Compounds 3a Research Articles

Rational design, synthesis and anticancer screening of 1,2,4-oxadiazole incorporated thieno[2,3-d]thiazole-isoxazole-pyridine derivatives

We have design and synthesized a new series of 1,2,4-oxadiazole incorporated thieno[2,3-d]thiazole-isoxazole-pyridine analogues (13a-j) and were confirmed by 1H NMR, 13C NMR and mass spectral data. Further, the newly synthesized compounds (13a–j) were evaluated for their preliminary anticancer activity against a panel of four human cancer cell lines such as MCF-7 (breast cancer), A549 (lung cancer), Colo-205 (colon cancer) & A2780 (ovarian cancer) by using of MTT method, the known chemotherapeutic agent as etoposide used as positive control. Most of the tested compounds were displayed good to moderate activities on all cell lines. The IC50 values showed compound ranges from 0.01 ± 0.009 µM to 8.41 ± 5.48 µM. Where positive control showed values range from 3.34 ± 0.152 µM to 0.17 ± 0.034 µM. Among them, compound 13a, 13b, 13c, 13d, 13e and 13f were showed more potent activity than etoposide. Predominantly, The compound 13a showed potent anticancer activity against MCF-7, A549, Colo-205, and A2780 cancer cell lines with IC50 values of 0.02 ± 0.007 µM, 0.01 ± 0.009 µM, 0.13 ± 0.052 µM, and 0.11 ± 0.083 µM.

Discovery of novel Macrocyclic small molecules Based on 2-Amino-4-thiazolylpyridineas selective EGFR inhibitors with high Blood-Brain barrier penetration for the treatment of glioblastoma

Because epidermal growth factor receptor (EGFR) is the most commonly mutated oncogene in glioblastoma (GBM), the development of EGFR inhibitors has become a promising direction for the treatment of GBM. However, due to factors such as limited blood–brain barrier (BBB) permeability and pathway compensation mechanisms, current EGFR inhibitors targeting GBM are not satisfactory. In the previous study, we obtained compound 10c with strong anti-cell proliferation activity. Since macrocyclization can effectively change the physical and chemical properties of molecules, and optimize their selectivity. Therefore, a series of 2-amino-4-thiazolyl pyridine scaffold macrocyclic derivatives were designed and synthesized using compound 10c as the lead compound in this study. Compound 3a, which inhibited the growth of glioblastoma cell lines U87MG and U87-EGFRVIII, had average IC50 values of 4.69 µM and 4.98 µM, respectively. Compound 3a was highly selective to 9 kinases in the ErbB family, including ErbB2 and ErbB4. In addition, compound 3a demonstrated good blood–brain barrier permeability in mice, the blood–brain concentration of the drug remained above 20 % within 5–60 min following intravenous administration in mice. In conclusion, compound 3a is a promising candidate for novel EGFR inhibitors targeting GBM.

Synthesis, Antimicrobial - Cytotoxic Evaluation, and Molecular Docking Studies of Quinolin-2-one Hydrazones Containing Nitrophenyl or Isonicotinoyl/Nicotinoyl Moiety.

By applying the hybrid molecular strategy, in this study, we reported the synthesis of fifteen quinolin-2-one hydrazones containing nitrophenyl or nicotinonyl/isonicotinoyl moiety, followed by in vitro and in silico evaluations of their potential antimicrobial and anticancer activities. In vitro antimicrobial evaluation of the target compounds on seven pathogenic strains, applying the broth microdilution method, revealed that compound 4a demonstrated the most potential antifungal activity against C. albicans (MIC 512 μg mL-1) and C. krusei (MIC 128 μg mL-1). In vitro cytotoxic evaluation of the target compounds on three human cancer cell lines, employing the MTT method, suggested that compound 5c exhibited the most potential cytotoxicities against HepG2 (IC50 10.19 μM), A549 (IC50 20.43 μM), and MDA-MB-231 (IC50 16.82 μM) cells. Additionally, molecular docking studies were performed to investigate the binding characteristics of compounds 4a and 5c with fungal lanosterol 14α-demethylase and human topoisomerase I-II, respectively, thereby contributing to the elucidation of their in vitro antifungal and cytotoxic properties. Furthermore, compounds 4a and 5c, via SwissADME prediction, could exhibit favorable physicochemical and pharmacokinetic properties. In conclusion, this study provides valuable insights into the potential of quinolin-2-one hydrazones as promising candidates for the development of novel antimicrobial and anticancer agents in the future.

New Acetophenone Scaffolds: Synthesis, Antifungal Activities, Biocompatibility, Molecular Docking, ADMET Analysis, and Dynamic Simulations

In this work, the chemical reactivity of 2-cyano-N'-(1-phenylethylidene)acetohydrazide (3) towards different aldehydes is utilized to synthesize binary and fused heterocyclic compounds, including arylidenes 6, 7, 12, 13, 14, 18a-c, 19a,b, 20, chromone 23, and chromene derivatives 24, 26a-c, 29, and 30. The capability of newly synthesized compounds to inhibit fungal growth of Aspergillus niger ATCC 16404, A. flavus ATCC 9643, Penicillium chrysogenum ATCC 10106, and Rhizopus oryazae ATCC 96382 are assessed. It is observed that compound 29 had strong antifungal activity against all fungi with MFIC values varying from 250 to 1000 μg/ml, while compound 18a demonstrated potent antifungal effect against A. niger and A. flavus. In addition, it is found that compound 29 was cytotoxic to Vero cells at doses of 1000-500 μg/ml; however, no discernible variation was observed between the concentrations of 250-31.25 μg/ml. Moreover, the interactions between the promising compounds 18a, 19b, and 29 and antifungal target proteins are assessed using molecular docking. The results of the docking simulations demonstrated that these compounds demonstrated optimal binding energies and effectively engaged with the active sites of FDC1 protein in A. niger, UDP-N-acetylglucosamine in A. fumigatus, Adenosine 5′-phosphosulfate kinase in P. chrysogenum, and protease in Rhizopus oryazae. These interactions involved various types of molecular interactions, indicating that these compounds have the ability to impede enzymes and exhibit strong antimicrobial effects. Furthermore, the in-silico ADMET profiles of compounds 18a, 19b, and 29 reveal that they adhere to the Lipinski rules, suggesting favorable physicochemical properties. Also, MD simulations revealed stable complexes of 29 with anti-fungal receptors including fdc1, UDP-N-acetylglucosamine, APS kinase, and protease with RMSD (0.1-0.8, 0.19-0.25, 0.20-0.30, and 0.20-0.35 nm), RMSF (0.1-0.8 nm), SASA (140-155, 130-140, 135-145, and 120-130 nm2), and Rg (1.90-2.00, 1.80-1.90, 2.40-2.50, and 2.10-2.20 nm) respectively. Our results provide potential and promising compounds for fungal infection diseases.

A multi-computational and crystallographic investigation for the antibiotic mechanism of two 2,4-bis(4-methoxyphenamino)pyrimidines

2,4-bis(4-methoxyphenamino)pyrimidines are effective anti-bacterial against various bacteria. The compounds 1a and 1b displayed IC50 values of 3µM and 6.1µM, respectively, against Salmonella Typhimurium. The research aims to comprehensively understand the mechanisms of action of these compounds against bacteria using a diverse array of experimental and computational techniques. The findings from the single-crystal X-ray crystallographic investigation reveal several key insights. First, compounds 1a and 1b adopt distinct conformations of the same structure. Second, the amine-pyrimidine resonance is favored over the amine-methoxy aryl resonance. Third, H⸱⸱⸱H, O⸱⸱⸱H, and N⸱⸱⸱H interactions are the primary driver of molecular assembly. Lastly, Van der Waals and hydrophobic interactions significantly influence the crystal architecture and are conformation-dependent. Computational results suggest that, depending upon the molecular volume, both compounds can inhibit SseF with a marginal difference by stable binding with the same conformer observed in the solid state of 1a through hydrophobic interactions due to the presence of electron-rich phenyl rings. The compound 1b exhibited greater structural variability in the binding site compared to 1a, leading to lower stability. Moreover, the higher molecular volume of 1b, attributed to the methyl group, results in its comparatively lesser fitting in the SseF pore compared to 1a.

Design, Synthesis, Biological Evaluation, and In Silico Study of N‐(Pyridin‐2/3‐yl)alkanamide Derivatives as Quorum Sensing Inhibitors Against Pseudomonas aeruginosa

AbstractThe effectiveness of treating bacterial infections is seriously jeopardized by the emergence of bacterial resistance to chemical therapy. The development of biofilm in bacteria is one of the main causes of resistance to antimicrobial drugs. By developing new antibiofilm medications, quorum sensing (QS) inhibitor was developed as an alternate therapy. QS inhibition, which focuses on the QS signaling pathway, obstructs cell–cell communication. The aim of this work is to develop newer QS inhibitors against Pseudomonas aeruginosa. N‐(Pyridin‐2/3‐yl)alkanamide derivatives were designed as QS inhibitors, and these designed molecules were synthesized. QS inhibitor activity was evaluated for the synthesized compounds (3a–l, 4a–h). The highest QS inhibitor activities for compounds 3k, 4a, and 4c were 11.66 ± 0.11, 14.66 ± 0.15, and 10.66 ± 0.05 mm, respectively. Subsequent molecular docking analyses exhibited moderate to good binding affinity values between −7.1 and −9.3 kcal/mol. Using the in silico method, the physicochemical characteristics of these prepared compounds were examined. Additionally, molecular dynamic simulation was employed to gain a deeper comprehension of stability of the protein and ligand complexes of compounds 3k, 4a, and 4c. The overall findings of the study indicated that N‐(pyridin‐2/3‐yl)alkanamide derivatives might be significant for the development of newer QS inhibitors.

Tuning the photophysical and NLO properties of β-diketonates derived from coumarin-triphenylamine-chalcones: effect of the BF2 group.

Herein the synthesis of three difluoroboron β-diketonate complexes (7a-c) and one chalcone (7d) with coumarin and triphenylamine fragments is described. The effect of the inclusion of the difluoroboron (BF2) group and a phenyl linker on the photophysical properties, intramolecular charge transfer (ICT) and nonlinear optical (NLO) properties was studied. These dyes exhibited excellent ICT properties due to their A-π-D and D-π-A-π-D type push-pull configuration. Thus, all compounds presented a strong solvatochromism, given the absorption and emission maxima shifted to red because of the increase in the polarity of the medium. In addition to this, 7a-d showed the formation of a twisted intramolecular charge transfer (TICT) state, which quenched fluorescence in polar solvents. Compounds 7a, 7b and 7d exhibited aggregation-induced emission (AIE) in MeCN/H2O mixtures, while 7c did not have this behavior. In addition, all compounds showed emission in the solid state. Using DFT and TD-DFT calculations, the molecular geometries of the ground state S0 and the first excited state S1 were elucidated, which confirmed the formation of a TICT state. Furthermore, the theoretical and experimental absorption electronic transitions were correlated by testing different functionals: B3LYP, CAM-B3LYP, PBE0, wB97XD, HSEH1PBE and M062X. Frontier molecular orbitals (FOMs) and molecular electrostatic potentials (MEPs) supported the ICT from the donor to the acceptor group. The global reactivity descriptors were studied and the NLO properties were predicted by calculating first (βtot) and second-order (γave) hyperpolarizabilities, revealing that 7a-d would present promising NLO behavior.

New quinoxaline-oxadiazole hybrids as tubulin inhibitors: Synthesis, cytotoxicity, and molecular dynamics simulations

This study describes the synthesis and biological evaluation of a series of novel quinoxaline-oxadiazole hybrid compounds. These compounds were designed to enhance anticancer activity through the incorporation of specific pharmacophoric groups. Structural characterization using NMR and HRMS spectroscopy confirmed the successful synthesis of the hybrids. Cytotoxicity assays revealed that several compounds exhibited significant activity against various cancer cell lines. Compounds 8a and 8f demonstrated potent activity against A549 cells, while 8a, 8b, and 8c were effective against HaCaT cells. Additionally, compounds 8i and 8a showed activity against HepG2 cells. Molecular docking and dynamics simulations suggested that compounds 8c and 8d bind strongly to the tubulin protein, a target for anticancer drugs. These compounds exhibited binding affinities comparable to known anticancer compounds. The results of this study highlight the potential of quinoxaline-oxadiazole hybrids, especially those with halogen substitutions, as promising candidates for the development of novel anticancer therapeutics.

Chlorine containing tetrahydropyrimidines: Synthesis, characterization, anticancer activity and mechanism of action

The aim of the presented research was to explore anticancer potential of eleven newly synthesized tetrahydropyrimidine derivatives. The compounds were synthesized via Biginelli multicomponent one-pot reaction using different derivatives of vanillin, ethyl 4-chloroacetoacetate and (N-methyl)urea. The cytotoxic effects of the compounds were examined on three human malignant cell lines (HeLa, K562, and MCF7), and normal lung fibroblasts MRC-5. The mechanisms of anticancer activity were examined for two compounds 4a and 4b which showed the strongest and selective cytotoxicity against chronic myelogenous leukaemia K562 cells (IC50 = 1.76 ± 0.09, and.1.66 ± 0.05, respectively). The changes of matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 9 (MMP9), and vascular endothelial growth factor A (VEGFA) were investigated in the K562 cell line, as well as oncomiRNA miR-10b, miR-23a described to have both features, depending on a specific type of malignancy, and miR-34a with mostly described as a tumour suppressor.

Synthesis, biological evaluation, docking and molecular dynamics studies of Biginelli-type tetrahydropyrimidine analogues: Antimicrobial, cytotoxicity and antioxidant activity

Tetrahydropyrimidines have a fascinating scaffold that has garnered substantial attention from pharmacists and medicinal chemists. They are heterocyclic compounds used in anti-cancer, anti-microbial, and antioxidants therapies. Herein, a group of tetrahydropyrimidines were provided by using urea, α-ketoacid/β-ketoester, and appropriate aromatic aldehydes. Then, the antioxidant properties of the derivatives were investigated by the DPPH assay. Besides, the cytotoxicity activity of derivatives was evaluated on two MCF-7 and HepG-2 cell lines. The anti-microbial activity of derivatives was also assessed on two positive gram strains, two negative gram strains, and a fungal strain. Derivatives 4a and 4e showed the strongest antioxidant properties, with IC50s of 0.83 and 0.07 mg/mL, respectively. Compounds 4a and 4d were the most potent compounds, with IC50s of 15.81 and 12.34 µM, respectively, on both cancer cell lines. Furthermore, compounds 4b, 4j, and 4i showed the highest anti-microbial activity on S. aureus (MIC = 7.31 µM), B. subtilis (MIC = 10.81 µM), and E. coli (MIC = 11.45 µM), P. aeruginosa (MIC = 8.12 µM), and C. albicans (MIC = 12.03 µM), respectively. Then, the oral bioavailability and pharmacokinetic properties of compounds were predicted. Moreover, the most possible sites of the molecules that are metabolized by the main cytochromes were estimated. Then, the in silico cardiotoxicity and Cyto-safe properties of the compounds were studied. Finally, to determine the stability of the analogues in the Eg5 active site, docking and molecular dynamics simulations were performed.

Synthesis, characterization, and evaluation of pyrimidinone-linked thiazoles: DFT analysis, molecular docking, corrosion inhibition, and bioactivity studies

The paper describes the construction of a new series of pyrimidinone-linked thiazole derivatives through bromination of the initial Biginelli reaction product followed by the Hantzsch thiazole synthesis route. Various analytical techniques, including FT-IR, 1H NMR, 13C NMR, and LCMS analysis, were employed to confirm the formation of the products. The synthesized compounds were primarily evaluated for their antibacterial activity, with a specific focus on their IC50 values. Compound 4c demonstrated the most potent efficacy, displaying MIC and MBC values that varied from 0.23 to 0.71 mg/mL and 0.46–0.95 mg/mL, respectively. The anti-inflammatory potential was also observed in analogs 4a and 4c with marked activity in the 33.2–82.9 μM concentration range. Moreover, compounds 4a, and 4c demonstrated strong antioxidant effects, as reflected by their excellent IC50 values of 38.6–43.5 μM respectively. DFT investigation showed that B. cereus was more susceptible, and E. coli was more resistant, with chloro-substituted compounds exhibiting potential reactivity. Some molecules with chloro-substituents showed promising results in density functional theory when compared to other substituents. In addition, the molecules underwent a corrosion study and demonstrated a high level of inhibition efficiency (4c) in comparison to other molecules. Further in silico studies of the synthesized thiazoles confirmed the good interactions with the target.

Pyrrolidine derivatives as α-amylase and α-glucosidase inhibitors: Design, synthesis, structure-activity relationship (SAR), docking studies and HSA binding

In our pursuit of developing effective inhibitors for the enzymes α-amylase and α-glucosidase, which play a crucial role in carbohydrate metabolism related to type-2 diabetes, we synthesized compounds featuring a pyrrolidine ring. The synthesis involved coupling N-Boc-proline with various aromatic amines, resulting in the formation of distinct N-Boc proline amides. To investigate the influence of the Boc group on enzyme inhibition, the Boc group was subsequently removed. In vitro, testing against α-amylase and α-glucosidase, with metformin and acarbose as reference standards, revealed that the 4-methoxy analogue 3g showed noteworthy inhibitory activity, with IC50 values of 26.24 and 18.04 μg/mL, respectively. Compounds 3a with an IC50 value of 36.32 μg/mL and 3f with an IC50 value of 27.51 μg/mL displayed significant inhibitory activity against α-amylase and α-glucosidase, respectively. The results of molecular docking studies of the most potent pyrrolidine derivatives 3a and 3g with α-amylase and 3f and 3g with α-glucosidase showed good agreement with experimental data. Moreover, compound 3g showed strong binding interactions with HSA having binding constant values of 7.08 × 105 M−1 and 4.77 × 105 M−1 using UV–visible and fluorescence spectrophotometry, respectively.

Synthesis of New Indazole Analogs of Curcumin as Antioxidant and Anti-inflammatory Candidates: An <i>In Vitro</i> Investigation

The development of analog curcumin compounds by modifying the structure of monocarbonyl into an analog indazole of curcumin (AIC) is recognized to have a great potential. Still, only a few reports have been available. Rarely occurring in nature, indazole molecules are typically created through chemical synthesis. Therefore, this study aimed to synthesize six new AIC compounds with a particular focus on testing in vitro antioxidant activity using the DPPH and FRAP methods, as well as anti-inflammatory activity using the protein denaturation method. The results showed that the compounds formed had high anti-inflammatory activity but low antioxidant activity. All synthesis products produced higher anti-inflammatory activity than standard diclofenac sodium and curcumin compounds. Specifically, compound 3a showed the highest anti-inflammatory activity with an IC50 = 0.548 ± 0.062 μM. Therefore, it was concluded that compound 3a has the potential to be further studied for anti-inflammatory activity.

Naphthyl-functionalized acetamide derivatives: Promising agents for cholinesterase inhibition and antioxidant therapy in Alzheimer’s disease

This study presents the synthesis and characterization of a series of 13 novel acetamides. These were subjected to Ellman’s assay to determine the efficacy of the AChE and BChE inhibitors. Finally, we report their antioxidant activity as an alternative approach for the search for drugs to treat AD. These studies revealed that compounds 1a–1k and 2l–2m were obtained in moderate yield. Four amides (1h, 1j, 1k, and 2l) were selective for one of the enzymes (BChE); thus, those that inhibited BChE were more active than the positive control (galantamine) and showed better IC50 values (3.30–5.03 µM). The theoretical free binding energies calculated by MM-GBSA indicated that all inhibitors were more stable than rivastigmine, and the inhibition mechanisms involved the entire active site: peripheral anionic site, oxyanion hole, acyl-binding pockets, and catalytic site. We examined the cytotoxicity of compounds 1h, 1j, 1k, and 2l in human dermal cells and found that they did not exhibit any toxic effects under the tested conditions. Additionally, these compounds, which also inhibited BChE, displayed mixed inhibition and did not exhibit hemolytic effects on human erythrocytes. Furthermore, the ABTS and DPPH assays indicated that, although none of the compounds showed activity in the DPPH assay, the EC50 values for radical trapping by the ABTS method showed that compounds 1a, 1d, 1e, and 1g had EC50 values lower than 10 µg/mL, indicating their strong radical scavenging capacity. We also report the crystal structures of compounds 1c, 1d, 1f, and 1g, which are found in monoclinic crystal systems.

Synthesis of new phenothiazine derivatives: Molecular docking, assessment of cytotoxic activity and oxidant-antioxidant properties on PCS-201-012, HT-29, and SH-SY5Y cell lines.

Phenothiazine (PTZ) derivatives have been acknowledged as versatile compounds with significant implications across various areas of medicine, particularly, in cancer research. The cytotoxic effects of synthesized compounds on both normal and cancerous cells, along with their oxidant-antioxidant properties, are pivotal factors in cancer treatment strategies. In the current study, eight new PTZ derivatives were synthesized and the compounds' cytotoxic activities were assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay while the oxidant-antioxidant properties were evaluated by oxidative stress index (OSI) calculation in SH-SY5Y (a human neuroblastoma cell line), HT-29 (a human colorectal adenocarcinoma cell line), and PCS-201-012 (a human primary dermal fibroblast cell line) cells. Consequently, the half-maximal inhibitory concentration (IC50) values of compound 3a were determined to be 218.72, 202.85, and 227.86 μM while the IC50 values of compound 3b were defined to be 227.42, 199.27, and 250.11 μM in PCS-201-012, HT-29, and SH-SY5Y cells, respectively. Additionally, it was determined that the synthesized compounds demonstrated the lowest OSI in PCS-201-012 cells as compared to the other cell lines.

Curcuminoid Chalcones: Synthesis and Biological Activity against the Human Colon Carcinoma (Caco-2) Cell Line.

There are many current scientific reports on the synthesis of various derivatives modelled on the structure of known small-molecular and natural bioactive compounds. Curcuminoid chalcones are an innovative class of compounds with significant therapeutic potential against various diseases and they perfectly fit into the current trends in the search for new biologically active substances. The aim of this study was to design and synthesise a series of curcuminoid chalcones. The objective of this scientific paper was to synthesise twelve curcuminoid chalcones and confirm their structures using spectral methods. Additionally, the biological activity of three of the synthesised compounds was evaluated using various assays, and their anticancer properties and toxicity were studied. The proposed derivatives were obtained via the Claisen-Schmidt reaction of selected acetophenones and aldehydes in various conditions using both classical methods: the solutions and solvent-free microwave (MW) or ultrasound (US) variants. The most optimal synthetic method for the selected curcuminoid chalcones was the classical Claisen-Schmidt condensation in an alkaline (NaOH) medium. Spectral methods were used to confirm the structures of the compounds. The resazurin reduction assay, caspase-3 activity assay, and RT-qPCR method were performed, followed by measurements of the intracellular reactive oxygen species (ROS) level and the lactate dehydrogenase (LDH) release level. Twelve designed curcuminoid chalcones were successfully synthesized and structurally confirmed by NMR, MS, and IR spectroscopy. Examination of the anticancer activity was carried out for the three most interesting chalcone products. The results suggested that compound 3a increased the metabolism and/or proliferation of the human colon carcinoma (Caco-2) cell line, while compounds 3b and 3f showed significant toxicity against the Caco-2 cell line. Overall, the preliminary results suggested that compound 3b exhibited the most favourable anticancer activity.

Rational design, synthesis, computational studies and biological evaluation of new diazepanone derivatives: Crystal structure of 2,7-bis(4-chlorophenyl)-1,3-dimethyl-1,4-diazepan-5-one

Structural and biological evaluation of newly designed and synthesized diazepanone derivatives (3a-c) with modified functionalities is reported in this paper, as liponucleoside class of antibiotics possessing 1,4-diazepanone as core moiety are under investigation since last decade to improvise their drug action. FT-IR, HR-ESI-MS, 1H NMR and 13C NMR spectral studies are used for the structural characterization of synthesized compounds (3a-c). 1H NMR spectral data reveal that the diazepanone ring exhibits chair conformation in solution state. The solid state geometry for compound 3a acquired by SC-XRD study also in favour of chair conformation of the diazepanone ring with equatorial orientation of all the substituents. Comparison of experimental bond parameters with theoretical results attained by DFT studies using B3LYP/6–311G++ (d,p) basis set are in good agreement. Molecular electrostatic potential surface (MEPS) and HOMO-LUMO energies are used to elucidate the topology and physicochemical parameters of 3a. Nature of crystal packing is ascertained by Hirshfeld surface and its delineated 2D-Fingerprint plot in addition with the SC-XRD evidences. Antibacterial evaluation of (3a-c) against tested bacterial strains reveals that the compounds have remarkable antibacterial potencies compared to tested standard drug. Among the compounds 3a-c, the compound 3c with fluoro-substitution on the phenyl ring shows highest activity.

Crystal structures of seven mixed-valence gold compounds of the form [(R 1 R 2 R 3PE)2AuI]+[AuIII X 4]- (R = tert-butyl or isopropyl, E = S or Se, and X = Cl or Br).

During our studies of the oxidation of gold(I) complexes of tri-alkyl-phosphane chalcogenides, general formula R 1 R 2 R 3PEAuX, (R = tert-butyl or isopropyl, E = S or Se, X = Cl or Br) with PhICl2 or elemental bromine, we have isolated a set of seven mixed-valence by-products, the bis-(tri-alkyl-phosphane chalcogenido)gold(I) tetra-halogenidoaurates(III) [(R 1 R 2 R 3PE)2Au]+[AuX 4]-. These corres-pond to the addition of one halogen atom per gold atom of the AuI precursor. Com-pound 1, bis-(triiso-propyl-phosphane sulfide)-gold(I) tetra-chlorido-aur-ate(III), [Au(C9H21PS)2][AuCl4] or [( i Pr3PS)2Au][AuCl4], crystallizes in space group P21/n with Z = 4; the gold(I) atoms of the two cations lie on twofold rotation axes, and the gold(III) atoms of the two anions lie on inversion centres. Compound 2, bis-(tert-butyl-diiso-propyl-phosphane sulfide)-gold(I) tetra-chlorido-aurate(III), [Au(C10H23PS)2][AuCl4] or [( t Bu i Pr2PS)2Au][AuCl4], crystallizes in space group P1 with Z = 4; the asymmetric unit contains two cations and two anions with no imposed symmetry. A least-squares fit of the two cations gave an r.m.s. deviation of 0.19 Å. Compound 3, bis-(tri-tert-butyl-phosphane sulfide)-gold(I) tetra-chlorido-aurate(III), [Au(C12H27PS)2][AuCl4] or [( t Bu3PS)2Au][AuCl4], crystallizes in space group P1 with Z = 1; both gold atoms lie on inversion centres. Compound 4a, bis-(tert-butyl-diiso-propyl-phosphane sulfide)-gold(I) tetra-bromi-doaurate(III), [Au(C10H23PS)2][AuBr4] or [( t Bu i Pr2PS)2Au][AuBr4], crystallizes in space group P21/c with Z = 4; the cation lies on a general position, whereas the gold(III) atoms of the two anions lie on inversion centres. Compound 4b, bis-(tert-butyl-diiso-propyl-phosphane selenide)gold(I) tetra-bromido-aurate(III), [Au(C10H23PSe)2][AuBr4] or [( t Bu i Pr2PSe)2Au][AuBr4], is isotypic with 4a. Compound 5a, bis-(tri-tert-butyl-phosphane sulfide)-gold(I) tetra-bromido-aurate(III), [Au(C12H27PS)2][AuBr4] or [( t Bu3PS)2Au][AuBr4], is isotypic with compound 4a. Compound 5a, bis-(tri-tert-butyl-phosphane sulfide)-gold(I) tetra-bromido-aurate(III), [Au(C12H27PS)2][AuBr4] or [( t Bu3PS)2Au][AuBr4], crystallizes in space group P1 with Z = 1; both gold atoms lie on inversion centres. Compound 5b, bis-(tri-tert-butyl-phosphane selenide)gold(I) tetra-bromido-aurate(III), [Au(C12H27PSe)2][AuBr4] or [( t Bu3PSe)2Au][AuBr4], is isotypic with 5a. All AuI atoms are linearly coordinated and all AuIII atoms exhibit a square-planar coordination environment. The ligands at the AuI atoms are anti-periplanar to each other across the S⋯S vectors. There are several short intra-molecular H⋯Au and H⋯E contacts. Average bond lengths (Å) are: P-S = 2.0322, P-Se = 2.1933, S-Au = 2.2915, and Se-Au = 2.4037. The complex three-dimensional packing of 1 involves two short C-Hmethine⋯Cl contacts (and some slightly longer contacts). For 2, four C-Hmethine⋯Cl inter-actions combine to produce zigzag chains of residues parallel to the c axis. Additionally, an S⋯Cl contact is observed that might qualify as a 'chalcogen bond'. The packing of 3 is three-dimensional, but can be broken down into two layer structures, each involving an S⋯Cl and an H⋯Cl contact. For the bromido derivatives 4a/b and 5a/b, loose associations of the anions form part of the packing patterns. For all four compounds, these combine with an E⋯Br contact to form layers parallel to the ab plane.

Design, Synthesis, Molecular Docking Studies and Antimicrobial Profiling of 7-Nitroquinazoline Derivatives against Staphylococcus aureus (MRSA)

The alarming increase in antibiotic resistance contributes to the growing risk posed by Staphylococcus aureus (MRSA) in the worldwide healthcare sector. To address the challenge, this study designed, synthesized and evaluated novel quinazoline derivatives, specifically 7-nitroquinazolines, for their antimicrobial efficacy against Staphylococcus aureus (MRSA). Molecular docking studies revealed that compounds 8a and 8b exhibited superior binding affinity to the protein 1T2W, with binding energies of -9.6 kcal/mol and -8.8 kcal/mol, surpassing ciprofloxacin. The derivatives demonstrated favourable pharmacokinetic properties, including moderate lipophilicity, optimal polarity and good water solubility. Compound 8b shows a potent minimum inhibitory concentration (MIC) of 31.1 µg/mL against S. aureus (MRSA ATCC6538), outperforming ciprofloxacin. These findings indicate that compound 8b and related derivatives hold promise as novel therapeutic agents against MRSA, warranting further research to combat the growing issue of antibiotic resistance.

Synthesis of the double spiked µ5-sulfide pentanuclear clusters using thermic reactions of Ru3-mercaptopyridine complexes

The treatment of [Ru3(CO)10(μ-dppm)] with 6-methyl-2-mercaptopyridine (1) or 5-trifluoromethyl-2-mercaptopyridine (2) in refluxing THF for 10 h results in the formation of μ5 sulfide-capped pentanuclear clusters [Ru5(CO)11(μ-H)(μ5-S){μ-κ2N,C-NC5H3(R)})(μ-κ2P2-dppm)2] (R = CH3, 3a, 3a'; R=CF3, 3b,3b') respectively. These compounds exhibit unique structural features, with a μ5-S capped binding trinuclear and dinuclear fragments. The mercaptopyridine ligands undergo S-C bond scission, forming an orthometalated pyridine ligand coordinated to a Ru-Ru bond with a concomitant μ-hydride ligand formation. The structures also feature two dppm ligands, one in the Ru-Ru, which bears the μ-H, and the other bridging the Ru-Ru bond with the orthometallated pyridine. In solution, linkage isomers were observed; they differ in the coordination position of the orthometallated pyridine bonded to the same Ru-Ru bond. A single-crystal X-ray diffraction study confirmed the molecular structures of compounds 3a and 3b. NMR, IR, and HRMS were also carried out.