti-infective efficacy in vivo. Overall, complex Ir3 can serve as a new antibacterial agent for combating Gram-positive bacterial infections.

Unveiling the potent activity of a synthetic ion transporter against multidrug-resistant Gram-positive bacteria and biofilms.

The increasing prevalence of drug-resistant infections caused by Gram-positive bacteria poses a significant threat to public healthcare. These pathogens exhibit not only smart resistance mechanisms but also form impenetrable biofilms on various surfaces, rendering them resilient to conventional therapies. In this study, we present the potent antibacterial activity of a synthetic ion transporter T against multi-drug resistant (MDR) Gram-positive pathogens, with minimum inhibitory concentration (MIC) values ranging from 0.5 to 2 μg mL-1. The compound demonstrates high selectivity with negligible toxicity towards mammalian cells (HC50 = 810 μg mL-1). It exhibits fast killing kinetics, completely eliminating >5 log bacterial cells within 12 h. Moreover, the compound displays efficacy against both planktonic bacteria and preformed biofilms of methicillin-resistant S. aureus (MRSA), reducing the bacterial burden within the biofilm by 2 log. Mechanistic investigations reveal that the ion transporter depolarizes the bacterial membrane potential and enhances membrane permeability. Additionally, it generates reactive oxygen species, contributing to its bactericidal activity. Notably, MRSA did not exhibit detectable resistance to the ion transporter even after serial passaging for 10 days. Collectively, this novel class of ion transporter holds promise as a therapeutic candidate for combating infections caused by multi-drug resistant Gram-positive bacteria.

Validation of microwave acid digestion, diffusive gradients in thin-film preconcentration and inductively coupled plasma optical emission spectrometry methodology for the determination of REEs in natural zeolites.

The determination of rare earth element (REE) content in different natural minerals is of high interest due to their extensive use in modern and sustainable technologies. The REEs occurring in natural zeolites are specific to each deposit. This study presents the validation and evaluation of the measurement uncertainty for the determination of REEs (Ce, Dy, Er, Eu, Gd, La, Lu, Nd, Pr, Sm, Y, and Yb) in natural zeolites using microwave-assisted acid digestion and inductively coupled plasma optical emission spectrometry (ICP-OES) after diffusive gradients in thin-film preconcentration. A mixture of HNO3 : HCl : HF of 3 : 9 : 2 (v/v/v) and microwave digestion provided suitable recoveries for the analysis of two certified reference materials, CRM BCS-CRM 375/1 and CRM OREAS 460. Good linearity over the calibration range of 0-2 μg mL-1, with correlation coefficients of 0.9995-1.0000, was obtained for each REE by ICP-OES. The limits of quantification (LOQS), calculated considering the instrumental LOQs and the sample preparation by microwave digestion, were in the range of 0.20-0.60 mg kg-1. A supplementary step of preconcentration/matrix separation based on the passive sampling by diffusive gradients in thin-films (DGT) technique improved the LOQs by about 20 times after three days of passive accumulation, allowing the measurement of the concentrations of all studied REEs in natural zeolite samples. The proposed methodology is a suitable approach for the measurement of REEs at low concentrations in natural zeolite samples by ICP-OES, and it can be extended to other geological samples. The measurement uncertainty was calculated based on the validation data. The proposed method provides reliable results for the measurement of REEs in natural zeolites and was used to measure the specific concentrations of REEs in natural zeolite samples from three Romanian quarries. The REE concentration can be used as a fingerprint for each deposit.

O-Alkyl derivatives of ferulic and syringic acid as lipophilic antioxidants: effect of the length of the alkyl chain on the improvement of the thermo-oxidative stability of sunflower oil.

Lipid oxidation is the major cause of the deterioration of fat-containing foods, especially those containing polyunsaturated fatty acids (PUFAs). Antioxidant additives of synthetic origin are added to matrices rich in PUFAs, such as sunflower oil (SO). However, there is controversy regarding their safety, and their low solubility in both water and fat has led to the search for new covalent modifications through lipophilicity. This work presents the synthesis of O-alkyl acid derivatives from ferulic and syringic acids and the study of their antioxidant capacity and effect on the thermoxidative degradation of SO. Antioxidant activities were evaluated by employing ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays in a concentration range of 10-100 µg mL-1. The IC50 values for DPPH scavenging activity ranged from 15.61-90.43 µg mL-1. The results of the FRAP assay for both O-alkyl ferulic (3a-f) and syringic (5a-f) series revealed a "cut-off" effect on antioxidant activity in carbon five (C5). Thermoxidation study of additives 3b-c and 5b-c showed a decrease in the slope of extinction coefficients K 232 and K 270 in comparison with SOcontrol. Furthermore, 3c presented higher antioxidant activity than 3b and 1, with a power to decrease the thiobarbituric acid reactive species (TBARS) 6 times higher than SOcontrol at 220 °C. Additives 5b-c exerted a protective effect on the thermoxidation of SO. The results suggest that increasing lipophilic and thermal properties of antioxidants through O-alkyl acid derivatization is an effective strategy for accessing lipophilic antioxidant additives with potential use in food matrices.

Green catalyst of cobalt ferrite magnetic nanoparticles using petai peel extract for the synthesis of thiazolidinedione-based chalcone 4H-thiopyran as an antioxidant.

CoFe2O4 magnetic nanoparticles were successfully synthesized using the green synthesis method with petai peel extract (PPE) as the capping and reducing agent. These nanoparticles were characterized using various techniques, including XRD, VSM, FTIR spectroscopy, UV-DRS, FESEM, EDX, TEM, HR-TEM, and SAED. The synthesized nanoparticles possess cubic morphology with an average size of 37.67 nm. CoFe2O4 magnetic nanoparticles were used as a catalyst for the synthesis of organic compounds, namely, chalcones. The synthesized organic compounds were characterized using FTIR, UV-Vis, LC-HRMS, and melting point test. The best result for chalcone synthesis was 62.26% using CoFe2O4 magnetic nanoparticles (5 mol%) in ethanol at reflux condition for 2 h. The nanocatalyst could be used for 5 cycles without any significant loss of yields. The synthesized organic compounds were further examined for their antioxidant activity. The 4H-thiopyran 2-acetyl pyridine variant (product 2) exhibited the highest antioxidant activity with an IC50 value of 90.80 μg mL-1. This was supported by the bond dissociation enthalpy (BDE) values of the C-H groups of benzo[g]thiochromene and pyridine, which were 74.0 kcal mol-1 and 105.1 kcal mol-1, respectively. The objective of this study is to develop a method for synthesizing organic compounds using green catalysts in order to reduce the adverse environmental impact. Furthermore, this research also aims to investigate the antioxidant potential of the thiazolidinedione-based chalcone 4H-thiopyran compounds in order to overcome oxidative stress.

Stixis scandens leaf extract-loading ZnO nanoparticles for porcine epidemic diarrhea virus (PEDV) treatment.

Porcine epidemic diarrhea (PED) is one of the diseases that causes great losses for livestock farmers. Because vaccines against the disease are not very effective, there is a great demand for biological products with effective resistance to PED virus (PEDV). One of the most important trends today is the use of active ingredients from nature in animal husbandry. This study aimed to create an effective agent against PEDV from the extract of Stixis scandens, which has been shown to inhibit PEDV. The aqueous (denoted as TCN) and ethanolic extracts (denoted as TCC) of Stixis scandens leaves were first prepared and then qualitatively analyzed for their chemical compositions. The TCN was used to synthesize ZnO nanoparticles (NPs) at various sizes from 20 to 120 nm. Subsequently, TCC was loaded on ZnO NPs to form ZnO-extract nanoformulations with an extract loading content of 5.8-7.6%. Total polyphenols (TP) and total alkaloids (TA) in TCC were 38.51 ± 0.25 μg GAE per mg and 22.37 ± 0.41 μg AtrE per mg, respectively. TP was less loaded but more released from the nanoformulations than TA. The A1T nanoformulation, containing only 7.6% extract, had a minimum PEDV inhibitory concentration of 3.9 μg mL-1, which was comparable to that of TCC. The experiments confirmed that the nanoformulations are promising for PEDV inhibition applications.

A hydrogel-functionalized silver nanocluster for bacterial-infected wound healing.

The ever-growing challenges of traditional antibiotic therapy and chronic wound healing have created a hot topic for the development and application of new antimicrobial agents. Silver nanoclusters (Ag NCs) with ultrasmall sizes (<2 nm) and antibacterial effects are promising candidates for next-generation antibiotics, particularly against multi-drug resistant strains. However, the biosafety in the clinical application of Ag NCs remains suboptimal despite some existing studies of Ag NCs for biomedical applications. Considering this, an ultrasmall Ag NC with excellent water solubility was synthesized by a two-phase ligand-exchange method, which exhibits broad-spectrum antibacterial performance. The minimum inhibitory concentrations of Ag NCs against MRSA, S. aureus, P. aeruginosa and E. coli were evaluated as 50, 80, 5 and 5 μg mL-1, respectively. Furthermore, a carbomer hydrogel was prepared to be incorporated into the Ag NCs for achieving excellent biocompatibility and biosafety. In vitro experiments demonstrate that the Ag NC-gel exhibits good antibacterial properties with lower cytotoxicity. Finally, in vivo experiments suggest that this ultrasmall Ag NC functionalized with the hydrogel can serve as an effective and safe antimicrobial agent to aid in wound healing.