A diminutive chemical library of acyl thiotriazinoindole (ATTI) based bioactive scaffolds was synthesized, instigated by taking the economical starting material Isatin, through a series of five steps. Isatin was first nitrated followed by the attachment of pentyl moiety via nucleophilic substitution reaction. The obtained compound was reacted with thiosemicarbazide to obtain thiosemicarbazone derivative, which was eventually cyclized using basic conditions in water as solvent. Finally, the reported series was obtained through reaction of nitrated thiotriazinoindole moiety with differently substituted phenacyl bromides. The synthesized compounds were characterized using NMR spectroscopy and elemental analysis. Finally, the synthesized motifs were scrutinized for their potential to impede urease, α-glucosidase, DPPH, and α-amylase. Compound 5 h with para cyano group manifested the most pivotal biological activity among all, displaying IC50 values of 29.7 ± 0.8, 20.5 ± 0.5 and 36.8 ± 3.9 µM against urease, α-glucosidase, and DPPH assay, respectively. Simultaneously, for α-amylase compound 5 g possessing a p-CH3 at phenyl ring unfolded as most active, with calculated IC50 values 90.3 ± 1.1 µM. The scaffolds were additionally gauged for their antifungal and antibacterial activity. Among the tested strains, 5d having bromo as substituent exhibited the most potent antibacterial activity, while it also demonstrated the highest potency against Aspergillus fumigatus. Other derivatives 5b, 5e, 5i, and 5j also exhibited dual inhibition against both antibacterial and antifungal strains. The interaction pattern of derivatives clearly displayed their SAR, and their docking scores were correlated with their IC50 values. In molecular docking studies, the importance of interactions like hydrogen bonding was further asserted. The electronic factors of various substituents engendered variety of interactions between the ligands and targets implying their importance in the structures of the synthesized heterocyclic scaffolds. To conclude, the synthesized compounds had satisfactory biological activity against various important targets. Further studies are therefore encouraged by attachment of different substitutions in the structure at various positions to enhance the activity of these compounds. Exploring Acyl Thiotriazinoindole based Pharmacophores: Design, Synthesis, and SAR studies with Molecular Docking and Biological Activity Profiling against Urease, α-amylase, α-glucosidase, Antimicrobial, and Antioxidant Targets An updated synthetic pathway to furnish acyl thiotriazinoindole based scaffolds was developed starting from Isatin and the novel compounds were assessed for various biological applications.

Three newly synthesized amantadine thiourea conjugates namely MS-1 N-(((3 s,5 s,7 s)-adamantan-1-yl)carbamothioyl)benzamide, MS-2 N-(((3 s,5 s,7 s)-adamantan-1-yl)carbamothioyl)-4-methylbenzamide and MS-3 N-((3 s,5 s,7 s)-adamantan-1-ylcarbamothioyl)-4-chlorobenzamide were investigated for their structures, bindings (DNA/ elastase), and for their impact on healthy and cancerous cells. Theoretical (DFT/docking) and experimental {UV-visible (UV-), fluorescence (Flu-), and cyclic voltammetry (CV)} studies indicated binding interactions of each conjugate with DNA and elastase enzyme. Theoretically and experimentally calculated binding parameters for conjugate - DNA interaction revealed MS-3 - DNA to have most significant binding with comparatively greater values of binding parameters {(K-b/M-1: docking, 3.8 x 10(5); UV-, 5.95 x 10(3); Flu-,1.55 x 10(5); CV, 1.52 x 10(4)), (triangle G/ kJmol(-1): docking, -32.09; UV-, -22.40; Flu-,-30.81; CV, -24.82)}. The docked structures, greater bindings site size values (n), and the trend in DNA viscosity changes in the presence of each conjugate concentration confirmed a mixed binding mode of interaction among them. Conjugate - elastase binding by docking agreed with the experimental anti-elastase findings. Cytotoxicity studies of each tested conjugate demonstrated greater cytotoxicity for cancerous (MG-U87) cells in comparison to control, while for the normal (HEK-293) cells the cytotoxicity was found comparatively low. Overall exploration suggested that MS-3 is the most effective candidate for DNA binding, anti-elastase, and for anti-glioma activities.

Diabetes mellitus is a multi-systematic chronic metabolic disorder and life-threatening disease resulting from impaired glucose homeostasis. The inhibition of glucosidase, particularly α-glucosidase, could serve as an effective methodology in treating diabetes. Attributed to the catalytic function of glucosidase, the present research focuses on the synthesis of sulfonamide-based acyl pyrazoles (5a-k) followed by their in vitro and in silico screening against α-glucosidase. The envisaged structures of prepared compounds were confirmed through NMR and FTIR spectroscopy and mass spectrometry. All compounds were found to be more potent against α-glucosidase than the standard drug, acarbose (IC50 = 35.1 ± 0.14 µM), with IC50 values ranging from 1.13 to 28.27 µM. However, compound 5a displayed the highest anti-diabetic activity (IC50 = 1.13 ± 0.06 µM). Furthermore, in silico studies revealed the intermolecular interactions of most potent compounds (5a and 5b), with active site residues reflecting the importance of pyrazole and sulfonamide moieties. This interaction pattern clearly manifests various structure–activity relationships, while the docking results correspond to the IC50 values of tested compounds. Hence, recent investigation reveals the medicinal significance of sulfonamide-clubbed pyrazole derivatives as prospective therapeutic candidates for treating type 2 diabetes mellitus (T2DM).

IC 50 values of the new synthesized pyrazoline-acyl thioureas revealed 5b and 5g as potent urease inhibitors. Whilst compound 5b is a potent α-glucosidase inhibitor, compound 5f is a potent amylase inhibitor, compound 5b is a potent antioxidant.

In this work, it is designed and synthesized therapeutically active anti-urease agents based on 3-bromosulfanilamide-based acyl thioureas (4a-j) through reaction of brominated sulfanilamide with aromatic acids via isothiocyanate formation and characterized by using FT-IR, 1HNMR, 13C NMR and MS analysis. The freshly prepared compounds were screened for in vitro urease inhibition assay. The derivative 4a with an un-substituted phenyl group showed IC50 value of 17.02 ± 0.011 against urease as compared to the standard thiourea (IC50 = 21 ± 0.12 µM). Structure activity relationship (SAR) revealed that the electronic and positional effects of substituents on phenyl ring play important role for the inhibition of clinically important enzymes. Additionally, in silico investigation was carried out which demonstrated that the compounds have exhibited polar and nonpolar interaction with the crucial residues in the binding site of urease. The in vitro and in silico studies are in agreement as per kinetics and docking results indicating that the synthesized 3-bromosulfanilamide-based acyl thiourea derivatives may serve as potential hits for the discovery of new urease inhibitors.

The conventional approach of drug development, which focused on inhibiting a single target, has been superseded by a more advanced strategy known as multi-target design. In this study, we describe the synthesis of new N-adamantyl-2-(2-(phenyl)hydrazone)-3-oxobutanamide (6a-k). These compounds were designed with the intention of serving as prospective drug like candidates that can target both alpha glucosidase and urease enzymes. For this purpose, both in-vitro and in-silico investigations were performed after synthesis and characterization. The density functional theory calculations were employed to calculate optimized geometries, global reactivity descriptors and frontier molecular orbital (FMO) analysis. All compounds were found reactive and compounds 6b, 6c, 6d and 6e were found the most stable. The synthesized compounds were also tested for their ability to inhibit the enzyme activities of urease and α-glucosidase. The compound 6c exhibited strong inhibition of urease enzyme, with IC50 value of 13.10 ± 0.55 µM, in comparison to the IC50 value of the standard inhibitor thiourea i.e., 16.4 ± 1.02 µM. In addition to this, compounds 6d and 6e demonstrated a significant α-glucosidase inhibition with IC50 values of 17.16 ± 0.91 µM but found less potent as compared to the standard inhibitor Acarbose, i.e. 9.80 ± 0.20 μM. The structure–activity relationship (SAR) was established and the in-vitro results were further supported by the molecular docking investigations and molecular dynamic simulation studies. The in-vitro and in-silico results demonstrated a strong correlation in assessing the drug-like characteristics of all synthesized compounds (6a-k). The in silico investigation confirmed the findings in the search for inhibitors against the listed enzymes by elucidating the binding relationship between most of the active compounds and the active site of urease and α-glucosidase.

In the present work, 2-imino-1,3-thiazolines featuring highly fluorinated fragments were synthesized through a straightforward cyclization of diversely substituted thioureas with 2-bromo-1-(4-fluorophenyl)ethan-1-one. The target compounds were obtained in good yields, and structures were established by FTIR and H-1- and C-13 NMR spectroscopic methods. The in vitro biological assay revealed that all the compounds significantly obstruct the alpha-glucosidase. Compound 6d (3-fluoro-N-(3-(2-fluorophenyl)-4-(4-fluorophenyl)thiazol-2(3H)-ylidene)benzamide) showed the highest antidiabetic potential with an IC50 value of 1.47 +/- 0.05 mu M. In addition, computational analysis revealed the binding energy of -11.1 kcal/mol for 6d which was lower than the positive standard, acarbose (-7.9 kcal/mol). Several intermolecular interactions between the active site residues and 6d highlight the significance of 2-imino-1,3-thiazoline core in attaining the potent efficacy and making these compounds a valuable pharmacophore in drug discovery.

The current study was aimed to synthesize a series of adamantane-linked aminothiazole derivatives (6a-) and to assess their enzyme inhibitory activities. These derivatives were synthesized based on the structural features of known enzyme inhibitors, and their structures were characterized using various spectroscopic techniques, including FTIR, 1H NMR, 13C NMR, and mass spectrometry. The synthesized compounds were further evaluated for their inhibitory activities against the enzymes urease, α-glucosidase and carbonic anhydrase. The results of the enzyme inhibitory activity showed that compounds 6c, 6g and 6k possessed an excellent urease inhibitory activities, with IC50 values of 18.07 ± 0.11, 13.05 ± 0.2 and 17.12 ± 0.1 µM, respectively. These values were significantly lower than the IC50 value of the standard inhibitor thiourea (21,021 ± 0.02 µM). Additionally, compound 6c and 6e showed good α-glucosidase inhibitory activities. Therefore, compound 6c and 6e has excellent activity of IC50 value as 18.4 ± 0.11 and 58.01 ± 0.8 µM against α-glucosidase enzyme, respectively, and considerable relative potency compared with the known α-glucosidase inhibitor i.e., acarbose having an IC50 value of 883.93 ± 2.18 µM. The inhibitory effect of the compound 6f, 6k, 6j was considerably high against carbonic anhydrase, with their IC50 values of 3.02 ± 0.31 µM, 4.5 ± 0.041 µM and 2.7 ± 0.004 µM, respectively, as compared to acetazolamide with an IC50 value of IC50 0.12 ± 0.03 µM. The molecular docking of the active compounds docked in the active site of urease, α-glucosidase enzyme and carbonic anhydrase and depicted a good-binding score for all active derivatives. The present results indicate the significance of the structure–activity relationship in the development of potent enzyme inhibitors. Hence, the results obtained from the current study may be useful for designing further studies on related compounds with potential medicinal importance.

Bis-acyl-thiourea derivatives, namely N,N’-(((4-nitro-1,2-phenylene)bis(azanediyl)) bis(carbonothioyl))bis(2,4-dichlorobenzamide) (UP-1), N,N’-(((4-nitro-1,2-phenylene) bis(azanediyl))bis(carbonothioyl))diheptanamide (UP-2), and N,N’-(((4-nitro-1,2-phenylene)bis(azanediyl))bis(carbonothioyl))dibutannamide (UP-3), were synthesized in two steps. The structural characterization of the derivatives was carried out by FTIR, 1H-NMR, and 13C-NMR, and then their DNA binding, anti-urease, and anticancer activities were explored. Both theoretical and experimental results, as obtained by density functional theory, molecular docking, UV-visible spectroscopy, fluorescence (Flu-)spectroscopy, cyclic voltammetry (CV), and viscometry, pointed towards compounds’ interactions with DNA. However, the values of binding constant (Kb), binding site size (n), and negative Gibbs free energy change (ΔG) (as evaluated by docking, UV-vis, Flu-, and CV) indicated that all the derivatives exhibited binding interactions with the DNA in the order UP-3 > UP-2 > UP-1. The experimental findings from spectral and electrochemical analysis complemented each other and supported the theoretical analysis. The lower diffusion coefficient (Do) values, as obtained from CV responses of each compound after DNA addition at various scan rates, further confirmed the formation of a bulky compound–DNA complex that caused slow diffusion. The mixed binding mode of interaction as seen in docking was further verified by changes in DNA viscosity with varying compound concentrations. All compounds showed strong anti-urease activity, whereas UP-1 was found to have comparatively better inhibitory efficiency, with an IC50 value of 1.55 ± 0.0288 µM. The dose-dependent cytotoxicity of the synthesized derivatives against glioblastoma MG-U87 cells (a human brain cancer cell line) followed by HEK-293 cells (a normal human embryonic kidney cell line) indicated that UP-1 and UP-3 have greater cytotoxicity against both cancerous and healthy cell lines at 400 µM. However, dose-dependent responses of UP-2 showed cytotoxicity against cancerous cells, while it showed no cytotoxicity on the healthy cell line at a low concentration range of 40–120 µM.

A series of ten novel compounds were synthesized by incorporating a 1,3 thiazole core into amantadine and their structures were validated using different analytical and spectral methods such as FTIR, EI-MS, 1H NMR, and 13C NMR. The antibacterial and enzyme inhibitory properties of these newly synthesized compounds were evaluated. Remarkably, the compounds exhibited significant antibacterial activity against Escherichia coli and Bacillus subtilis. Additionally, the in vitro inhibitory activities of the synthesized compounds, against α-amylase, α-glucosidase, and urease were investigated. Among the tested compounds, compound 6d demonstrated potent and selective inhibition of α-amylase IC50 = 97.37 ± 1.52 μM, while acarbose was used as positive control and exhibited IC50 = 5.17 ± 0.25 μM. Compound 6d and 6e exhibited prominent inhibition against α-glucosidase IC50 = 38.73 ± 0.80 μM and 41.63 ± 0.26 μM respectively. Furthermore, compound 6d inhibited urease with exceptional efficacy IC50 = 32.76 μM, while positive control thiourea showed more prominent activity having IC50 = 1.334 μM. Molecular docking studies disclosed the binding mechanism and affinity of these new inhibitors within the binding sites of various amino acids. To investigate the association between molecular structural characteristics and inhibitory actions of synthesized derivatives, preliminary structure-activity relationship (SAR) studies were performed. These findings indicated that compounds 6a, 6c, 6d and 6e are potential candidates for hit-to-lead follow-up in the drug-discovery process for treating diabetes and hyperglycemia.

Carbonic anhydrases (CAs) representing the class of metalloenzymes are expressed widely and play a crucial role in various physiological and pathological processes. The Alkyl substituted Acyl Thiourea was synthesized and characterized by NMR spectroscopic technique. Single crystal X-ray diffraction was applied to determine the molecular and crystal structures. Synthesized compound crystallized in monoclinic system P 2(1)/c space group. Intermolecular N-H center dot center dot center dot S hydrogen bonds and Intramolecular N-H center dot center dot center dot O hydrogen bond were found in crystal structure. H ... H interactions have major contributions in crystal packing as depicted by Hirshfeld surface analysis. No large cavity was observed during void volume analysis in the crystal packing. Stabilization was dominated via the dispersion energy contributions in the synthesized compound. In Vitro analysis showed that synthesized compound inhibited the carbonic anhydrase activity to an appreciable extent. Quantum mechanical descriptors were calculated using DFT studies. In molecular docking, reactive parts of the synthesized molecule contributed in forming the hydrogen bond with receptor protein target. Finally, ADMET Analysis were performed to assess the drug-like behavior of synthesized compound. Carbonic Anhydrase enzyme inhibitor of pharmaceutical significance can be developed using the synthesized molecule ES-2 as a lead molecule.

Molecular hybridization has emerged as an interesting strategy to improve the effectiveness and the scope of well-known drugs. Nimesulide has been used as non-steroidal anti-inflammatory (NSAID) drug for decades and marketed as NIMS™. Nimesulide (3) possesses a nitro group which shows toxic behavior. To enhance the scope and efficacy of the drug nitro group was reduced to amino group (4) and reacted with isothiocyanates of different substituted acid chlorides to afford Nimesulide-acyl thiourea conjugates (5a-n). In the present research work 14 derivatives were synthesized and tested for carbonic anhydrase I, II and α-glucosidase Inhibition assay. These findings established that all new derivatives are more effective α-amylase inhibitors than Acarbose (IC50: 10000 ​nM) used as a positive control α-amylase inhibitor. Among the tested compounds 5g, 5l and 5m were determined to be the best hCA I, II inhibitors.

Porcine Pancreatic Elastase (PPE) is a serine protease that is homologous to trypsin and chymotrypsin that are involved in various pathologies like inflammatory disease, Chronic Obstructive Pulmonary Disease (COPD), acute respiratory distress syndrome, cystic fibrosis, and atherosclerosis. PPE if remained uninhibited would lead to digestion of important connective tissue. We developed new structurally diverse series of adamantyl-iminothiazolidinone hybrids to divulge elastase inhibition assay. To identify potent derivatives, in silico screening was conducted and in vitro studies disclosed that the compounds 5a, 5f, 5g, and 5h showed excellent binding energies and low IC50 values. In silico studies including molecular docking, DFT studies (using the B3LYP/SVP basis set in the gas phase) drug likeness scores and molecular dynamic simulation studies were conducted to evaluate protein-ligand interactions and to determine the stability of top ranked conformation. In silico studies further supported the results of in vitro experiments and suggest these derivatives as novel inhibitors of elastase enzyme.

A small library of ten new Nimesulide-iminothiazolines conjugates was synthesized by the reduction of nitro group of Nimesulide followed by conversion into variously substituted acyl thioureas. Heterocyclization of the latter with phenacyl bromide afforded the products (7a-j) in good to excellent yields and high purity. The newly synthezied (7a-j) were screend for inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), carbonic anhydrase I (hCA I) and carbonic anhydrase II (hCA II). Most of the synthesized molecules were more effective than standard inhibitors tacrine, and acetazolamide against AchE, BchE and against CA I and CA II respectively. Compounds 7h, 7f, 7d and 7i were the most potent compounds against hCA I&II. Whilst compounds 7a, 7d and 7f showed highest inhibition against acetylcholinesterase (AChE), butyrylcholinesterase (BChE) when compared with standard inhibitor Tacrine. In silico studies were also performed to find the type of interactions. Molecular docking was accomplished to explore the putative binding mode of interactions of selective inhibitors. Finally, the ADMET analysis of the molecules was also performed.

Carbonic anhydrases (CA), having Zn2+ metal atoms, are responsible for the catalysis of CO2 and water to bicarbonate and protons. Any abnormality in the functioning of these enzymes may lead to morbidities such as glaucoma and different types of cancers including brain, renal and pancreatic carcinomas. To cope with the lack of presence of a promising therapeutic agent against these cancers, searching for an efficient and suitable carbonic anhydrase inhibitor is crucial. In the current study, ten novel 3-ethylaniline hybrid imino-thiazolidinones were synthesized and characterized by FTIR, NMR (1H, 13C), and mass spectrometry. Synthesis was carried out by diethyl but-2-ynedioate cyclization and different acyl thiourea substitutions of 3-ethyl amine. The CA (II) enzyme inhibition profile for all synthesized derivatives was determined. It was observed that compound 6e demonstrated highest inhibition of CA-II with an IC50 value of 1.545 ± 0.016 µM. In order to explore the pharmacophoric properties and develop structure activity relationship, in silico screening was performed. In silico investigations included density functional theory (DFT) studies, pharmacophore-guided model development, molecular docking, molecular dynamic (MD) simulations, and prediction of drug likeness scores. DFT investigations provided insight into the electronic characteristics of compounds, while molecular docking determined the binding orientation of derivatives within the CA-II active site. Compounds 6a, 6e, and 6g had a reactive profile and generated stable protein-ligand interactions with respective docking scores of −6.12, −6.99, and −6.76 kcal/mol. MD simulations were used to evaluate the stability of the top-ranked complex. In addition, pharmacophore-guided modeling demonstrated that compound 6e produced the best pharmacophore model (HHAAARR) compared to standard brinzolamide. In vitro and in silico investigations anticipated that compound 6e would be an inhibitor of carbonic anhydrase II with high efficacy. Compound 6e may serve as a potential lead for future synthesis that can be investigated at the molecular level, and additional in vivo studies are strongly encouraged.

Tyrosinase is a multi-copper enzyme found in plants, animals and microorganisms, plays a critical role in the melanogenesis and browning process critical to cosmetics and food industries. Many natural, semi-synthetic and synthetic inhibitors have been discovered. To this end, a small library of symmetrical Bis-Azo-Azamethine hybrids 5a-j was synthesized and characterized through spectroscopic and analytical data and explored for mushroom tyrosinase and free radical scavenging activity. All of the molecules 5a-j explicated better potential compared to the standard Kojic acid. On the whole, compound 5i having IC50 value 0.002 +/- 0.004 mu M was found to be the most potent derivative. The Kinetic studies were performed for 5i and indicating the mode of inhibition in a competitive manner. Structure Activity Relationship (SAR) analysis and docking studies were carried out. Thus compound 5i bearing bulky naphthyl groups was most potent and, The molecular docking indicated formation of two hydrogen bonds with Arg268 and one hydrophobic interaction with Glu322. The carbonyl oxygen of 5i interacts with Arg268 and form two hydrogen bonds having lengths 2.44 and 2.62 angstrom, respectively. In the same way, compounds 5a-j were appraised for DPPH free radical scavenging ability and five of them 5d, 5e, 5h, 5i and 5j were found to exhibit higher % scavenging potency compared with vitamin C, as the standard. Interesting compound 5i was again the most potent in the series. The current investigation points towards the role of naphthyl group in design of new inhibitors of melanogenesis and the antioxidants with improved efficacy. Communicated by Ramaswamy H. Sarma

This article describes the design and synthesis of a series of novel amantadine-thiourea conjugates (3a–j) as Jack bean urease inhibitors. The synthesized hybrids were assayed for their in vitro urease inhibition. Accordingly, N-(adamantan-1-ylcarbamothioyl)octanamide (3j) possessing a 7-carbon alkyl chain showed excellent activity with IC50 value 0.0085 ± 0.0011 µM indicating that the long alkyl chain plays a vital role in enzyme inhibition. Whilst N-(adamantan-1-ylcarbamothioyl)-2-chlorobenzamide (3g) possessing a 2-chlorophenyl substitution was the next most efficient compound belonging to the aryl series with IC50 value of 0.0087 ± 0.001 µM. The kinetic mechanism analyzed by Lineweaver–Burk plots revealed the non-competitive mode of inhibition for compound 3j. Moreover, in silico molecular docking against target protein (PDBID 4H9M) indicated that most of the synthesized compounds exhibit good binding affinity with protein. The compound 3j forms two hydrogen bonds with amino acid residue VAL391 having a binding distance of 1.858 Å and 2.240 Å. The interaction of 3j with amino acid residue located outside the catalytic site showed its non-competitive mode of inhibition. Based upon these results, it is anticipated that compound 3j may serve as a lead structure for the design of more potent urease inhibitors.