Identification of sulphonamide-tethered N-((triazol-4-yl)methyl)isatin derivatives as inhibitors of SARS-CoV-2 main protease.

SARS-CoV-2 pandemic in the end of 2019 led to profound consequences on global health and economy. Till producing successful vaccination strategies, the healthcare sectors suffered from the lack of effective therapeutic agents that could control the spread of infection. Thus, academia and the pharmaceutical sector prioritise SARS-CoV-2 antiviral drug discovery. Here, we exploited previous reports highlighting the anti-SARS-CoV-2 activities of isatin-based molecules to develop novel triazolo-isatins for inhibiting main protease (Mpro) of the virus, a crucial enzyme for its replication in the host cells. Particularly, sulphonamide 6b showed promising inhibitory activity with an IC50= 0.249 µM. Additionally, 6b inhibited viral cell proliferation with an IC50 of 4.33 µg/ml, and was non-toxic to VERO-E6 cells (CC50 = 564.74 µg/ml) displaying a selectivity index of 130.4. In silico analysis of 6b disclosed its ability to interact with key residues in the enzyme active site, supporting the obtained in vitro findings.

Natural inspired piperine-based ureas and amides as novel antitumor agents towards breast cancer.

In this work, the natural piperine moiety was utilised to develop two sets of piperine-based amides (5a-i) and ureas (8a-y) as potential anticancer agents. The anticancer action was assessed against triple negative breast cancer (TNBC) MDA-MB-231, ovarian A2780CP and hepatocellular HepG2 cancer cell lines. In particular, 8q stood out as the most potent anti-proliferative analogue against TNBC MDA-MB-231 cells with IC50 equals 18.7 µM, which is better than that of piperine (IC50 = 47.8 µM) and 5-FU (IC50 = 38.5 µM). Furthermore, 8q was investigated for its possible mechanism of action in MDA-MB-231 cells via Annexin V-FITC apoptosis assay and cell cycle analysis. Moreover, an in-silico analysis has proposed VEGFR-2 as a probable enzymatic target for piperine-based derivatives, and then has explored the binding interactions within VEGFR-2 active site (PDB:4ASD). Finally, an in vitro VEGFR-2 inhibition assay was performed to validate the in silico findings, where 8q showed good VEGFR-2 inhibitory activity with IC50 = 231 nM.

Development of Novel Quinoline-Based Sulfonamides as Selective Cancer-Associated Carbonic Anhydrase Isoform IX Inhibitors.

A new series of quinoline-based benzenesulfonamides (QBS) were developed as potential carbonic anhydrase inhibitors (CAIs). The target QBS CAIs is based on the 4-anilinoquinoline scaffold where the primary sulphonamide functionality was grafted at C4 of the anilino moiety as a zinc anchoring group (QBS 13a-c); thereafter, the sulphonamide group was switched to ortho- and meta-positions to afford regioisomers 9a-d and 11a-g. Moreover, a linker elongation approach was adopted where the amino linker was replaced by a hydrazide one to afford QBS 16. All the described QBS have been synthesized and investigated for their CA inhibitory action against hCA I, II, IX and XII. In general, para-sulphonamide derivatives 13a-c displayed the best inhibitory activity against both cancer-related isoforms hCA IX (KIs = 25.8, 5.5 and 18.6 nM, respectively) and hCA XII (KIs = 9.8, 13.2 and 8.7 nM, respectively), beside the excellent hCA IX inhibitory activity exerted by meta-sulphonamide derivative 11c (KI = 8.4 nM). The most promising QBS were further evaluated for their anticancer and pro-apoptotic activities on two cancer cell lines (MDA-MB-231 and MCF-7). In addition, molecular docking simulation studies were applied to justify the acquired CA inhibitory action of the target QBS.

Assessment of the Prevalence of Non-Organ-Specific Autoantibodies in Egyptian Patients with HCV.

The relation between non-organ specific autoantibodies (NOSA) and hepatitis C virus (HCV) infection has been investigated within different communities resulting in different prevalence rates and patterns. The purpose of this study was to investigate the prevalence of some NOSA such as RF-IgG, ANA, ASMA, and LKM-1 in Egyptian patients with HCV group as compared with Egyptian healthy controls group. A total of 186 HCV positive serum samples in addition to 81 samples from healthy control were screened for the presence of some common autoantibodies (RF-IgG, ANA, ASMA, and LKM-1) using ELISA technique for ANA, ASMA, and LK-1 while RF-IgG was assayed by latex agglutination technique. The presence of these autoantibodies was tested in relation to some demographic variables and viral titers. Associations were assessed using logistic regression analysis adjusted for potential confounders. Among patients, 100 (53.7%) of 186 and 6 (7.4%) of 81 healthy control group were positive for at least one autoantibody. Furthermore, 2 patients (1%) were positive for three autoantibodies, whereas 22 patients (11.7%) were positive for 2 autoantibodies. The most prevalent autoantibody in anti-HCV-positive group was RF-IgG (87, 46.7%) followed by ASMA (26, 14%). The frequency of autoantibodies was bit higher in women as compared to men. Taken together, this study reports a non-significant difference in prevalence of NOSA between patients with HCV infection and healthy individuals except for ASMA. Likewise, no significant difference was found in prevalence of such autoantibodies when correlated with some demographic variables.

The Multivalent Adhesion Molecule SSO1327 plays a key role in Shigella sonnei pathogenesis.

Shigella sonnei is a bacterial pathogen and causative agent of bacillary dysentery. It deploys a type III secretion system to inject effector proteins into host epithelial cells and macrophages, an essential step for tissue invasion and immune evasion. Although the arsenal of bacterial effectors and their cellular targets have been studied extensively, little is known about the prerequisites for deployment of type III secreted proteins during infection. Here, we describe a novel S. sonnei adhesin, SSO1327 which is a multivalent adhesion molecule (MAM) required for invasion of epithelial cells and macrophages and for infection in vivo. The S. sonnei MAM mediates intimate attachment to host cells, which is required for efficient translocation of type III effectors into host cells. SSO1327 is non-redundant to IcsA; its activity is independent of type III secretion. In contrast to the up-regulation of IcsA-dependent and independent attachment and invasion by deoxycholate in Shigella flexneri, deoxycholate negatively regulates IcsA and MAM in S. sonnei resulting in reduction in attachment and invasion and virulence attenuation in vivo. A strain deficient for SSO1327 is avirulent in vivo, but still elicits a host immune response.

Silver nanoparticles: Antimicrobial activity, cytotoxicity, and synergism with N-acetyl cysteine.

The fast progression of nanotechnology has led to novel therapeutic interventions. Antimicrobial activities of silver nanoparticles (Ag NPs) were tested against standard ATCC strains of Staphylococcus aureus (ATCC 9144), Escherichia coli (O157:H7), Pseudomonas aeruginosa (ATCC 27853), and Candida albicans (ATCC 90028) in addition to 60 clinical isolates collected from cancer patients. Antimicrobial activity was tested by disk diffusion method and MIC values for Ag NPs alone and in combination with N-acetylcysteine (NAC) against tested pathogens were determined by broth microdilution method. Ag NPs showed a robust antimicrobial activity against all tested pathogens and NAC substantially enhanced the antimicrobial activity of Ag NPs against all tested pathogens. Synergism between Ag NPs and NAC has been confirmed by checkerboard assay. The effect of Ag NPs on tested pathogens was further scrutinized by Transmission Electron Microscope (TEM) which showed disruption of cell wall in both bacteria and fungi. Ag NPs abrogated the activity of respiratory chain dehydrogenase of all tested pathogens and released muramic acid content from S. aureus in culture. The cytotoxic effect of Ag NPs alone and in combination with NAC was examined using human HepG2 cells and this revealed no cytotoxicity at MIC values of Ag NPs and interestingly, NAC reduced the cytotoxic effect of Ag NPs at concentrations higher than their MIC values. Taken together, Ag NPs have robust antimicrobial activity and NAC substantially enhances their antimicrobial activities against MDR pathogens which would provide a novel safe, effective, and inexpensive therapeutic approach to control the prevalence of MDR pathogens.

Inhibition of quorum sensing-mediated biofilm formation in Pseudomonas aeruginosa by a locally isolated Bacillus cereus.

Quorum sensing has been shown to play a crucial role in Pseudomonas aeruginosa pathogenesis where it activates expression of myriad genes that regulate the production of important virulence factors such as biofilm formation. Antagonism of quorum sensing is an excellent target for antimicrobial therapy and represents a novel approach to combat drug resistance. In this study, Chromobacterium violaceum biosensor strain was employed as a fast, sensitive, reliable, and easy to use tool for rapid screening of soil samples for Quorum Sensing Inhibitors (QSI) and the optimal conditions for maximal QSI production were scrutinized. Screening of 127 soil isolates showed that 43 isolates were able to breakdown the HHL signal. Out of the 43 isolates, 38 isolates were able to inhibit the violet color of the biosensor and to form easily detectable zones of color inhibition around their growth. A confirmatory bioassay was carried out after concentrating the putative positive cell-free lysates. Three different isolates that belonged to Bacillus cereus group were shown to have QSI activities and their QSI activities were optimized by changing their culture conditions. Further experiments revealed that the cell-free lysates of these isolates were able to inhibit biofilm formation by P. aeruginosa clinical isolates.

Novel fluorescent probes based on sulfur and nitrogen co-doped carbon dots for determination of three N-substituted phenothiazine derivatives in dosage forms.

In the current work, sulfur and nitrogen co-doped carbon dots (S,N-CDs) as simple, sensitive, and selective turn-off fluorescent nanosensors were utilized for analysis of three phenothiazine derivatives, including acetophenazine (APZ), chlorpromazine (CPH), and promethazine (PZH). S,N-CDs were synthesized through a green one-pot microwave-assisted technique using widely available precursors (thiourea and ascorbic acid). HRTEM, EDX, FTIR spectroscopy, UV-Vis absorption spectroscopy, and fluorescence spectroscopy were used to characterize the as-synthesized CDs. When excited at 330 nm, the carbon dots produced a maximum emission peak at 410 nm. The cited drugs statically quenched the S,N-CDs fluorescence as revealed by the Stern-Volmer equation. The current method represents the first spectrofluorimetric approach for the determination of the studied drugs without the need for chemical derivatization or harsh reaction conditions. The importance of the proposed work is magnified as the cited drugs do not have any fluorescent properties. The fluorescence of the developed sensor exhibited a linear response to APZ, CPH, and PZH in the concentration ranges of 5.0-100.0, 10.0-100.0, and 10.0-200.0 µM with detection limits of 1.53, 1.66, and 2.47 µM, respectively. The developed fluorescent probes have the advantages of rapidity and selectivity for APZ, CPH, and PZH analysis in tablets with acceptable % recoveries of (98.06-101.66 %). Evaluation of the method's greenness was performed using the Complementary Green Analytical Procedure Index (ComplexGAPI) and Analytical GREEnness metric (AGREE) metrics, indicating that the method is environmentally friendly. Validation of the proposed method was performed according to ICHQ2 (R1) guidelines.

Analytical quality-by-design approach for development and validation of HPLC method for the simultaneous estimation of omarigliptin, metformin, and ezetimibe: application to human plasma and dosage forms.

A simple, selective, and sensitive RP-HPLC method was proposed for the simultaneous determination of two co-administered antidiabetic drugs (omarigliptin and metformin) with an anti-hyperlipidemic drug (ezetimibe) in a medicinally-recommended ratio of 2.5:50:1, respectively. The proposed procedure was optimized by adopting a quality-by-design approach. The influence of different factors on chromatographic responses was optimized by applying the two-level full factorial design (25). The optimum chromatographic separation was achieved using Hypersil BDS C18 column at 45 °C, and the mobile phase pumped isocratically composed of methanol: potassium dihydrogen phosphate buffer (6.6 mM; pH 7, 67:33% v/v) at a flow rate of 0.814 mL/min using 235 nm as a detection wavelength. The developed method was capable of separating this novel mixture in less than 8 min. The calibration plots of omarigliptin, metformin, and ezetimibe showed acceptable linearity over the ranges of 0.2-2.0, 0.5-25.0, and 0.1-2.0 µg/mL with quantitation limits of 0.06, 0.50, and 0.06 µg/mL, respectively. The proposed method was successfully applied to determine the studied drugs in their commercial tablets with high % recoveries (96.8-102.92%) and low % RSD values (less than 2%). The applicability of the method was extended to the in-vitro assay of the drugs in spiked human plasma samples with high % recoveries (94.3-105.7%). The suggested method was validated in accordance with ICH guidelines.

3-Acetyl-11-keto-ß-boswellic Acid-Based Hybrids Alleviate Acetaminophen-Induced Hepatotoxicity in HepG2 by the Regulation of Inflammatory and Oxidative Stress Pathways: An Integrated Approach.

In an effort to develop new compounds for managing drug-induced liver injury, we prepared 23 novel hybrids based on 3-acetyl-11-keto-ß-boswellic acid (AKBA) using various biocompatible linkers. A bioguided approach was employed to identify the most promising hybrid. Eight compounds exhibited superior anti-inflammatory activity compared to the parent compound. Two of these hybrids (5b and 18) were able to reduce gene expression of TNF-α in LPS-induced inflammation in RAW 264.7 cells, similar to dexamethasone. Subsequently, the hepatoprotective potential of these hybrids was evaluated against acetaminophen (APAP) toxicity in HepG2 cells at doses of 1 and 10 µM. Both hybrids effectively restored cytokine levels, which had been elevated by APAP, to normal levels. Furthermore, they normalized depleted superoxide dismutase and reduced glutathione levels while significantly reducing malondialdehyde (MDA) levels. Network pharmacology analysis suggested that AKBA-based hybrids exert their action by regulating PI3K and EGFR pathways, activating anti-inflammatory mechanisms, and initiating tissue repair and regeneration. Molecular docking studies provided insights into the interaction of the hybrids with PI3K. Additionally, the hybrids demonstrated good stability at different pH levels, following first-order kinetics, with relatively long half-lives, suggesting potential for absorption into circulation without significant degradation.

Theophylline-based hybrids as acetylcholinesterase inhibitors endowed with anti-inflammatory activity: synthesis, bioevaluation, in silico and preliminary kinetic studies.

In this study, we investigated the conjugation of theophylline with different compounds of natural origin hoping to construct new hybrids with dual activity against cholinergic and inflammatory pathways as potential agents for the treatment of Alzheimer's disease (AD). Out of 28 tested hybrids, two hybrids, acefylline-eugenol 6d and acefylline-isatin 19, were able to inhibit acetylcholinesterase (AChE) at low micromolar concentration displaying IC50 values of 1.8 and 3.3 µM, respectively, when compared to the galantamine standard AChE inhibitor. Moreover, the prepared hybrids exhibited a significant anti-inflammatory effect against lipopolysaccharide induced inflammation in RAW 264.7 and reduced nitric oxide (NO), tumor necrosis alpha (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) levels in a dose dependent manner. These hybrids demonstrated significant reductions in nitric oxide (NO), tumor necrosis alpha (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) levels in RAW 264.7 cells induced by lipopolysaccharide (LPS). The findings of this study were further explained in light of network pharmacology analysis which suggested that AChE and nitric oxide synthase were the main targets of the most active compounds. Molecular docking studies revealed their ability to bind to the heme binding site of nitric oxide synthase 3 (NOS-3) and effectively occupy the active site of AChE, interacting with both the peripheral aromatic subsite and catalytic triad. Finally, the compounds demonstrated stability in simulated gastric and intestinal environments, suggesting potential absorption into the bloodstream without significant hydrolysis. These findings highlight the possible therapeutic potential of acefylline-eugenol 6d and acefylline-isatin 19 hybrids in targeting multiple pathological mechanisms involved in AD, offering promising avenues for further development as potential treatments for this devastating disease.

Sulfur and nitrogen co-doped carbon quantum dots as fluorescent probes for the determination of some pharmaceutically-important nitro compounds.

In this study, highly fluorescent sulfur and nitrogen co-doped carbon quantum dots (SN-CQDs) were synthesized by a simple one-pot hydrothermal method using thiosemicarbazide and citric acid as starting materials. Various spectroscopic and microscopic techniques were applied to characterize the prepared SN-CQDs. The synthesized SN-CQDs' maximum fluorescence emission was obtained at 430 nm after excitation at 360 nm. Rifampicin (RFP), tinidazole (TNZ), ornidazole (ONZ), and metronidazole (MNZ) all quantitatively and selectively quenched the SN-CQDs' native fluorescence, which was the base-for their-spectrofluorimetric estimation without the need for any tedious pre-treatment steps or high-cost instrumentation. SN-CQDs demonstrated a "turn-off" fluorescence response to RFP, TNZ, ONZ, and MNZ over the ranges of 1.0-30.0, 10.0-200.0, 6.0-200.0, and 5.0-100.0 µM with detection limits of 0.31, 1.76, 0.57, and 0.75 µM and quantitation limits of 0.93, 5.32, 1.74, and 2.28 µM respectively. The suggested method was successfully used to determine the investigated drugs in their commercial dosage forms. The method was further extended to their determination in spiked human plasma samples, with satisfactory mean % recoveries (99.44-100.29) and low % RSD values (< 4.52). The mechanism of fluorescence quenching was studied and discussed. The suggested method was validated in accordance with ICH recommendations.

Tetrahydrobenzo[h]quinoline derivatives as a novel chemotype for dual antileishmanial-antimalarial activity graced with antitubercular activity: Design, synthesis and biological evaluation.

Derivatives with tetrahydrobenzo[h]quinoline chemotype were synthesized via one-pot reactions and evaluated for their antileishmanial, antimalarial and antitubercular activities. Based on a structure-guided approach, they were designed to possess antileishmanial activity through antifolate mechanism, via targeting Leishmania major pteridine reductase 1 (Lm-PTR1). The in vitro antipromastigote and antiamastigote activity are promising for all candidates and superior to the reference miltefosine, in a low or sub micromolar range of activity. Their antifolate mechanism was confirmed via the ability of folic and folinic acids to reverse the antileishmanial activity of these compounds, comparably to Lm-PTR1 inhibitor trimethoprim. Molecular dynamics simulations confirmed a stable and high potential binding of the most active candidates against leishmanial PTR1. For the antimalarial activity, most of the compounds exhibited promising antiplasmodial effect against P. berghei with suppression percentage of up to 97.78%. The most active compounds were further screened in vitro against the chloroquine resistant strain P. falciparum, (RKL9) and showed IC50 value range of 0.0198-0.096 µM, compared to IC50 value of 0.19420 µM for chloroquine sulphate. Molecular docking of the most active compounds against the wild-type and quadruple mutant pf DHFR-TS structures rationalized the in vitro antimalarial activity. Some candidates showed good antitubercular activity against sensitive Mycobacterium tuberculosis in a low micromolar range of MIC, compared to 0.875 µM of isoniazid. The top active ones were further tested against a multidrug-resistant strain (MDR) and extensively drug-resistant strain (XDR) of Mycobacterium tuberculosis. Interestingly, the in vitro cytotoxicity test of the best candidates displayed high selectivity indices emphasizing their safety on mammalian cells. Generally, this work introduces a fruitful matrix for new dual acting antileishmanial-antimalarial chemotype graced with antitubercular activity. This would help in tackling drug-resistance issues in treating some Neglected Tropical Diseases.

OXA-163-producing Klebsiella pneumoniae in Cairo, Egypt, in 2009 and 2010.

Two genetically unrelated OXA-163-carrying Klebsiella pneumoniae strains were identified from two infection cases in June 2009 and May 2010 in Cairo, Egypt. OXA-163-producing Enterobacteriaceae had been previously reported in Argentina only. Both patients had no history of travel abroad. The emergence of this newly recognized OXA-48-related ß-lactamase able to hydrolyze cephalosporins and carbapenems is especially worrying in a geographic area where OXA-48 is endemic and effective surveillance for antibiotic resistance is largely unaffordable.

Green synthesis, characterization, and antimicrobial applications of silver nanoparticles as fluorescent nanoprobes for the spectrofluorimetric determination of ornidazole and miconazole.

A green and simple method was proposed for the synthesis of silver nanoparticles (Ag-NPs) using Piper cubeba seed extract as a reducing agent for the first time. The prepared Ag-NPs were characterized using different spectroscopic and microscopic techniques. The obtained Ag-NPs showed an emission band at 320 nm when excited at 280 nm and exhibited strong green fluorescence under UV-light. The produced Ag-NPs were used as fluorescent nanosensors for the spectrofluorimetric determination of ornidazole (ONZ) and miconazole nitrate (MIZ) based on their quantitative quenching of Ag-NPs native fluorescence. The current study introduces the first spectrofluorimetric method for the determination of the studied drugs using Ag-NPs without the need for any pre-derivatization steps. Since the studied drugs don't exhibit native fluorescent properties, the importance of the proposed study is magnified. The proposed method displayed a linear relationship between the fluorescence quenching and the concentrations of the studied drugs over the range of 5.0-80.0 µM and 20.0-100.0 µM with limits of detection (LOD) of 0.35 µM and 1.43 µM for ONZ and MIZ, respectively. The proposed method was applied for the determination of ONZ and MIZ in different dosage forms and human plasma samples with high % recoveries and low % RSD values. The developed method was validated according to ICH guidelines. Moreover, the synthesized Ag-NPs demonstrated significant antimicrobial activities against three different bacterial strains and one candida species. Therefore, the proposed method may hold potential applications in the antimicrobial therapy and related mechanism research.

Nitrogen and sulfur-doped carbon quantum dots as fluorescent nanoprobes for spectrofluorimetric determination of olanzapine and diazepam in biological fluids and dosage forms: application to content uniformity testing.

A validated, sensitive, and simple spectrofluorimetric method was developed for the analysis of two important CNS-acting drugs, olanzapine and diazepam, in their commercial tablets without the need for any pretreatment steps. The developed method relied on the quantitative quenching effect of each of olanzapine and diazepam on the native fluorescence of nitrogen and sulfur-doped carbon quantum dots (NS@CQDs). NS@CQDs were prepared from thiosemicarbazide and citric acid by a facile one-pot hydrothermal technique. The synthesized NS@CQDs were characterized by different spectroscopic and microscopic techniques. NS@CQDs produced a maximum emission peak at 430 nm using 360 nm as an excitation wavelength. Calibration curves showed a good linear regression over the range of 5.0-200.0 and 1.0-100.0 µM with detection limits of 0.68 and 0.29 µM for olanzapine and diazepam, respectively. The adopted method was used for the determination of the investigated drugs in their tablets with high % recoveries (98.84-101.70%) and low % RSD values (< 2%). As diazepam is one of the most commonly abused benzodiazepines, the developed method was successfully applied for its determination in spiked human plasma with high % recoveries and low % RSD values, providing further insights for monitoring its potential abuse. The quenching mechanism was also studied and confirmed to be through dynamic and static quenching for olanzapine and diazepam, respectively. Due to the high selectivity and sensitivity, content uniformity testing of low-dose tablets was successfully performed by applying the United States Pharmacopoeia guidelines. The method's validation was performed in compliance with ICHQ2 (R1) recommendations.

Multi-Spectroscopic, thermodynamic and molecular dynamic simulation studies for investigation of interaction of dapagliflozin with bovine serum albumin.

Dapagliflozin (DAPA) is a selective sodium-glucose cotransporter-2 inhibitor that reduces renal glucose reabsorption. The drug has recently become a crucial milestone in the management of diabetes and heart failure. In this study, the interaction of DAPA with bovine serum albumin (BSA) was investigated for the first time using various fluorescence spectroscopic techniques, UV-absorption spectroscopy, molecular docking, and molecular dynamic (MD) simulation. The fluorescence spectroscopic titration study performed at different temperatures showed that DAPA quenched the fluorescence of BSA through a combination of dynamic and static mechanisms, which was confirmed by UV absorption, fluorescence-resonance energy transfer measurements, and MD simulation. The binding thermodynamic parameters demonstrated that the binding stoichiometry between BSA and DAPA was 1:1. Competitive binding experiments using site-specific markers as well as molecular docking studies showed that DAPA binds to site I on BSA. The positive values of enthalpy change (ΔH) and entropy change (ΔS) revealed that hydrophobic forces played a predominant role in the binding of DAPA to BSA, whereas the negative value of Gibbs free energy change (ΔG) indicated the spontaneity of the interaction. Moreover, the synchronous fluorescence spectroscopy has shown that DAPA binding to the protein molecule occurs in the vicinity of the tryptophan residue. These findings were confirmed by the molecular docking and MD simulation studies.

Application of sulfur and nitrogen doped carbon quantum dots as sensitive fluorescent nanosensors for the determination of saxagliptin and gliclazide.

In this study, highly fluorescent sulfur and nitrogen doped carbon quantum dots (S,N-CQDs) were used as fluorescent nanosensors for direct spectrofluorimetric estimation of each of gliclazide (GLZ) and saxagliptin (SXG) without any pre-derivatization steps for the first time. S,N-CQDs were synthesized employing a simple hydrothermal technique using citric acid and thiosemicarbazide. The produced S,N-CQDs were characterized using different techniques including fluorescence emission spectroscopy, UV spectrophotometry, high-resolution transmission electron microscopy and FT-IR spectroscopy. Following excitation at 360 nm, S,N-CQDs exhibited a strong emission peak at 430 nm. The native fluorescence of S,N-CQDs was quantitatively enhanced by addition of increased concentrations of the studied drugs. The fluorescence enhancement of S,N-CQDs and the concentrations of the studied drugs revealed a wide linear relationship in the range of 30.0-500.0 µM and 75.0-600.0 µM with limits of detection of 5.0 and 10.15 µM for GLZ and SXG, respectively. The proposed method was efficiently used for determination of cited drugs in their commercial tablets with % recoveries ranging from 98.6% to 101.2% and low % relative standard deviation values (less than 2%). The mechanism of interaction between S,N-CQDs and the two drugs was studied. Validation of the proposed method was carried out in accordance with International Conference on Harmonization (ICH) guidelines.

Identification of novel piperazine-tethered phthalazines as selective CDK1 inhibitors endowed with in vitro anticancer activity toward the pancreatic cancer.

Pharmacologic inhibition of the oncogenic protein kinases using small molecules is a promising strategy to combat several human malignancies. CDK1 is an example of such a valuable target for the management of pancreatic ductal adenocarcinomas (PDAC); its overexpression in PDAC positively correlates with the size, histological grade and tumor aggressiveness. Here we report the identification of novel series of 1-piperazinyl-4-benzylphthalazine derivatives (8a-g, 10a-i and 12a-d) as promising anticancer agents with CDK1 inhibitory activity. The anti-proliferative activity of these agents was first screened on a panel of 11 cell lines representing 5 cancers (pancreas, melanoma, leukemia, colon and breast), and then confirmed on two CDK1-overexpressing PDAC cell lines (MDA-PATC53 and PL45 cells). Phthalazines 8g, 10d and 10h displayed potent activity against MDA-PATC53 (IC50 = 0.51, 0.88 and 0.73 µM, respectively) and PL45 (IC50 = 0.74, 1.14 and 1.00 µM, respectively) cell lines. Furthermore, compounds 8g, 10d and 10h exhibited potent and selective inhibitory activity toward CDK1 with IC50 spanning in the range 36.80-44.52 nM, whereas they exerted weak inhibitory effect on CDK2, CDK5, AXL, PTK2B, FGFR, JAK1, IGF1R and BRAF kinases. Western blotting of CDK1 in MDA-PATC53 cells confirmed the ability of target phthalazines to diminish the CDK1 levels, and cell cycle analyses revealed their ability to arrest the cell cycle at G2/M phase. In conclusion, a panel of potent and selective CDK1 inhibitors were identified which can serve as lead compounds for designing further CDK1 inhibitors.

Complete genome sequences of two Escherichia coli clinical isolates from Egypt carrying mcr-1 on IncP and IncX4 plasmids.

Colistin is a last-resort antibiotic used in the treatment of multidrug resistant Gram-negative bacteria. However, the activity and efficacy of colistin has been compromised by the worldwide spread of the mobile colistin resistance genes (mcr-1 to mcr-10). In this study, two clinical Escherichia coli strains, named EcCAI51, and EcCAI73, harbored mcr-1, showed multidrug-resistant phenotypes (with colistin MIC = 4 µg/ml), and belonged to phylogroup D: multilocus sequence type 1011 (ST1011) and phylogroup A: ST744, respectively. Findings revealed the existence of mcr-1 gene on two conjugable plasmids, pAMS-51-MCR1 (∼122 kb IncP) and pAMS-73-MCR1 (∼33 kb IncX4), in EcCAI51, and EcCAI73, respectively. The mcr-1-pap2 element was detected in the two plasmids. Additionally, the composite transposon (ISApl1-IS5D-pap2-mcr-1-ISApl1) was identified only in pAMS-51-MCR1 suggesting the potential for horizontal gene transfer. The two strains carried from 16 to 18 different multiple acquired antimicrobial resistance genes (ARGs). Additionally, two different multireplicon virulence plasmids (∼117 kb pAMS-51-Vr and ∼226 kb pAMS-73-Vr) carrying the sit operon, the Salmochelin siderophore iroBCDE operon and other several virulence genes were identified from the two strains. Hierarchical clustering of core genome MLST (HierCC) revealed clustering of EcCAI73, and EcCAI51 with global E. coli lineages at HC levels of 50 (HC50) to 100 (HC100) core genome allelic differences. To the best of our knowledge, this study presented the first complete genomic sequences of mcr-1-carrying IncP and IncX4 plasmids from human clinical E. coli isolates in Egypt. In addition, the study illustrated the mcr-1 broad dissemination in diverse plasmids and dissimilar E. coli clones.