Compounds 3f Research Articles

Exploring the synthesis, molecular structure and biological activities of novel Bis-Schiff base derivatives: A combined theoretical and experimental approach

A library of six novel bis-Schiff base derivatives (2a-f) were synthesized, characterized through modern spectroscopic techniques and screened for their α-glucosidase and α-amylase inhibitory activities (in vitro). In the series, compound 2a (IC50 = 5.64 ± 2.22 µM) and 2f (IC50 = 22.78 ± 2.37 µM) were the most potent α-amylase inhibitors while the remaining four compounds showed significant to less activity. In case of α-glucosidase inhibition, four compounds 2e (IC50 = 2.83 ± 0.18 µM), 2c (IC50 = 7.03 ± 0.15 µM), 2f (IC50 = 9.99 ± 0.20 µM), and 2d (IC50 = 14.68 ± 0.21 µM) displayed excellent inhibitory activity while two compounds showed good inhibitory activity, comparing with the standard acarbose drug. The DFT assay was used to measure the FMO of the synthesized molecules, which indicated their stability, bioactivity and charge transfer. The MEP analysis revealed the distribution of electrostatic potential on the molecular surface of 2a-f, which is helpful for understanding reactivity and interactions. The AIM study showed low hydrogen bond energy and non-covalent interactions. This implies that these molecules may have weak hydrogen bonding and non-covalent interactions, which could affect their chemical behavior. The molecular docking study has provided valuable insights into the interactions between the synthesized derivatives of 2,4-dihydroxyacetophenone with α-glucosidase and α-amylase proteins. The results not only shed light on the binding affinity and key interaction sites but also offer potential avenues for the design of novel drug candidates to control postprandial glucose level in diabetic patients.

New 1,2,4-triazol-3-one derivatives with 4-fluorobenzene: Synthesis, characterization, DFT, antimicrobial-antiproliferative activities and molecular docking study

(E)-5-(4-fluorobenzyl)-4-((2-fluorobenzylidene)amino)-2,4-dihydro-3H-1,2,4-triazol-3-one (2F), (E)-5-(4-fluorobenzyl)-4-((3-fluorobenzylidene)amino)-2,4-dihydro-3H-1,2,4-triazol-3-one (3F) and (E)-5-(4-fluorobenzyl)-4-((4-fluorobenzylidene)amino)-2,4-dihydro-3H-1,2,4-triazol-3-one (4F) were synthesized and confirmed by FT-IR and 1H, 13CNMR spectroscopic methods. Theoretical study for compounds 2F-4F was performed by using DFT/B3LYP/6–311++G(d,p) method. The optimized structures, IR and NMR data, the frontier molecular orbitals (HOMO and LUMO) and the molecular electrostatic potential (MEP) map of compounds 2F-4F were calculated. In addition, newly synthesized compounds (2F-4F) were tested against eight bacteria and two yeast strains and their the minimum inhibitory concentration (MIC) values were determined. The MTT test was performed to measure the antiproliferative effects of the 2F-4F compounds on cell proliferation (NCI-60 screening methodology). Molecular docking calculations were performed to investigate ligand-protein interactions between the compounds (2F and 3F) and the Epidermal Growth Factor Receptor (EGFR) and the Vascular Endothelial Growth Factor Receptor (VEGFR1).

1,2,3-Triazolyl Phenylhydrazones as Antioxidant Agents: An Ultrasound Promoted Catalyst-Free Synthesis and Molecular Docking Study

An efficient, ultrasound assisted catalyst-free, green protocol has been developed for the synthesis of 1,2,3-triazolyl phenylhydrazone derivatives under environmentally benign condition. The antioxidant activity for all the synthesized derivatives were evaluated in vitro by using 1,1-diphenylpicrylhydrazyl (DPPH) radical scavenging method. The compounds 6a, 6e, 6f, and 6i were shows an excellent antioxidant activity than the standard drug butylated hydroxy toluene with IC50 values in the range 12.03 ± 0.11–14.07 ± 0.31 µg/mL. Molecular docking study was also performed to elaborate their possible interactions with Myeloperoxidase enzyme. Furthermore, in silico ADME properties for all the compounds were also studied.

Synthesis, docking, MD simulation, ADMET, drug likeness, and DFT studies of novel furo[2,3-b]indol-3a-ol as promising Cyclin-dependent kinase 2 inhibitors

A new series of furo[2,3-b]indol-3a-ol derivatives was synthesized to investigate their potential as inhibitors of the Cyclin-dependent kinase 2 (CDK2) enzyme. CDK2 is a serine/threonine protein kinase belonging to a family of kinases involved in the control of the cell cycle. Based on results from clinical studies, it has been shown that overexpression of CDK2 may play a role in the development of cancer. In order to discover highly effective derivatives, a process of in silico screening was carried out. The obtained results revealed that compound 3f. had excellent binding energies. In this study, in silico screening was used to investigate protein–ligand interactions and assess the stability of the most favorable conformation. The methods utilized included molecular docking, density functional theory (DFT) calculations using the B3LYP/6-31++G(d,p) basis set in the gas phase, molecular dynamic (MD) simulation, as well as the evaluation of drug-likeness scores. The pharmacokinetic and drug-likeness properties of the novel furo[2,3-b]indol-3a-ol derivatives suggest that these compounds have the potential to be considered viable candidates for future development as anticancer drugs.

Dual COX-2 and 15-LOX inhibition study of novel 4-arylidine-2-mercapto-1-phenyl-1H-imidazolidin-5(4H)-ones: Design, synthesis, docking, and anti-inflammatory activity.

Novel arylidene-5(4H)-imidazolone derivatives 4a-r were designed and evaluated as multidrug-directed ligands, that is, inflammatory, proinflammatory mediators, and reactive oxygen species (ROS) inhibitors. All of the tested compounds showed cyclooxygenase (COX)-1 inhibitory effect more than celecoxib and less than indomethacin and also demonstrated an improved inhibitory activity against 15-lipoxygenase (15-LOX). Compounds 4f, 4l, and 4p exhibited COX-2 selectivity comparable to that of celecoxib, while 4k was the most selective COX-2 inhibitor. Interestingly, the screened results showed that compound 4k exhibited a superior inhibition effect against 15-LOX and was found to be the most selective COX-2 inhibitor over celecoxib, whereas compound 4f showed promising COX-2 and 15-LOX inhibitory activities besides its inhibitory effect against ROS production and its lowering effect of both tumor necrosis factor-α and interleukin-6 levels by ∼80%. Moreover, compound 4f attenuated the lipopolysaccharide-mediated increase in NF-κB activation in RAW 264.7 macrophages. The preferred binding affinity of these molecules was confirmed by docking studies. We conclude that arylidene-5(4H)-imidazolone scaffolds provide promising hits for developing new synthons with anti-inflammatory and antioxidant activities.

Metal Catalyst-Free One-pot Synthesis of Carboxamide Derivatives via Ugi-4CC Reaction and Its Anti-tubercular Study

Background: A new series of ten composites with sulphur based carboxylic acid and benzylamine were synthesized by Ugi 4-components reaction (Ugi-4CR) and screened for antituberculosis activity against the Mycobacterium tuberculosis H37Rv strain. Objective: Target compounds were isolated, purified, identified, and characterized by MS, FT-IR, 1HNMR, APT, and 13C-NMR then the antituberculosis activity was examined by Microplate Alamar Blue Assay (MABA) method. Methods: This study was based on the articulation of carboxamide linkage bearing S-linkage in the core unit by reacting four different units, i.e., 2-(pyrimidin-2-ylthio)acetic acid, aromatic aldehyde, benzylamine and tertiary butyl isocyanide at RT in an atom economy route of synthesis. The desired product (5a- 5j) was synthesized via one-pot and Metal-free conditions. Results: Compounds (5a-5j) synthesized in good yields and compared to MIC values of Isoniazid 0.05 (μg/mL), Rifampicin 0.1 (μm/mL), and Ethambutol 1.56 (μg/mL) as a positive control. Conclusion: Synthesized compounds give excellent yield. Among the ten derivatives, compound 5f has comparable antituberculosis activity.

Discovery of new thymol-3,4-disubstituted thiazole hybrids as dual COX-2/5-LOX inhibitors with in vivo proof

New thymol–3,4-disubstitutedthiazole hybrids were synthesised as dual COX-2/5-LOX inhibitors. Compounds 6b, 6d, 6e, and 6f displayed in vitro inhibitory activity against COX-2 (IC50= 0.037, 0.042, 0.046, and 0.039 µM) nearly equal to celecoxib (IC50= 0.045 µM). 6b, 6d, and 6f showed SI (379, 341, and 374, respectively) higher than that of celecoxib (327). 6a–l elicited in vitro 5-LOX inhibitory activity higher than quercetin. 6a–f, 6i–l, 7a, and 7c possessed in vivo inhibition of formalin induced paw edoema higher than celecoxib. 6a, 6b, 6f, 6h–l, and 7b showed gastrointestinal safety profile as celecoxib and diclofenac sodium in the population of fasted rats. Induced fit docking and molecular dynamics simulation predicted good fitting of 6b and 6f without changing the packing and globularity of the apo protein. In conclusion, 6b and 6f achieved the target goal as multitarget inhibitors of inflammation.

Synthesis of novel [1,2,3]triazolo[4′,5′:3,4]pyrrolo[1,2‐a]thieno[2,3‐d] pyrimidines: Potent EGFR targeting anti‐breast cancer agents

AbstractIn this study, we designed and synthesized several novel fused [1,2,3]triazolo [4′,5′:3,4]pyrrolo[1,2‐a]thieno[2,3‐d]pyrimidine derivatives using in a single [3 + 2] reaction cycloaddition reaction of 3‐(3‐iodoprop‐2‐yn‐1‐yl)thieno[2,3‐d]pyrimidin‐4(3H)‐one (4) followed by C‐C bond coupling with various aryl azides in a PEG‐400 medium. All of the newly synthesized compounds were evaluated in vitro for EGFR kinase inhibitory action as well as anti‐breast cancer activity against MDA‐MB‐231 and MCF‐7 breast cancer cell lines. When compared to the reference molecule, erlotinib, the majority of the compounds demonstrated adequate efficacy. The most promising compounds, 5g and 5i, demonstrated excellent anticancer activity against both cancer cell lines, with IC50 values ranging from 04.17 ± 0.55 to 8.65 ± 0.89 μM, respectively, as well as excellent kinase inhibitory activities (EGFR: IC50 = 0.467 ± 0.063 and 0.412 ± 0.081 μM). The in silico studies of five potent compounds 5f, 5g, 5h, 5i, and 5k were also carried out to identify the interactions against the EGFR receptor and found that the energy calculations were covenant with the obtained IC50 values.

2-Thioxo-3,4-dihydropyrimidine and thiourea endowed with sulfonamide moieties as dual EGFRT790M and VEGFR-2 inhibitors: Design, synthesis, docking, and anticancer evaluations.

The effectiveness of a new series of thiopyrimidine and thiourea containing sulfonamides moieties was tested on HCT-116, MCF-7, HepG2, and A549. HepG2 cell line was the one that all the new derivatives affected the most. The greatest potent compounds against the four HepG2, HCT116, MCF-7, and A549 cell lines were 8f and 8g with IC50 = 4.13, 6.64, 5.74, 6.85 µM and 4.09, 4.36, 4.22, 7.25 µM correspondingly. Compound 8g exhibited higher activity than sorafenib against HCT116 and MCF-7 but exhibited lower activity against HepG2 and A549. Moreover, compounds 8f and 8g exhibited higher activities than erlotinib on HepG2, HCT116, and MCF-7 but demonstrated lower activity on A549. The most potent cytotoxic derivatives 6f, 6g, 8c, 8d, 8e, 8f, and 8g were examined on normal VERO cell lines. Our derivatives have low toxicity on VERO cells with IC50 values ranging from 32.05 to 53.15 μM. Additionally, all compounds were assessed for dual VEGFR-2 and EGFRT790M inhibition effects. Compounds 8f and 8g were the most potent derivatives inhibited VEGFR-2 at IC50 value of 0.88 and 0.90 µM, correspondingly. As well, derivatives 8f and 8g could inhibit EGFRT790M demonstrating strongest effects with IC50 = 0.32 and 0.33 µM sequentially. Additionally, the greatest active derivatives ADMET profile was evaluated in relationship with sorafenib and erlotinib as reference agents. The data attained from docking were greatly related to that achieved from the biological testing.

Design, synthesis, anti-mycobacterial activity, molecular docking and ADME analysis of spiroquinoxaline-1,2,4-oxadiazoles via [3 + 2] cycloaddition reaction under ultrasound irradiation.

The development of anti-tuberculosis (anti-TB) drugs has become a challenging task in medicinal chemistry. This is because Mycobacterium tuberculosis (TB), the pathogen that causes tuberculosis, has an increasing number of drug-resistant strains, and existing medication therapies are not very effective. This resistance significantly demands new anti-TB drug profiles. Here, we present the design and synthesis of a number of hybrid compounds with previously known anti-mycobacterial moieties attached to quinoxaline, quinoline, tetrazole, and 1,2,4-oxadiazole scaffolds. A convenient ultrasound methodology was employed to attain spiroquinoxaline-1,2,4-oxadiazoles via [3 + 2] cycloaddition of quinoxaline Schiff bases and aryl nitrile oxides at room temperature. This approach avoids standard heating and column chromatography while producing high yields and shorter reaction times. The target compounds 3a-p were well-characterized, and their in vitro anti-mycobacterial activity (anti-TB) was evaluated. Among the screened compounds, 3i displayed promising activity against the Mycobacterium tuberculosis cell line H37Rv, with an MIC99 value of 0.78µg/mL. However, three compounds (3f, 3h, and 3o) exhibited potent activity with MIC99 values of 6.25µg/mL. To further understand the binding interactions, the synthesized compounds were docked against the tuberculosis protein 5OEQ using in silico molecular docking. Moreover, the most active compounds were additionally tested for their cytotoxicity against the RAW 264.7 cell line, and the cytotoxicity of compounds 3f, 3h, 3i, and 3o was 27.3, 28.9, 26.4, and 30.2µg/mL, respectively. These results revealed that the compounds 3f, 3h, 3i, and 3o were less harmful to humans. Furthermore, the synthesized compounds were tested for ADME qualities, and the results suggest that this series is useful for producing innovative and potent anti-tubercular medicines in the future.

Design and cytotoxic activity of thiazolidinones via one-pot, three component reaction under microwave and traditional method

Treatment of sulfamethoxazole (SMZ ) (1) with different aromatic aldehydes 2a-f within few minutes (5-8 min) afforded the corresponding Schiff bases 3a-f which were subjected to react with thioglycolic acid (4) under refluxing toluene/dimethlformamide (DMF) in (1:1) ratio for 12-17 h, yielded N-(5-methylisoxazol-3-yl)-4-(4-oxo-2-phenyl-1,3-thiazolidin-3-yl)benzenesulfon- amide derivatives 5a-f. On the other hand, the same products 5a-f were obtained when SMZ (1) was treated with a mixture of the same aromatic aldehydes 2a-f and thioglycolic acid 4 via one-pot, three-component reaction under microwave irradiation. The key advantages of this process were high yields 79-88%, shorter reaction times 6-11 min., easy work-up, and problems associated with toxic solvent use (cost, safety, pollution) were avoided. The structures of newly compounds were elucidated by elemental and spectral analyses. Three compounds 5a, 5b and 5f were tested for cytotoxicity against four human cancer cell lines MCF-7, HePG2, HCT 116 and 116 PC-3. Compound 5b exhibited the most potent cytotoxic properties on HePG2 and PC-3. Furthermore, it showed inhabitory effect against MCF-7 and HCT 116 cells.
 KEY WORDS: Sulfamethoxazole, 4-Thiazolidinones, Schiff bases, Multicomponent reaction, Microwave, Traditional methods and cytotoxicity
 Bull. Chem. Soc. Ethiop. 2024, 38(2), 481-491. 
 DOI: https://dx.doi.org/10.4314/bcse.v38i2.15

Synthesis and characterization of new palladium (II) and silver (I) thiosemicarbazone derived by acenaphthenequinone complexes and their antimicrobial activity

The ability of substituted acenaphthenequinone-thiosemicarbazones to do complexation with Pd(II) and Ag(I) salts was investigated. The obtained Pd(II) 5a-f and Ag(I) 7a-f complexes showed that ligation was occurred during the reaction of two equivalents of the ligands with one equivalent of the metal salts. In case of Pd complexes 5a-f, two moles of HCl were eliminated during complexation process. Whereas direct ligation was occurred during complexation of one mole of AgNO3 and two moles of ligands to form the corresponding cationic-anionic salts 7a-f. IR, NMR, and UV–vis spectra were used to deduce the structure of the formed metal complexes. X-ray structure analysis proved the syn-form of bis(bidentate) structure of Pd complex 5e, as Pd showed a square planar coordination with two sulfur and two nitrogen atoms. The cationic-anionic nature of silver complexes was revealed by molar conductance. UV–visible spectra were also investigated by means of Time-Dependent Density-Functional Theory (TD-DFT) computations. The obtained metal complexes were also investigated asantibacterial and antifungal agents. Compounds 5f, 5e, 7d, and 7f were found to be the most active and effective against the four bacterial strains, with compound 7f having the most potent action. Compound 7f (R = 3-OMe-Ph) showed MIC values of 0.066, 0.018, 0.018, and 0.033 µg/mL against B. subtilis, S. aureus, E. coli, and K. pneumoniae, respectively. For compound 7d (R = Benzyl), the MIC values are found as 0.028, 0.057, 0.028, and 0.028 µg/mL against the same previous bacterial strains. Compounds 5d, 5e, 7c, and 7f demonstrated promising antifungal activity against C. albicans with MIC values of 0.029, 0.023, 0.018, and 0.027 µg/ml, respectively, when compared to the reference fluconazole, which had a MIC value of 0.020 µg/ml. Compound 7f revealed inhibitory activity of E. coli DNA gyrase (IC50 = 210 ± 15 nM, respectively) being 1.2-folds less potent than the reference novobiocin (IC50 = 170 ± 20 nM).

Structure–Activity relationship (SAR) of 18β-glycyrrhetinic acid derivatives on their antitumor activity through the PPARγ receptor and caspase-3 pathway

Licorice is extensively utilized in the food industry, and glycyrrhetinic acid is among the most critical active constituents in licorice. This ingredient has garnered increasing attention in recent years. In a previous study, we identified a new series of Glycyrrhetinic acid derivatives containing piperazine skeleton, using virtual screening techniques based on docking. In this study, we conducted further optimization of the lead compound 4c, with a focus on enhancing the hydrophobic interactions in the binding site to improve agonist efficacy for peroxisome proliferator-activated receptor γ (PPARγ). The obtained compounds were characterized using 1H NMR, 13C NMR, HRMS, and HPLC. Furthermore, these compounds were evaluated strong antitumor activity. Some compounds with potent antitumor activities were tested for their PPARγ agonist activity. Especially, compound 4f showed the most potent antitumor activity with half maximal inhibitory concentration (IC50) values of 2.382 μM against the tested tumor cell lines Siha. Docking simulation was performed to position compound 4f into the PPARγ active site to determine the probable binding conformation. Consequently, we discovered a novel PPARγ agonist 4f that demonstrated high in vitro agonist activity.

Synthesis, anti-browning effect and mechanism research of kojic acid-coumarin derivatives as anti-tyrosinase inhibitors

Thirteen kojic acid-coumarin derivatives were synthesized using the principle of molecular hybridization, and their structures were characterized by 1H NMR, 13C NMR, and HRMS. In vitro enzyme inhibition experiments showed that all newly synthesized derivatives have excellent inhibition of tyrosinase (TYR) activity. As a mixed inhibitor, compound 6f has the strongest activity, with an IC50 value of 0.88 ± 0.10 µM. Multispectral experiments have confirmed that the mode of action of compound 6f on TYR was static quenching. In addition, compound 6f formed a new complex with TYR, which increased the hydrophobicity of the enzyme microenvironment, reduced the content of the α-helix in the enzyme, and changed the secondary structure. The experimental results showed that compound 6f effectively inhibited the browning of lotus root slices and had low cytotoxicity. Therefore, compound 6f is believed to have great development potential as a TYR inhibitor in the food industry.

Synthesis and molecular docking of pyrimidine derivatives as antibacterial agents

In this study, we aimed to synthesise and evaluate the antimicrobial activity of sulphanilamide-condensed pyrimidine derivatives. The compounds were synthesised using a one-pot, three-component reaction. The structures of the synthesised compounds were confirmed using spectroscopic techniques such as FT-IR, 1H NMR, mass spectrometry, and elemental analysis. The antibacterial activity of all the synthesised compounds was tested against Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis), two types of Gram-positive bacteria. The thiamine-pyrophosphate riboswitch E. coli and the purine riboswitch B. subtilis were chosen as targets to determine how compounds bind to them. The molecular docking data showed that compound 6f bound well and had the lowest binding energy in the active site areas of both targets. This was in line with the tests done in vitro. The majority of the compounds have been demonstrated to be antibacterial.

Design and synthesis of quinazolin-4-one derivatives as potential anticancer agents and investigation of their interaction with RecQ helicases

The upregulation of RecQ helicases has been associated with cancer cell survival and resistance to chemotherapy, making them appealing targets for therapeutic intervention. In this study, twenty-nine novel quinazolinone derivatives were designed and synthesized. The anti-proliferative activity of all compounds was evaluated against 60 cancer cell lines at the National Cancer Institute Developmental Therapeutic Program, with six compounds (11f, 11g, 11k, 11n, 11p, and 11q) being promoted to a five-dose screen. Compound 11g demonstrated high cytotoxic activity against all examined cell lines. The compounds were further assayed for Bloom syndrome (BLM) helicase inhibition, where 11g, 11q, and 11u showed moderate activity. These compounds were counter-screened against WRN and RECQ1 helicases, where 11g moderately inhibited both enzymes. An ATP competition assay confirmed that the compounds bound to the ATP site of RecQ helicases, and molecular docking simulations were used to study the binding mode within the active site of BLM, WRN, and RECQ1 helicases. Compound 11g induced apoptosis in both HCT-116 and MDA-MB-231 cell lines, but also caused an G2/M phase cell cycle arrest in HCT-116 cells. This data revealed the potential of 11g as a modulator of cell cycle dynamics and supports its interaction with RecQ helicases. In addition, compound 11g displayed non-significant toxicity against FCH normal colon cells at doses up to 100 µM, which confirming its high safety margin and selectivity on cancer cells. Overall, these findings suggest compound 11g as a potential pan RecQ helicase inhibitor with high anticancer potency and a favorable safety margin and selectivity.

Design, Synthesis, and Evaluation of New 1H-Benzo[d]imidazole Based PqsR Inhibitors as Adjuvant Therapy for Pseudomonas aeruginosa Infections.

Pseudomonas aeruginosa is one of the top priority pathogens that requires immediate attention according to the World Health Organisation (WHO). Due to the alarming shortage of novel antimicrobials, targeting quorum sensing (QS), a bacterial cell to cell signaling system controlling virulence, has emerged as a promising approach as an antibiotic adjuvant therapy. Interference with the pqs system, one of three QS systems in P. aeruginosa, results in reduction of bacterial virulence gene expression and biofilm maturation. Herein, we report a hit to lead process to fine-tune the potency of our previously reported inhibitor 1 (IC50 3.2 μM in P. aeruginosa PAO1-L), which led to the discovery of 2-(4-(3-((6-chloro-1-isopropyl-1H-benzo[d]imidazol-2-yl)amino)-2-hydroxypropoxy)phenyl)acetonitrile (6f) as a potent PqsR antagonist. Compound 6f inhibited the PqsR-controlled PpqsA-lux transcriptional reporter fusion in P. aeruginosa at low submicromolar concentrations. Moreover, 6f showed improved efficacy against P. aeruginosa CF isolates with significant inhibition of pyocyanin, 2-alkyl-4(1H)-quinolones production.

Elucidating the Molecular Determinants of the Binding Modes of a Third-Generation HIV-1 Integrase Strand Transfer Inhibitor: The Importance of Side Chain and Solvent Reorganization.

The first- and second-generation clinically used HIV-1 integrase (IN) strand transfer inhibitors (INSTIs) are key components of antiretroviral therapy (ART), which work by blocking the integration step in the HIV-1 replication cycle that is catalyzed by a nucleoprotein assembly called an intasome. However, resistance to even the latest clinically used INSTIs is beginning to emerge. Developmental third-generation INSTIs, based on naphthyridine scaffolds, are promising candidates to combat drug-resistant viral variants. Among these novel INSTIs, compound 4f exhibits two distinct conformations when binding with intasomes from HIV-1 and the closely related prototype foamy virus (PFV) despite the high structural similarity of their INSTI binding pockets. The molecular mechanism and the key active site residues responsible for these differing binding modes in closely related intasomes remain elusive. To unravel the molecular determinants governing the two distinct binding modes, we applied a novel molecular dynamics-based free energy method that utilizes alchemical pathways to overcome the sampling challenges associated with transitioning between the two bound conformations of ligand 4f within the crowded environments of the INSTI binding pockets in these intasomes. The calculated conformational free energies successfully recapitulate the experimentally observed binding mode preferences in the two viral intasomes. Analysis of the simulated structures suggests that the observed binding mode preferences are caused by amino acid residue differences in both the front and the central catalytic sub-pocket of the INSTI binding site in HIV-1 and PFV. Additional free energy calculations on mutants of HIV-1 and PFV revealed that while both sub-pockets contribute to binding mode selection, the central sub-pocket plays a more important role. These results highlight the importance of both side chain and solvent reorganization, as well as the conformational entropy in determining the ligand binding mode, and will help inform the development of more effective INSTIs for combatting drug-resistant viral variants.

Synthesis and biological evaluation of novel D-ring fused steroidal N(2)-substituted-1,2,3-triazoles.

In this study, a series of 13 new D-ring fused steroidal N(2)-substituted-1,2,3-triazoles were synthesized, characterized and evaluated for their biological activities. The relative binding affinities of the synthesized compounds for the ligand-binding domains of estrogen receptors α and β, androgen receptor and glucocorticoid receptor demonstrated that androstane derivatives 3a and 3h and estratriene derivative 4e showed highly specific and strong binding affinity for estrogen receptor β, while 3b, 3e, 4a and 4b displayed high binding affinity for the glucocorticoid receptor. The synthesized compounds were tested for their ability to inhibit aldo-keto reductases 1C3 and 1C4 in vitro by monitoring NADPH consumption using fluorescence spectroscopy. The most potent aldo-keto reductase 1C3 inhibitors were compounds 3h (71.17%) and 3f (69.9%). Moreover, a molecular docking study was carried out for compounds 3f and 3h against aldo-keto reductase 1C3 and results showed that compounds 3h and 3f could bind in the same site and orientation as EM1404. However, polar atoms in the triazole group enable additional hydrogen bonding deeper in SP1 with Tyr319, Tyr216 and the NADP+ cofactor, which are not visible in the AKR1C3-EM1404 crystal structure. The synthesized compounds were screened for their anticancer activity against four cancer cell lines. Compound 3f demonstrated moderate toxic effects across various cancer types, while displaying lower toxicity towards the healthy cell line. In summary, our findings indicate that N(2)-substituted-1,2,3-triazoles are high-affinity ligands for estrogen receptor β and glucocorticoid receptor, inhibitors of aldo-keto reductase 1C3 enzyme, and exhibit antiproliferative effects against cancer cells, suggesting that they could serve as scaffolds for anticancer drug development.

Synthesis of a new series of 4-pyrazolylquinolinones with apoptotic antiproliferative effects as dual EGFR/BRAFV600E inhibitors.

The current study focuses on developing a single molecule that acts as an antiproliferative agent with dual or multi-targeted action, reducing drug resistance and adverse effects. A new series of 4-pyrazolylquinolin-2-ones (5a-j) with apoptotic antiproliferative effects as dual EGFR/BRAFV600E inhibitors were designed and synthesized. Compounds 5a-j were investigated for their cell viability effect against a normal cell line (MCF-10A). Results showed that none of the compounds were cytotoxic, and all 5a-j demonstrated more than 90% cell viability at 50 μM concentration. Using erlotinib as a reference, the MTT assay investigated the antiproliferative impact of targets 5a-j against four human cancer cell lines. Compounds 5e, 5f, 5h, 5i, and 5j were the most potent antiproliferative agents with GI50 values of 42, 26, 29, 34, and 37 nM, making compounds 5f and 5h more potent than erlotinib (GI50 = 33 nM). Moreover, compounds 5e, 5f, 5h, 5i, and 5j were further investigated as dual EGFR/BRAFV600E inhibitors, and results revealed that compounds 5f, 5h, and 5i are potent antiproliferative agents that act as dual EGFR/BRAFV600E inhibitors. Cell cycle analysis and apoptosis detection revealed that compound 5h displaying cell cycle arrest at the G1 transition could induce apoptosis with a high necrosis percentage. Docking studies revealed that compound 5f exhibited a strong affinity for EGFR and BRAFV600E, with high docking scores of -8.55 kcal mol-1 and -8.22 kcal mol-1, respectively. Furthermore, the ADME analysis of compounds 5a-j highlighted the diversity in their pharmacokinetic properties, emphasizing the importance of experimental validation.