Synthesis and antiproliferative activity of a tetrahydrofuran analog of FR901464.

FR901464 is a natural product that exhibits antiproliferative activity at single-digit nanomolar concentrations in cancer cells. Its tetrahydropyran-spiroepoxide covalently binds the spliceosome. Through our medicinal chemistry campaign, we serendipitously discovered that a bromoetherification formed a tetrahydrofuran. The tetrahydrofuran analog was three orders of magnitude less potent than the corresponding tetrahydropyran analogs. This study shows the significance of the tetrahydropyran ring that presents the epoxide toward the spliceosome.

[Reversal Effect of Arctigenin on the Drug Resistance in Leukemia K562/A02 Cells and Its Mechanism].

OBJECTIVE: To study the effect of arctigenin(ARG) on adriamycin(ADM) resistance of leukemia cell line K562/A02 and the underlying mechanism. METHODS: Human leukemia cell line K562 and ADM-resistant cell line K562/A02 were cultured and treated with 2.5-50 µmol/L ADM. Cell proliferation was measured using CCK-8 method, and half maximal inhibitory concentration (IC50) was calculated. K562/A02 cells were treated with different concentrations of ARG (1, 2, 4, 8, 16 mmol/L) to detect the effect of ARG on K562/A02 cells, and a suitable concentration (2 mmol/L) was selected for subsequent experiments. K562/A02 cells were treated with 2 mmol/L ARG and 5 µmol/L ADM, and cell apoptosis was detected by flow cytometry, the expression of P-gp, MRP, cleaved caspase-3, Bax, Bcl-2 proteins and the TLR4/NF-κB signaling pathway-related proteins were measured by Western blot. TLR4 overexpression plasmid was transfected into K562/A02 cells which were co-treated with ARG and ADM, then drug sensitivity and cell apoptosis were measured. RESULTS: The IC50 value of ADM on K562/A02 cells was 36.57 µmol/L, which was significantly higher than that on K562 cells (1.30 µmol/L). ARG with a concentration of ≤2 mmol/L did not have a significant effect on K562/A02 cells. 2 mmol/L ARG significantly reduced the IC50 of ADM on K562/A02 cells. In 5 µmol/L ADM-treated K562/A02 cells, compared with the control group, the apoptosis rate of K562/A02 cells in the ARG group was significantly increased, the expressions of cleaved caspase-3, Bax proteins were significantly upregulated, the expressions of P-gp, MRP, Bcl-2, TLR4, MyD88, and p-NF-κB proteins were significantly downregulated, and the differences were statistically significant (P < 0.05). After transfection with TLR4 overexpression plasmid, the sensitivity of ARG-treated K562/A02 cells to ADM was reduced (P < 0.05), the cell apoptosis was decreased, and the expressions of P-gp, MRP, Bcl-2 and TLR4/NF-κB signaling pathway-related proteins were significantly elevated, while the expressions of cleaved caspase-3 and Bax proteins were significantly decreased (all P < 0.05). CONCLUSION: ARG may reverse the resistance of human leukemia cell line K562/A02 to ADM by inhibiting TLR4/NF-κB signaling pathway.

Promoting the Anticancer Activity with Multidentate Furan-2-Carboxamide Functionalized Aroyl Thiourea Chelation in Binuclear Half-Sandwich Ruthenium(II) Complexes.

A new set of binuclear arene ruthenium complexes [Ru2(p-cymene)2(k4-N2OS)(L1-L3)Cl2] (Ru2L1-Ru2L3) encompassing furan-2-carboxamide-based aroylthiourea derivatives (H2L1-H2L3) was synthesized and characterized by various spectral and analytical techniques. Single-crystal XRD analysis unveils the N^O and N^S mixed monobasic bidentate coordination of the ligands constructing N, S, Cl/N, O, and Cl legged piano stool octahedral geometry. DFT analysis demonstrates the predilection for the formation of stable arene ruthenium complexes. In vitro antiproliferative activity of the complexes was examined against human cervical (HeLa), breast (MCF-7), and lung (A549) cancerous and noncancerous monkey kidney epithelial (Vero) cells. All the complexes are more efficacious against HeLa and MCF-7 cells with low inhibitory doses (3.86-11.02 µM). Specifically, Ru2L3 incorporating p-cymene and -OCH3 fragments exhibits high lipophilicity, significant cytotoxicity against cancer cells, and lower toxicity on noncancerous cells. Staining analysis indicates the apoptosis-associated cell morphological changes expressively in MCF-7 cells. Mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) analyses reveal that Ru2L3 can raise ROS levels, reduce MMP, and trigger mitochondrial dysfunction-mediated apoptosis. The catalytic oxidation of glutathione (GSH) to its disulfide form (GSSG) by the complexes may simultaneously increase the ROS levels, alluding to their observed cytotoxicity and apoptosis induction. Flow cytometry determined the quantitative classification of late apoptosis and S-phase arrest in MCF-7 and HeLa cells. Western blotting analysis confirmed that the complexes promote apoptosis by upregulating Caspase-3 and Caspase-9 and downregulating BCL-2. Molecular docking studies unfolded the strong binding affinities of the complexes with VEGFR2, an angiogenic signaling receptor, and BCL2, Cyclin D1, and HER2 proteins typically overexpressed on tumor cells.

MCC950 attenuates plasma cell mastitis in an MDSC-dependent manner.

Plasma cell mastitis (PCM) is a sterile inflammatory condition primarily characterized by periductal inflammation and ductal ectasia. Currently, there is a lack of non-invasive or minimally invasive treatment option other than surgical intervention. The NLRP3 inflammasome has been implicated in the pathogenesis and progression of various inflammatory diseases, however, its involvement in PCM has not yet been reported. In this study, we initially observed the pronounced upregulation of NLRP3 in both human and mouse PCM tissue and elucidated the mechanism underlying the attenuation of PCM through inhibition of NLRP3. We established the PCM murine model and collected samples on day 14, when inflammation reached its peak, for subsequent research purposes. MCC950, an NLRP3 inhibitor, was utilized to effectively ameliorate PCM by significantly reducing plasma cell infiltration in mammary tissue, as well as attenuate the expression of pro-inflammatory cytokines including IL-1ß, TNF-α, IL-2, and IL-6. Mechanistically, we observed that MCC950 augmented the function of myeloid-derived suppressor cells (MDSCs), which in turn inhibited the infiltration of plasma cells. Furthermore, it was noted that depleting MDSCs greatly compromised the therapeutic efficacy of MCC950. Collectively, our findings suggest that the administration of MCC950 has the potential to impede the progression of PCM by augmenting MDSCs both numerically and functionally, ultimately treating PCM effectively. This study provides valuable insights into the utilization of pharmacological agents for PCM treatment.

Integrated Proteomics Characterization of NLRP3 Inflammasome Inhibitor MCC950 in Monocytic Cell Line Confirms Direct MCC950 Engagement with Endogenous NLRP3.

Inhibition of the NLRP3 inflammasome is a promising strategy for the development of new treatments for inflammatory diseases. MCC950 is a potent and selective small-molecule inhibitor of the NLRP3 pathway and has been validated in numerous species and disease models. Although the capacity of MCC950 to block NLRP3 signaling is well-established, it is still critical to identify the mechanism of action and molecular targets of MCC950 to inform and derisk drug development. Quantitative proteomics performed in disease-relevant systems provides a powerful method to study both direct and indirect pharmacological responses to small molecules to elucidate the mechanism of action and confirm target engagement. A comprehensive target deconvolution campaign requires the use of complementary chemical biology techniques. Here we applied two orthogonal chemical biology techniques: compressed Cellular Thermal Shift Assay (CETSA) and photoaffinity labeling chemoproteomics, performed under biologically relevant conditions with LPS-primed THP-1 cells, thereby deconvoluting, for the first time, the molecular targets of MCC950 using chemical biology techniques. In-cell chemoproteomics with inlysate CETSA confirmed the suspected mechanism as the disruption of inflammasome formation via NLRP3. Further cCETSA (c indicates compressed) in live cells mapped the stabilization of NLRP3 inflammasome pathway proteins, highlighting modulation of the targeted pathway. This is the first evidence of direct MCC950 engagement with endogenous NLRP3 in a human macrophage cellular system using discovery proteomics chemical biology techniques, providing critical information for inflammasome studies.

Structure-based design and synthesis of sulfonylureas as novel NLRP3 inhibitors for Alzheimer's disease.

Alzheimer's disease (AD) remains an incurable neurodegenerative condition that poses a threat to humanity. Immune signaling in the brain, particularly the NLR family pyrin domain containing 3 (NLRP3), is currently targeted for AD treatment. Based on the crystal structure of the NACHT domain of NLRP3 and its renowned inhibitor MCC950, we designed and synthesized nineteen sulfonylurea compounds and evaluated their capacity to inhibit caspase-1 and interleukin-1ß (IL-1ß). Of these, nine were selected for measuring their IC50 for caspase-1 and cytotoxicity analysis. Finally, three compounds were chosen to assess their inhibitory effect on IL-1ß in mice. The results showed that compound 5m had a superior ability to reduce IL-1ß levels in the brain compared to MCC950 at a lower dosing concentration, indicating that 5m has the potential to penetrate the blood-brain barrier (BBB) and inhibit inflammation both in vitro and in vivo. Docking studies of compound 5m on NLRP3 revealed a binding mode similar to MCC950. These findings suggest that compound 5m holds promise as an NLRP3 inhibitor for AD treatment.

Cytotoxic effects of kinetin riboside and its selected analogues on cancer cell lines.

N6-[(Furan-2-yl)methyl]adenosine (kinetin riboside) and its seven synthesized analogues were examined for the ability to inhibit the growth of five human carcinoma cell lines and for comparison of normal human lung fibroblast cell line (MRC-5). Out of the compounds evaluated, 8-azakinetin riboside was shown to exhibit significant cytotoxic activity for 72 h treatment against ovarian OVCAR-3 and pancreatic MIA PaCa-2 cancer cells (IC50 = 1.1 µM) with an observed weaker effect against MRC-5 cells (IC50 = 4.6 µM). Kinetin riboside, as well as its N6-[(furan-3-yl)methyl]- and N6-[(thien-2-yl)methyl]- counterparts, also exhibited cytotoxic activities at low micromolar levels but were non-selective over MRC-5 cells.

MCC950 alleviates seizure severity and angiogenesis by inhibiting NLRP3/ IL-1ß signaling pathway-mediated pyroptosis in mouse model of epilepsy.

Epilepsy is one of the most common serious chronic brain disorders, affecting up to 70 million people worldwide. Vascular disruption, including blood-brain barrier impairment and pathological angiogenesis, exacerbates its occurrence. However, its underlying mechanisms remain elusive. MCC950 is a specific small-molecule inhibitor that selectively blocks NLRP3 inflammatory vesicle activation across the blood-brain barrier, limits downstream IL-1ß maturation and release, and exerts therapeutic effects across multiple diseases. In the present study, an epilepsy model was established by intraperitoneal administration of Kainic acid to adult male C57BL/6J wild-type mice. The results revealed that the epilepsy susceptibility of MCC950-treated mice was decreased, and neural damage following seizure episodes was reduced. In addition, immunofluorescence staining, RT-qPCR, and Western blot demonstrated that MCC950 inhibited the expression of the NLRP3 inflammasome and its related proteins in microglia, whereas microangiogenesis was found to be increased in the cerebral cortex and hippocampus of epileptic mice, and these effects could be reversed by MCC950. Furthermore, neurobehavioral impairment was observed in the epileptic mouse model, and MCC950 similarly alleviated the aforementioned pathological process. To the best of our knowledge, this is the first study to establish that pathological microangiogenesis is associated with NLRP3/IL-1ß signaling pathway activation in a Kainic acid-induced epilepsy mouse model and that MCC950 administration attenuates the above-mentioned pathological changes and exerts neuroprotective effects. Therefore, MCC950 is a promising therapeutic agent for the treatment of epilepsy.

Microtubule destabilising activity of selected 7-methoxy-2-phenylbenzo[b]furan derivative against primary and metastatic melanoma cells.

Herein, we report the results of anticancer screening of two 2-phenylbenzo[b]furan derivatives functionalised at the 3-position with 4-hydroxy-3,5-dimethoxybenzoyl (BF2) or 3,4,5-trimethoxybenzoyl (BF3) against 60 different cancer cell lines. The results confirmed the anticancer potential of the tested compounds against different cancer cell types, especially colon cancer, brain cancer and melanoma. BF3 was defined as the most potent (also as a tubulin polymerisation inhibitor). Its anticancer activity against melanoma cell lines that originated from different stages, i.e., primary skin-derived A375 and metastatic WM9/MDA-MB-435S, was evaluated (as the clinical success of melanoma therapy strictly depends on the disease stage). Moreover, to determine the BF3 mode of action and its effect on cell proliferation, intracellular microtubule networks, cell cycle phase distribution and apoptosis were evaluated. Our study revealed that BF3 inhibited cell proliferation in a dose-dependent manner, with IC50 yielding 0.09 ± 0.01 µM, 0.11 ± 0.01 µM and 0.18 ± 0.05 µM for A375, MDA-MB435S and WM9, respectively. The strong antiproliferative activity of compound BF3 correlated well with its inhibitory effect on tubulin polymerisation. Molecular docking proved that BF3 belongs to the colchicine binding site inhibitors (CBSIs), and experimental studies revealed that it disturbs cell cycle progression leading to G2/M arrest and apoptosis.

Neuroprotective Profile of Triazole Grandisin Analogue against Amyloid-Beta Oligomer-Induced Cognitive Impairment.

Alzheimer's disease (AD) is a neurodegenerative disorder caused by accumulation of amyloid-ß oligomers (AßO) in the brain, neuroinflammation, oxidative stress, and cognitive decline. Grandisin, a tetrahydrofuran neolignan, exhibits relevant anti-inflammatory and antioxidant properties. Interestingly, grandisin-based compounds were shown to prevent AßO-induced neuronal death in vitro. However, no study has assessed the effect of these compounds on the AD animal model. This study focuses on a triazole grandisin analogue (TGA) synthesized using simplification and bioisosteric drug design, which resulted in improved potency and solubility compared with the parent compound. This study aimed to investigate the possible in vivo effects of TGA against AßO-induced AD. Male C57/Bl6 mice underwent stereotaxic intracerebroventricular AßO (90 µM) or vehicle injections. 24 h after surgery, animals received intraperitoneal treatment with TGA (1 mg/kg) or vehicle, administered on a 14 day schedule. One day after treatment completion, a novel object recognition task (NORT) was performed. Memantine (10 mg/kg) was administered as a positive control. NORT retention sessions were performed on days 8 and 16 after AßO injection. Immediately after retention sessions, animals were euthanized for cortex and hippocampus collection. Specimens were subjected to oxidative stress and cytokine analyses. TGA reduced the level of cortex/hippocampus lipoperoxidation and prevented cognitive impairment in AßO-injected mice. Additionally, TGA reduced tumor necrosis factor (TNF) and interferon-γ (IFN-γ) levels in the hippocampus. By contrast, memantine failed to prevent cortex/hippocampus lipid peroxidation, recognition memory decline, and AßO-induced increases in TNF and IFN-γ levels in the hippocampus. Thus, memantine was unable to avoid the AßO-induced persistent cognitive impairment. The results showed that TGA may prevent memory impairment by exerting antioxidant and anti-inflammatory effects in AßO-injected mice. Moreover, TGA exhibited a persistent neuroprotective effect compared to memantine, reflecting an innovative profile of this promising agent against neurodegenerative diseases, such as AD.

Adenine model of chronic renal failure in rats to determine whether MCC950, an NLRP3 inflammasome inhibitor, is a renopreventive.

BACKGROUND: Chronic renal failure (CRF) is defined by a significant decline in renal function that results in decreased salt filtration and inhibition of tubular reabsorption, which ultimately causes volume enlargement. This study evaluated the potential renopreventive effects of the NLRP3 inflammasome inhibitor MCC950 in adenine-induced CRF in rats due to conflicting evidence on the effects of MCC950 on the kidney. METHODS: Since the majority of the kidney tubular abnormalities identified in people with chronic renal disease are comparable to those caused by adding 0.75 percent of adenine powder to a rat's diet each day for four weeks, this method has received broad approval as a model for evaluating kidney damage. Throughout the test, blood pressure was checked weekly and at the beginning. Additionally, oxidative stress factors, urine sample examination, histological modifications, and immunohistochemical adjustments of caspase-3 and interleukin-1 beta (IL-1) levels in renal tissues were carried out. RESULTS: Results revealed that MCC950, an inhibitor of the NLRP3 inflammasome, had a renopreventive effect, which was demonstrated by a reduction in blood pressure readings and an improvement in urine, serum, and renal tissue indicators that indicate organ damage. This was also demonstrated by the decrease in neutrophil gelatinase-associated lipocalin tubular expression (NGAL). The NLRP3 inflammasome inhibitor MCC950 was found to significantly alleviate the worsening renal cellular alterations evidenced by increased expression of caspase-3 and IL-1, according to immunohistochemical tests. CONCLUSION: The NLRP3 inflammasome inhibitor MCC950 demonstrated renopreventive effects in the CRF rat model, suggesting that it might be used as a treatment strategy to stop the progression of CRF.

Novel Strigolactone Mimics That Modulate Photosynthesis and Biomass Accumulation in Chlorella sorokiniana.

In terrestrial plants, strigolactones act as multifunctional endo- and exo-signals. On microalgae, the strigolactones determine akin effects: induce symbiosis formation with fungi and bacteria and enhance photosynthesis efficiency and accumulation of biomass. This work aims to synthesize and identify strigolactone mimics that promote photosynthesis and biomass accumulation in microalgae with biotechnological potential. Novel strigolactone mimics easily accessible in significant amounts were prepared and fully characterized. The first two novel compounds contain 3,5-disubstituted aryloxy moieties connected to the bioactive furan-2-one ring. In the second group of compounds, a benzothiazole ring is connected directly through the cyclic nitrogen atom to the bioactive furan-2-one ring. The novel strigolactone mimics were tested on Chlorella sorokiniana NIVA-CHL 176. All tested strigolactones increased the accumulation of chlorophyll b in microalgae biomass. The SL-F3 mimic, 3-(4-methyl-5-oxo-2,5-dihydrofuran-2-yl)-3H-benzothiazol-2-one (7), proved the most efficient. This compound, applied at a concentration of 10-7 M, determined a significant biomass accumulation, higher by more than 15% compared to untreated control, and improved the quantum yield efficiency of photosystem II. SL-F2 mimic, 5-(3,5-dibromophenoxy)-3-methyl-5H-furan-2-one (4), applied at a concentration of 10-9 M, improved protein production and slightly stimulated biomass accumulation. Potential utilization of the new strigolactone mimics as microalgae biostimulants is discussed.

Novel Sulfonylurea-Based NLRP3 Inflammasome Inhibitor for Efficient Treatment of Nonalcoholic Steatohepatitis, Endotoxic Shock, and Colitis.

The NLRP3 inflammasome is a critical component of innate immunity involved in the pathophysiology of various inflammatory diseases. In this study, we designed and synthesized a series of NLRP3 inflammasome inhibitors based on MCC950. Specifically, we optimized the furan moiety, which is considered to be potentially associated with drug-induced liver injury. The representative inhibitor N14, 4-(2-(dimethylamino)ethyl)-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)benzenesulfonamide, not only maintains the NLRP3 inhibitory activity of MCC950 with IC50 of 25 nM but also demonstrates improved tolerability in human hepatic cells line and mouse primary hepatocytes. In addition, N14 exhibits superior pharmacokinetic properties, with an oral bioavailability of 85.2%. In vivo studies demonstrate that N14 is more effective than MCC950 in multiple NLRP3-related animal model diseases, including nonalcoholic steatohepatitis, lethal septic shock, and colitis. Our research has provided a lead compound that directly targets the NLRP3 inflammasome and can be developed as a novel therapeutic candidate for NLRP3-driven diseases.

Furan fatty acid extracted from Hevea brasiliensis latex increases muscle mass in mice.

Skeletal muscle is essential for locomotion and plays a crucial role in energy homeostasis. It is regulated by nutrition, genetic factors, physical activity and hormones. Furan fatty acids (FuFAs) are minor fatty acids present in small quantities in food from plants and animals origin. Recently, we showed that a preventive nutritional supplementation with furan fatty acid in a DIO mouse model reduces metabolic disorders. The present study was designed to determine the influence of FuFA-F2 extracted from Hevea brasiliensis latex on skeletal muscle phenotype. In C2C12 myotubes we found that FuFA-F2 whatever the concentration used increased protein content. We revealed that in C2C12 myotubes FuFA-F2 (10 µM) increases protein synthesis as shown by the stimulation of mTOR phosphorylation. Next, to confirm in vivo our results C57Bl6 mice were supplemented by oral gavage with vehicle or FuFA-F2 (20 mg/kg) for 3 and a half weeks. We found that mice supplemented with FuFA-F2 had a greater lean mass than the control mice. In line with this observation, we revealed that FuFA-F2 increased muscle mass and promoted more oxidative muscle metabolism in mice as attested by cytochrome c oxidase activity. In conclusion, we demonstrated that FuFA-F2 stimulates muscle anabolism in mice in vitro and in vivo, mimicking in part physical activity. This study highlights that in vivo FuFA-F2 may have health benefits by increasing muscle mass and oxidative metabolism.

Arctigenin derivatives improve exercise performance in mice: synthesis and biological evaluation.

Arctigenin (ARG) has potent antifatigue activity, but its clinical application has been restricted for its poor water solubility. In this study, seven ARG derivatives containing different amino acids coupled via an ethoxy linker were synthesized, and tested for their solubility, as well as activities to improve exercise performance in mice. All of the derivatives showed improved solubility compared to that of ARG. Derivative Z-A-6 exhibited the highest activity, showing that the mice ran a 4.88-fold greater distance in the running wheel test and swam a 2.86-fold greater time in the swimming test than those in the blank control group. Z-A-6 treatment increased the plasma superoxide dismutase and catalase concentrations as well as reduced lactic acid and blood urea nitrogen accumulation during exercise. Z-A-6 treatment enhanced the phosphorylation of adenosine monophosphate-activated protein kinase, and no acute toxicity was observed. The results will contribute to the development of potential antifatigue agents.

In Vitro Anti-Microbial Activity and Anti-Cancer Potential of Novel Synthesized Carbamothioyl-Furan-2-Carboxamide Derivatives.

A series of carbamothioyl-furan-2-carboxamide derivatives were synthesized using a one-pot strategy. Compounds were obtained in moderate to excellent yields (56-85%). Synthesized derivatives were evaluated for their anti-cancer (HepG2, Huh-7, and MCF-7 human cancer cell lines) and anti-microbial potential. Compound p-tolylcarbamothioyl)furan-2-carboxamide showed the highest anti-cancer activity at a concentration of 20 µg/mL against hepatocellular carcinoma, with a cell viability of 33.29%. All compounds showed significant anti-cancer activity against HepG2, Huh-7, and MCF-7, while indazole and 2,4-dinitrophenyl containing carboxamide derivatives were found to be less potent against all tested cell lines. Results were compared with the standard drug doxorubicin. Carboxamide derivatives possessing 2,4-dinitrophenyl showed significant inhibition against all bacterial and fungal strains with inhibition zones (I.Z) in the range of 9-17 and MICs were found to be 150.7-295 µg/mL. All carboxamide derivatives showed significant anti-fungal activity against all tested fungal strains. Gentamicin was used as the standard drug. The results showed that carbamothioyl-furan-2-carboxamide derivatives could be a potential source of anti-cancer and anti-microbial agents.

Chemical, Pharmacological, and Structural Characterization of Novel Acrylamide-Derived Modulators of the GABAA Receptor.

Acrylamide-derived compounds have been previously shown to act as modulators of members of the Cys-loop transmitter-gated ion channel family, including the mammalian GABAA receptor. Here we have synthesized and functionally characterized the GABAergic effects of a series of novel compounds (termed "DM compounds") derived from the previously characterized GABAA and the nicotinic α7 receptor modulator (E)-3-furan-2-yl-N-p-tolyl-acrylamide (PAM-2). Fluorescence imaging studies indicated that the DM compounds increase apparent affinity to the transmitter by up to 80-fold in the ternary αßγ GABAA receptor. Using electrophysiology, we show that the DM compounds, and the structurally related (E)-3-furan-2-yl-N-phenylacrylamide (PAM-4), have concurrent potentiating and inhibitory effects that can be isolated and observed under appropriate recording conditions. The potentiating efficacies of the DM compounds are similar to those of neurosteroids and benzodiazepines (ΔG ∼ -1.5 kcal/mol). Molecular docking, functionally confirmed by site-directed mutagenesis experiments, indicate that receptor potentiation is mediated by interactions with the classic anesthetic binding sites located in the transmembrane domain of the intersubunit interfaces. Inhibition by the DM compounds and PAM-4 was abolished in the receptor containing the α1(V256S) mutation, suggestive of similarities in the mechanism of action with that of inhibitory neurosteroids. Functional competition and mutagenesis experiments, however, indicate that the sites mediating inhibition by the DM compounds and PAM-4 differ from those mediating the action of the inhibitory steroid pregnenolone sulfate. SIGNIFICANCE STATEMENT: We have synthesized and characterized the actions of novel acrylamide-derived compounds on the mammalian GABAA receptor. We show that the compounds have concurrent potentiating effects mediated by the classic anesthetic binding sites, and inhibitory actions that bear mechanistic resemblance to but do not share binding sites with, the inhibitory steroid pregnenolone sulfate.

Design and Synthesis of 4-Fluorophenyl-5-methylene-2(5H)-furanone Derivatives as Potent Quorum Sensing Inhibitors.

Quorum sensing inhibitors (QSIs) are a class of compounds that can reduce the pathogenicity of bacteria without affecting bacterial growth. In this study, we designed and synthesized four series of 4-fluorophenyl-5-methylene-2(5H)-furanone derivatives and evaluated their QSI activities. Among them, compound 23e not only showed excellent inhibitory activity against various virulence factors but also significantly enhanced the inhibitory activity of antibiotics ciprofloxacin and clarithromycin against two strains of Pseudomonas aeruginosa in vitro. What is even more exciting is that it remarkably increased the antibacterial effect in vivo in combination with ciprofloxacin in the bacteremia model infected with P. aeruginosa PAO1. Moreover, 23e had little hemolytic activity to mouse erythrocytes. Further, the results of GFP reporter fluorescence strain inhibition and ß-galactosidase activity inhibition experiments demonstrated that 23e simultaneously targeted the three quorum sensing systems in P. aeruginosa. As a result, compound 23e could be used as an effective QSI for further development against bacterial infections.

Silver(I) pyrrole- and furan-2-carboxylate complexes - From their design and characterization to antimicrobial, anticancer activity, lipophilicity and SAR.

Two silver(I) complexes with biologically relevant heterocyclic ligands, pyrrole and furan-2- carboxylic acid, were synthesized and their composition was confirmed using elemental, spectral, thermal and structural analyses. The {[Ag(Py2c)]}n (AgPy2c, Py2c = pyrrole-2-carboxylate) and {[Ag(Fu2c)]}n (AgFu2c, Fu2c = furan-2-carboxylate) solubility and stability in biological test stock solution were confirmed by 1H NMR spectroscopy. The X-ray analysis has enabled us to determine typical argentophilic interactions and bridging carboxylate coordination mode of both ligands. Potentiometric data analysis by BSTAC program resulted in the determination of the stability constant of only one species, i.e., the ML (M = Ag+, L = Fu2c-), log ßML = 0.59 ± 0.04. Antimicrobial and anticancer tests were performed against selected microorganisms and cell lines with new silver(I) complexes and compared with AgSD (silver(I) sulfadiazine) and cisplatin. From their microbial toxicity point of view, selectivity was determined against lactobacilli (AgPy2c is 8× more effective against S. aureus and E. coli and AgFu2c is 8× more effective against E. coli and 4× against S. aureus). AgFu2c significant anticancer activity was determined against Jurkat cell lines (IC50 = 8.00 µM) and was similar to cisPt (IC50 = 6.3 µM) similarly to its selectivity (SI (AgFu2c) = 7.3, SI (cisPt) = 6.4, SI = selectivity index). In addition, cell cycle arrest was observed already in the Sub-G0 phase during a flow cytometry experiment. To evaluate the AgPy2c and AgFu2c bioavailability we also discuss their Lipinski's Rule of Five.

Design, synthesis, and biological evaluation of furan-bearing pyrazolo[3,4-b]pyridines as novel inhibitors of CDK2 and P53-MDM2 protein-protein interaction.

The novel series of furan-bearing pyrazolo[3,4-b]pyridines were designed as cyclin-dependent kinase 2 (CDK2) inhibitors and as p53-murine double minute 2 (MDM2) inhibitors. The newly synthesized compounds were screened for their antiproliferative activity toward hepatocellular carcinoma (HepG2) and breast cancer (MCF7) cell lines. The most active compounds on both cell lines were additionally evaluated for their in vitro CDK2 inhibitory activity. Compounds 7b and 12f displayed enhanced activity (half-maximal inhibitory concentration [IC50 ] = 0.46 and 0.27 µM, respectively) in comparison to the standard roscovitine (IC50 = 1.41 ± 0.03 µM), in addition to, cell cycle arrest at S phase and G1/S transition phase in MCF7 cells treated with both compounds, respectively. Moreover, the most active spiro-oxindole derivative against MCF7 cell line, 16a, exhibited enhanced inhibitory activity against p53-MDM2 interaction in vitro (IC50 = 3.09 ± 0.12 µM) compared to nutlin, and increased the levels of both p53 and p21 by nearly fourfold in comparison to the negative control. Molecular docking studies demonstrated the plausible interaction patterns of the most potent derivatives 17b and 12f in the CDK2 binding pocket and the spiro-oxindole 16a with p53-MDM2 complex, respectively. Consequently, the new chemotypes 7b, 12f, and 16a can be presented as promising antitumor hits for further studies and optimization.