scholarly journals In vitro antibacterial and in silico docking studies of two Schiff bases on Staphylococcus aureus and its target proteins

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ragi K ◽  
Joby Thomas Kakkassery ◽  
Vinod P. Raphael ◽  
Reeja Johnson ◽  
Vidhya Thomas K

Abstract Background Schiff base compounds have extensive applications in various fields such as analytical, inorganic, organic, and biological fields. They have excellent pharmacology application prospects in the modern era and are widely used in the pharmaceutical industry. In the present work in vitro antibacterial and in silico docking studies of two Schiff base compounds 2,2’-(5,5-dimethylcyclohexane-1,3-diylidene)bis(azan-1-yl-1-ylidene)diphenol (DmChDp) and N,N’-(5,5-dimethylcyclohexane-1,3-diylidene)dianiline (DmChDa) were carried out against the bacterial strain Staphylococcus aureus and its target proteins. Results The tests proved that the ligands have potential antibacterial activity. In the computational analysis, the drug-like properties of the compounds were first pre-filtered using the Lipinski rule of five. Then, molecular docking study was conducted using the AutoDock 4.2 program, to establish the mechanism by which the molecules inhibit the growth of S. aureus. For this purpose, 6 different target proteins (PDB ID: 1T2P, 3U2D, 2W9S, 1N67, 2ZCO, and 4H8E) of S. aureus were selected. Both the Schiff bases showed a good binding affinity with the target protein dihydrofolate reductase enzyme (PDB ID: 2W9S) but in different sites. Maximum binding energies of about − 10.3 and − 10.2 kcal/mol were observed when DmChDp and DmChDa were docked with 2W9S. Conclusion Schiff base compounds DmChDp and DmChDa have appreciable growth-inhibitory power against S. aureus, which can be attributed to the deactivation of the enzyme, dihydrofolate reductase.

2019 ◽  
Vol 15 (2) ◽  
pp. 257-267 ◽  
Author(s):  
Paritosh Shukla ◽  
Ashok Sharma ◽  
Leena Fageria ◽  
Rajdeep Chowdhury

Background: Cancer being a deadly disease, many reports of new chemical entities are available. Pyranopyrazole (PPZ) compounds have also been disclosed as bioactive molecules but mainly as antimicrobial agents. Based on one previous report and our interest in anticancer drug design, we decided to explore PPZs as anticancer agents. To the best of our knowledge, we found that a comprehensive study, involving synthesis, in-vitro biological activity determination, exploration of the mechanism of inhibition and finally in-silico docking studies, was missing in earlier reports. This is what the present study intends to accomplish. Methods: Ten spiro and eleven non-spiro PPZ molecules were synthesized by environment-friendly multicomponent reaction (MCR) strategy. After subjecting each of the newly synthesized molecules to Hep3b hepatocellular carcinoma cell lines assay, we selectively measured the Optical Density (OD) of the most active ones. Then, the compound exhibiting the best activity was docked against human CHK- 1 protein to get an insight into the binding affinities and a quick structure activity relationship (SAR) of the PPZs. Results: The two series of spiro and non-spiro PPZs were easily synthesized in high yields using microwave assisted synthesis and other methods. Among the synthesized compounds, most compounds showed moderate to good anticancer activity against the MTT assay. After performing the absorbance studies we found that the non-spiro molecules showed better apoptosis results and appeared to bind to DNA causing disruption in their structures. Finally, the docking results of compound 5h (having N,Ndimethylamino substituted moiety) clearly showed good binding affinities as predicted by our experimental findings. Conclusion: The paper describes a comprehensive synthesis, in-vitro and docking studies done on new PPZs. The newly synthesized series of spiro and non-spiro PPZs were found to possess antineoplasmic activity as evinced by the studies on hep3b cells. Also, the UV visible absorbance study gave clues to the possible binding of these molecules to the DNA. Docking studies corroborated well with the experimental results. Thus, these new molecules appear to be potential anticancer agents, but further studies are required to substantiate and elaborate on these findings.


Author(s):  
Quan Shi ◽  
Qi He ◽  
Weiming Chen ◽  
Jianwen Long ◽  
Bo Zhang

IntroductionOleuropein (OLP) is polyphenol obtained from olive oil; it is proved in Chinese traditional medicine for its use in disorders including autoimmune and inflammatory disorders. Psoriasis (PSR) is an autoimmune and inflammatory disorder triggered by T-helper-17 (Th17) cells.Material and methodsWe developed an imiquimod (IMQ)-mediated PSR model in mice to study the anti-inflammatory role of OLP in psoriasis. The mice were given 50 mg/kg and 100 mg/kg dose of OLP. Histology was done to assess the inflammation of lesions. Western blot analysis was done for JAK3/STAT3 in isolated T cells, expression of RORgt was done by RT-PCR. The In silico molecular docking studies were done for interaction of OLP with target protein STAT3 and JAK3.ResultsTreatment of OLP attenuated proliferation in IMQ-mediated keratinocytes, improved infiltration of CD3+ cells in the skin lesions and in CD4+ and CD8+ T cells and also ameliorated the levels of cytokines. In in vitro studies in isolated T cells, OLP blocked the differentiation of Th17 cells and also the levels of IL-17 and the JAK3/STAT3 pathway. The in silico docking showed that OLP had potential binding affinity with JAK3 and STAT3 which was parallel to in vivo and in vitro findings.ConclusionsOLP ameliorates psoriasis skin lesions by blocking Th17-mediated inflammation. OLP may be an interesting molecule for treating autoimmunity in psoriasis.


2018 ◽  
Vol 21 (3) ◽  
pp. 194-203 ◽  
Author(s):  
Shilpy Aggarwal ◽  
Deepika Paliwal ◽  
Dhirender Kaushik ◽  
Girish Kumar Gupta ◽  
Ajay Kumar

Background: Malaria is one of the most vital infectious diseases caused by protozoan parasites of the Plasmodium genus. As P. falciparum, the cause of most of the severe cases of malaria, is increasingly resistant to available drugs such as amodioquine, chloroquine, artemisinin, and antifolates, there is an urgent need to identify new targets for chemotherapy. Objective: This study screened novel pyrazole derivatives carrying iminium & benzothiazole group for antimalarial potential against P. falciparum chloroquine sensitive (3D7) strain. Materials & Methods: Several pyrazole schiff base hybrids with a wide range of substitution have been synthesized via condensation of substituted aniline with substituted 4-formylpyrazole and evaluated for their in vitro antimalarial activity against asexual blood stages of human malaria parasite, Plasmodium falciparum. The interaction of these conjugate hybrids was also investigated by molecular docking studies in the binding site of P. falciparum cystein protease falcipain-2. The pharmacokinetic properties were also studied using ADME prediction. Results: Among all compounds, 6bf and 6bd were found to be potential molecules with EC50 1.95µg/ml and 1.98µg/ml respectively. Docking study results reveal that the pyrazole schiff base derivatives occupy the PfFP binding sites and they show good interactions with significant values of binding energies. Conclusion: We provide evidence which implicates pyrazole Schiff base hybrids as potential prototypes for the development of antimalarial agents.


2021 ◽  
Vol 33 (5) ◽  
pp. 1090-1098
Author(s):  
M.R. Ezhilarasi ◽  
A.B. Senthieel Khumar ◽  
P. Elavarasan

A new series of novel 4-(furan-2-yl)-6-(4-morpholinophenyl)pyrimidine-amines (4a-c) were synthesized and characterized by elemental analysis and spectral analysis like IR, 1D 1H & 13C NMR. The synthesized compounds 4a-c were evaluated for their biological studies. The zone of inhibitions were examined for synthesized compounds 4a-c besides the identical set of microbial strains, especially that compound 4a against S. aureus, S. pyogenes, E. coli, compound 4b against P. aeruginosa has excellent antibacterial activity. Compound 4c shows good inhibition against C. albicans. Also in silico molecular docking and ADME predictions were carried for all the compounds. The docking studies were examined by two different proteins like 1UAG protein and 1OQA protein. in silico docking provides of the compounds have good docking score compared with the standard. In the ADME predictions all the compounds were met criteria. The synthesized compounds all of them obeyed the drug-likeness properties.


2020 ◽  
Author(s):  
Mustafa Alhaji Isa ◽  
Muhammad M Ibrahim

The 3-hydroquinate synthase (DHQase) is an enzyme that catalyzes the third step of the shikimate pathway in <i>Mycobacterium tuberculosis</i> (MTB), by converting 3-dehydroquinate into 3-dehydroshikimate. In this study, the novel inhibitors of DHQase from MTB was identified using in silico approach. The crystal structure of DHQase bound to 1,3,4-trihydroxy-5-(3-phenoxypropyl)-cyclohexane-1-carboxylic acid (CA) obtained from the Protein Data Bank (PDB ID: 3N76). The structure prepared through energy minimization and structure optimization. A total of 9699 compounds obtained from Zinc and PubChem databases capable of binding to DHQase and subjected to virtual screening through Lipinski’s rule of five and molecular docking analysis. Eight (8) compounds with good binding energies, ranged between ─8.99 to ─8.39kcal/mol were selected, better than the binding energy of ─4.93kcal/mol for CA and further filtered for pharmacokinetic properties (Absorption, Distribution, Metabolism, Excretion, and Toxicity or ADMET). Five compounds (ZINC14981770, ZINC14741224, ZINC14743698, ZINC13165465, and ZINC8442077) which had desirable pharmacokinetic properties selected for molecular dynamic (MD) simulation and molecular generalized born surface area (MM-GBSA) analyses. The results of the analyses showed that all the compounds formed stable and rigid complexes after the 50ns MD simulation and also had a lower binding as compared to CA. Therefore, these compounds considered as good inhibitors of MTB after in vitro and in vivo validation.”


2021 ◽  
Vol 33 (7) ◽  
pp. 1504-1512
Author(s):  
Manju Mathew ◽  
Muthuvel Ramanathan Ezhilarasi

A series of 4(5-(4-chlorophenyl)furan-2-yl)-6-phenylpyrimidin-2-amine derivatives (5a-h) were synthesized from 2-(4-chlorophenyl)-5-styrylfuran (3a-h) with guanidine nitrate in absolute ethanol under conventional method and evaluated for their in vitro anticancer, antimicrobial activities and in silico studies. The chemical structure of the furan moiety containing substituted amino pyrimidine derivatives (5a-h) were elucidated from spectroscopic analysis like infrared, 1H & 13C NMR spectral data and CHN analysis. in silico docking studies were predicted for the synthesized compounds (5a-h) using bacterial protein 1UAG and in silico ADME predictions were also carried for the synthesized compounds (5a-h). The in vitro anticancer study was carried the compound 5b by MMT assay. Compound 5b shows the LC50 value of 120.15 ± 0.003 μg/mL. in vitro Antimicrobial activities were screened for the compounds (5a-h) using different strains. Compound 5h has electron withdrawing group in benzene ring substituted in the para position showed good antimicrobial activity against all the bacterial strains and fungal strains. in silico studies, compound 5h shows excellent docking score (-9.7 kcal/mol) compared with ciprofloxacin (-7.8 kcal/mol).


Author(s):  
Gayathri Segaran ◽  
Lokesh Ravi ◽  
Mythili Sathiavelu

Objective: The objective of the study was to determine and compare the antibacterial effect of different ornamental plants and to isolate the effective bioactive compound with antibacterial activity from Polyalthia longifolia. Methods: Petroleum ether and methanol extracts of Bougainvillea glabra, Polyalthia longifolia, Ixora coccinea Linn. ,Plumeria rubra and Euphorbia milli leaves were investigated for antimicrobial activity by performing agar well difusion method. The plant extract with the highest antibacterial activity was selected and further used for the isolation of antibacterial compounds. In silico docking studies and in vitro antibacterial assay was performed to analyze the biological activity of pure compound. Results: The highest antibacterial activity was found in the pet ether of Polyalthia longifolia against all the tested bacterial strains and the extract was further selected for compound separation. A novel compound 3,3’-(propane-2,2-diyl)bis(3,4,5,6,7,8-hexahydro-1H-isochromene) (PHDC) with a molecular weight of 316.35 g/mol and molecular formula C21H32O2 was identified from Polyalthia longifolia by using spectroscopic studies. In the in vitro antibacterial assay, PHDC demonstrated significant antibacterial showed against Protease mirabilis. In silico docking studies revealed that PHDC showed antibacterial activity by inhibiting tRNA Synthetase (IleRS). PHDC exhibited the lowest binding energy of - 8.7Kcal/Mol for Isoleucyl tRNA Synthetase (IleRS), the protein responsible for protein synthesis. Conclusion: The emergence of multiple antibiotics resistant microbes has become huge nowadays and the infections caused by these resistant microbes cannot be treated with antibiotics. PHDC is a novel compound extracted from Polyalthia longifolia showed significant antibacterial effect and we suggest that the compound can be further used as lead molecules to overcome the infections caused by antibiotic resistant bacteria.


Author(s):  
MUTHUSWAMY UMAMAHESWARI ◽  
Preetha Prabhu ◽  
KUPPUSAMY ASOKKUMAR ◽  
THIRUMALAISAMY SIVASHANMUGAM ◽  
Varadharajan Subhadradevi ◽  
...  

Marine Drugs ◽  
2019 ◽  
Vol 17 (2) ◽  
pp. 91 ◽  
Author(s):  
Jinhyuk Lee ◽  
Mira Jun

Alzheimer′s disease (AD) is one of the most common neurodegenerative diseases with a multifactorial nature. β-Secretase (BACE1) and acetylcholinesterase (AChE), which are required for the production of neurotoxic β-amyloid (Aβ) and the promotion of Aβ fibril formation, respectively, are considered as prime therapeutic targets for AD. In our efforts towards the development of potent multi-target, directed agents for AD treatment, major phlorotannins such as eckol, dieckol, and 8,8′-bieckol from Ecklonia cava (E. cava) were evaluated. Based on the in vitro study, all tested compounds showed potent inhibitory effects on BACE1 and AChE. In particular, 8,8′-bieckol demonstrated the best inhibitory effect against BACE1 and AChE, with IC50 values of 1.62 ± 0.14 and 4.59 ± 0.32 µM, respectively. Overall, kinetic studies demonstrated that all the tested compounds acted as dual BACE1 and AChE inhibitors in a non-competitive or competitive fashion, respectively. In silico docking analysis exhibited that the lowest binding energies of all compounds were negative, and specifically different residues of each target enzyme interacted with hydroxyl groups of phlorotannins. The present study suggested that major phlorotannins derived from E. cava possess significant potential as drug candidates for therapeutic agents against AD.


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