scholarly journals Rationale design and synthesis of some novel imidazole linked thiazolidinone hybrid molecules as DNA minor groove binders

2020 ◽  
Vol 11 (2) ◽  
pp. 120-132
Author(s):  
Javeed Ahmad War ◽  
Santosh Kumar Srivastava

A new series of imidazole linked thiazolidinone hybrid molecules was designed and subsequently synthesized through a feasible, three step reaction protocol. The structures of these molecules were established using FT-IR, 1H NMR, 13C NMR and HRMS techniques. In vitro susceptibility tests against some Gram positive (Staphylococcus aureus and Bacillus subtilis) and Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa) exhibited broad spectrum potency of the molecules. The most potent molecule (S2A7) amongst the screened molecules, showed minimum inhibitory concentration (MIC) value not less than 2.0 µg/mL which was at par with the reference drug Streptomycin. Structure activity relationships revealed nitro and chloro groups being crucial for bioactivity when present at meta position of arylidene ring in 3-(3-(imidazol-1-yl)propyl)-5-(benzylidene)-2-(phenylimino)thiazolidin-4-one. Deoxyribonucleic acid (DNA)and bovine serum albumin (BSA) binding studies for S2A7 under simulated physiological pH were probed using UV-Visible, fluorescence quenching, gel electrophoresis and molecular docking techniques. These studies established that S2A7 has strong binding affinity towards DNA and binds at the minor groove of DNA with binding constant (Kb) of 0.1287×102 L/mol. Molecular docking simulations of S2A7 with DNA and BSA predicted binding affinity of -9.2 and -7.2 kcal/mol, respectively. Van der Waals forces and hydrogen bonding interactions were predicted as the main forces of interaction. With DNA, S2A7 exhibited specific binding affinity towards adenine-thiamine base pairs. The compound S2A7 forms a stable complex with BSA by binding at subdomain IIIA implying high bio-distribution of the compound.

Author(s):  
Haiming Zhou ◽  
Jing Zhang ◽  
Xiaoqing Chen ◽  
Shili Guo ◽  
Huimei Lin ◽  
...  

Background and Objective: Beauvericin (BEA), a cyclic hexadepsipeptide mycotoxin, is a potent inhibitor of the acyl-CoA: cholesterol acyltransferase enzyme 1 (ACAT1) which involved in multiple tumor-correlated pathways. However, the binding mechanisms between BEA and ACAT1 were not elucidated. Methods: BEA was purified from a mangrove entophytic Fusarium sp. KL11. Single-crystal X-ray diffraction was used to determine the structure of BEA. Wound healing assays of BEA against KB cell line and MDA-MB-231 cell line were evaluated. Inhibitory potency of BEA against ACAT1 was determined by ELISA assays. Molecular docking was carried out to illuminate the bonding mechanism between BEA and ACAT1. Results: The structure of BEA was confirmed by X-ray diffraction, indicating a monoclinic crystal system with P21 space group (α = 90°, β = 92.2216(9)o, γ= 90o). BEA displayed migration-inhibitory activities against KB cells and MDA-MB-231 cells in vitro. ELISA assays revealed the protein expression level of ACAT1 in KB cells was significantly decreased after BEA treatment (P <0.05). Molecular docking demonstrated that BEA formed hydrogen bond with His425 and pi-pi staking with Tyr429 in ACAT1. Conclusions: BEA sufficiently inhibited the proliferation and migration of KB cells and MDA-MB-231 cells by downregulating ACAT1 expression. In addition, BEA potentially possessed a strong binding affinity with ACAT1. BEA may serve as a potential lead compound for the development of a new ACAT1-targeted anticancer drug.


2018 ◽  
Vol 10 (5) ◽  
pp. 117
Author(s):  
Savita Mishra ◽  
Sandhya Hora ◽  
Vibha Shukla ◽  
Mukul Das ◽  
Harsha Kharkwal ◽  
...  

Objective: The aim of this study was to develop polymer coated sustained release tablet using sorafenib and silibinin combination for the treatment of hepatocellular carcinoma.Methods: The qualitative analysis such as weight variation, friability, hardness, interaction studies, disintegration and in vitro release were performed to validate formulated tablets. We have maintained the acceptable official limits for weight variation, friability, hardness and disintegration time according to prescribed pharmacopoeial recommendation. In vitro drug release studies were performed using USP-II (paddle type) dissolution apparatus. The MTT assay was performed for assessment of Cell viability of drug combination for tablet formulation. Molecular docking studies have been performed to determine the combinatorial mode of action for the tablet formulation.Results: Friability and weight variation were less than 1% for each formulation, which were within range of prescribed pharmacopoeial recommendation. The hardness of 20 tablets showed 5-6.5Kg/cm2 for all formulations 5-6.5Kg/cm2. The optimized formulation resulted in 98% drug release after 28 h. The present study reports the synergistic effects of drug combination to inhibit cell growth in HepG2 cell line. Molecular docking studies showed that sorafenib has high binding affinity for B-Raf vascular endothelial growth factor receptor β and protein kinase B. Silibinin showed binding affinity with MAP kinase-11, protein phosphatase 2 A and tankyrase.Conclusion: The present study reports for the first time a novel formulation for sustained release and reduced toxicity of sorafenib with enhanced inhibitory effect of the drug combination on cancerous hepatic cell line as well collaborative mechanism of action for the formulation.


2021 ◽  
pp. 122-137
Author(s):  
Chingju Lin ◽  
Fuu-Jen Tsai ◽  
Yuan-Man Hsu ◽  
Tsung-Jung Ho ◽  
Guo-Kai Wang ◽  
...  

Negative impacts of COVID-19 on human health and economic and social activities urge scientists to develop effective treatments. Baicalin is a natural flavonoid, extracted from a traditional medicinal plant, previously reported with anti-inflammatory activity. In this study, we used pharmacophore fitting and molecular docking to screen and determine docking patterns and the binding affinity of baicalin on 3 major targets of SARS-CoV-2 (3-chymotrypsin-like cysteine protease [3CLpro], papain-like protease [PLpro], and RNA-dependent RNA polymerase). The obtained data revealed that baicalin has high pharmacophore fitting on 3CLpro and predicted good binding affinity on PLpro. Moreover, using the enzymatic assay, we examined the inhibitory effect of baicalin in vitro on the screened enzymes. Baicalin also exhibits inhibitory effect on these proteases in vitro. Additionally, we performed pharmacophore-based screening of baicalin on human targets and conducted pathway analysis to explore the potential cytoprotective effects of baicalin in the host cell that may be beneficial for COVID-19 treatment. The result suggested that baicalin has multiple targets in human cell that may induce multiple pharmacological effects. The result of pathway analysis implied that these targets may be associated with baicalin-induced bioactivities that are involved with signals of pro-inflammation factors, such as cytokine and chemokine. Taken together with supportive data from the literature, the bioactivities of bailalin may be beneficial for COVID-19 treatment by reducing cytokine-induced acute inflammation. In conclusion, baicalin is potentially a good candidate for developing new therapeutic to treat COVID-19.


1983 ◽  
Vol 212 (2) ◽  
pp. 249-257 ◽  
Author(s):  
M J Imber ◽  
S V Pizzo

These studies explore the role of carbohydrate recognition systems and the direct involvement of terminal alpha 1-3-linked fucose in the clearance of lactoferrin from the murine circulation and in the specific binding of lactoferrin to receptors on murine peritoneal macrophages. As previously reported, radiolabelled lactoferrin cleared very rapidly (t1/2 less than 1 min) after intravenous injection into mice. However, competing levels of ligands specific for the hepatic galactose receptor (asialo-orosomucoid), the hepatic fucose receptor (fucosyl-bovine serum albumin), and the mononuclear-phagocyte system pathway recognizing mannose, N-acetylglucosamine and fucose (mannosyl-, N-acetylglucosaminyl- and fucosyl-bovine serum albumin) did not block radiolabelled lactoferrin clearance in vivo or binding to mouse peritoneal macrophage monolayers in vitro. Almond emulsin alpha 1-3-fucosidase was used to prepare defucosylated lactoferrin in which 88% of the alpha 1-3-linked fucose was hydrolysed. No difference in clearance or receptor binding was observed between radiolabelled native and defucosylated lactoferrin. Fucoidin, a fucose-rich algal polysaccharide, completely inhibits the clearance in vivo and macrophage binding in vitro of lactoferrin. This effect, however, is probably not the result of competition for binding to the fucose receptor, since gel-filtration studies demonstrated formation of a stable complex between lactoferrin and fucoidin. The present results indicate that the lactoferrin-clearance pathway is distinct from several pathways mediating glycoprotein clearance through recognition of terminal galactose, fucose, N-acetylglucosamine or mannose. Furthermore, alpha 1-3-linked fucose on lactoferrin is not essential for lactoferrin clearance in vivo or specific binding to macrophage receptors in vitro.


Author(s):  
Aldina Amalia Nur Shadrina ◽  
Yetty Herdiyati ◽  
Ika Wiani ◽  
Mieke Hemiawati Satari ◽  
Dikdik Kurnia

Background: Streptococcus sanguinis can contribute to tooth demineralization, which can lead to dental caries. Antibiotics used indefinitely to treat dental caries can lead to bacterial resistance. Discovering new antibacterial agents from natural products like Ocimum basilicum will help combat antibiotic resistance. In silico analysis (molecular docking) can help determine the lead compound by studying the molecular interaction between the drug and the target receptor (MurA enzyme and DNA gyrase). It is a potential candidate for antibacterial drug development. Objective: The research objective is to isolate the secondary metabolite of O. basilicum extract that has activity against S. sanguinis through in vitro and in silico analysis. Methods: n-Hexane extract of O. basilicum was purified by combining column chromatography with bioactivity-guided. The in vitro antibacterial activity against S. sanguinis was determined using the disc diffusion and microdilution method, while molecular docking simulation of nevadensin (1) with MurA enzyme and DNA gyrase was performed used PyRx 0.8 program. Results: Nevadensin from O. basilicum was successfully isolated and characterized by spectroscopic methods. This compound showed antibacterial activity against S. sanguinis with MIC and MBC values of 3750 and 15000 μg/mL, respectively. In silico analysis showed that the binding affinity to MurA was -8.5 Kcal/mol, and the binding affinity to DNA gyrase was -6.7 Kcal/mol. The binding of nevadensin-MurA is greater than fosfomycin-MurA. Otherwise, Nevadensin-DNA gyrase has a weaker binding affinity than fluoroquinolone-DNA gyrase and chlorhexidine-DNA gyrase. Conclusion: Nevadensin showed potential as a new natural antibacterial agent by inhibiting the MurA enzyme rather than DNA gyrase.


2021 ◽  
Author(s):  
Heerak Chugh ◽  
Pramod Kumar ◽  
Neeraj Kumar ◽  
Rajesh K. Gaur ◽  
Gagan Dhawan ◽  
...  

Noscapine binds human hemoglobin spontaneously forming a stable complex that affects noscapine's ADMET profile, bioavailability and toxicity.


2020 ◽  
Vol 3 (4) ◽  
pp. 989-1000
Author(s):  
Mustapha Abdullahi ◽  
Shola Elijah Adeniji

AbstractMolecular docking simulation of thirty-five (35) molecules of N-(2-phenoxy)ethyl imidazo[1,2-a]pyridine-3-carboxamide (IPA) with Mycobacterium tuberculosis target (DNA gyrase) was carried out so as to evaluate their theoretical binding affinities. The chemical structure of the molecules was accurately drawn using ChemDraw Ultra software, then optimized at density functional theory (DFT) using Becke’s three-parameter Lee–Yang–Parr hybrid functional (B3LYP/6-311**) basis set in a vacuum of Spartan 14 software. Subsequently, the docking operation was carried out using PyRx virtual screening software. Molecule 35 (M35) with the highest binding affinity of − 7.2 kcal/mol was selected as the lead molecule for structural modification which led to the development of four (4) newly hypothetical molecules D1, D2, D3 and D4. In addition, the D4 molecule with the highest binding affinity value of − 9.4 kcal/mol formed more H-bond interactions signifying better orientation of the ligand in the binding site compared to M35 and isoniazid standard drug. In-silico ADME and drug-likeness prediction of the molecules showed good pharmacokinetic properties having high gastrointestinal absorption, orally bioavailable, and less toxic. The outcome of the present research strengthens the relevance of these compounds as promising lead candidates for the treatment of multidrug-resistant tuberculosis which could help the medicinal chemists and pharmaceutical professionals in further designing and synthesis of more potent drug candidates. Moreover, the research also encouraged the in vivo and in vitro evaluation study for the proposed designed compounds to validate the computational findings.


2002 ◽  
Vol 80 (4) ◽  
pp. 249-257 ◽  
Author(s):  
Hudson de Sousa Buck ◽  
Brice Ongali ◽  
Gaétan Thibault ◽  
Charles J Lindsey ◽  
Réjean Couture

Kinins have been elected to the status of central neuromediators. Their effects are mediated through the activation of two G-protein-coupled receptors, denoted B1 and B2. Functional and binding studies suggested that B1 and B2 receptors are upregulated in the medulla and spinal cord of hypertensive and diabetic rats. The aim of this study was to localize and quantify kinin receptors in post-mortem human medulla obtained from normotensive, hypertensive, and diabetic subjects, using in vitro receptor autoradiography with the radioligands [125I]HPP-HOE140 (B2 receptor) and [125I]HPP[des-Arg10]-HOE140 (B1 receptor). Data showed specific binding sites for B2 receptor (0.4–1.5 fmol/mg tissue) in 11 medullary nuclei from 4 control specimens (paratrigeminal > ambiguus > cuneate, gelatinous layer of the caudal spinal trigeminal nucleus > caudal and interpolar spinal trigeminal, external cuneate, solitary tract > hypoglossal > gracile > inferior olivary nuclei). Increased density of B2 receptor binding sites was observed in seven medullary nuclei of four hypertensive specimens (paratrigeminal > external cuneate > interpolar and caudal spinal trigeminal, gracile, inferior olivary > hypoglossal nuclei). B2 receptor binding sites were seemingly increased in the same medullary nuclei of two diabetic specimens. Specific binding sites for B1 receptor (1.05 and 1.36 fmol/mg tissue) were seen only in the inferior olivary nucleus in two out of the ten studied specimens. The present results support a putative role for kinins in the regulation of autonomic, nociceptive, and motor functions at the level of the human medulla. Evidence is also provided that B2 receptors are upregulated in medullary cardiovascular centers of subjects afflicted of cardiovascular diseases.Key words: bradykinin, hypertension, diabetes, human brain.


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