Compounds 4l Research Articles

Synthesis of novel pyrimido[4,5-b]quinoline derivatives as dual EGFR/HER2 inhibitors as anticancer agents.

A series of novel N-aryl-5-aryl-6,7,8,9-tetrahydropyrimido[4,5-b]quinolin-4-amines 4a-4l was synthesized as potential anticancer agents through Dimroth rearrangement reaction of intermediates 3a-3c. Pyrimido[4,5-b]quinolines 4a-4l showed promising activity against the Michigan Cancer Foundation-7 (MCF-7) cell line, compared with lapatinib as the reference drug. Compounds 4d, 4h, 4i, and 4l demonstrated higher cytotoxic activity than lapatinib, with IC50 values of 2.67, 6.82, 4.31, and 1.62 µM, respectively. Compounds 4d, 4i, and 4l showed promising epidermal growth factor receptor (EGFR) inhibition with IC50 values of 0.065, 0.116, and 0.052 µM, respectively. These compounds were subjected to human epidermal growth factor receptor 2 (HER2) inhibition and showed IC50 values of 0.09, 0.164, and 0.055 µM, respectively. Compounds 4d, 4i, and 4l are good candidates as dual EGFR/HER2 inhibitors. The most active compound, 4l, was subjected to cell-cycle analysis and induced cell-cycle arrest at the S phase. Compound 4l induced apoptosis 60-fold compared with control untreated MCF-7 cells. 4l can inhibit cancer metastasis. It reduced MCF-7 cell infiltration and metastasis by 45% compared with control untreated cells.

Synthesis of Some New 1,3,4-Oxadiazole Derivatives and Evaluation of Their Anticancer Activity.

In this work, some new 2-[(5-((2-acetamidophenoxy)methyl)-1,3,4-oxadiazol-2-yl)thio]acetamide derivatives (4a-4l) were synthesized and studied for their anticancer activity. Twelve new compounds were tested on the A549 human lung cancer cell line, C6 rat glioma cell line, and L929 murine fibroblast cell line. Compounds 4f, 4i, 4k, and 4l (IC50: 1.59-7.48 μM), and especially 4h (IC50: <0.14 μM), exhibited excellent cytotoxic profile on A549 with selectivity. Compounds 4g and 4h showed remarkable antiproliferative activity on the C6 cell line with IC50 values of 8.16 and 13.04 μM, respectively. The compounds with the lowest IC50 value on the A549 cell line (4f, 4h, 4i, 4k, and 4l) were further studied to determine the mechanism of action. These compounds were found to induce apoptosis with a higher ratio (16.10-21.54%) than that of the standard drug cisplatin (10.07%). Compound 4f displayed mitochondrial membrane depolarization and caspase-3 activation at most, whereas compounds 4h (89.66%) and 4i (78.78%) had outstanding retention rates in the G0/G1phase of the cell cycle (cisplatin 74.75%). Compounds 4f, 4g, 4h, and 4l exhibited matrix metalloproteinase-9 (MMP-9) inhibition higher than 75% at 100 μg/mL; even IC50 values were found to be 1.65 and 2.55 μM for 4h and 4l. In addition, in silico physicochemical properties of the compounds and molecular docking interaction of compound 4h on the MMP-9 enzyme were evaluated; the desired and expected results were obtained.

Design and Evaluation of Synthesized Pyrrole Derivatives as Dual COX-1 and COX-2 Inhibitors Using FB-QSAR Approach.

This study delves into the intricate dynamics of the inflammatory response, unraveling the pivotal role played by cyclooxygenase (COX) enzymes, particularly COX-1 and COX-2 subtypes. Motivated by the pursuit of advancing scientific knowledge, our contribution to this field is marked by the design and synthesis of novel pyrrole derivatives. Crafted as potential inhibitors of COX-1 and COX-2 enzymes, our goal was to unearth molecules with heightened efficacy in modulating enzyme activity. A meticulous exploration of a synthesis library, housing around 3000 compounds, expedited the identification of potent candidates. Employing advanced docking studies and field-based Quantitative Structure-Activity Relationship (FB-QSAR) analyses enriched our understanding of the complex interactions between synthesized compounds and COX enzymes. Guided by FB-QSAR insights, our synthesis path led to the identification of compounds 4g, 4h, 4l, and 4k as potent COX-2 inhibitors, surpassing COX-1 efficacy. Conversely, compounds 5b and 5e exhibited heightened inhibitory activity against COX-1 relative to COX-2. The utilization of pyrrole derivatives as COX enzyme inhibitors holds promise for groundbreaking advancements in the domain of anti-inflammatory therapeutics, presenting avenues for innovative pharmaceutical exploration.

Exploring a new class of efficient boranil-like fluorescent benzoxazaborinines engendered from amino acid counterparts: A synthetic and spectral investigation

A series of new benzoxazaborinines was prepared from the salicylaldehyde Schiff bases derived from amino acid esters by a simple complexation reaction between the Schiff bases and boron trifluoride with up to 85 % yield. Single crystal X-ray diffraction studies on 4b further threw light on the three-dimensional structure of the compound. The absorption and emission maxima for all the compounds were observed in the range of 330–353 nm and 435–517 nm, respectively. Compounds 4f and 4l with a tryptophan moiety displayed significantly higher Stokes shifts of 187 and 151 nm respectively, compared with the other derivatives which were in the range of 86–94 nm. Most of the compounds displayed significant quantum yields of up to 80.8 %. The band gaps of the compounds were also calculated by DFT calculations and were found to complement the same calculated by the UV–Vis spectra and were in the range of 2.46–3.93 eV. The tryptophan derivatives, 4f and 4l were found to possess the lowest band gap.

Design, synthesis, and biological evaluation of N-(pyridin-3-yl)pyrimidin-4-amine analogues as novel cyclin-dependent kinase 2 inhibitors for cancer therapy

The discovery and development of CDK2 inhibitors has currently been validated as a hot topic in cancer therapy. Herein, a series of novel N-(pyridin-3-yl)pyrimidin-4-amine derivatives were designed and synthesized as potent CDK2 inhibitors. Among them, the most promising compound 7l presented a broad antiproliferative efficacy toward diverse cancer cells MV4-11, HT-29, MCF-7, and HeLa with IC50 values of 0.83, 2.12, 3.12, and 8.61 μM, respectively, which were comparable to that of Palbociclib and AZD5438. Interestingly, these compounds were less toxic on normal embryonic kidney cells HEK293 with high selectivity index. Further mechanistic studies indicated 7l caused cell cycle arrest and apoptosis on HeLa cells in a concentration-dependent manner. Moreover, 7l manifested potent and similar CDK2/cyclin A2 nhibitory activity to AZD5438 with an IC50 of 64.42 nM. These findings revealed that 7l could serve as ahighly promisingscaffoldfor CDK2 inhibitors as potential anticancer agents and functional probes.

Dihydrobenzothiazole coupled N-piperazinyl acetamides as antimicrobial agents: Design, synthesis, biological evaluation and molecular docking studies.

Substituted saturated N-heterocycles have gained momentum as effective scaffolds for the development of new drugs. In this study, we coupled partly saturated benzothiazoles with substituted piperazines and evaluated their antimicrobial activity. Following a three-step reaction sequence from commercially available cyclic 1,3-diones, a series of novel 2-[4-substituted-1-piperazinyl]-N-(7-oxo-4,5,6,7-tetrahydrobenzo[d]thiazol-2-yl)acetamides (7a-af) were synthesised. 2-Amino-5,6-dihydro-benzo[d]thiazol-7(4H)-ones, obtained through the condensation of cyclohexane-1,3-diones with thiourea, were acetylated with chloroacetic chloride and then reacted with N-substituted piperazines 6a-p to give the desired products 7a-af in excellent yields. All 32 new compounds were fully characterised by their 1 H-nuclear magnetic resonance (NMR), 13 C-NMR and high-resolution mass spectrometry spectra. The synthetic compounds 7a-af were tested in vitro for their efficacy as antimicrobials against pathogenic strains of Gram-positive and Gram-negative bacteria, Streptococcus mutans and Salmonella typhi, respectively, as well as against fungal strains, including Candida albicans 3018 and C. albicans 4748. Ciprofloxacin and fluconazole served as the reference drugs. While compounds 7c and 7l showed inhibition against fungal strains with zones of inhibition of 11 and 1 mm, respectively, four analogues (7d, 7l, 7n, and 7r) demonstrated strong antibacterial action (zone of inhibition in the range of 10-15 mm). Three compounds (7j, 7l, and 7w) also exhibited moderate antitubercular activity (MIC: 6.25 µg/mL) against Mycobacterium tuberculosis H37Rv. Molecular docking investigations and the predicted physicochemical and ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties for the potent compounds made this scaffold useful as a pharmacologically active framework for the development of potential antimicrobial hits.

Novel sulfonamide-phosphonate conjugates as carbonic anhydrase isozymes inhibitors.

The three-components one-pot Kabachnik-Fields reaction of sulfapyridine, diethyl phosphite, and aldehyde under thermal catalysis reaction condition in the presence of bismuth (III) triflate as a catalyst afford the corresponding sulfonamide-phosphonates (3a-3p) in good to excellent yields (78%-91%). The structures of the new synthesized compounds were elucidated and confirmed by variable spectroscopic studies. Single crystal X-ray studies for 3a, 3d, and 3i verified the proposed structure. The newly developed sulfonamide-phosphonates were evaluated for their inhibitory properties against four isoforms of human carbonic anhydrase (hCA I, II, IX, and XII). The results demonstrated that they exhibited greater potency in inhibiting hCA XII compared to hCA I, II, and IX, with Ki ranging from 5.1 to 51.1 nM. Compounds 3l and 3p displayed the highest potency, exhibiting selectivity ratios of I/XII >298.7 and 8.5, and II/XII ratios of 678.1 and 142.1, respectively. Molecular docking studies were conducted to explore their binding patterns within the binding pocket of CA XII. The results revealed that the sulfonamide NH group coordinated with the Zn2+ ion, and hydrogen bond interactions were observed with residue Thr200. Additionally, hydrophobic interactions were identified between the benzenesulfonamide phenyl ring and Leu198. Compounds 3p and 3l exhibited an additional hydrogen bonding interaction with other amino acid residues. These supplementary interactions may contribute to the enhanced potency and selectivity of these compounds toward the CA XII isoform.

Metal-Free Catalyzed Oxidation/Decarboxylative [3+2] Cycloaddition Sequences of 3-Formylchromones to Access Pyrroles with Anti-Cancer Activity.

An efficient and direct approach to pyrroles was successfully developed by employing 3-formylchromones as decarboxylative coupling partners, and facilitated by microwave irradiation. The protocol utilizes easily accessible feedstocks, a catalytic amount of DBU without any metals, resulting in high efficiency and regioselectivity. Notably, all synthesized products were evaluated against five different cancer cell lines and compound 3l selectively inhibited the proliferation of HCT116 cells with an IC50 value of 10.65 μM.

Synthesis of novel 18β-glycyrrhetinic acid sulfonate derivatives displaying significant anti-oomycete activity against Phytophthora capsici

Using 18β-glycyrrhetinic acid (GA) as the lead compound, fourteen GA sulphonate derivatives (3a–n) were prepared by modifying its C-3 OH group, and their structures were well confirmed by 1H NMR, 13C NMR, HRMS and melting points. Moreover, we screened the anti-oomycete activity of these compounds against Phytophthora capsici by using the mycelial growth rate method. Among the fourteen GA sulphonate derivatives evaluated, four compounds 3f, 3j, 3k and 3l exhibited more potent anti-oomycete activity than that of the positive control zoxamide (EC50 = 25.17 mg/L), and had the median effective concentration (EC50) values of 23.04, 16.16, 22.55, and 13.93 mg/L, respectively. Especially compound 3l showed the best anti-oomycete activity against P. capsici with EC50 value of 13.93 mg/L. Overall, the introduction of sulfonyloxy groups at the C-3 position of GA has a significant impact on its anti-oomycete activity, and the corresponding derivative activity varies significantly with different substituents R.

Synthesis of Tetracyclic Spirooxindolepyrrolidine-Engrafted Hydantoin Scaffolds: Crystallographic Analysis, Molecular Docking Studies and Evaluation of Their Antimicrobial, Anti-Inflammatory and Analgesic Activities

In a sustained search for novel potential drug candidates with multispectrum therapeutic application, a series of novel spirooxindoles was designed and synthesized via regioselective three-component reaction between isatin derivatives, 2-phenylglycine and diverse arylidene-imidazolidine-2,4-diones (Hydantoins). The suggested stereochemistry was ascertained by an X-ray diffraction study and NMR spectroscopy. The resulting tetracyclic heterocycles were screened for their in vitro and in vivo anti-inflammatory and analgesic activity and for their in vitro antimicrobial potency. In vitro antibacterial screening revealed that several derivatives exhibited remarkable growth inhibition against different targeted microorganisms. All tested compounds showed excellent activity against the Micrococccus luteus strain (93.75 µg/mL ≤ MIC ≤ 375 µg/mL) as compared to the reference drug tetracycline (MIC = 500 µg/mL). Compound 4e bearing a p-chlorophenyl group on the pyrrolidine ring exhibited the greatest antifungal potential toward Candida albicans and Candida krusei (MIC values of 23.43 µg/mL and 46.87 µg/mL, respectively) as compared to Amphotericin B (MIC = 31.25 and 62.50 µg/mL, respectively). The target compounds were also tested in vitro against the lipoxygenase-5 (LOX-5) enzyme. Compounds 4i and 4l showed significant inhibitory activity with IC50 = 1.09 mg/mL and IC50 = 1.01 mg/mL, respectively, more potent than the parent drug, diclofenac sodium (IC50 = 1.19 mg/mL). In addition, in vivo evaluation of anti-inflammatory and analgesic activity of these spirooxindoles were assessed through carrageenan-induced paw edema and acetic acid-induced writhing assays, respectively, revealing promising results. In silico molecular docking and predictive ADMET studies for the more active spirocompounds were also carried out.

In Vitro α-Glucosidase and α-Amylase Inhibition, Cytotoxicity and Free Radical Scavenging Profiling of the 6-Halogeno and Mixed 6,8-Dihalogenated 2-Aryl-4-methyl-1,2-dihydroquinazoline 3-Oxides.

Series of the 6-bromo/iodo substituted 2-aryl-4-methyl-1,2-dihydroquinazoline-3-oxides and their mixed 6,8-dihalogenated (Br/I and I/Br) derivatives were evaluated for inhibitory properties against α-glucosidase and/or α-amylase activities and for cytotoxicity against breast (MCF-7) and lung (A549) cancer cell lines. The 6-bromo-2-phenyl substituted 3a and its corresponding 6-bromo-8-iodo-2-phenyl-substituted derivative 3i exhibited dual activity against α-glucosidase (IC50 = 1.08 ± 0.02 μM and 1.01 ± 0.05 μM, respectively) and α-amylase (IC50 = 5.33 ± 0.01 μM and 1.18 ± 0.06 μM, respectively) compared to acarbose (IC50 = 4.40 ± 0.05 μM and 2.92 ± 0.02 μM, respectively). The 6-iodo-2-(4-fluorophenyl)-substituted derivative 3f, on the other hand, exhibited strong activity against α-amylase and significant inhibitory effect against α-glucosidase with IC50 values of 0.64 ± 0.01 μM and 9.27 ± 0.02 μM, respectively. Compounds 3c, 3l and 3p exhibited the highest activity against α-glucosidase with IC50 values of 1.04 ± 0.03, 0.92 ± 0.01 and 0.78 ± 0.05 μM, respectively. Moderate cytotoxicity against the MCF-7 and A549 cell lines was observed for these compounds compared to the anticancer drugs doxorubicin (IC50 = 0.25 ± 0.05 μM and 0.36 ± 0.07 μM, respectively) and gefitinib (IC50 = 0.19 ± 0.04 μM and 0.25 ± 0.03 μM, respectively), and their IC50 values are in the range of 10.38 ± 0.08-25.48 ± 0.08 μM and 11.39 ± 0.12-20.00 ± 0.05 μM, respectively. The test compounds generally exhibited moderate to strong antioxidant capabilities, as demonstrated via robust free radical scavenging activity assays, viz., DPPH and NO. The potential of selected derivatives to inhibit superoxide dismutase (SOD) was also investigated via enzymatic assay in vitro. Molecular docking revealed the N-O moiety as essential to facilitate electrostatic interactions of the test compounds with the protein residues in the active site of α-glucosidase and α-amylase. The presence of bromine and/or iodine atoms resulted in increased hydrophobic (alkyl and/or π-alkyl) interactions and therefore increased inhibitory effect against both enzymes.

New Imidazo[1,2-a]pyridin-2-yl Derivatives as AChE, BChE, and LOX Inhibitors; Design, Synthesis, and Biological Evaluation

Background: Inhibition of cholinesterase enzyme has been recognized as an important target in the symptomatic treatment of Alzheimer’s disease. Objective: In the current work, a series of new N-(4-(imidazo[1,2-a]pyridin-2-yl)phenyl)cinnamamide derivatives were synthesized and their inhibitory activities against acetyl cholinesterase, butrylcholines terase, and Lipoxygenase were evaluated. Methods: The target compounds were synthesized as the literature reported with some modifications. The AChE, BChE, and LOX inhibitory activities of the synthesized compounds were evaluated using in vitro methods. The docking and kinetic studies were performed for the most potent compounds to evaluate the inhibition mechanism. Results: The structural elucidation of the synthesized imidazo-pyridine derivatives was performed by different spectroscopic techniques including IR, NMR, and Mass. Most of the synthesized compounds demonstrated good AChE, BChE, and LOX inhibitory activities. The most active AChE, BChE, and sLOX-1 inhibitors were found for compounds 4a, 4g, and 4l, respectively. The docking study also revealed that the three compounds, 4a, 4g, and 4l, have important binding interactions with the AChE, BChE, and sLOX-1 enzyme active sites, respectively. Conclusion: The results of current study shows imidazo[1,2-a]pyridine derivatives have potential for development of novel drug candidate for AD as AChE, BChE and sLOX-1 inhibitors.

Synthesis, in silico and in vitro studies of novel quinazolinone derivatives as potential SARS-CoV-2 3CLpro inhibitors

A series of new quinazolinone derivatives (5a-l) were designed as 3CL protease inhibitors for SARS-CoV-2 infection. The designed derivatives were efficiently synthesized by S-alkylation/arylation of an intermediate, 6-fluoro-3-(4-fluorophenyl)-2-mercaptoquinazolin-4(3H)-one and their successful synthesis was established by analytical methods, viz. IR, 1H NMR, &13C NMR spectroscopy. The in silico inhibitory potential against 3CLpro of SARS-CoV-2 were studied by means of docking and dynamics simulations, and compared with the co-crystallized ligand (VR4) of SARS-CoV-2 3CLpro. The compounds interacted strongly within the active catalytic dyad (Cys-His) site, thereby anticipated to obstruct the function of 3CLpro of SARS-CoV-2. Compounds 5b, 5c, 5i, 5j and 5l showed efficient binding with protease 3CLpro with XP Gscore of −7.4, −8.3, −7.8, −7.5 and −8.2 respectively. Furthermore, molecular dynamic simulation study of these compounds (5b, 5c, 5i, 5j and 5 l) showed stable interaction over 50 ns production run. Swiss ADME and pkCSM web tools showed favorable physicochemical and pharmacokinetic properties and fulfilled the criteria for drug-likeness of these selected studied compounds. The toxicity determination of these selected compounds predicted that some compounds were hepatotoxic, but were not AMES toxic. Compounds 5b, 5c, 5i, 5j and 5 l revealed their inhibitory potential against the SARS-CoV-2 3CLpro, and their IC50 values were attained at 1.58, 1.25, 1.97, 0.44 and 2.56 µM, respectively. In addition, these compounds were found to have devoid of any significant cytotoxicity even at a higher concentration of 20 µM against VeroE6 cells. These quinazolinone derivatives showed potent binding and inhibitory potential against SARS-CoV-2 3CLpro and may emerge as compounds that might act as prospective inhibitors.

Quinoline-2-one derivatives as promising antibacterial agents against multidrug-resistant Gram-positive bacterial strains.

This study describes the discovery of a variety of quinoline2-one derivatives with significant antibacterial action vs a spectrum of multidrug-resistant Gram-positive bacterial strains, especially methicillin-resistant Staphylococcus aureus (MRSA). Compounds 6c, 6l, and 6o exhibited significant antibacterial activity versus the Gram-positive bacterial pathogens evaluated. In comparison to the reference daptomycin, compound 6c demonstrated the most effective activity among the assessed derivatives, with MIC concentrations of 0.75 μg/mL versus MRSA and VRE and 2.50 μg/mL against MRSE. We also reported on these compounds' biofilm and dihydrofolate reductase inhibitory activities. Compound 6c showed the greatest antibiofilm action in a dose-dependent way and a substantial decrease of biofilm development in the MRSA ACL51 strain at concentrations of 0.5, 0.25, and 0.12 MIC, with reductions of 79%, 55%, and 38%, consecutively, whereas the corresponding values for vancomycin were 20%, 12%, and 9%. These findings imply that these quinoline compounds could be used to develop a new category of antibiotic representatives to prevent Gram-positive drug-resistant bacterial strains.

Design, synthesis, biological evaluation and molecular docking study of new pyrazolo[1,5-a]pyrimidines as PIM kinase inhibitors and apoptosis inducers

This study involved designing and synthesizing new derivatives of pyrazolo[1,5-a]pyrimidine 5a-l, which were prepared via reaction of 4-Arylazo-1H-pyrazole-3,5-diamines 3a,b with arylidenemalononitriles (4a-f) in refluxing methanol. The structure of the synthesized derivatives were confirmed using different spectroscopic techniques. Virtual screening was achieved for the newly designed derivatives using docking simulation between the target pyrazolo[1,5-a]pyrimidine 5j and the active binding site of the PIM-1 enzyme. The cytotoxicity of novel derivatives of pyrazolo[1,5-a]pyrimidine framework was screened on the cancer cell lines: colon (HCT-116), hepatocellular (Hep-G2), and breast (MCF-7). Comparing with doxorubicin, compounds 2,5-diamino-7-(4-ethoxyphenyl)-3-(p-tolyldiazenyl)pyrazolo[1,5-a]pyrimidine-6-carbonitrile; 5h, 2,5-diamino-7-(4-hydroxy-3-methoxyphenyl)-3-(p-tolyldiazenyl)pyrazolo[1,5-a]pyrimidine-6-carbonitrile; 5j, and 2,5-diamino-7-(furan-2-yl)-3-(p-tolyldiazenyl)pyrazolo[1,5-a]pyrimidine-6-carbonitrile; 5l exhibited noteworthy anticancer properties, with half maximal inhibitory concentration (IC50 range) = 1.26–3.22 μM. In addition, the most potent compound, 5j demonstrated a lower level of toxicity towards normal cells (WI-38 cell line), suggesting an increased level of safety. Compounds 5h, 5j, and 5l were evaluated for their activity against three different PIM kinases (PIM-1, PIM-2, and PIM-3 enzymes) in an effort to elucidate their inhibitory potential on PIM kinases. Additionally, the apoptotic potency of 5j was assessed on MCF-7 cells. Results revealed that compound 5j was potent against both PIM-1 and PIM-2 having IC50 0.158 and 0.297 μM, respectively, comparing to staurosporine's IC50 0.294 and 0.477 μM against both enzymes, respectively, while its inhibitory activity against PIM-3 enzyme was moderate. In addition, compound 5j promoted apoptosis via elevating the levels of Bax, p53, and caspase-3 and dropping down Bcl-2 level. G1 phase arrest of cell cycle was also observed. Furthermore, docking analyses of 5j in the PIM-1 binding site was conducted.

Synthesis, Antifungal Ergosterol Inhibition, Antibiofilm Activities, and Molecular Docking on β-Tubulin and Sterol 14-Alpha Demethylase along with DFT-Based Quantum Mechanical Calculation of Pyrazole Containing Fused Pyridine-Pyrimidine Derivatives.

Multidrug-resistant fungal infections have become much more common in recent years, especially in immune-compromised patients. Therefore, researchers and pharmaceutical professionals have focused on the development of novel antifungal agents that can tackle the problem of resistance. In continuation to this, a novel series of pyrazole-bearing pyrido[2,3-d]pyrimidine-2,4(1H,3H)-dione derivatives (4a-4o) have been developed. These compounds have been screened against Candida albicans, Aspergillus niger, and Aspergillus clavatus. The synthesized compounds were characterized by well-known spectroscopic techniques, i.e., IR, 1H NMR, 13C NMR, and mass spectrometry. In vitro antifungal results revealed that compound 4n showed activity against C. albicans having MIC value of 200 μg/mL. To know the plausible mode of action, the active derivatives were screened for anti-biofilm and ergosterol biosynthesis inhibition activities. The compounds 4h, 4j, 4k, and 4n showed greater ergosterol biosynthesis inhibition than the control DMSO. To comprehend how molecules interact with the receptor, studies of molecular docking of 4k and 4n have been performed on the homology-modeled protein of β-tubulin. The molecular docking revealed that the active compounds 4h, 4j, 4k, 4l, and 4n interacting with the active site amino acid of sterol 14-alpha demethylase (PDB ID: 5v5z) indicate one of the possible modes of action of ergosterol inhibition activity. The synthesized compounds 4c, 4e, 4h, 4i, 4j, 4k, 4l, and 4n inhibited biofilm formation and possessed the potential for anti-biofilm activity. DFT-based quantum mechanical calculations were carried out to optimize, predict, and compare the vibration modes of the molecule 4a.

Design, Synthesis, and Molecular Docking Studies of 1,3,4-Oxadiazole Scaffolds as Potential Antimicrobial Agents

In search of suitable antimicrobial compounds, we report here the synthesis, characterization, and biological activities of 2-((5-(2-nitrophenyl)-1,3,4-oxadiazol-2-yl)thio)-N-arylacetamide (5a-5p). The molecules were characterized by infrared, mass, hydrogen-1 nuclear magnetic resonance (1H NMR), 13C NMR, and elemental analysis. The in vitro antimicrobial activity was investigated against pathogenic Gram-positive and Gram-negative bacterial and fungal strains. The results were explained with a molecular docking study against microbial DNA gyrase. It was found that the compounds 5h, 5i, 5j, 5k, 5l, 5n, and 5p showed significant activities against tested organisms as compared to standard drugs (fluconazole and ciprofloxacin).

Design, Synthesis, and Biological Evaluation of Novel Derivatives of the Marine Natural Product Laurene.

Plant pathogenic fungi and viruses are seriously threatening agricultural production. There is an urgent need to develop novel fungicides and antiviral agents with low toxicity and high efficiency. In this study, we designed and synthesized 32 thiazole-, hydrazone-, and amide-containing derivatives of laurene and systematically evaluated their antiviral activities and fungicidal activities. Structure-simplified compounds 5a-5c, 5i, 5k, 5l, 11a, 11j, and 12c displayed higher antiviral activities than that of ningnanmycin. Compound 11a with a simple chemical structure, convenient synthetic route, and excellent antiviral activity emerged as a secondary lead compound. The docking results show that compounds 5i, 5k, and 11a have strong interactions with the tobacco mosaic virus coat protein (TMV CP). These compounds also exhibited significant fungicidal activities. Compounds 5g, 5k, 11j, and 11l displayed 9.15-17.45 μg/mL EC50 values against Pyricularia grisea, and compounds 5h (EC50: 8.01 μg/mL) and 11i (EC50: 15.23 μg/mL) exhibited a similar level of EC50 values with chlorothalonil (EC50: 7.33 μg/mL) against Physalospora piricola. Preliminary fungicidal mechanism research indicated that compound 5h has a certain destructive effect on the hyphae of P. piricola. This work lays a foundation for the application of laurene derivatives in plant protection.

Design, synthesis, in vitro and in silico evaluation of novel substituted 1,2,4-triazole analogues as dual human VEGFR-2 and TB-InhA inhibitors

Cancer is a leading cause of death globally and has been associated with Mycobacterium tuberculosis (Mtb). The angiogenesis-related VEGFR-2 is a common target between cancer and Mtb. Here, we aimed to synthesize and validate potent dual human VEGFR-2 inhibitors as anticancer and anti-mycobacterial agents. Two series of 1,2,4-triazole-based compounds (6a-l and 11a-e) were designed and synthesized through a molecular hybridization approach. Activities of all synthesized compounds were evaluated against human VEGFR-2 in addition to drug-sensitive, multidrug-resistant and extensive-drug resistant Mtb. Compounds 6a, 6c, 6e, 6f, 6h, 6l, 11a, 11d and 11e showed promising inhibitory effect on VEGFR-2 (IC50 = 0.15 – 0.39 µM), anti-proliferative activities against cancerous cells and low cytotoxicity against normal cells. The most potent compounds (6e and 11a) increased apoptosis percentage. Additionally, compounds 6h, 6i, 6l and 11c showed the highest activities against all Mtb strains, and thus were evaluated against enoyl-acyl carrier protein reductase (InhA) which is essential for Mtb cell wall synthesis. Interestingly, the compounds showed excellent InhA inhibition activities with IC50 range of 1.3 – 4.7 µM. Docking study revealed high binding affinities toward targeted enzymes; human VEGFR-2 and Mtb InhA. In conclusion, 1,2,4-triazole analogues are suggested as potent anticancer and antimycobacterial agents via inhibition of human VEGFR-2 and Mtb InhA.

Anti-Proliferative, Anti-EGFR and In Silico Studies of a Series of New Imidazole Tethered 1,2,4-Oxadiazoles

Herein, we prepared some new imidazole-1,2,4-oxadiazole hybrids (6a–6o) and investigated their antiproliferative potential on three human cancer cell lines (HepG2, A549 and MCF-7) using Erlotinib as standard drug. In common, most of the compounds showed better potential on MCF-7 in comparison to HepG2 and A549. Out of all, compound 6o had greater activity on MCF-7, while, it, had most promising activity on HEPG2 and A549. Compounds 6f, 6j and 6l also exhibited significant activity on MCF-7. As well, in vitro anti-EGFR evaluation of most active compounds 6f, 6j, 6l, and 6o revealed that compound 6o displayed most promising activity as compared to Erlotinib. Molecular docking studies revealed the possible binding interactions of derivatives 6f, 6j, 6l, and 6o with EGFR (PDB ID-4HJO). Finally, compounds 6f, 6j, 6l, and 6o are possessing ‘druglikeness’ with CLogP values ranging from 1.86 to 3.13.