Acetamide Analogs Research Articles

Design and synthesis of new benzothiazole-piperazine derivatives and in vitro and in silico investigation of their anticancer activity

In this work, novel benzothiazole-piperazine acetamide (2a-2l) analogs were synthesized and evaluated their anticancer activity. The 1HNMR , 13CNMR and LC-MS/MS spectral data and elemental analyses were used to clarify the structure of the final molecules. The title compounds were procured by reacting 2‑chloro-N-(6-substituted benzothiazole-2-yl) acetamide with some piperazine derivatives. Cytotoxicity and apoptosis parameters including Annexin V binding capacities, effect on cell cycle, caspase-3 activation and mitochondrial membrane depolarization effect were evaluated to determine anticancer profile of the final molecules on A549 (human lung adenocarcinoma), C6 (glioma cell line) and NIH/3T3 (mouse embryoblast cell line). Mostly, the final molecules showed significant cytotoxic profile with prominent selectivity. 2c (IC50: 7.23±1.17, SI: 6.93), 2d (IC50: 17.50±4.95; SI: 11.59), and 2 h (IC50: 10.83±0.76; SI: 29.23) showed significant and selective cytotoxic activity. Compounds 2b, 2c and 2e provoked apoptosis of A549 cells with potential higher than cisplatin as determined by flow cytometry. The cell cycle analysis of 2b, 2e, 2 g, and 2 h suggested that the A549 cells were affected during G0/G1 phase. Caspase-3 activation was observed on cells by compounds 2a, 2e, 2i and 2l at most. The highest mitochondrial membrane depolarization ratios were seen treated by compounds 2e, 2 h, and 2j. None of the analogs displayed any obvious inhibition activity on MMP-9. The physicochemical properties were predicted for all compounds and also molecular docking and dynamics simulation studies were realized for compound 2e, namely N-(6-methoxybenzothiazol-2-yl)-2-(4-(p-tolyl) piperazin-1-yl) acetamide. The results indicated that merging benzothiazole and piperazine derivatives via acetamide bridge is promising in cancer research because these moieties can interact with the loop and ß-sheet regions of MMP-9. So, 2e was considered as a potential therapeutic agent against lung carcinoma.

Multi-Step Synthesis, Characterization and Bioevaluation of Novel 2-(3-Methoxy-9H-carbazol-9-yl)-N-phenyl Acetamide Analogues

In this work, the multi-step synthesis and characterization of novel 2-(3-methoxy-9H-carbazol-9-yl)-N-phenyl acetamide analogues is presented. These analogues were synthesized from 2-(3-methoxy-9H-carbzol-9-yl)acetyl chloride with substituted aromatic primary amines in the presence of organic base such as triethylamine and methylene dichloride under reflux conditions. The elemental analysis and structures of these novel compounds were elucidated by analyzing spectral data obtained through 1H NMR, 13C NMR and LCMS techniques. The bioevaluation of these newly synthesized compounds has been studied by evaluating their antibacterial and antifungal activities against various kinds of bacterial and fungal strains, respectively.

Activity refinement of aryl amino acetamides that target the P. falciparum STAR-related lipid transfer 1 protein

Malaria is a devastating disease that causes significant morbidity worldwide. The development of new antimalarial chemotypes is urgently needed because of the emergence of resistance to frontline therapies. Independent phenotypic screening campaigns against the Plasmodium asexual parasite, including our own, identified the aryl amino acetamide hit scaffold. In a prior study, we identified the STAR-related lipid transfer protein (PfSTART1) as the molecular target of this antimalarial chemotype. In this study, we combined structural elements from the different aryl acetamide hit subtypes and explored the structure-activity relationship. It was shown that the inclusion of an endocyclic nitrogen, to generate the tool compound WJM-715, improved aqueous solubility and modestly improved metabolic stability in rat hepatocytes. Metabolic stability in human liver microsomes remains a challenge for future development of the aryl acetamide class, which was underscored by modest systemic exposure and a short half-life in mice. The optimized aryl acetamide analogs were cross resistant to parasites with mutations in PfSTART1, but not to other drug-resistant mutations, and showed potent binding to recombinant PfSTART1 by biophysical analysis, further supporting PfSTART1 as the likely molecular target. The optimized aryl acetamide analogue, WJM-715 will be a useful tool for further investigating the druggability of PfSTART1 across the lifecycle of the malaria parasite.

Design, Synthesis, and Evaluation of Cephamycin-Based Antisporulation Agents targeting Clostridioides difficile.

With the aim of discovering small molecule inhibitors of the sporulation process in Clostridioides difficile, we prepared a series of C-7 α-(4-substituted-1H-1,2,3-triazol-1-yl)acetamide analogues of cefotetan, a known inhibitor of the C. difficile sporulation-specific protein target CdSpoVD. These analogues were evaluated using both in vitro binding assays with CdSpoVD and antisporulation assays against C. difficile. Further design concepts were aided utilizing the predicted docking scores (DS) using both AlphaFold (AF) models, and a crystal structure of the CdSpoVD protein (PDB 7RCZ). Despite being 1 order of magnitude more potent as a sporulation inhibitor than cefotetan, in vivo studies on compound 6a in a murine-model of C. difficile infection demonstrated comparable spore shedding capabilities as cefotetan. Importantly, compound 6a had no concerning broad spectrum antibacterial activities, toxicity, or hemolytic activity and thus has potential for further drug development.

Design, Synthesis, Characterization, and Analysis of Antimicrobial Property of Novel Benzophenone Fused Azetidinone Derivatives through In Vitro and In Silico Approach.

A sequence of novel 2-(4-benzoyl-2-methyl-phenoxy)-N-(3-chloro-2-oxo-4-phenyl-azetidin-1-yl)-acetamide analogues 9(a-n) were synthesized by multistep synthesis. The newly synthesized compounds were well characterized, and their antimicrobial activities were carried out by disc diffusion and broth dilution methods. Further, all the novel series of compounds (9a-n), were tested against a variety of bacterial and fungal strains in comparison to Ketoconazole, Chloramphenicol, and Amoxicillin as standard drugs, respectively. Compounds 9a, 9e, and 9g as a lead molecule demonstrated a good inhibition against tested strains. Further, molecular docking studies have been performed for the potent compounds to check the three-dimensional geometrical view of the ligand binding to the targeted proteins.

Synthesis and Molecular Modeling Studies of 2-[2-(3-nitrophenyl)-1h-benzimidazol-1-yl]-acetamide Derivatives as Anthelmintic

Benzimidazole derivatives of substituted 2 [2-(3-nitrophenyl)-1H-benzimidazole-1-yl] acetamide analogues were synthesized and studied for antihelminthic activity. Compounds 3a–o were obtained in three steps, starting with the Oxidative Condensation of the appropriate 3-nitrobenzaldeyde, o-phenylenediamine and sodium hydrogen sulfite to form 2-(3-nitrophenyl)-1H-benzimidazole (1a). In second step Nucleophilic substitution, Chlorine atom of ethylchloroacetate will attach on nitrogen of benzimidazole by replacing hydrogen with elimination of hydrochloric acid to form ethyl [2-(3-nitrophenyl)-1H-benzimidazole-1-Yl acetate (2a).In third step amide formation from ester takes place by substitution of electrophilic with loss of ethanol to form substituted 2 [2-(3-nitrophenyl)-1H-benzimidazole-1-yl] acetamide 3a–o The antihelminthic activity showed that compounds 3f, 3h, 3i, 3j and 3k good activity against Indian earthworms (Pheretima posthuma) in comparison to albendazole.

Modulation of DNA damage response by targeting ATM kinase using newly synthesized di-phenoxy acetamide (DPA) analogs to induce anti-neoplasia.

Imbalance and instability in the structure of the DNA have become major characteristics of cancer. In response to DNA damage, DNA damage response (DDR) protein, ataxia telangiectasia mutated (ATM), plays a pivotal role in the modulation of regulatory regions responsible for inhibition of apoptosis, thereby neoplastic progression. A new series of DPA (7a-t) were synthesized, characterized. Anti-proliferative studies to identify the lead compound were carried out by LDH and MTT assay. Apoptosis/DNA damage was measured through FACS, Annexin-v staining, TUNEL and Comet assay. Elucidation of molecular mechanism through immunoblot and further validation of the drug effect through in vivo approaches. Initial in vitro anti-proliferative screening of Compounds DPA (7a-t) against multiple cancer cell lines identified Compound DPA (7n) as a potent cytotoxic molecule with IC50 value of 4.3μM. Down the line, in vitro and in vivo evaluation of Compound DPA (7n) inferred that it has apoptotic inducing potentiality. Further, evaluation of molecular mechanism inferred that Compound DPA (7n) effectively modulates ATM phosphorylation only, eventually altering downstream signalling pathways. Compound DPA (7n) emerged as a potent proapoptotic and anti-neoplastic agent by inhibiting ATM kinase activity both in vitro and in vivo. The conferring results ascertain that the drug could be developed as a new ATM kinase inhibitor with anti-cancer capacity.

Synthesis and activity of N-(5-hydroxy-3,4,6-trimethylpyridin-2-yl)acetamide analogues as anticolitis agents via dual inhibition of TNF-α- and IL-6-induced cell adhesions

Tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) are the critical pro-inflammatory cytokines involved in the pathogenesis of inflammatory bowel disease (IBD). Inhibition of these cytokines and related signaling pathways has been a target for the development of IBD therapeutics. In the current study, 6-acetamido-2,4,5-trimethylpyridin-3-ol (1) and various analogues with the amido scaffold were synthesized and examined for their inhibitory activities in in vitro and in vivo IBD models. The parent compound 1 (1 μM) showed an inhibitory activity against TNF-α- and IL-6-induced adhesion of monocytes to colon epithelial cells, which was similar to tofacitinib (1 μM), a JAK inhibitor, but much better than mesalazine (1,000 μM). All the analogues showed a positive relationship (R2 = 0.8943 in a linear regression model) between the inhibitory activities against TNF-α-induced and those against IL-6-induced adhesion. Compound 2–19 turned out to be the best analogue and showed much better inhibitory activity against TNF-α- and IL-6-induced adhesion of the cells than tofacitinib. In addition, oral administration of compound 1 and 2–19 resulted in a significant suppression of clinical signs of TNBS-induced rat colitis, including weight loss, colon tissue edema, and myeloperoxidase activity, a marker for inflammatory cell infiltration in colon tissues. More importantly, compound 2–19 (1 mg/kg) was more efficacious in ameliorating colitis than compound 1 and sulfasalazine (300 mg/kg), the commonly prescribed oral IBD drug. Taken together, the results suggest that compound 2–19 can be a novel platform for dual-acting IBD drug discovery targeting both TNF-α and IL-6 signaling.

Sulfonamides incorporating ketene N,S-acetal bioisosteres as potent carbonic anhydrase and acetylcholinesterase inhibitors.

In this study, 15 novel compounds in a series of sulfonamide-based ketenes (7a-o) were synthesized and characterized using Fourier-transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and mass spectrometry. All compounds were tested for their ability to inhibit the human carbonic anhydrase (hCA) isoforms I and II, and acetylcholinesterase (AChE). The halogen-appended compounds, 7g, 7o, and 7i, exhibited the highest hCA I/II and AChE inhibition, with the KI values in the low nanomolar range (KI = 9.01 ± 0.08, 7.41 ± 0.03, and 7.37 ± 0.31 nM, respectively), as compared with their corresponding parent 2-[2,2-dicyano-1-(phenylamino)vinylthio]-N-(4-sulfamoylphenyl)acetamide analogs 7a-o. Besides, derivatives 7c and 7e selectively inhibited the isoform hCA I, whereas compounds 7m and 7n selectively inhibited isoform hCA II. These findings indicated that all compounds can inhibit metabolic dysfunctions, such as edema, epilepsy, glaucoma, and Alzheimer's disease, by specifically targeting both the hCA isoforms and AChE expression. Herein, also the interactions between ligands and receptors were highlighted through in silico molecular docking studies. The molecular mechanics-generalized Born surface area method was utilized to compute the binding free energy and the energy contribution of the critical residues in the active site was estimated. All these results would help us to perfectly understand the relationship between activity and structural characteristics of derivatives and to further improve newly and highly effective analogs targeting hCA and AChE.

Magnetic silica nanoparticle-supported copper complex as an efficient catalyst for the synthesis of novel triazolopyrazinylacetamides with improved antibacterial activity

A novel superparamagnetic iron oxide modified with copper via 2-aminobenzamide is synthesized by the modification of Fe3O4@SiO2 with amine, followed by the reaction with isatoic anhydride. The catalyst is fully characterized by various methods. The catalytic activity of the catalyst is evaluated in the synthesis of a series of novel N-alkyl-2-aryl-2-(6-oxo-6,7-dihydro[1,2,3]triazolo[1,5-a]pyrazin-5(4H)-yl)acetamide analogs. Antibacterial activity of the synthesized compounds is evaluated. The catalyst is recoverable and shows excellent reusability in 10 sequential runs.

Design and synthesis of sulphonyl acetamide analogues of quinazoline as anticancer agents

A series of sulphonyl acetamide analogues were generated on the quinazoline ring through a multistep reaction starting from 2-mercapto-3H-quinazolin-4-one. The library of synthesised analogues was screened for in vitro cytotoxic activity against various human cancer cell lines such as HCT-1 and HT-15 (colon), MCF-7(Breast), PC-3 (Prostrate), SF268 (CNS) using MTT method. From the bioassay results, it was observed that even though most of the synthesised derivatives exhibited a good potency against various screened cancer cell lines, but compound 10d, 10k, and 10n were found to show very potent anticancer activity on all tested cancer cell lines with compound 10d showing IC50 value of 0.08, 0.3 and 0.55 µM on HT-29, MCF-7 and PC-3 cell lines, respectively, compound 10k showing IC50 value of 0.12, 0.03 and 0.08 µM on HCT-15, HT-29 and PC-3 cell lines, respectively, and compound 10n showing IC50 values of 0.1, 0.34, 0.52 and 0.26 on HCT-15, HT-29, MCF-7 and PC-3 cell lines, respectively.

Spectroscopic, quantum mechanical studies, ligand protein interactions and photovoltaic efficiency modeling of some bioactive benzothiazolinone acetamide analogs

In the present work, the molecules, N-(4-chlorophenyl)-2-[6-(benzoyl)-2-benzothiazolinone-3-yl]acetamide (CBBA), N-(6-methyl-2-pyridyl)-2-[6-(2-chlorobenzoyl)-2-benzothiazolinone-3-yl]acetamide (MCBA), N-(3-Chlorophenyl)-2-[6-(2-fluorobenzoyl)-2-benzothiazolinone-3-yl]acetamide (CFBA) and N-(6-methyl-2-pyridyl)-2-[6-(2-fluorobenzoyl)-2-benzothiazolinone-3-yl]acetamide (MFBA) have been synthesized followed by the study of vibrational spectra and electronic properties. Photochemical and thermochemical modeling of the title compounds is also performed to analyze its ability to be used as phtosensitizers in dye-sensitized solar cells (DSSCs) and the compounds are found to show good light harvesting efficiency (LHE) and good free energy of electron injection to be used in the photo-voltaic cells. The non-linear optical (NLO) activity of the compounds has been investigated and second-order hyperpolarizability values vary in the order CFBA > CBBA > MCBA > MFBA. Natural bond orbital analysis provided insights into the various possible intramolecular interactions. Molecular docking has been accomplished by the Schrodinger suite to understand the binding interactions of the analyzed ligands with Cyclooxygenase 1 (COX1). Molecular docking studies indicated that compound MFBA had the best binding affinity.

Synthesis of new analogs of 3-methyl-[1,2,4] triazolo [3,4-a] phthalazines via Suzuki coupling and evaluation of their anticancer and antimicrobial activity

A series of new N-aryl substituted phenyl acetamide analogs of 3-methyl-[1,2,4] triazolo[3,4-a] phthalazines were synthesized starting from commercially available, in-expensive phthalic anhydride in good yields (65-75 %) via Suzuki Coupling. These compounds were tested for inhibition activity against HCT 116 cancer cell line by using MIT assay. Among the library of compounds, N-(3-methoxyphenyl)-2-(4-(3-methyl-[1,2,4]triazolo[3,4-a]phthalazin-6-yl)phenyl) acetamide followed by 2-(4-(3-methyl-[1,2,4]triazolo[3,4-a]phthalazin-6-yl)phenyl)-N-(m-tolyl) acetamide and  N-(3-chlorophenyl)-2-(4-(3-methyl-[1,2,4]triazolo[3,4-a]phthalazin-6-yl)phenyl) acetamide  were found to be active compounds with IC50 of 70 to and 90 µg mL-1. Further, the compounds were also screened for their antimicrobial activities.

Synthesis and Reactivities of Triphenyl Acetamide Analogs for Potential Nonlinear Optical Material Uses

We have synthesized aniline based amides (3a–h) via palladium catalyzed Suzuki cross coupling of N-(2,5-dibromophenyl) acetamide with different arylboronic acids in moderate to good yields. A variety of functional groups were well tolerated in reaction conditions. For exploring the possible applications as optoelectronic devices, the nonlinear optical (NLO) properties of all synthesized derivatives (3a–h) were investigated with the help of density functional theory (DFT) methods. The frontier molecular orbitals analysis and reactivity descriptors were investigated for exploring the reactivities.

4-Aminophenyl acetamides and propanamides as potent transient receptor potential vanilloid 1 (TRPV1) ligands

A series of 2-(3,5-substituted 4-aminophenyl)acetamide and propanamide derivatives were investigated as human TRPV1 antagonists. The analysis of the structure-activity relationship indicated that 2-(3,5-dihalo 4-aminophenyl)acetamide analogues displayed excellent antagonism of hTRPV1 activation by capsaicin and showed improved potency compared to the corresponding propanamides. The most potent antagonist (36) exhibited potent and selective antagonism for hTRPV1 not only to capsaicin but also to NADA and elevated temperature; however, it only displayed weak antagonism to low pH. Further studies indicated that oral administration of antagonist 36 blocked the hypothermic effect of capsaicin in vivo but demonstrated hyperthermia at that dose. A docking study of 36 was performed in our established hTRPV1 homology model to understand its binding interactions with the receptor and to compare with that of previous antagonist 1.

N-hydroxy-substituted 2-aryl acetamide analogs: A novel class of HIV-1 integrase inhibitors.

An in silico method has been used to discover N-hydroxy-substituted 2-aryl acetamide analogs as a new class of HIV-1 integrase inhibitors. Based on the molecular requirements of the binding pocket of catalytic active site, two molecules (compounds 2 and 4b) were designed as fragments. These were further synthesized and biologically evaluated. In vitro potency along with docking studies highlighted compound 4b as an active fragment which was further used to synthesize new leads as HIV-1 integrase inhibitors. Finally, six promising compounds (compounds 5b, 5c, 5e, 6-2c, 6-3b, and 6-5b) were identified by integrase inhibition assay (>50% inhibition). Based on in vitro anti-HIV-1 activity in a reporter gene-based cell assay system, compounds 5d, 6s, and 6k were found as novel HIV-1 integrase inhibitors due to its better selectivity index. Additionally, docking study revealed the importance of H-bond as well as hydrophobic interactions with Asn155, Lys156, and Lys159 which were required for their anti-HIV-1 activity.

Synthesis of novel pyrazolo[3,4-b]quinolinyl acetamide analogs, their evaluation for antimicrobial and anticancer activities, validation by molecular modeling and CoMFA analysis

A series of novel alkyl amide functionalized 2,3-pyrazole fused quinoline derivatives 5, 6 and 7 have been prepared starting from quinoline-2(1H)one 1 in a series of steps. All the final products were screened for antibacterial activity, the promising lead compound 5r was identified with MIC values ranging between 3.9 and 7.8 μg/mL against different bacterial strains. Compound 5r also showed good antifungal and anti-biofilm activities against the tested panel of various fungal and bacterial strains. Compound 5r when treated on mature biofilms of S. aureus strain MLS16, showed increased levels of intracellular ROS accumulation suggesting its contribution to the bactericidal activity. All the compounds were also screened for anticancer activity against a panel of four human cancer cell lines. Based on these studies, compounds 5c, 5d, 5r and 7f were considered as promising and exhibited significant cytotoxicity with IC50 values of <15 μM. The biological activity data was further validated by molecular modeling and CoMFA studies.

Synthesis and Characterization of S(-)1-Phenyl-1,2,3,4-Tetrahydro Isoquinoline Acetamide Analogues

Synthesis and Characterization of S(-)1-Phenyl-1,2,3,4-Tetrahydro Isoquinoline Acetamide Analogues

Novel and High Affinity 2-[(Diphenylmethyl)sulfinyl]acetamide (Modafinil) Analogues as Atypical Dopamine Transporter Inhibitors.

The development of pharmacotherapeutic treatments of psychostimulant abuse has remained a challenge, despite significant efforts made toward relevant mechanistic targets, such as the dopamine transporter (DAT). The atypical DAT inhibitors have received attention due to their promising pharmacological profiles in animal models of cocaine and methamphetamine abuse. Herein, we report a series of modafinil analogues that have an atypical DAT inhibitor profile. We extended SAR by chemically manipulating the oxidation states of the sulfoxide and the amide functional groups, halogenating the phenyl rings, and/or functionalizing the terminal nitrogen with substituted piperazines, resulting in several novel leads such as 11b, which demonstrated high DAT affinity (Ki = 2.5 nM) and selectivity without producing concomitant locomotor stimulation in mice, as compared to cocaine. These results are consistent with an atypical DAT inhibitor profile and suggest that 11b may be a potential lead for development as a psychostimulant abuse medication.

Design and synthesis of diamide-coupled benzophenones as potential anticancer agents

A series of diamide-coupled benzophenone, 2-(4-benzoyl-phenoxy)-N-{2-[2-(4-benzoyl-phenoxy)-acetylamino]-phenyl}-acetamide analogues (9a-l) were synthesized by multistep reactions and all compounds were well characterized. Among the series (9a-l), compound 9k with three methyl groups at ortho position in rings A, B, and D and bromo group at the para position in ring E was selected as a lead compound by screening through multiple cancer cell types by in-vitro cytotoxic and antiproliferative assay systems. Also, the cytotoxic nature of the compound 9k resulted the regression of the tumor growth in-vivo, which could be due to decreased vascularisation in the peritoneum lining of the mice which regress the tumor growth. The results were reconfirmed in-vivo chorioallantoic membrane model which indicates a scope of developing 9k into potent anticancer drug in near future.