Synthesis of novel derivatives of oxindole, their urease inhibition and molecular docking studies

Clodronic Acid has Strong Inhibitory Interactions with the Urease Enzyme of Helicobacter pylori: Computer-aided Design and in vitro Confirmation

BACKGROUND

Helicobacter pylori (HP) infection could lead to various gastrointestinal diseases. Urease is the most important virulence factor of HP. It protects the bacterium against gastric acid.

OBJECTIVE

Therefore, we aimed to design urease inhibitors as drugs against HP infection.

METHODS

The DrugBank-approved library was assigned with 3D conformations and the structure of the urease was prepared. Using a re-docking strategy, the proper settings were determined for docking by PyRx and GOLD software. Virtual screening was performed to select the best inhibitory drugs based on binding affinity, FitnessScore, and binding orientation to critical amino acids of the active site. The best inhibitory drug was then evaluated by IC50 and the diameter of the zone of inhibition for bacterial growth.

RESULTS

The structures of prepared drugs were screened against urease structure using the determined settings. Clodronic acid was determined to be the best-identified drug, due to higher PyRx binding energy, better GOLD FitnessScore, and interaction with critical amino acids of urease. In vitro results were also in line with the computational data. IC50 values of Clodronic acid and Acetohydroxamic Acid (AHA) were 29.78 ± 1.13 and 47.29 ± 2.06 μg/ml, respectively. Diameters of the zones of inhibition were 18 and 15 mm for Clodronic acid and AHA, respectively.

CONCLUSION

Clodronic acid has better HP urease inhibition potential than AHA. Given its approved status, the development of a repurposed drug based on Clodronic acid would require less time and cost. Further, in vivo studies would unveil the efficacy of Clodronic acid as a urease inhibitor.

The Synthesis, In Vitro Bio-Evaluation, and In Silico Molecular Docking Studies of Pyrazoline-Thiazole Hybrid Analogues as Promising Anti-α-Glucosidase and Anti-Urease Agents

In the present work, a concise library of benzothiazole-derived pyrazoline-based thiazole (1-17) was designed and synthesized by employing a multistep reaction strategy. The newly synthesized compounds were screened for their α-glucosidase and urease inhibitory activities. The scaffolds (1-17) were characterized using a combination of several spectroscopic techniques, including FT-IR, 1H-NMR, 13C-NMR, and EI-MS. The majority of the synthesized compounds demonstrated a notable potency against α-glucosidase and urease enzymes. These analogues disclosed varying degrees of α-glucosidase and urease inhibitory activities, with their IC50 values ranging from 2.50 to 17.50 μM (α-glucosidase) and 14.30 to 41.50 (urease). Compounds 6, 7, 14, and 12, with IC50 values of 2.50, 3.20, 3.40, and 3.50 μM as compared to standard acarbose (IC50 = 5.30 µM), while the same compounds showed 14.30, 19.20, 21.80, and 22.30 comparable with thiourea (IC50 = 31.40 μM), respectively, showed excellent inhibitory activity. The structure-activity relationship revealed that the size and electron-donating or electron-withdrawing effects of substituents influenced the enzymatic activities such as α-glucosidase and urease. Compound 6 was a dual potent inhibitor against α-glucosidase and urease due to the presence of -CF3 electron-withdrawing functionality on the phenyl ring. To the best of our knowledge, these synthetic compounds were found to be the most potent dual inhibitors of α-glucosidase and urease with minimum IC50 values. Moreover, in silico studies on most active compounds, i.e., 6, 7, 14, and 12, were also performed to understand the binding interaction of most active compounds with active sites of α-glucosidase and urease enzymes.

A nitroreductase DnrA catalyzes the biotransformation of several diphenyl ether herbicides in Bacillus sp. Za

Diphenyl ether herbicides, typical globally used herbicides, threaten the agricultural environment and the sensitive crops. The microbial degradation pathways of diphenyl ether herbicides are well studied, but the nitroreduction of diphenyl ether herbicides by purified enzymes is still unclear. Here, the gene dnrA, encoding a nitroreductase DnrA responsible for the reduction of nitro to amino groups, was identified from the strain Bacillus sp. Za. DnrA had a broad substrate spectrum, and the K_m values of DnrA for different diphenyl ether herbicides were 20.67 μM (fomesafen), 23.64 μM (bifenox), 26.19 μM (fluoroglycofen), 28.24 μM (acifluorfen), and 36.32 μM (lactofen). DnrA also mitigated the growth inhibition effect on cucumber and sorghum through nitroreduction. Molecular docking revealed the mechanisms of the compounds fomesafen, bifenox, fluoroglycofen, lactofen, and acifluorfen with DnrA. Fomesafen showed higher affinities and lower binding energy values for DnrA, and residue Arg244 affected the affinity between diphenyl ether herbicides and DnrA. This research provides new genetic resources and insights into the microbial remediation of diphenyl ether herbicide-contaminated environments. KEY POINTS: • Nitroreductase DnrA transforms the nitro group of diphenyl ether herbicides. • Nitroreductase DnrA reduces the toxicity of diphenyl ether herbicides. • The distance between Arg244 and the herbicides is related to catalytic efficiency.

Antidiarrheal Potential of Viola canescens: In Vivo and In Silico Approaches

Viola canescens Wall. is an important medicinal plant with reported therapeutic benefits. The current work sought to investigate the antidiarrheal properties of V. canescens extracts both in vivo and in silico. This study applied molecular docking to unravel the molecular mechanism of V. canescens and to find the most effective phytocompounds with antidiarrheal effects. The antidiarrheal activity of V. canescens was assessed utilizing the castor oil-induced diarrhea assay and the charcoal meal assay. Antidiarrheal characteristics were evaluated by measuring parameters such as intestinal motility, fecal score, and hypersecretion. The V. canescens extract had a dose-dependent and statistically significant impact in the charcoal meal assay and castor oil-induced diarrhea assay. In the castor oil-induced diarrhea assay, the ethyl acetate fraction (65.96%) showed the highest percentage of defecation inhibition at the highest dose (300 mg/kg (bw)), followed by the uncorrected crystalline compound (63.83%), crude alkaloids (63.83%), chloroform fraction (63.83%), and crude flavonoids (55.32%), while the aqueous fraction (40.43%) and n-Hexane fraction (42.55%) revealed the lowest antidiarrheal potential. In addition, the molecular docking investigation showed emetine, quercetin, and violanthin, isolated chemicals of V. canescens, to have the highest binding affinity to the target μ and δ opioid receptors with significant inhibitory capacity. These pharmacologically active metabolites in V. canescens were effective in treating diarrhea. This study lends credence to the traditional usage of V. canescens in treating gastrointestinal disorders.

1,2-Dibenzoylhydrazine as a Multi-Inhibitor Compound: A Morphological and Docking Study

In the framework of the multitarget inhibitor study, we report an in silico analysis of 1,2-dibenzoylhydrazine (DBH) with respect to three essential receptors such as the ecdysone receptor (EcR), urease, and HIV-integrase. Starting from a crystallographic structural study of accidentally harvested crystals of this compound, we performed docking studies to evaluate the inhibitory capacity of DBH toward three selected targets. A crystal morphology prediction was then performed. The results of our molecular modeling calculations indicate that DBH is an excellent candidate as a ligand to inhibit the activity of EcR receptors and urease. Docking studies also revealed the activity of DBH on the HIV integrase receptor, providing an excellent starting point for developing novel inhibitors using this molecule as a starting lead compound.

Molecular docking and simulation studies of synthetic protease inhibitors against COVID-19: a computational study

COVID-19 is the most recent threat to global health. Many people preferred treatment in case of infection instead of vaccination. The inhibition of viral replication is a good strategy for the treatment of COVID-19 infection. 3CLpro and PLpro are two important viral proteases responsible for proteolysis, infection, and replication of the virus. Therefore, targeting of these two enzymes is an attractive way to deal with COVID-19. The aim of this study was to screen some synthetic protease inhibitors to determine an appropriate hit molecule against COVID-19 using molecular docking and molecular dynamic simulations. The strategy depends on docking existing synthetic compounds mostly HIV protease inhibitors against two COVID-19 proteases to identify promising drugs for the treatment of COVID-19. We used protein data bank to obtain the X-ray crystal structure of the most important COVID-19 proteases 3CL pro (PDB ID: 6M2N) and PL pro (PDB ID: 6WX4). In this conceptual context, an attempt has been made to suggest an in silico computational relationship between 50 synthetic protease inhibitors and COVID-19 proteases. Out of 50 screened compounds, the best docking scores were found for these five protease inhibitors BDBM7021, BDBM698, BDBM694, BDBM93239, BDBM700. A 100-ns MD simulation was carried out to assess the stability of COVID-19 proteases and inhibitors, revealing an average RMSD value of 0.7 and favorable binding free energy (MM-GBSA) for all complexes confirming their potency as powerful binders in the COVID-19 proteases' binding pocket. Furthermore, the current results must be confirmed using in-vitro and in-vivo antiviral methods.Communicated by Ramaswamy H. Sarma.

Design, synthesis, and molecular docking studies of diphenylquinoxaline-6-carbohydrazide hybrids as potent α-glucosidase inhibitors

A novel series of diphenylquinoxaline-6-carbohydrazide hybrids 7a-o were rationally designed and synthesized as anti-diabetic agents. All synthesized compounds 7a-o were screened as possible α-glucosidase inhibitors and exhibited good inhibitory activity with IC50 values in the range of 110.6 ± 6.0 to 453.0 ± 4.7 µM in comparison with acarbose as the positive control (750.0 ± 10.5 µM). An exception in this trend came back to a compound 7k with IC50 value > 750 µM. Furthermore, the most potent derivative 7e bearing 3-fluorophenyl moiety was further explored by kinetic studies and showed the competitive type of inhibition. Additionally, the molecular docking of all derivatives was performed to get an insight into the binding mode of these derivatives within the active site of the enzyme. In silico assessments exhibited that 7e was well occupied in the binding pocket of the enzyme through favorable interactions with residues, correlating to the experimental results.

Molecular dynamics simulations reveal the inhibitory mechanism of Withanolide A against α-glucosidase and α-amylase

Diabetes mellitus (DM) is a global chronic disease characterized by hyperglycemia and insulin resistance. The unsavory severe gastrointestinal side-effects of synthetic drugs to regulate hyperglycemia have warranted the search for alternative treatments to inhibit the carbohydrate digestive enzymes (e.g. α-amylase and α-glucosidase). Certain phytochemicals recently captured the scientific community's attention as carbohydrate digestive enzyme inhibitors due to their low toxicity and high efficacy, specifically the Withanolides-loaded extract of Withania somnifera. That said, the present study evaluated in silico the efficacy of Withanolide A in targeting both α-amylase and α-glucosidase in comparison to the synthetic drug Acarbose. Protein-ligand interactions, binding affinity, and stability were characterized using pharmacological profiling, high-end molecular docking, and molecular-dynamic simulation. Withanolide A inhibited the activity of α-glucosidase and α-amylase better, exhibiting good pharmacokinetic properties, absorption, and metabolism. Also, Withanolide A was minimally toxic, with higher bioavailability. Interestingly, Withanolide A bonded well to the active site of α-amylase and α-glucosidase, yielding the lowest binding free energy of -82.144 ± 10.671 kcal/mol and -102.1043 ± 11.231 kcal/mol compared to the Acarbose-enzyme complexes (-63.220 ± 13.283 kcal/mol and -82.148 ± 10.671 kcal/mol). Hence, the findings supported the therapeutic potential of Withanolide A as α-amylase and α-glucosidase inhibitor for DM treatment.Communicated by Ramaswamy H. Sarma.

An overview on the synthetic urease inhibitors with structure-activity relationship and molecular docking

Urease is a kind of enzyme which could be found in various bacteria, fungi, plants, and algae, which can quickly catalyze the hydrolysis of urea into ammonia and carbon dioxide. With the ammonia concentration increasing, the activity of Helicobacter pylori has got an obvious enhancement and leads to mucosal damage in the stomach, gastroduodenal infection, peptic ulcers, and gastric cancer. The infectious diseases caused by Helicobacter pylori can be controlled to a certain extent by inhibiting urease activity with urease inhibitors. Hence, studies of urease inhibitors have attracted great attention all over the world and a variety of effective urease inhibitors have been synthesized in recent years. In this review, we will draw summaries for these inhibitors including urease inhibitory activity, inhibition kinetics, structure-activity relationship, and molecular docking. The collected information is expected to provide rational guidance and effective strategy to develop novel, potent, and safe urease inhibitors for better practical applications in the future.

Synthesis and Evaluation of 1,3,5-Triaryl-2-Pyrazoline Derivatives as Potent Dual Inhibitors of Urease and α-Glucosidase Together with Their Cytotoxic, Molecular Modeling and Drug-Likeness Studies

In the present work, a concise library of 1,3,5-triaryl-2-pyrazolines (2a-2q) was designed and synthesized by employing a multistep strategy, and the newly synthesized compounds were screened for their urease and α-glucosidase inhibitory activities. The compounds (2a-2q) were characterized using a combination of several spectroscopic techniques including FT-IR, 1H NMR, 13C NMR, and EI-MS. All the synthesized compounds, except compound 2i, were potent against urease as compared to the standard inhibitor thiourea (IC50 = 21.37 ± 0.26 μM). These analogs disclosed varying degrees of urease inhibitory activities ranging from 9.13 ± 0.25 to 18.42 ± 0.42 μM. Compounds 2b, 2g, 2m, and 2q having IC50 values of 9.36 ± 0.27, 9.13 ± 0.25, 9.18 ± 0.35, and 9.35 ± 0.35 μM, respectively, showed excellent inhibitory activity as compared to standard thiourea (IC50 = 21.37 ± 0.26 μM). A kinetic study of compound 2g revealed that compound 2g inhibited urease in a competitive mode. Among the synthesized pyrazolines, the compounds 2c, 2k, 2m, and 2o exhibited excellent α-glucosidase inhibitory activity with the lowest IC50 values of 212.52 ± 1.31, 237.26 ± 1.28, 138.35 ± 1.32, and 114.57 ± 1.35 μM, respectively, as compared to the standard acarbose (IC50 = 375.82 ± 1.76 μM). The compounds (2a-2q) showed α-glucosidase IC50 values in the range of 114.57 ± 1.35 to 462.94 ± 1.23 μM. Structure-activity relationship revealed that the size and electron-donating or -withdrawing effects of substituents influenced the activities, which led to the urease and α-glucosidase inhibiting properties. Compound 2m was a dual potent inhibitor against urease and α-glucosidase due to the presence of 2-CF3 electron-withdrawing functionality on the phenyl ring. To the best of our knowledge, these synthetic compounds were found to be the most potent dual inhibitors of urease and α-glucosidase with minimum IC50 values. The cytotoxicity of the compounds (2a-2q) was also investigated against human cell lines MCF-7 and HeLa. Compound 2l showed moderate cytotoxic activity against MCF-7 and HeLa cell lines. Moreover, in silico studies on most active compounds were also performed to understand the binding interaction of most active compounds with active sites of urease and α-glucosidase enzymes. Some compounds exhibited drug-like characteristics due to their lower cytotoxic and good ADME profiles.

Synthesis and Characterization of a Minophosphonate Containing Chitosan Polymer Derivatives: Investigations of Cytotoxic Activity and in Silico Study of SARS-CoV-19

Chitosan is broadly used as a biological material since of its excellent biological activities. This work describes investigations of chitosan interaction with SARS-CoV-2, which is occupied by human respiratory epithelial cells through communication with the human angiotension-converting enzyme II (ACE2). The β-chitosan derivatives are synthesized and characterized by FT-IR, nuclear magnetic resonance (¹H and ¹³C NMR), mass spectrometry, X-ray diffraction, TGA, DSC, and elemental analysis. The β-chitosan derivatives were screened for cytotoxic activity against the HepG2 and MCF-7 (breast) cancer cell lines. Compound 1h (GI₅₀ 0.02 µM) is moderately active against the HepG2 cancer cell line, and Compound 1c is highly active (GI₅₀ 0.01 µM) against the MCF-7 cancer cell line. In addition, chitosan derivatives (1a-1j) docking against the SARS coronavirus are found by in-silico docking analysis. The findings show that compound 1c exhibits notable inhibition ability compared with other compounds, with a binding energy value of -7.9 kcal/mol. Based on the molecular docking results, the chitosan analog is proposed to be an alternative antiviral agent for SARS-CoV2.

Larvicidal activity of novel anthraquinone analogues and their molecular docking studies

To investigate the larvicidal activities of novel anthraquinones (1a-1k) against Culex quinquefasciatus mosquito larvae. Novel anthraquinones (1a-1k) derivatives were synthesis via condensation method. The compounds were confirmed through FT-IR spectroscopy, ¹H & ¹³C NMR spectrum, and mass spectral studies. The larvicidal activity of compound 1c was highly active LD₅₀ 20.92 µg/mL against Culex quinquefasciatus compared standard permethrin with LD₅₀ 25.49 µg/mL. Molecular docking studies were carried out for compound 1c against Odorant-binding protein of Culex quinquefasciatus. The compound 1c (-9.8 Kcal/mol) was a potent larvicide with more binding energy than control permethrin (-9.7 Kcal/mol). Therefore, compound (1c) may be more significant inhibitors of mosquito larvicidal.

Antimicrobial activity of novel 5-benzylidene-3-(3-phenylallylideneamino)imidazolidine-2,4-dione derivatives causing clinical pathogens: Synthesis and molecular docking studies

BACKGROUND

This work is development of new hydantoin molecules as treatment of potential antibacterial and antifungal activity against clinical pathogens causing infectious disease. Synthesized compounds were evaluated in molecular docking studies, the most effective compound is used to dock against the targets of 1U1Z, and 1AI9 kinases, to evaluate its binding affinity, hoping to rationalize and obtain potent of antibacterial, antifungal agents.

MATERIAL AND METHOD

The FTIR, ¹H &¹³C NMR, and mass spectra were used to conform new molecules and their evaluation of antimicrobial activity. Gram-negative bacteria of Pseudomonas aeruginosa (ATCC-27853), Klebsiella pneumoniae (recultured) and Escherichia coli (ATCC-25922), and gram-positive bacteria of Enterococcus faecalis (recultured) and Staphylococcus aureus (ATCC-25923) were evaluated for all compounds. The in vitro antifungal activity was evaluated against Cryptococcus neoformans (recultured), Candida albicans (recultured), Aspergillus niger, Microsporum audouinii (recultured) and Aspergillus fumigatus (recultured) for all synthesized compounds.

RESULT

Antibacterial screening, we identified highly active antimicrobial agents for this study for example; gram-negative bacterial screening of 3g was highly (MIC: 0.25 μg/mL) active in contradiction of P. aeruginosa, whereas bacterial screening of 3e and 3h were more active (MIC: 2 μg/mL) in contradiction of K. pneumoniae and also 3g was more (MIC: 2 μg/mL) active in contradiction of E. faecalis than standard ciprofloxacin. Antifungal activity, the 3b was more active (MIC: 0.25 μg/mL) against C. albicance,3g (MIC: 2 μg/mL) and 3h (MIC: 4 μg/mL) were more potential of A. funigatus, and the compound 3c was highly (MIC: 4 μg/mL) active on M. audouinii than clotrimazole. Molecular docking studies also supported the new finding of potent antimicrobial agents, the compound 3g, 3b, and controls Ciprofloxacin, Clotrimazole were checked again proteins 1U1Z and 1AI9 by Autodock Vina program. The compound 3g was highest binding affinity (-8.4 kcal/mol) than ciprofloxacin (-8.2 kcal/mol) in 1U1Z protein and the compound 3b was highest binding affinity (-8.8 kcal/mol) than clotrimazole (-6.8 kcal/mol) in 1AI9 protein respectively.

CONCLUSION

A novel set of imidazolidine-2,4-dione compounds 3a-h have synthesized and characterized successfully. The screening of antimicrobial activity shows that all compounds possess antimicrobial activities. In addition, the objective of the study was succeeded with a few of the promising molecules, which are proving to be a potential treatment of bacterial infection candidates.

Synthesis of novel coumarin analogues: Investigation of molecular docking interaction of SARS-CoV-2 proteins with natural and synthetic coumarin analogues and their pharmacokinetics studies

The severe acute respiratory syndrome coronavirus, identified as SARS-CoV-2, initially established in Wuhan, China at the end of 2019, affects respiratory infections known as COVID-19. In an extraordinary manner, COVID-19 is affecting human life and has transformed a global public health issue into a crisis. Natural products are already recognized owing to the massive advantageous window and efficient antioxidant, antiviral immunomodulatory, and anti-inflammatory belongings. Additionally, the object of the present study was to demonstrate the inhibitory potential of the natural products coumarins and its analogues alongside SARS coronavirus. The present work, focuses on the synthesis of new coumarin analogues and characterized by FT-IR, ¹H and ¹³C NMR, elemental analyses, and mass spectra. The recently synthesised compounds were projected conceptual association for COVID-19 protease and also to explore in anticipation if this protein will help target protease inhibitor drugs such as Calanolide A, Cardatolide A, Collinin, Inophyllum A, Mesuol, Isomesuol, Pteryxin, Rutamarin, Seselin and Suksdorin. The natural coumarin analogues docking scores were compared to standard Hydroxychloroquine. While the 3D module of SARS coronavirus main protease was predicted with the SWISS MODEL web server, as well as biochemical interaction tests were performed with the AutoDock Vina tool between the target protein with ligands. This research further showed that all the protease inhibitors accessed the target protein with negative dock energy. Molecular docking studies found that the natural coumarin analogue Inophyllum A showed an exceptional potential for inhibition with a binding energy of −8.4 kcal/mol. The synthetic coumarin analogues 1m and 1p both demonstrated a similar binding energy, inhibition potential of −7.9 kcal / mol as opposed to hydroxychloroquine and co-crystallized ligand alpha-ketoamide with binding energy values of −5.8 and −6.6 kcal / mol. All compounds evaluated were known as drug-like in nature, passing Lipinski's “Law of 5” with 0 violations except for alpha-ketoamide, passing Lipinski's “Rule of 5” with 1 violation (MW > 500). The inhibitor binding in silico research thus offers a structural understanding of COVID-19 and molecular interactions across the known protease inhibitors centred on the findings of the multiple sequence alliance.

In silico molecular docking: Evaluation of coumarin based derivatives against SARS-CoV-2

BACKGROUND

The unique anthropological coronavirus which has been titled as SARS-CoV-2 was originally arisen in late 2019 in Wuhan, China affecting respiratory infection named as COVID-19. Coronavirus is disturbing human life in an exceptional method and has converted a public health global crisis. Natural products are ahead consideration due to the huge beneficial window and effective anti-inflammatory, immunomodulatory, antioxidant and antiviral possessions. Consequently, the present study was intended to display inhibition ability of natural products coumarins and their analogues against SARS coronavirus.

METHODS

The present study, aims to forecast theoretical assembly for the protease of COVID-19 and to discover advance whether this protein may assist as a target for protease inhibitors such as psoralen, bergapten, imperatorin, heraclenin, heraclenol, saxalin, oxepeucedanin, angelicin, toddacoumaquinone, and aesculetin. The docking score of these natural coumarin analogues compared with standard Hydroxychloroquine. Whereas the 3D assembly of main protease of SARS coronavirus was forecast with SWISS MODEL web server, and molecular interaction studies amongst target protein and ligands were done with AutoDock Vina software.

RESULTS

The study more exposed that all the inhibitors acquired with negative dock energy against the target protein. Molecular docking investigation displayed that natural coumarin analogue toddacoumaquinone displayed a remarkable inhibition ability with the binding energy of -7.8 kcal/mol than other compounds against main protease of SARS coronavirus in intricate with α-ketoamide (PDB ID: 5N5O). The synthetic coumarin analogue (1 m) also displayed the comparable inhibition ability with a binding energy of -7.1 kcal/mol against main protease of SARS coronavirus in intricate with α-ketoamide. Keeping the overhead results of ADME and toxicity, all tested compounds were recognized as drug-like nature, passing Lipinski's "Rule of 5" with 0 violation except α-ketoamide passes Lipinski's "Rule of 5" with 1 violation MW > 500. The projected constraints are within the assortment of recognized values.

CONCLUSIONS

Based upon the results of the manifold sequence alliance, natural and synthetic coumarin binding sites were preserved. The present in silico examination thus, delivers structural awareness about the protease of COVID-19 and molecular relations with some of the recognised protease inhibitors.

Synthesis, Cytotoxic Analysis, and Molecular Docking Studies of Tetrazole Derivatives via N-Mannich Base Condensation as Potential Antimicrobials

Purpose

A new series of tetrazole derivatives, which are renowned antimicrobials possessing a five-membered aromatic heterocyclic group, are synthesized herein and subjected to antimicrobial and cytotoxicity screening.

Methods

The tetrazole derivatives were synthesized via ultrasonication using Mannich base condensation. Structural verification of the products was performed using IR, ¹H NMR, and ¹³C NMR spectroscopy, as well as mass spectroscopic and elemental analyses. The compounds were then screened for antimicrobial and cytotoxic activity against HepG2 (liver), MCF-7 (breast), and HeLa (cervical) cell lines. Inter- and intra-molecular binding interactions were determined using molecular docking studies. The exact binding mode between the most active tetrazole derivatives (ie, 1b, 2a, and 2b) and the proteins (ie, 4OR7, 1AI9, and 4FM9) was established using Autodock Vina 1.1.2 software and compared to the binding mode of the reference compounds (ie, cefazolin, clotrimazole, and fluorouracil).

Results

Compound 1b was extremely active against Enterococcus faecalis relative to the positive control cefazolin. Compounds 1b and 1e were active against Candida albicans and Microsporum audouinii compared to the positive control clotrimazole in antifungal screening. The HepG2 (liver) and MCF-7 (breast) cancer cell lines were particularly susceptible to the synthesized compounds. Compared to the control compound fluorouracil, 2a and 2b were extremely active against all three cancer cell lines. Molecular docking studies showed that 2b exhibited higher binding affinity (−7.8 kcal/mol) to the 4OR7 protein than the control cefazolin (−7.2 kcal/mol).

Conclusion

Generally, 1b, 2a, and 2b exhibited impressive inhibitory capabilities in antibacterial, antifungal, and cytotoxic screenings relative to the reference compounds. The results of the molecular docking studies and both the microbial and anticancer screenings indicate that these novel derivatives could be developed into potential therapeutic agents for medical applications.

Synthesis of diindolylmethane (DIM) bearing thiadiazole derivatives as a potent urease inhibitor

The current study describes synthesis of diindolylmethane (DIM) derivatives based-thiadiazole as a new class of urease inhibitors. Diindolylmethane is natural product alkaloid reported to use in medicinal chemistry extensively. Diindolylmethane-based-thiadiazole analogs (1–18) were synthesized and characterized by various spectroscopic techniques ¹HNMR, ¹³C-NMR, EI-MS and evaluated for urease (jack bean urease) inhibitory potential. All compounds showed excellent to moderate inhibitory potential having IC₅₀ value within the range of 0.50 ± 0.01 to 33.20 ± 1.20 µM compared with the standard thiourea (21.60 ± 0.70 µM). Compound 8 (IC₅₀ = 0.50 ± 0.01 µM) was the most potent inhibitor amongst all derivatives. Structure-activity relationships have been established for all compounds. The key binding interactions of most active compounds with enzyme were confirmed through molecular docking studies.

Synthesis of symmetrical bis-Schiff base-disulfide hybrids as highly effective anti-leishmanial agents

Leishmaniasis has affected a wider part of population around the globe. Most often, the existing regiments to battle against leishmaniasis are inadequate and limited. In our ongoing efforts to develop new leishmanicidal agents, we have synthesized a series of novel and symmetrical bis-Schiff base-disulfide hybrids 1-27. Intermediate disulfide was synthesized from corresponding 2-aminothiol followed by reacting the coupled adduct with various aromatic aldehydes. All these compounds showed outstanding inhibition when compared with standard (Table 1). Out of twenty seven analogues, twenty two analogues i.e. 1-5, 7-13, 17-21, 23-27 analogues showed excellent inhibitory potential with EC₅₀ values ranging from 0.010 ± 0.00 to 0.096 ± 0.01 μM while five compounds i.e. 6, 14-16, and 22 showed good inhibitory potential with EC₅₀ values ranging from 0.10 ± 0.00 to 0.137 ± 0.01 μM when compared with the standard Amphotericin B. Structure-activity relationship has been established while molecular docking studies were performed to pin the binding interaction of active molecules. This study will help to develop new antileishmanial lead compounds.

Molecular perspective and anticancer activity of medicinal plants

To evaluate phytochemical constituents from the methanolic extracts of medicinal plants Aloe castellorum and Aloe pseudorubroviolacea. The cytotoxic activity of Aloe castellorum and Aloe pseudorubroviolacea leaf extracts against Human colon cancer cell line (HCT-116) was also assessed. The two medicinal plant extracts having significant cytotoxic activity, meanwhile the methanolic extract of Aloe castellorum shows higher cytotoxic activity than Aloe pseudorubroviolacea extract. The Aloe castellorum shows remarkable activity against respective cell line than control. The characteristic chemical constituents of Aloe castellorum and Aloe pseudorubroviolacea leaf extracts were recognized from Gas chromatography and Mass spectrometry (GC–MS) technique. The molecular docking studies also support the cytotoxic activity.

Lead Molecules for Targeted Urease Inhibition: An Updated Review from 2010 -2018

The field of enzyme inhibition is a tremendous and quickly growing territory of research. Urease a nickel containing metalloenzyme found in bacteria, algae, fungi, and plants brings hydrolysis of urea and plays important role in environmental nitrogen cycle. Apart from this it was found to be responsible for many pathological conditions due to its presence in many microorganisms such as H. Pylori, a ureolytic bacteria having urease which elevates pH of gastric medium by hydrolyzing urea present in alimentary canal and help the bacteria to colonize and spread infection. Due to the infections caused by the various bacterial ureases such as Bacillus pasteurii, Brucella abortus, H. pylori, H. mustelae, Klebsiella aerogenes, Klebsiella tuberculosis, Mycobacterium tuberculosis, Pseudomonas putida, Sporosarcina pasteurii and Yersinia enterocolitica, it has been the current topic of today's research. About a wide range of compounds from the exhaustive literature survey has been discussed in this review which is enveloped into two expansive classes, as Inhibitors from synthetic origin and Inhibitors from natural origin. Moreover active site details of enzyme, mechanism of catalysis of substrate by enzyme, uses of plant urease and its pathogenic behavior has been included in the current review. So, overall, this review article diagrams the current landscape of the developments in the improvements in the thriving field of urease inhibitory movement in medicinal chemistry from year 2010 to 2018, with an emphasis on mechanism of action of inhibitors that may be used for more development of recent and strong urease inhibitors and open up new doors for assist examinations in a standout amongst the most lively and promising regions of research.

Indole bearing thiadiazole analogs: synthesis, β-glucuronidase inhibition and molecular docking study

Indole based thiadiazole derivatives (1-22) have synthesized, characterized by NMR and HREI-MS and evaluated for β-Glucuronidase inhibition. All compounds showed outstanding β-glucuronidase activity with IC50 values ranging between 0.5 ± 0.08 to 38.9 ± 0.8 µM when compared with standard d-saccharic acid 1,4 lactone (IC50 value of 48.1 ± 1.2 µM). The compound 6, a 2,3-dihydroxy analog was found the most potent among the series with IC50 value 0.5 ± 0.08 µM. Structure activity relationship has been established for all compounds. To confirm the binding interactions of these newly synthesized compounds, molecular docking study have been carried out which reveal that these compounds established stronger hydrogen bonding networks with active site residues.

Synthesis, anti-leishmanial and molecular docking study of bis-indole derivatives

We have synthesized new series of bisindole analogs (1–27), characterized by ¹HNMR and HR-EI-MS and evaluated for their anti-leishmanial potential. All compounds showed outstanding inhibitory potential with IC₅₀ values ranging from 0.7 ± 0.01 to 13.30 ± 0.50 µM respectively when compared with standard pentamidine with IC₅₀ value of 7.20 ± 0.20 µM. All analogs showed greater potential than standard except 10, 19 and 23 when compared with standard. Structure activity relationship has been also established for all compounds. Molecular docking studies were carried out to understand the binding interaction of active molecules.

Bioassay Directed Isolation, Biological Evaluation and in Silico Studies of New Isolates from Pteris cretica L

Members of genus Pteris have their established role in the traditional herbal medicine system. In the pursuit to identify its biologically active constituents, the specie Pteris cretica L. (P. cretica) was selected for the bioassay-guided isolation. Two new maleates (F9 and CB18) were identified from the chloroform extract and the structures of the isolates were elucidated through their spectroscopic data. The putative targets, that potentially interact with both of these isolates, were identified through reverse docking by using in silico tools PharmMapper and ReverseScreen3D. On the basis of reverse docking results, both isolates were screened for their antioxidant, acetylcholinesterase (AChE) inhibition, α-glucosidase (GluE) inhibition and antibacterial activities. Both isolates depicted moderate potential for the selected activities. Furthermore, docking studies of both isolates were also studied to investigate the binding mode with respective targets followed by molecular dynamics simulations and binding free energies. Thereby, the current study embodies the poly-pharmacological potential of P. cretica.

Benzylidine indane-1,3-diones: As novel urease inhibitors; synthesis, in vitro, and in silico studies

Current study deals with the evaluation of indane-1,3-dione based compounds as new class of urease inhibitors. For that purpose, benzylidine indane-1,3-diones (1-30) were synthesized and fully characterized by different spectroscopic techniques including EI-MS, HREI-MS, ¹H, and ¹³C NMR. All synthetic molecules 1-30 were evaluated for urease inhibitory activity and showed good to moderate inhibitory potential within the range of (IC₅₀ = 11.60 ± 0.3-257.05 ± 0.7 µM) as compared to the standard acetohydroxamic acid (IC₅₀ = 27.0 ± 0.5 µM). Compound 1 (IC₅₀ = 11.60 ± 0.3 µM) was found to be most potent inhibitor amongst all derivatives. The key binding interactions of most active compounds within the enzyme pocket were evaluated through in silico studies.