Compounds 4c Research Articles

Synthesis of Bisindole Alkaloids and Their Mode of Action against Methicillin-Resistant Staphylococcus Aureus.

About 100,000 deaths are attributed annually to infections with methicillin-resistant Staphylococcus aureus (MRSA) despite concerted efforts toward vaccine development and clinical trials involving several preclinically efficacious drug candidates. This necessitates the development of alternative therapeutic options against this drug-resistant bacterial pathogen. Using the Masuda borylation-Suzuki coupling (MBSC) sequence, we previously synthesized and modified naturally occurring bisindole alkaloids, alocasin A, hyrtinadine A and scalaradine A, resulting in derivatives showing potent in vitro and in vivo antibacterial efficacy. Here, we report on a modified one-pot MBSC protocol for the synthesis of previously reported and several undescribed N-tosyl-protected bisindoles with anti-MRSA activities and moderate cytotoxicity against human monocytic and kidney cell lines. In continuation of the mode of action investigation of the previously synthesized membrane-permeabilizing hit compounds, mechanistic studies reveal that bisindoles impact the cytoplasmic membrane of Gram-positive bacteria by promiscuously interacting with lipid II and membrane phospholipids while rapidly dissipating membrane potential. The bactericidal and lipid II-interacting lead compounds 5c and 5f might be interesting starting points for drug development in the fight against MRSA.

Rutaecarpine-inspired scaffold-hopping strategy and Ullmann cross-coupling based synthetic approach: Identification of pyridopyrimidinone-indole based novel anticancer chemotypes

Natural products as starting templates have shown historically major contribution to development of drugs. Inspired by the structure–function of an anticancer natural alkaloid Rutaecarpine, the Scaffold-hopped Acyclic Analogues of Rutaecarpine (SAAR) with ‘N’-atom switch (1°-hop) and ring-opening (2°-hop) were investigated. A new synthetic route was developed for an effective access to the analogues, i.e. 2-indolyl-pyrido[1,2-a]pyrimidinones, which involved preparation of N-Boc-N’-phthaloyltryptamine/mexamine-bromides and pyridopyrmidinon-2-yl triflate, a nickel/palladium-catalysed Ullmann cross-coupling of these bromides and triflate, deprotection of phthalimide followed by N-aroylation, and Boc-deprotection. Fourteen novel SAAR-compounds were prepared, and they showed characteristic antiproliferative activity against various cancer cells. Three most active compounds (11a, 11b, and 11c) exhibited good antiproliferative activity, IC50 7.7–15.8 µM against human breast adenocarcinoma cells (MCF-7), lung cancer cells (A549), and colon cancer cells (HCT-116). The antiproliferative property was also observed in the colony formation assay. The SAAR compound 11b was found to have superior potency than original natural product Rutaecarpine and an anticancer drug 5-FU in antiproliferative activities with relatively lower cytotoxicity towards normal breast epithelial cells (MCF10A) and significantly higher inhibitory effect on cancer cells’ migration. The compound 11b was found to possess favourable in silico physicochemical characteristics (lipophilicity-MLOGP, TPSA, and water solubility-ESOL, and others), bioavailability score, and pharmacokinetic properties (GI absorption, BBB non-permeant, P-gp, and CYP2D6). Interestingly, the compound 11b did not show any medicinal chemistry structural alert of PAINS and Brenk filter. The study represents for the first time the successful discovery of new potent anticancer chemotypes using Rutaecarpine natural alkaloid as starting template and reaffirms the significance of natural product-inspired scaffold-hopping technique in drug discovery research.

Synthesis and Photophysical Characterization of Fluorescent Naphtho[2,3-d]thiazole-4,9-Diones and Their Antimicrobial Activity against Staphylococcus Strains.

The chemical reaction of 2-(methylsulfinyl)naphtho[2,3-d]thiazole-4,9-dione (3) using different amines, including benzylamine (4a), morpholine (4b), thiomorpholine (4c), piperidine (4d), and 4-methylpiperazine (4e), produced corresponding new tricyclic naphtho[2,3-d]thiazole-4,9-dione compounds (5a-e) in moderate-to-good yields. The photophysical properties and antimicrobial activities of these compounds (5a-e) were then characterized. Owing to the extended π-conjugated system of naphtho[2,3-d]thiazole-4,9-dione skeleton and substituent effect, 5a-e showed fluorescence both in solution and in the solid state. The introduction of nitrogen-containing heterocycles at position 2 of the thiazole ring on naphtho[2,3-d]thiazole-4,9-dione led to large bathochromic shifts in solution, and 5b-e exhibited orange-red fluorescence with emission maxima of over 600 nm in highly polar solvents. Staphylococcus aureus (S. aureus) is a highly pathogenic bacterium, and infection with its antimicrobial-resistant pathogen methicillin-resistant S. aureus (MRSA) results in serious clinical problems. In this study, we also investigated the antimicrobial activities of 5a-e against S. aureus, MRSA, and S. epidermidis. Compounds 5c with thiomorpholine group and 5e with 4-methylpiperazine group showed potent antimicrobial activity against these bacteria. These results will lead to the development of new fluorescent dyes with antimicrobial activity in the future.

Design, Synthesis and Bioactivities of Novel Pyridyl Containing Pyrazole Oxime Ether Derivatives.

In this research, with an aim to develop novel pyrazole oxime ether derivatives possessing potential biological activity, thirty-two pyrazole oxime ethers, including a substituted pyridine ring, have been synthesized and structurally identified through 1H NMR, 13C NMR, and HRMS. Bioassay data indicated that most of these compounds owned strong insecticidal properties against Mythimna separata, Tetranychus cinnabarinus, Plutella xylostella, and Aphis medicaginis at a dosage of 500 μg/mL, and some title compounds were active towards Nilaparvata lugens at 500 μg/mL. Furthermore, some of the designed compounds had potent insecticidal effects against M. separata, T. cinnabarinus, or A. medicaginis at 100 μg/mL, with the mortalities of compounds 8a, 8c, 8d, 8e, 8f, 8g, 8o, 8s, 8v, 8x, and 8z against A. medicaginis, in particular, all reaching 100%. Even when the dosage was lowered to 20 μg/mL, compound 8s also expressed 50% insecticidal activity against M. separata, and compounds 8a, 8e, 8f, 8o, 8v, and 8x displayed more than 60% inhibition rates against A. medicaginis. The current results provided a significant basis for the rational design of biologically active pyrazole oxime ethers in future.

Design, synthesis, and anti-oomycete activity of 3-acyloxymaltol/ethyl maltol derivatives

Twenty 3-acyloxymaltol/ethyl maltol derivatives (7a-j and 8a-j) were synthesized and evaluated in vitro for their anti-oomycete activity against Phytophthora capsici, respectively. Among all of twenty derivatives, more than half of the compounds 7f, 7h, 8a-h and 8j had anti-oomycete activity higher than the positive control zoxamide (EC50 = 22.23 mg/L), and the EC50 values of 18.66, 20.32, 12.80, 16.18, 10.59, 14.98, 16.80, 10.36, 15.32, 12.64, and 13.59 mg/L, respectively. Especially, compounds 8c and 8f exhibited the best anti-oomycete activity against P. capsici with EC50 values of 10.59 and 10.36 mg/L, respectively. Overall, hydroxyl group of maltol/ethyl maltol is important active modification site.

Exploring 2-Pyrazoline derivatives as potent antidiabetic agents and cholinesterase inhibitors: Their synthesis and molecular docking studies

Herein, unique pyrazoline derivatives were synthesized, and their structures were elucidated by various spectroscopic techniques. Moreover, potential in vitro acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-glucosidase, and α-amylase inhibition effects of the compounds were also investigated. Molecular docking studies were performed to further elucidate the enzyme inhibitory activities. The compound 2c (IC50 = 1.64±0.04 and 4.18±0.22 µM, respectively) exhibited the strongest inhibitory activity against AChE and BChE, while compounds 2 m (IC50 = 4.29±0.20 µM) and 2i (IC50 = 4.31±0.08 µM) showed promising AChE inhibitory activity. On the other hand, compounds 2a (IC50= 5.01±0.13 µM) and 2i (IC50 = 5.06±0.72 µM) significantly inhibited BChE. In addition, all compounds except 2c and 2f showed great inhibitory activity against α-amylase at lower concentrations compared to acarbose (IC50 = 72.57 ± 3.16 µM). Similarly, all compounds except 2k exhibited higher inhibitory activity than acarbose (IC50 = 207.08±12.20 µM) against α-glucosidase. Among the compounds, 2a (IC50 = 15.05±5.64 µM), 2b (IC50 = 14.34±5.05 µM), and 2e (IC50 = 11.72±0.46 µM) had excellent inhibitory activity at certain concentrations. The data obtained from the molecular docking studies supported inhibitory activity results. This study presents potential leads for the development of antidiabetic and Alzheimer's therapeutics.

Synthesis and biological evaluation of panaxadiol ester derivatives possessing pyrazole and pyrrole moiety as HIF-1α inibitors

Hypoxia-inducing factor-1α (HIF-1α) is overexpressed in variety of tumor patients and plays an important role in the regulation of hypoxia response in tumor cells. Therefore, its inhibitors have become one of the targets for the treatment of a variety of cancers. Two series of panaxadiol (PD) ester derivatives containing pyrazole (18a–j) and pyrrole (19a–n) moiety were synthesized and their HIF-1α inhibitory activities were evaluated. Among all the target compouds, compounds 18c, 19d, and 19n (IC50 = 8.70–10.44 μM) showed better HIF-1α inhibitory activity than PD (IC50 = 13.35 μM). None of these compounds showed cytotoxicity above 100 μM and inhibited HIF-1α transcription in a dose-dependent manner. These compounds showed good antitumor activity and provide lead compounds for further design and activity study of PD ester derivatives.

Synthesis of new N-(5,6-methylenedioxybenzothiazole-2-yl)-2-[(substituted)thio/piperazine]acetamide/propanamide derivatives and evaluation of their AChE, BChE, and BACE-1 inhibitory activities.

In this study, the synthesis of N-(5,6-methylenedioxybenzothiazole-2-yl)-2-[(substituted)thio/piperazine]acetamide/propanamide derivatives (3a-3k) and to investigate their acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and β-secretase 1 (BACE-1) inhibition activity were aimed. Mass, 1H NMR, and 13C NMR spectra were utilized to determine the structure of the synthesized compounds. Compounds 3b, 3c, 3f, and 3j showed AChE inhibitory activity which compound 3c (IC50 = 0.030 ± 0.001 µM) showed AChE inhibitory activity as high as the reference drug donepezil (IC50 = 0.0201 ± 0.0010 µM). Conversely, none of the compounds showed BChE activity. Compounds 3c and 3j showed the highest BACE-1 inhibitory activity and IC50 value was found as 0.119 ± 0.004 µM for compound 3j whereas IC50 value was 0.110 ± 0.005 µM for donepezil, which is one of the reference substance. Molecular docking studies have been carried out using the data retrieved from the server of the Protein Data Bank (PDBID: 4EY7 and 2ZJM). Using in silico approach behavior active compounds (3c and 3j) and their binding modes clarified.

New benzimidazole-oxadiazole derivatives as potent VEGFR-2 inhibitors: Synthesis, anticancer evaluation, and docking study.

We report herein, the design and synthesis of benzimidazole-oxadiazole derivatives as new inhibitors for vascular endothelial growth factor receptor-2(VEGFR-2). The designed members were assessed for their in vitro anticancer activity against three cancer cell lines and two normal cell lines; A549, MCF-7, PANC-1, hTERT-HPNE and CCD-19Lu. Compounds 4c and 4d were found to be the most effective compounds against three cancer cell lines. Compounds 4c and 4d were then tested for their in vitro VEGFR-2 inhibitory activity, safety profiles, and selectivity indices using the normal hTERT-HPNE and CCD-19Lu cell lines. It was determined that compound 4c was the most effective and safe member of the produced chemical family. Vascular endothelial growth factor A(VEGFA) immunolocalizations of compounds 4c and 4d were evaluated relative to control by VEGFA immunofluorescence staining. Compounds 4c and 4d inhibited VEGFR-2 enzyme with half-maximal inhibitory concentration values of 0.475 ± 0.021and 0.618 ± 0.028 µM, respectively. Molecular docking of the target compounds was carried out in the active site of VEGFR-2 (Protein Data Bank: 4ASD).

Synthesis of novel benzo[d] imidazole bearing α-aminophosphonate and their antimicrobial evaluation

The antimicrobial activity of seven α-aminophosphonate derivatives was evaluated. These new compounds were synthesized via a one-pot reaction of the Kabachnik-Fields between 2-((1H-benzo[d]imidazol-2-yl)thio)acetohydrazide, aldehyde derivatives, and diethyl phosphite in the presence of magnesium triflate as a catalyst. The novel compounds are identified by analytical and spectroscopic techniques. The use of magnesium triflate as a catalyst revealed short reaction time (1 h), in 10 mol%.The activity of the new compounds was against the Gram-positive bacteria Bacillus cereus, and Staphylococcus aureus, as well as the Gram-negative bacteria Salmonella typhimurium, Escherichia coli, Pseudomonas aeruginose, and the fungus Candida albicans. The results indicated that most of the new compounds have moderate to high potency as antibacterial and antifungal agents. And the theoretical study confirmed that the compounds excel in binding with a more stable binding energy than the antibiotic penicillin, and this was confirmed by laboratory results. In the case of Escherichia coli ATCC® 25922™, only 5a and 5e displayed significant inhibitory activities equal to or greater than the reference drug. Most of the new compounds (5c–5 g) revealed high potency against Salmonella typhimurium ATCC® 14028™. The highest value is for 5d which has the high inhibitory activity against Cadida albicans.

Insight on Some Newly Synthesized Trisubstituted Imidazolinones as VEGFR-2 Inhibitors.

Two series of ten new 1,2,4-trisubstituted imidazolin-5-ones were synthesized and screened against MCF-7 breast cancer and A549 lung cancer cell lines to test their potential in vitro anticancer activity. The results revealed preferential activity of the tested compounds toward MCF-7 cell lines compared to A549 cell lines. The most promising ten compounds (3a, 3c, 3f, 3g, 3h, 3i, 3j, 6a, 6f, and 6i) were subjected to VEGFR-2 enzyme inhibitory activity testing to further explore their mechanism of action. The tested compounds showed remarkable enzyme inhibition in micromolar concentrations ranging from 0.07 to 0.36 μM, compared with Sorafenib and Sunitinib with IC50 values of 0.06 and 0.12 μM, respectively. The most promising candidate, 3j, was further evaluated for its cell cycle phases, apoptotic induction ability, as well as its antiproliferative activity and inhibitory potential for endothelial cell migration, analyzed by a cell scratch assay. Furthermore, in silico studies were also performed to identify and detect the stability of the binding poses.

Rationale design of novel substituted 1,3,5-triazine candidates as dual IDH1(R132H)/ IDH2(R140Q) inhibitors with high selectivity against acute myeloid leukemia: In vitro and in vivo preclinical investigations

In this study, novel substituted 1,3,5-triazine candidates (4a-d, 5a-j, and 6a-d) were designed as second-generation small molecules to act as dual IDH1 and IDH2 inhibitors according to the pharmacophoric features of both vorasidenib and enasidenib. Compounds 6a and 6b for leukemia cell lines showed from low to sub-micromolar GI50. Moreover, compounds 4c, 5f, and 6b described the frontier antitumor activity against THP1 and Kasumi Leukemia cancer cells with IC50 values of (10 and 12), (10.5 and 7), and (6.2 and 5.9) µg/mL, which were superior to those of cisplatin (25 and 28) µg/mL, respectively. Interestingly, compounds 4c, 6b, and 6d represented the best dual IDH1(R132H)/IDH2(R140Q) inhibitory potentials with IC50 values of (0.72 and 1.22), (0.12 and 0.93), and (0.50 and 1.28) µg/mL, respectively, compared to vorasidenib (0.02 and 0.08) µg/mL and enasidenib (0.33 and 1.80) µg/mL. Furthermore, the most active candidate (6b) has very promising inhibitory potentials towards HIF-1α, VEGF, and SDH, besides, a marked increase of ROS was observed as well. Besides, compound 6b induced the upregulation of P53, BAX, Caspases 3, 6, 8, and 9 proteins by 3.70, 1.99, 2.06, 1.73, 1.75, and 1.85-fold changes, respectively, and the downregulation for the BCL-2 protein by 0.55-fold change compared to the control. Besides, the in vivo behavior of compound 6b as an antitumor agent was evaluated in female mice bearing solid Ehrlich carcinoma tumors. Notably, compound 6b administration resulted in a prominent decrease in the weight and volume of the tumors, accompanied by improvements in biochemical, hematological, and histological parameters.

Discovering the anti-diabetic potential of thiosemicarbazone derivatives: In vitro α-glucosidase, α-amylase inhibitory activities with molecular docking and DFT investigations

This work describes the synthesis of para-substituted thiosemicarbazone derivatives by refluxing 4-ethoxybenzaldehyde (1) and 4-nitrobenzaldehyde (2) with thiosemicarbazide in ethanol with acetic acid catalyst. The resultant thiosemicarbazones were then treated with various phenacyl bromides to get the product compounds. 1H NMR and EI-MS spectroscopic methods were employed to confirm the structures of these derivatives and screened the compounds for their in vitro α-glucosidase and α-amylase inhibitory activities. Six compounds (4e, 3e, 3c, 3b, 4b, and 4c) exhibited highest α-glucosidase activity in the range of IC50 values of 2.81 ± 1.92 to 16.16 ± 0.15 µM. Similar to this, five compounds (3e, 4e, 3b, 3c, and 4c) attributed excellent inhibitory activity in the range of IC50 values from 3.12 ± 0.13 to 16.56 ± 0.17 µM against the α-amylase enzyme when compare with the standard acarbose. The density functional theory (DFT) study demonstrated the stability, bioactivity, and charge transfer of the compounds, while the molecular docking analysis has provided significant understanding of how the compounds interact with the enzymes. These findings provide prospective directions for the development of innovative therapeutic candidates to regulate postprandial glucose levels in diabetic patients.

Design and discovery of urease and Helicobacter pylori inhibitors based on benzofuran/benzothiophene-sulfonate and sulfamate scaffolds for the treatment of ureolytic bacterial infections

A series of sulfonate and sulfamate derivatives bearing benzofuran or benzothiophene scaffold exhibited potent inhibitory effect on urease enzyme. Most of the derivatives exhibited significantly higher potency than thiourea, the standard inhibitor. Compound 1s was identified as the most potent urease inhibitor with an IC50 value of 0.42 ± 0.08 μM, which is 53-fold more potent than thiourea, positive control (IC50 = 22.3 ± 0.031 μM). The docking results further revealed the binding interactions towards the urease active site. Phenotypic screening revealed that compounds 1c, 1d, 1e, 1f, 1j, 1n, and 1t exhibit high potency against H. pylori with MIC values ranging from 0.00625 to 0.05 mM and IC50 values ranging from 0.0031 to 0.0095 mM, much more potent than the positive control, acetohydroxamic acid (MIC and IC50 values were 12.5 and 7.38 mM, respectively). Additional studies were performed to investigate the toxicity of these compounds against the gastric epithelial cell line (AGS) and their selectivity profile against E. coli, and five Lactobacillus species representative of the gut microflora. Permeability characteristics of the most promising derivatives were investigated in Caco-2 cell line. The results indicate that the compounds could be targeted in the GIT only without systemic side effects.

Convenient synthesis and antibacterial evaluation of new bipyrazolyl and pyrazolopyridazine derivatives utilizing 4‐acetyl‐5‐methyl‐N‐phenyl‐1‐(p‐tolyl)‐1H‐pyrazole‐3‐carboxamide as a versatile precursor

Abstract4‐(3‐(Dimethylamino)acryloyl)‐5‐methyl‐N‐phenyl‐1‐(p‐tolyl)‐1H‐pyrazole‐3‐carboxamide was prepared via refluxing of 4‐acetyl‐5‐methyl‐N‐phenyl‐1‐(p‐tolyl)‐1H‐pyrazole‐3‐carboxamide with dimethylformamide dimethyl acetal. The target bipyrazoles were obtained from regioselective reaction of the latter enaminone with different hydrazonoyl halides at reflux in chloroform in the presence of trimethylamine. The regioselectivity was confirmed chemically upon refluxing with hydrazine hydrate in ethanol. The structures of the newly synthesized compounds were established on the basis of their elemental analyses and spectral data. The specified compounds were tested for antibacterial activity against gram‐negative bacteria (Escherichia coli) and (Pseudomonas aeruginosa) and a gram‐positive bacteria (Bacillus subtilis) and (Staphylococcus aureus) using disk diffusion method. Antibacterial studies revealed that compounds 8a, 10b, 10c, 11d, and 14b showed weak to moderate activity against the tested bacteria compared to ampicillin.

Novel Pyrido[4,3-d]pyrimidine Derivatives as Potential Sterol 14α-Demethylase Inhibitors: Design, Synthesis, Inhibitory Activity, and Molecular Modeling.

Thirty-four new pyrido[4,3-d]pyrimidine analogs were designed, synthesized, and characterized. The crystal structures for compounds 2c and 4f were measured by means of X-ray diffraction of single crystals. The bioassay results showed that most target compounds exhibited good fungicidal activities against Pyricularia oryzae, Rhizoctonia cerealis, Sclerotinia sclerotiorum, Botrytis cinerea, and Penicillium italicum at 16 μg/mL. Compounds 2l, 2m, 4f, and 4g possessed better fungicidal activities than the commercial fungicide epoxiconazole against B. cinerea. Their half maximal effective concentration (EC50) values were 0.191, 0.487, 0.369, 0.586, and 0.670 μg/mL, respectively. Furthermore, the inhibitory activities of the bioactive compounds were determined against sterol 14α-demethylase (CYP51). The results displayed that they had prominent activities. Compounds 2l, 2m, 4f, and 4g also showed better inhibitory activities than epoxiconazole against CYP51. Their half maximal inhibitory concentration (IC50) values were 0.219, 0.602, 0.422, 0.726, and 0.802 μg/mL, respectively. The results of molecular dynamics (MD) simulations exhibited that compounds 2l and 4f possessed a stronger affinity to CYP51 than epoxiconazole.

In Vitro and In Vivo Evaluation of the Effects of Drug 2c and Derivatives on Ovarian Cancer Cells

Background: The identification of novel therapeutic strategies for ovarian cancer (OC), the most lethal gynecological neoplasm, is of utmost urgency. Here, we have tested the effectiveness of the compound 2c (4-hydroxy-2,6-bis(4-nitrobenzylidene)cyclohexanone 2). 2c interferes with the cysteine-dependent deubiquitinating enzyme (DUB) UCHL5, thus affecting the ubiquitin-proteasome-dependent degradation of proteins. Methods: 2c phenotypic/molecular effects were studied in two OC 2D/3D culture models and in a mouse xenograft model. Furthermore, we propose an in silico model of 2c interaction with DUB-UCHL5. Finally, we have tested the effect of 2c conjugated to several linkers to generate 2c/derivatives usable for improved drug delivery. Results: 2c effectively impairs the OC cell line and primary tumor cell viability in both 2D and 3D conditions. The effectiveness is confirmed in a xenograft mouse model of OC. We show that 2c impairs proteasome activity and triggers apoptosis, most likely by interacting with DUB-UCHL5. We also propose a mechanism for the interaction with DUB-UCHL5 via an in silico evaluation of the enzyme-inhibitor complex. 2c also reduces cell growth by down-regulating the level of the transcription factor E2F1. Eventually, 2c activity is often retained after the conjugation with linkers. Conclusion: Our data strongly support the potential therapeutic value of 2c/derivatives in OC.

Antibiofilm effect of rubrolide analogues and derived lactams on single-species biofilms

In this study, a series of 26 lactones and lactams have been investigated for their effect against 14 single-species biofilm of oral commensal and pathogenic species (Streptococcus oralis, S. mitis, S. sanguinis, S. gordonii, Actinomyces naeslundii, A. viscosus, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Streptococcus mutans, S. sobrinus, S. salivarius, Veillonella parvula). At the dose of 128 mg/mL, all substances inhibited biofilm formation of S. oralis by more than 60 %, and 19 caused >60 % reduction in the biofilm production by S. sanguinis and A. naeslundi. In addition, 16 compounds showed better results against P. intermedia and F. nucleatum, inhibiting biofilm formation by > 50 %, while 8 compounds caused >40 % reduction in the biofilm formation of A. actinomycetemcomitans. Compounds 5b, 5c, 5d, 5f, and 7 g were the only ones active against S. mutans, and 6d was the only one active against S. sobrinus biofilm formation. Amongst all compounds tested, 24 maintained cell viability above 50 % after 24 h of exposure. In summary, a set of lactones and lactams capable of inhibiting single-species biofilms of oral commensal and pathogenic bacteria without showing significant cytotoxicity against oral epithelial cells were identified. These results highlight the potential of using such antibiofilm compounds as an alternative approach to control oral biofilms.

Synthesis and in vitro antitumor evaluation of new thieno[2,3-d]pyrimidine derivatives as EGFR and DHFR inhibitors

New thienopyrimidine derivatives 2–16 have been synthesized and their in vitro cytotoxicity was evaluated against five different human cancer cell lines HCT-116, Hela, MDA-MB-231, MCF7 and PC3. Compounds 6e, 7a, 7b, 7d, 10c and 10e displayed the highest antitumor activity against all tested cell lines compared to Doxorubicin. Enzyme inhibition assay revealed that compounds 6e and 10e showed high inhibitory activity against EGFR-TK, with IC50 values of 0.133 and 0.151 µM, compared to Olmutinib (IC50 = 0.028 µM); while the highest DHFR inhibitory activity was shown by compounds 7d and 10e with IC50 values of 0.462 and 0.541 µM, compared to Methotrexate (IC50 = 0.117 µM). Cell cycle analysis following a flow cytometric study using colorectal HCT-116 cancer cell line proved that compound 6e induced cell cycle arrest in G0-G1 phase, while compound 10e arrested the cell cycle at both G0-G1 and S phases. Additionally, both compounds (6e and 10e) were potently able to induce apoptosis in HCT-116 cell line. Docking results of compounds 6e and 10e into the pocket of EGFR active site showed their similar main binding features with Olmutinib, while compounds 7d and 10e showed only moderate fitting into DHFR compared to methotrexate. In silico studies revealed that most of the tested compounds obeyed Lipinski’s RO5 and showed positive drug likeness scores.

Rational design, synthesis, biological evaluation, and molecular modeling of novel naphthamide derivatives possessing potent, reversible, and competitive inhibitory mode of action over human monoamine oxidase.

Herein, a novel series of naphthamide derivatives has been rationally developed, synthesized, and evaluated for their inhibitory activity against monoamine oxidase (MAO) and cholinesterase (ChE) enzymes. Compared to the reported naphthalene-based hit IV, the new naphthamide hybrids 2a, 2c, 2g and 2h exhibited promising MAO inhibitory activities; with an IC50 value of 0.294μM, compound 2c most potently inhibited MAO-A, while compound 2g exhibited most potent MAO-B inhibitory activity with an IC50 value of 0.519μM. Compounds 2c and 2g showed selectivity index (SI) values of 6.02 for MAO-A and 2.94 for MAO-B, respectively. On the other hand, most compounds showed weak inhibitory activity against ChEs except 2a and 2h over butyrylcholinesterase (BChE). The most potent compounds 2c and 2g were found to be competitive and reversible MAO inhibitors based on kinetic and reversibility studies. Plausible interpretations of the observed biological effects were provided through molecular docking simulations. The drug-likeness predicted by SwissADME and Osiris property explorer showed that the most potent compounds (2a, 2c, 2g, and 2h) obey Lipinski's rule of five. Accordingly, in the context of neurological disorders, hybrids 2c and 2g may contribute to the identification of safe and potent therapeutic approaches in the near future.