Synthesis and molecular docking study of some novel 2,3-disubstituted quinazolin-4(3H)-one derivatives as potent inhibitors of urease

A new series of 2,3-disubstituted quinazolin-4(3H)-one compounds including oxadiazole and furan rings was synthesized. Their inhibitory activities on urease were assessed in vitro. All newly synthesized compounds exhibited potent urease inhibitory activity in the range of IC₅₀ = 1.55 ± 0.07–2.65 ± 0.08 µg/mL, when compared with the standard urease inhibitors such as thiourea (IC₅₀ = 15.08 ± 0.71 µg/mL) and acetohydroxamic acid (IC₅₀ = 21.05 ± 0.96 µg/mL). 2,3-Disubstituted quinazolin-4(3H)-one derivatives containing furan ring (3a-e) were found to be the most active inhibitors when compared with the compounds 2a-e bearing oxadiazole ring. Compound 3a, bearing 4-chloro group on phenyl ring, was found as the most effective inhibitor of urease with the IC₅₀ value of 1.55 ± 0.11 µg/mL. The molecular docking studies of the newly synthesized compounds were performed to identify the probable binding modes in the active site of the Jack bean urease (JBU) enzymes.     

Design,synthesis, in vitro evaluation,molecular docking and ADME properties studies of hybrid bis-coumarin with thiadiazole as a new inhibitor of Urease

Hybrid bis-coumarin derivatives 1–18 were synthesized and evaluated for their in vitro urease inhibitory potential. All compounds showed outstanding urease inhibitory potential with IC₅₀ value (The half maximal inhibitory concentration) ranging in between 0.12 SD 0.01 and 38.04 SD 0.63 µM (SD standard deviation). When compared with the standard thiourea (IC₅₀ = 21.40 ± 0.21 µM). Among these derivatives, compounds 7 (IC₅₀ = 0.29 ± 0.01), 9 (IC₅₀ = 2.4 ± 0.05), 10 (IC₅₀ = 2.25 ± 0.05) and 16 (IC₅₀ = 0.12 ± 0.01) are better inhibitors of the urease compared with thiourea (IC₅₀ = 21.40 ± 0.21 µM). To find structure–activity relationship molecular docking as well as absorption, distribution, metabolism, and excretion (ADME) studies were also performed. Various spectroscopic techniques like ¹H NMR, ¹³C NMR, and EI-MS were used for characterization of all synthesized analogs. All compounds were tested for cytotoxicity and found non-toxic.     

Synthesis of 2-acylated and sulfonated 4-hydroxycoumarins: In vitro urease inhibition and molecular docking studies

Sixteen 4-hydroxycoumarin derivatives were synthesized, characterized through EI-MS and ¹H NMR and screened for urease inhibitory potential. Three compounds exhibited better urease inhibition than the standard inhibitor thiourea (IC₅₀ = 21 ± 0.11 μM) while other four compounds exhibited good to moderate inhibition with IC₅₀ values between 29.45 ± 1.1 μM and 69.53 ± 0.9 μM. Structure activity relationship was established on the basis of molecular docking studies, which helped to predict the binding interactions of the most active compounds.     

Synthesis, in vitro evaluation and molecular docking studies of new triazole derivatives as antifungal agents

On the basis of the active site of lanosterol 14α-demethylase from Candida albicans (CACYP51), a series of 1-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-1H-1,2,4-triazol-5(4H)-one derivatives were synthesized as fluconazole analogs. Results of the preliminary antifungal tests against eight human pathogenic fungi in vitro showed that these compounds exhibited activities to some extent, and some displayed excellent antifungal activities against C. albicans than reference drug fluconazole. Flexible molecular docking was used to analyze the structure-activity relationships (SARs) of the target compounds. The designed compounds interact with CACYP51 through hydrophobic, van der Waals and hydrogen-bonding interactions.     

Synthesis and molecular docking study of piperazine derivatives as potent urease inhibitors

Urease is known to be one of the major causes of diseases induced by Helicobacter pylori, thus allow them to survive at low pH inside the stomach and thereby, play an important role in the pathogenesis of gastric and peptic ulcer, apart from cancer as well. Keeping in view the great importance of urease inhibitors, here in this study we have synthesized piperazine derivatives (1–15) and evaluated for their urease inhibitory activity. All analogs showed excellent inhibitory potential with IC₅₀ values ranging between 1.1 ± 0.01 and 33.40 ± 1.50 µM when compared with the standard inhibitor thiourea (IC₅₀ = 21.30 ± 1.10 µM). Structure activity relationship has been established for all compounds which are mainly based upon the substitution on phenyl ring. Molecular docking study was performed in order to understand the binding interaction of the compounds in the active site of enzyme.     

Synthesis of novel quinoline-based thiadiazole,evaluation of their antileishmanial potential and molecular docking studies

New series of quinoline-based thiadiazole analogs (1–20) were synthesized, characterized by EI-MS, ¹H NMR and ¹³C NMR. All synthesized compounds were subjected to their antileishmanial potential. Sixteen analogs 1–10, 12, 13, 16, 17, 18 and 19 with IC₅₀ values in the range of 0.04 ± 0.01 to 5.60 ± 0.21 µM showed tremendously potent inhibition as compared to the standard pentamidine with IC₅₀ value 7.02 ± 0.09 µM. Analogs 11, 14, 15 and 20 with IC₅₀ 8.20 ± 0.35, 9.20 ± 0.40, 7.20 ± 0.20 and 9.60 ± 0.40 µM respectively showed good inhibition when compared with the standard. Structure-activity relationships have been also established for all compounds. Molecular docking studies were performed to determine the binding interaction of the compounds with the active site target.     

Design,molecular docking and synthesis of novel 5,6-dichloro-2-methyl-1H-benzimidazole derivatives as potential urease enzyme inhibitors

A novel series of 5,6-dichloro-2-methyl-1H-benzimidazole derivatives was synthesized and then screened for their urease inhibitory activity. All compounds showed more potent inhibitory activity in the range of IC₅₀ = 0.0294 ± 0.0015–0.1494 ± 0.0041 µM than thiourea (IC₅₀ = 0.5117 ± 0.0159 µM), as a reference inhibitor. Among all the tested compounds, the compound 15 (IC₅₀ = 0.0294 ± 0.0015 µM) having strong electron-withdrawing nitro group on the phenyl ring was recorded as the most potent inhibitor of urease. All compounds were docked at the active sites of the Jack bean urease enzyme to investigate the reason of the inhibitory activity and the possible binding interactions of enzyme-ligand complexes.     

Synthesis,in vitro urease inhibitory potential and molecular docking study of Benzimidazole analogues

Despite of many diverse biological activities exhibited by benzimidazole scaffold, it is rarely explored for the urease inhibitory potential. For that purpose, benzimidazole analogues 1–19 were synthesized and screened for in vitro urease inhibitory potential. Structures of all synthetic analogues were deduced by different spectroscopic techniques. All analogues revealed inhibition potential with IC₅₀ values of 0.90 ± 0.01 to 35.20 ± 1.10 μM, when compared with the standard thiourea (IC₅₀ = 21.40 ± 0.21 μM). Limited SAR suggested that the variations in the inhibitory potentials of the analogues are the result of different substitutions on phenyl ring. In order to rationalize the binding interactions of most active compounds with the active site of urease enzyme, molecular docking study was conducted.     

Synthesis,in vitro urease inhibitory activity,and molecular docking studies of thiourea and urea derivatives

The current study deals with the synthesis of urea and thiourea derivatives 1–37 which were characterized by various spectroscopic techniques including FAB-MS, ¹H-, and ¹³C NMR. The synthetic compounds were subjected to urease inhibitory activity and compounds exhibited good to moderate urease inhibitory activity having IC₅₀ values in range of 10.11–69.80 µM. Compound 1 (IC₅₀ = 10.11 ± 0.11 µM) was found to be most active and even better as compared to the standard acetohydroxamic acid (IC₅₀ = 27.0 ± 0.5 µM). A limited structure–activity relationship (SAR) was established and the compounds were also subjected to docking studies to confirm the binding interactions of ligands (compounds) with the active site of enzyme.     

Design,synthesis, anti-inflammatory activity,and molecular docking studies of perimidine derivatives containing triazole

We report here the design, synthesis, and anti-inflammatory activities of a series of perimidine derivatives containing triazole (5a–s). The chemical structures of the synthesized compounds have been assigned on the basis of IR, ¹H NMR, ¹³C NMR, and HRMS spectral analyses. The anti-inflammatory properties of the synthesized perimidine derivatives were evaluated in a lipopolysaccharide (LPS)-stimulated inflammation model. Among the tested compounds, compound 7-(3-methylbenzyl)-7H-[1,2,4]triazolo[4,3-a]perimidine (hereafter referred to as 5h) and compound 7-(2-fluorobenzyl)-7H-[1,2,4]triazolo[4,3-a]perimidine (hereafter referred to as 5n) caused a reduction in the levels of the pro-inflammatory cytokines—tumor necrosis factor (TNF)-α and interleukin (IL)-6—in RAW264.7 cells. The anti-inflammatory potential of compounds 5h and 5n was also evaluated in vivo in a xylene-induced ear inflammation model. Compound 5n showed the most potent anti-inflammatory activity with an inhibition of 49.26% at a dose of 50 mg/kg. This activity is more potent than that of the reference drug ibuprofen (28.13%), and slightly less than that of indometacin (49.36%). To further elucidate the mechanisms underlying these inhibitory effects, LPS-induced nuclear factor-κB (NF-κB) activation and mitogen-activated protein kinase (MAPK) phosphorylation were studied. The results of western blotting showed that the extract obtained from compound 5n inhibited NF-κB (p65) activation and MAPK (extracellular signal-regulated kinase (ERK) and p38) phosphorylation in a dose-dependent manner. Moreover, the results of a docking study of compound 5n into the COX-2 binding site revealed that its mechanism was possibly similar to that of naproxen, a COX-2 inhibitor. The effect of compound 5n on COX-2 antibody was showed it could significantly inhibit COX-2 activity.     

Acridine-based (thio)semicarbazones and hydrazones: Synthesis,in vitro urease inhibition,molecular docking and in-silico ADME evaluation

Urease is a bacterial enzyme that is responsible for virulence of various pathogenic bacteria such as Staphylococcus aureus, Proteus mirabilis, Klebsiella pneumoniae, Ureaplasma urealyticum, Helicobacter pylori and Mycobacterium tuberculosis. Increased urease activity aids in survival and colonization of pathogenic bacteria causing several disorders especially gastric ulceration. Hence, urease inhibitors are used for treatment of such diseases. In search of new molecules with better urease inhibitory activity, herein we report a series of acridine derived (thio)semicarbazones (4a-4e, 6a-6l) that were found to be active against urease enzyme. Molecular docking studies were carried out to better comprehend the preferential mode of binding of these compounds against urease enzyme. Docking against urease from pathogenic bacterium S. pasteurii was also carried out with favorable results. In silico ADME evaluation was done to determine drug likeness of synthesized compounds.     

Synthesis,COX-1/2 inhibition activities and molecular docking study of isothiazolopyridine derivatives

One of the main challenges for nowadays medicine is drugs selectivity. In COX-1 and COX-2, the active sites are composed of the same group of amino acids with the exception of the only one residue in position 523, in COX-1 is an isoleucine, while in COX-2 is a valine. Here, we presented a series of isothiazolopyridine/benzisothiazole derivatives substituted differently into an isothiazole ring, which were synthesized and investigated for their potencies to inhibit COX-1 and COX-2 enzymes by colorimetric inhibitor screening assay. All the tested compounds inhibited the activity of COX-1, the effect on COX-2 activity was differential. The mode of binding was characterized by a molecular docking study. Comparing biological activity of the investigated compounds, it was observed that compounds sharing the most similar position to flurbiprofen and meloxicam, representing the two main enzyme subdomains, achieved higher biological activity than others. It is directly related to the fit to the enzyme’s active site, which prevents too early dissociation of the compounds.     

Bisindolylmethane thiosemicarbazides as potential inhibitors of urease: Synthesis and molecular modeling studies

Bisindolylmethane thiosemicarbazides 1-18 were synthesized, characterized by ¹H NMR and ESI MS and evaluated for urease inhibitory potential. All analogs showed outstanding urease inhibitory potentials with IC₅₀ values ranging between 0.14?±?0.01 to 18.50?±?0.90?μM when compared with the standard inhibitor thiourea having IC₅₀ value 21.25?±?0.90?μM. Among the series, analog 9 (0.14?±?0.01?μM) with di-chloro substitution on phenyl ring was identified as the most potent inhibitor of urease. The structure activity relationship has been also established on the basis of binding interactions of the active analogs. These binding interactions were identified by molecular docking studies.     

Synthesis,anticancer, structural,and computational docking studies of 3-benzylchroman-4-one derivatives

A series of 3-Benzylchroman-4-ones were synthesized and screened for anticancer activity by MTT assay. The compounds were evaluated against two cancerous cell lines BT549 (human breast carcinoma), HeLa (human cervical carcinoma), and one noncancerous cell line vero (normal kidney epithelial cells). 3b was found to be the most active molecule against BT549 cells (IC₅₀?=?20.1?µM) and 3h against HeLa cells (IC₅₀?=?20.45?µM). 3b also exhibited moderate activity against HeLa cells (IC₅₀?=?42.8?µM). The molecular structures of 3h and 3i were solved by single crystal X-ray crystallographic technique. Additionally, the molecular docking studies between the tumour suppressor protein p53 with the lead compound 3h, which exhibited better anticancer activity against HeLa cells was examined.     

Synthesis,computational molecular docking analysis and effectiveness on tyrosinase inhibition of kojic acid derivatives

Tyrosinase inhibitors have become increasingly important as whitening agents and for the treatment of pigmentary disorders. In this study, the synthesis of kojic acid derivatives having 2-substituted-3-hydroxy-6-hyroxymethyl/chloromethyl/methyl/morpholinomethylpiperidinyl- methyl/pyrrolidinylmethyl-4H-pyran-4-one structure (compounds 1–30) with inhibitory effects on tyrosinase enzyme were described. One-pot Mannich reaction was carried out by using kojic acid/chlorokojic acid/allomaltol and substituted benzylpiperazine derivatives in presence of formaline. Subsequently, cyclic amine (morpholine, piperidine and pyrrolidine) derivatives of the 6th-position of chlorokojic acid were obtained with nucleophilic substitutions in basic medium. The structures of new compounds were identified by FT-IR, ¹H- and ¹³C NMR, ESI-MS and elemental analysis data. The potential mushroom tyrosinase inhibitory activity of the compounds were evaluated by the spectrophotometric method using l-DOPA as a substrate and kojic acid as the control agent. The potential inhibitory activity was also investigated in silico using molecular docking simulation method. Tyrosinase inhibitory action was significantly more efficacious for several compounds (IC₅₀: 86.2–362.1 µM) than kojic acid (IC₅₀: 418.2). Compound 3 bearing 3,4-dichlorobenzyl piperazine moiety was proven to have the highest inhibitory activity. The results of docking studies showed that according to the predicted conformation of compound 3 in the enzyme binding site, hydroxymethyl group provides a metal complex with copper ions and enzyme. Thus, this interaction explain the high inhibitory activities of the compounds 1, 3 and 4 possessing hydroxymethyl substituent supporting the mushroom assay results with docking studies. In accordance with the results, it is suggested that Mannich bases of kojic acid bearing substituted benzyl piperazine groups (compounds 1, 3, 4, 11, 13, 14, 23, 24, 28, and 29) could be promising antityrosinase agents. Additionally, considering the relationship between tyrosinase inhibitory activity results and molecular docking, a new tyrosinase inhibition mechanism can be proposed.     

Synthesis,thymidine phosphorylase,angiogenic inhibition and molecular docking study of isoquinoline derivatives

Isoquinoline analogues (KA-1 to 16) have been synthesized and evaluated for their E. coli thymidine phosphorylase inhibitory activity. Except compound 11, all other analogs showed outstanding thymidine inhibitory potential ranging in between 4.40 ± 0.20 to 69.30 ± 1.80 µM when compared with standard drug 7-Deazaxanthine (IC₅₀ = 38.68 ± 4.42 µM). Structure Activity Relationships has been established for all compounds, mainly based on substitution pattern on phenyl ring. All analogs were characterized by various spectroscopic techniques such as ¹H NMR, ¹³C NMR and EI-MS. The binding interactions of isoquinoline analogues with the active site of TP enzyme, the molecular docking studies were performed. Furthermore, the angiogenic inhibitory potentials of isoquinoline analogues (KA-1-9, 14, 12 and 16) were determined in the presence of standard drug Dexamethasone based on percentage inhibitions at various concentrations. Herein this work analogue KA-12, 14 and 16 emerged with most potent angiogenic inhibitory potentials among the synthesized analogues.     

Synthesis of novel N-(1,3-thiazol-2-yl)benzamide clubbed oxadiazole scaffolds: Urease inhibition,Lipinski rule and molecular docking analyses

Present work aimed to synthesize some unique bi-heterocyclic benzamides as lead compounds for the in vitro inhibition of urease enzyme, followed by in silico studies. These targeted benzamides were synthesized in good yields through a multi-step protocol and their structures were confirmed by IR, ¹H NMR, ¹³C NMR, EI-MS and elemental analysis. The in vitro screening results showed that most of the ligands exhibited good inhibitory potentials against the urease. Chemo-informatics analysis envisaged that all these compounds obeyed the Lipinski's rule. Molecular docking results showed that 7h exhibited good binding energy value (−8.40 kcal/mol) and was bound within the active region of urease enzyme. From the present investigation, it was inferred that some of these potent urease inhibitors might serve as novel templates in drug designing.     

Hybrid benzothiazole analogs as antiurease agent: Synthesis and molecular docking studies

Benzothiazole analogs (1–20) have been synthesized, characterized by EI-MS and ¹H NMR, and evaluated for urease inhibition activity. All compounds showed excellent urease inhibitory potential varying from 1.4 ± 0.10 to 34.43 ± 2.10 μM when compared with standard thiourea (IC₅₀ 19.46 ± 1.20 μM). Among the series seventeen (17) analogs 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, and 18 showed outstanding urease inhibitory potential. Analogs 15 and 19 also showed good urease inhibition activity. When we compare the activity of N-phenylthiourea 20 with all substituted phenyl derivatives (1–18) we found that compound 15 showed less activity than compound 20 having 3-methoxy substituent. The binding interactions of these active analogs were confirmed through molecular docking.     

Sulfonamides containing curcumin scaffold: Synthesis,characterization, carbonic anhydrase inhibition and molecular docking studies

Curcumin is a multi-functional pharmacologically safe natural agent with proven cytoprotective effects to healthy human cells. In this study, a new series of sulfonamides with curcumin scaffold were synthesized, characterized and investigated for their carbonic anhydrase isoenzyme I (human) and II (bovine) isoforms. The structures of newly synthesized compounds were described by IR, ¹H NMR and ¹³C NMR spectral data. Compound 14 showed the K_i value of 0.99 µM with highest inhibitory activity among all other synthesized compounds against hCA-I enzyme. Similarly enzyme kinetic studies of compound 14, 16 and 30 against bCAII enzyme showed Ki values of 0.71, 0.67 and 0.71 µM respectively. Our biological assays results showed that most of active compounds have similar inhibitory activities compared to standard acetazolamide drug. The molecular docking predicted binding modes showed that these compounds bind with hCA-1 enzyme in similar fashion.     

Synthesis,molecular docking and biological evaluation of some benzimidazole derivatives as potent pancreatic lipase inhibitors

In this study, a new series of benzimidazole and bisbenzimidazole derivatives were prepared via the reaction of iminoester hydrochlorides and o-phenylenediamines and then screened for their lipase inhibition properties. Among the synthesized molecules, compounds 7a, 8a and 8c showed the best inhibitory effect against lipase enzyme with IC₅₀ values of 1.72 ± 0.12 µM, 1.92 ± 0.28 and 0.98 ± 0.07 µM, respectively. Moreover, molecular modeling studies were performed in order to understand to the inhibitory activity of the molecules. Binding poses of the studied compounds were determined at the target sites using induced fit docking (IFD) algorithms.