Strong Inhibitory Effect Research Articles

Chemical profile, biological activities, and molecular docking of Algerian Juniperus phoenicea berries

The chemical composition, antioxidant activities, and α-amylase enzyme inhibitory activity of Algerian Juniperus phoenicea L berries were quantitatively and qualitatively determined in this study. Essential oil (EO) and non-polar crude extracts from cyclohexane and ethyl acetate were prepared, and the chemical profile was determined using GC-MS technique. The predominant compound in the EO was α-pinene (76.03%), while communic acid (23.66% and 22.38%) was the main compound in both non-polar crude extracts. The antioxidant potential of the samples was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,20-azino-bis(3-ethylbenzothiazoline-6-sulfonicacid)-diammonium salt (ABTS), and phenanthroline. All samples showed weak antioxidant capacity. The antidiabetic effect was assessed in vitro using the α-amylase assay; a strong inhibitory effect against the α-amylase enzyme was detected for both cyclohexane and ethyl acetate extracts with IC50 (IC50 = 186.91 ± 5.74 mg/mL and IC50 = 351.48 ± 0.17 mg/mL, respectively). Finally, an in silico study was performed for both α-amylase and α-glucosidase proteins to enhance our outcomes.

CDH2 and CDH13 as potential prognostic and therapeutic targets for adrenocortical carcinoma

ABSTRACT Cadherin 2 (CDH2, N-cadherin) and cadherin 13 (CDH13, T-cadherin, H-cadherin) affect the progress and prognoses of many cancers. However, their roles in adrenocortical carcinoma (ACC), a rare endocrine cancer, remain unclear. To decipher the roles of these proteins in ACC and to identify their regulatory targets, we analyzed their expression levels, gene regulatory networks, prognostic value, and targets in ACC, using various bioinformatic analyses. CDH2 was strongly downregulated and CDH13 was strongly upregulated in patients with ACC; the expression levels of these genes affected the prognosis. In 75 patients, the expression of CDH2 and CDH13 was altered by 8% and 5%, respectively. CDH2 and CDH13, as well as their neighboring genes, were predicted to form a complex network of interactions, mainly through coexpression and physical and genetic interactions. CDH2 and its altered neighboring genes (ANGs) mainly affect tumor-related gene expression, cell cycle, and energy metabolism. The regulation of tumor-related integrin function, gene transcription, metabolism, and amide and phospholipid metabolism are the main functions of CDH13 and its ANGs. MiRNA and kinase targets of CDH2 and CDH13 in ACC were identified. CDH13 expression in patients with ACC was positively associated with immune cell infiltration. Anti-PD1/CTLA-4/PD-L1 immunotherapy significantly downregulated the expression of CDH13 in patients with ACC. Foretinib and elesclomol were predicted to exert strong inhibitory effects on SW13 cells by inhibiting the expression of CDH2 and CDH13. These data indicate that CDH2 and CDH13 are promising targets for precise treatment of ACC and may serve as new biomarkers for ACC prognosis.

Screening Inhibitors of α-Amylase in Polygala Radix Based on an Online Targeted Detection System and Molecular Docking.

Targeted screening of inhibitors of key enzymes in the progression of diabetes from natural products is one of the effective methods for the treatment of diabetes. Polygala has been proved to reduce glucose levels; however, the bioactive compounds in Polygalae Radix (PR) that have anti-diabetic properties are unknown. The purpose of this study was to explore the material basis of the anti-diabetic effect of PR by inhibiting α-amylase through an online detection system and molecular docking. An online analysis platform was established and optimized for the screening of potent enzyme inhibitors from complex mixtures based on ultra-performance liquid chromatography-photodiode array-quadrupole-time-of-flight-mass spectrometry-α-amylase-fluorescence detector (UHPLC-PDA-Q-TOF-MSn-α-amylase-FLD) detection system and molecular docking, which could efficiently separate extracts, quickly detect α-amylase inhibitors, and determine their structures. Molecular docking confirms the inhibition of these compounds. The molecular interaction between α-amylase and the active compound was evaluated. Among the 101 compounds identified, 28 compounds had a strong inhibitory effect on α-amylase. Molecular docking screening confirmed the inhibition of these compounds and evaluated the molecular interactions between α-amylase and 30 active compounds, which strongly supported the experimental results. Among the evaluated compounds, onjisaponin R (83) and polygalaxanthone III (11) have the strongest inhibitory activity to α-amylase (the binding energies were -9.639 and -8.972 kcal/mol, respectively) and are potential lead compounds against diabetes. This study proved the feasibility of using the existing platform to screen the active ingredients in PR extract, and provided a practical method for the rapid screening of potential anti-diabetic active ingredients in traditional Chinese medicine.

Reversal Potentials of Tween 20 in ABC Transporter-Mediated Multidrug-Resistant Cancer and Treatment-Resistant Depression Through Interacting with Both Drug-Binding and ATP-Binding Areas on MDR proteins

Drug efflux transporters, especially those belonging to the ATP-binding cassette (ABC) transporter superfamily, play a crucial role in various drug resistance issues, including multidrug resistance (MDR) in cancer and treatment-resistant depression (TRD) in individuals with major depressive disorder. Key transporters in this context include P-glycoprotein (P-gp), multidrug resistance protein 1 (MRP1), and breast cancer resistance protein (BCRP). This study aimed to investigate the modulatory effects of polyoxyethylene (20) sorbitan monolaurate (Tween 20) on these efflux transporters in vitro and to evaluate its potential for overcoming drug resistance in two models: an in vitro cancer MDR model and an in vivo TRD model. The findings indicated that 0.001% Tween 20 significantly inhibited the efflux actions of all three transporters. Additionally, 0.005% Tween 20 effectively reversed resistance to paclitaxel, vincristine, doxorubicin, and mitoxantrone in various cancer MDR cell lines. In the in vivo depression-like behavior model, 0.01% Tween 20 markedly enhanced the antidepressant and anxiolytic effects of fluoxetine. Given its strong inhibitory effects on P-gp, MRP1, and BCRP, along with its capacity to reverse drug resistance both in vitro and in vivo, Tween 20 is a compelling candidate for tackling transporter-mediated drug resistance.

The role of hydroponic solution of Ulva fasciata in modulating the antibiotic resistance of Vibrio alginolyticus.

This study aimed to ascertain the active substances in the hydroponic solution of Ulva (U.) fasciata (HSUF) and their effects on antibiotics resistance of pathogenic bacteria Vibrio alginolyticus (Va.) at environmental levels. Analytical results of HSUF by solid-phase extraction and gas chromatography-mass spectrometry showed that HSUF contained rich active substances and dominated by 2,4,6-tribromophenol, acetal, mono (2-ethylhexyl) phthalate and 2- (4-hydroxybenzene) ethanol, etc. Thereinto, 2,4,6-tribromophenol had the lowest minimal inhibitory concentrations (MICs) of 64-128μg mL-1 for Va. strains. The rich antibacterial substances of HSUF inhibited 47%-63% of isolated Va. strains. After 20 generations of subculture for Va. strains in three dilutes (1/2 (HT), 1/20 (MT) and 1/50 (LT)) of HSUF (20g L-1), the resistance to streptomycin of Va. S1 and Va. M3 changed from intermediate resistance ability to susceptible level. The large promotion of reactive oxygen species was observed in different HSUF levels, but the biofilm formation of Va. S1 did not changed significantly. Transcriptome sequencing of Va. S1 demonstrated that antibiotic resistance gene lpxA was down-regulated at different HSUF levels. Live U. fasciata excreted a variety of active secondary metabolites (SMs) in HSUF, which exhibited strong inhibitory effects on three isolated Va. strains. HSUF changed the antibiotic resistance of Va. Strain, especially at a higher HSUF concentrations.

A new herbal extract carbon nanodot nanomedicine for anti-renal cell carcinoma through the PI3K/AKT signaling pathway.

New Re carbon nanodots with narrow size distribution, good water solubility and high cell membrane permeability were prepared from a herbal extract. They exhibited high inhibitory effects on renal cancer A498 cells and renal cell carcinoma. They could stimulate the production of ROS, induce mitochondrial dysfunction, and accelerate the release of intracellular calcium ions in the A498 cells. Transcriptomic tests were performed on A498 cells after administration, and the results were analyzed by qPCR and immunofluorescence. The results suggested that the Re carbon nanodots could downregulate the abnormally activated PI3K/AKT signaling pathway and perform cell cycle arrest in the S phase along with the inhibition of cell proliferation. Finally, in conjunction with the abnormal mitochondrial function, the Re carbon nanodots could ultimately promote the apoptosis of the A498 cells. In vivo tumor-bearing mouse experiments further showed that the Re carbon nanodots had a strong inhibitory effect on xenograft kidney cancer tumors. The prepared Re carbon nanodots have good anti-renal cancer A498 cell and renal cell carcinoma bioactivity and are expected to be a potential drug for the treatment of kidney cancer with low toxicity and high safety.

Assessment of Biofilm Formation and Anti-Inflammatory Response of a Probiotic Blend in a Cultured Canine Cell Model

Gut dysbiosis and an inflamed bowel are growing concerns in mammals, including dogs. Probiotic supplements have been used to restore the natural microbial community and improve gastrointestinal health. Biofilm formation, antimicrobial activities, and immunological responses of probiotics are crucial to improving gut health. Thus, we tested a commercial probiotic blend (LabMAX-3), a canine kibble additive comprising Lactobacillus acidophilus, Lacticaseibacillus casei, and Enterococcus faecium for their ability to inactivate common enteric pathogens; their ability to form biofilms; epithelial cell adhesion; and their anti-inflammatory response in the Madin-Darby Canine Kidney (MDCK) cell line. Probiotic LabMAX-3 blend or individual isolates showed a strong inhibitory effect against Salmonella enterica, Listeria monocytogenes, enterotoxigenic Escherichia coli, and Campylobacter jejuni. LabMAX-3 formed biofilms comparable to Staphylococcus aureus. LabMAX-3 adhesion to the MDCK cell line (with or without lipopolysaccharide (LPS) pretreatment) showed comparable adhesion and biofilm formation (p < 0.05) to L. casei ATCC 334 used as a control. LabMAX-3 had no cytotoxic effects on the MDCK cell line during 1 h exposure. The interleukin-10 (IL-10) and tumor necrosis factor alpha (TNFα) ratio of LabMAX-3, compared to the L. casei control, showed a significant increase (p < 0.05), indicating a more pronounced anti-inflammatory response. The data show that LabMAX-3, a canine kibble supplement, can improve gastrointestinal health.

Natural Products-Based Anticancer Agents: Synthesis and Anticancer Activities of Funtumine Amide/Sulfonamide Derivatives.

Funtumine is a pregnene-type steroidal alkaloid exhibiting moderate anticancer activity. To discover novel natural product-based anticancer drugs, a series of novel funtumine amide/sulfonamide derivatives were papered and identified using spectroscopic techniques. Additionally, the structures of compounds 2j, 3a, and 4k were further confirmed through X-ray diffraction analysis. Biological activity experiments conducted against three cancer cell lines revealed that several of the synthesized compounds demonstrated inhibition activities comparable to or exceeding those of the commercial anticancer agent, 5-Fluorouracil. Especially compound 4i demonstrated a notably strong growth inhibitory effect on HePG2 (IC50=14.89 μM) and HCT116 (IC50=15.67 μM) cell lines, while exhibiting minimal cytotoxicity towards human normal BEAS-2B cells. Preliminary structure-activity relationships (SARs) analysis indicated that the conversion of the carbonyl group at the C-20 position of funtumine to a hydroxyl group could yield more potent compounds.

Fluorescence Detection and Inhibition Mechanisms of DNTPH on Aβ42 Oligomers Characterized as Products in the Four Stages of Aggregation.

Aβ42 aggregation was implicated in the pathogenesis of Alzheimer's disease (AD) without effective treatment available currently. Future efforts in clinical trials should instead focus on applying those antiamyloid treatment strategies to the preclinical stage and "the earlier, the better". How to identify and inhibit Aβ42 oligomers in the different stages of aggregation is therefore becoming the key to controlling primary aggregation and consequent AD development. Aggregation-induced emission probe DNTPH was demonstrated recently, enabling detection of amyloid at wavelengths up to 710 nm and exhibiting strong inhibitory effects on Aβ fibrosis at low dose. However, the detection and inhibition mechanisms of Aβ oligomers at various early stages of aggregation remain unknown. To this end, we built four different morphologies of Aβ42 pentamers characterized by products in monomeric aggregate (PM), primary nucleation (PP), secondary nucleation (PS), and fibril stages (PF) to explore the distinguishable ability and inhibition mechanisms of DNTPH with different concentrations upon binding. The results showcased that DNTPH does detect the four different Aβ42 oligomers with conspicuous fluorescence (λPM = 657 nm, λPP = 639 nm, λPS = 630 nm, and λPF = 648 nm) but fails to distinguish them, indicating that additional improvements are required further for the probe to achieve it. The inhibition mechanisms of DNTPH on the four Aβ42 aggregation are however of amazing differences. For PM and PP, aggregation was inhibited by altering the secondary structural composition, i.e., by decreasing the β-sheet and toxic turn (residues 22-23) probabilities, respectively. For PS, inhibition was achieved by segregating and keeping the two disordered monomeric species (PSM) away from the ordered secondary seed species (PSF) and consequently blocking further growth of the PSF seed. The inhibition mechanism for PS is first probed and proposed so far, as far as we know, and the corresponding aggregation stage of PS is the most important one among the four stages. The inhibition of PF was triggered by distorting the fibril chains, disrupting the ordered fibril surface for the contact of monomers. In addition, the optimal inhibitory concentrations of DNTPH for PM, PP, and PF were determined to be 1:3, while for PS, it was 1:5. This outcome offers a novel perspective for designing drugs targeting Aβ42 oligomers at different aggregation stages.

Development and Optimization of a Redox Enzyme-Based Fluorescence Biosensor for the Identification of MsrB1 Inhibitors

MsrB1 is a thiol-dependent enzyme that reduces protein methionine-R-sulfoxide and regulates inflammatory response in macrophages. Therefore, MsrB1 could be a promising therapeutic target for the control of inflammation. To identify MsrB1 inhibitors, we construct a redox protein-based fluorescence biosensor composed of MsrB1, a circularly permutated fluorescent protein, and the thioredoxin1 in a single polypeptide chain. This protein-based biosensor, named RIYsense, efficiently measures protein methionine sulfoxide reduction by ratiometric fluorescence increase. We used it for high-throughput screening of potential MsrB1 inhibitors among 6868 compounds. A total of 192 compounds were selected based on their ability to reduce relative fluorescence intensity by more than 50% compared to the control. Then, we used molecular docking simulations of the compound on MsrB1, affinity assays, and MsrB1 activity measurement to identify compounds with reliable and strong inhibitory effects. Two compounds were selected as MsrB1 inhibitors: 4-[5-(4-ethylphenyl)-3-(4-hydroxyphenyl)-3,4-dihydropyrazol-2-yl]benzenesulfonamide and 6-chloro-10-(4-ethylphenyl)pyrimido[4,5-b]quinoline-2,4-dione. They are heterocyclic, polyaromatic compounds with a substituted phenyl moiety interacting with the MsrB1 active site, as revealed by docking simulation. These compounds were found to decrease the expression of anti-inflammatory cytokines such as IL-10 and IL-1rn, leading to auricular skin swelling and increased thickness in an ear edema model, effectively mimicking the effects observed in MsrB1 knockout mice. In summary, using a novel redox protein-based fluorescence biosensor, we identified potential MsrB1 inhibitors that can regulate the inflammatory response, particularly by influencing the expression of anti-inflammatory cytokines. These compounds are promising tools for understanding MsrB1’s role during inflammation and eventually controlling inflammation in therapeutic approaches.

Effect of olive leaf extract on the quality of Cantal cheese

This study aimed to evaluate the impact of olive leaf extract (OLE) on the quality of Cantal cheese. The cheeses were fortified with different concentrations (Control, 1, 2, and 3 %) of OLE and analysed for quality during storage. The cheeses were evaluated on days 1, 28, and 63 for physicochemical, compositional, textural, rheological parameters, colour, microbiological analysis, and antioxidant activity. The MIR and fluorescence spectroscopies were used to study the changes in the cheese structure. A positive impact of OLE was observed on the antioxidant capacity. A mild inhibitory effect was observed against some beneficial bacteria (such as Lactococcus and Lactobacillus), while a strong inhibitory effect was found against pathogen microorganisms. No negative impact was found on the texture and chemical composition. Significant colour and structural changes were observed. The results indicate the potential of OLE to be used as bioactive ingredient to improve the quality of cheese.

Unveiling the interaction between corrosion products and oxygen reduction on the corrosion of Mg–4Nd–0.4Zr alloy under thin electrolyte layers

Although hydrogen evolution reaction (HER) is considered to be the main cathodic reaction of Mg corrosion, oxygen reduction reaction (ORR) has been recently confirmed to be a secondary cathodic reaction. The factors affecting ORR of magnesium (Mg) alloys are still unclear, especially in cases under thin electrolyte layers (TEL). In this work, the influence of the corrosion product films on the cathodic reactions of Mg alloys under TEL and in a bulk solution was investigated. ORR does not influence the hydrogen evolution rates in the corrosion of Mg alloys. Therefore, with the existence of oxygen, corrosion rates of Mg alloys measured by hydrogen evolution tests are not accurate under TEL. And weight loss test is a more accurate method to evaluate Mg corrosion rates under TEL. ORR was confirmed to participate in the corrosion of Mg–4Nd–0.4Zr, Mg–4Nd and Mg–0.4Zr alloys under TEL. In 100-μm TEL, the highest contribution of ORR in cathodic reactions for the corrosion of Mg–4Nd–0.4Zr, Mg–4Nd and Mg–0.4Zr alloys are 28.6%, 39.1%, and 35.8%, respectively. The more protective film on Mg–4Nd–0.4Zr alloy provides a stronger inhibition effect against the diffusion of oxygen, leading to decreased ORR contribution in cathodic reactions. In addition, it is suggested that the preparation of Mg alloys with protective corrosion product films can inhibit the corrosion induced by ORR in the atmosphere. This work emphasizes the effects of corrosion product films on ORR in Mg corrosion, especially under TEL.

Kinetics of galactooligosaccharides (GOS) production with two β-galactosidases: Metallic ion effect and mathematical model

Galactooligosaccharides (GOS) are functional carbohydrates produced from different lactose sources like cheese whey. They are relevant products in the dairy industry. However, its enzymatic production implies a challenge due to its inhibition by metallic ions presence. Enzymatic production of GOS from lactose using β-galactosidase from Kluyveromyces lactis and Aspergillus oryzae were studied in the presence of metallic ions (calcium, potassium, sodium, and magnesium). Also, a kinetic enzymatic model was proposed and correlated to explain the metallic ion effect in the GOS production. For both enzymes, stronger inhibition effects were observed when calcium was present, followed by potassium, sodium, and magnesium. Consequently, additional efforts must be made for the calcium remotion before the enzymatic reaction for industrial applications. Moreover, the second-order kinetic model proposed in this work describes the GOS production using both enzymes with metallic ions presence. It was stablished that for GOS production using β-gal from K. lactis and A. oryzae with various salts, calcium showed the strongest inhibition for both enzymes, followed by potassium and sodium. A second-order kinetic model accurately described GOS production, better reflecting hydrolysis inhibition than transgalactosylation inhibition

A comprehensive review of structure-activity relationships and effect mechanisms of polyphenols on heterocyclic aromatic amines formation in thermal-processed food.

Heterocyclic aromatic amines (HAAs) are potent carcinogenic substances mainly generated in thermal-processed food. Natural polyphenols have been widely used for inhibiting the formation of HAAs, whereas the effect of natural polyphenols on HAAs formation is complex and the mechanisms are far from being clearly elucidated. In order to clarify the comprehensive effect of polyphenols on HAAs, this review focused on the structure-activity relationships and effect mechanisms of polyphenols on the formation of HAAs. In addition, the effects of polyphenols on HAAs toxicity were also first reviewed from cell, gene, protein, and animal aspects. An overview of the effect of polyphenol structures such as parent ring and exocyclic group on the mitigation of HAAs was emphasized, aiming to provide some valuable information for understanding their effect mechanism. The HAAs formation is inhibited by natural polyphenols in a dose-dependent manner largely through eliminating free radicals and binding precursors and intermediates. The inhibitory effect was probably affected by the quantity and position of hydroxyl groups in the aromatic rings, and polyphenols with m-hydroxyl group in the aromatic ring had the stronger inhibitory effect. However, the presence of other substituents and excessive hydroxyl groups in natural polyphenols might mitigate the inhibitory effect and even promote the formation of HAAs. This review can provide theoretical reference for effectively controlling the formation of HAAs in thermal-processed food by natural polyphenols and reducing their harm to human health.

The influence of photosynthetic pigment chlorophyllin in light-driven LPMO system on the hydrolytic action of cellulases

It has been demonstrated that LPMO reactions can be driven by light, using the photosynthetic pigment chlorophyllin to achieve efficient oxidative degradation of cellulose. However, the effect of chlorophyllin on cellulases remains unclear. This study discovered that chlorophyllin does not affect the hydrolytic activity of cellulases under dark conditions. However, under light exposure, chlorophyllin-derived reactive oxygen species (ROS) exhibit a strong inhibitory effect on cellulases. These ROS primarily inhibit the hydrolytic action of endoglucanase II (Cel5A) and cellobiohydrolase II (Cel6A), while the action of cellobiohydrolase I and β-glucosidase remains unaffected. Scavenger studies revealed that singlet oxygen (1O₂) is the key inhibitory ROS responsible for the inhibition of Cel5A and Cel6A. The removal of 1O₂ by sodium azide effectively mitigates this inhibition, increasing the conversion yield of cellulose to glucose by 25.9 % when using the light-driven LPMO system in conjunction with cellulases. This study provides new insights into the role of chlorophyllin-derived 1O₂ in hindering hydrolytic action of cellulases and demonstrates the successful mitigation of this inhibition by sodium azide, thereby enhancing the cooperative degradation of cellulose to glucose by the light-driven LPMO system and cellulases.

Silicate impedes arsenic release and oxidation from ferrihydrite

Silicate fertilization is a common farming practice and an effective method to mitigate arsenic (As) pollution in paddy. Investigating the interaction between silicate and ferrihydrite on As retention is key to comprehensively understand the mechanism of As sequestration by silicate fertilization. Our results indicated that the transformation of ferrihydrite into goethite and hematite was inversely proportional to Si/Fe ratios. The added silicate impeded the decrease of solution pH from neutral to acidity, and imposed strong inhibitory effect on goethite formation. The aqueous As in silicate-free system was 3.43 times higher than that with Si/Fe ratio at 0.33, but similar results were not observed in those with high-level As pollution due to the inhibitory effect of As on ferrihydrite transformation. Solid characterization showed that silicate was monomerically adsorbed to ferrihydrite through Si-O-Fe bond, which impeded the reductive dissolution, Fe atom exchange, internal atomic rearrangement and dehydration of ferrihydrite. As(III) oxidation weakened in silicate-coprecipitated ferrihydrite due to the lack of Fe(II) catalysis stem from ferrihydrite dissolution. This work demonstrated that As release could be effectively impeded through the inhibitory effect of silicate on ferrihydrite transformation, thereby providing new insights into the understanding of As accumulation reduction in rice by silicate fertilization.

Phytochemical Profile and Antibacterial-AntiQuorum Sensing Properties of Citrus medica L.

Introduction: Natural resources are becoming more and more important as the need to find solutions to the antibiotic resistance growing crisis. The assessment of medicinal plants' antibacterial and antiquorum-sensing properties is gaining popularity in this field of research every day. The study reported here aimed to investigate the inhibitory activity of the methanolic extract of Citrus medica L. on the inhibition of violacein pigment production in Chromobacterium violaceum ATCC 12472 and some virulence factors in Pseudomonas aeruginosa PAO1. Additionally, the phenolic content of the extract was also determined by HPLC analysis.Methods: The phytochemical content of the plant extract was determined and its antibacterial activity on some bacteria was tested. Also, antibiofilm effect on PAO1 was determined, and violasin pigment inhibition on C. violaceum was investigated.Results: It was observed that the methanolic extract had an inhibition effect of 32% on violacein pigment production and a strong inhibition effect of 88% on biofilm formation caused by PAO1. According to the results of the phytochemical content analysis, benzoic acid was determined as the major component of the extract with a concentration value of 41.9 μg/mL.Conclusion: Citrus medica L, like many plants, has antibacterial and antiquorum sensing activity and may be a potential agent in the fight against infectious diseases.

Co-Gelatinization Modification of Iodine–Starch and Its Performance in Drilling Fluid

Modified starch is used as a drilling fluid treatment agent in oilfields. During the drilling process, modified starch plays a vital role in the drilling fluid system, but its poor temperature resistance limits its application in oilfields. Therefore, this paper studied the performance of several starches in water-based drilling fluids through co-gelatinization modification; studied the effectiveness of several modifiers in gelatinized starch drilling fluids, combined with flow modification performance tests, bentonite linear expansion rate, salt resistance, and other experimental methods to complete the screening of the best modified starch; and systematically compared the temperature resistance, inhibition, compatibility, and salt resistance before and after gelatinization. The possible mechanism of action of modified starch treatment was analyzed and tested by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), laser particle size analyzer and scanning electron microscopy (SEM). The results showed that the decomposition temperatures of cassava starch (TS), potato starch (PS), and corn starch (CS) were different, and the decomposition temperature of cassava starch (TS) was the highest, at 150 °C. At this temperature, the optimal dosage of gelatinized TS is 2.5%, the maximum shear force is 2.25 Pa, and the filtration loss is only 12.6 mL. TS has obvious performance advantages over other starches. After co-gelatinization with 1.0% iodine and 2.5% TS at 140 °C, it has a good viscosity reduction and filtration loss effect, and the filtration loss is only 5.2 mL, which is 31.6% lower than that of untreated TS drilling fluid. The linear expansion rate at 120 min is 10.85%, indicating that it has a strong inhibitory effect on the hydration and dispersion of bentonite. In addition, iodine cassava starch (ITS) has good compatibility in drilling-fluid formulations and shows good salt resistance when mixed with different concentrations of KCl. The results of this study can be used to improve the temperature resistance of filtration agents and facilitate related research.

Synthesis of New Xanthene and Acridine Derivatives from Cyclohexan-1,3-dione and the Study of their Antiproliferative Activities

Background: Ionic immobilized liquids and multi-component reactions are integral to green chemistry, facilitating the synthesis of biologically active compounds, such as xanthene and acridine derivatives. These approaches have garnered significant attention in recent years. Objective: The aim of this study was to synthesize novel xanthene and acridine derivatives with diverse substituents and heterocyclic rings. Furthermore, the research sought to evaluate their anticancer activity against various cancer cell lines and analyze their structure-activity relationships (SAR) to determine how structural modifications impact their biological effectiveness. Method: The core compounds in this study were synthesized from cyclohexane-1,3-dione and triethoxymethane under two distinct reaction conditions. The first involved the use of a solvent with either Et₃N or NH₄OAc as a catalyst, while the second employed a solvent-free approach using an ionic liquid catalyst (ILs). Results: The anti-proliferative activity of all synthesized compounds was evaluated against six selected cancer cell lines, revealing that many compounds exhibited significant inhibitory effects. Furthermore, their inhibitory potential against tyrosine kinases and Pim-1 kinases was assessed, along with an investigation of their mechanism of action on tyrosine kinases. Conclusion: The anti-proliferative activity of the newly synthesized compounds was evaluated against six cancer cell lines. Many of the compounds exhibited strong inhibitory effects not only against the tested cancer cell lines but also against tyrosine kinases and Pim-1 kinases.

In Vitro Inhibitory Mechanism of Polyphenol Extracts from Multi-Frequency Power Ultrasound-Pretreated Rose Flower Against α-Glucosidase.

This paper explored the in vitro inhibitory mechanism of polyphenol-rich rose extracts (REs) from an edible rose flower against α-glucosidase using multispectral and molecular docking techniques. Results showed that REs had an inhibitory effect on α-Glu activity (IC50 of 1.96 μg/mL); specifically, the samples pretreated by tri-frequency ultrasound (20/40/60 kHz) exhibited a significantly (p < 0.05) stronger inhibitory effect on α-Glu activity with an IC50 of 1.33 μg/mL. The Lineweaver-Burk assay indicated that REs were mixed-type inhibitors and could statically quench the endogenous fluorescence of α-Glu. REs increased the chance of polypeptide chain misfolding by altering the microenvironment around tryptophan and tyrosine residues and disrupting the natural conformation of the enzyme. Molecular docking results showed that polyhydroxy phenolics had a high fit to the active site of α-Glu, so REs with high polymerization and numerous phenolic hydroxyl groups had a stronger inhibitory effect. Therefore, this study provides new insights into polyphenol-rich REs as potential α-glucosidase inhibitors.