Fucoidan is linked to a variety of biological processes. Differences in algae species, extraction, seasons, and locations generate structural variability in fucoidan, affecting its bioactivities. Nothing is known about fucoidan from the brown alga Dictyota bartayresiana, its anti-inflammatory properties, or its inherent mechanism. This study aimed to investigate the anti-inflammatory properties of fucoidan isolated from D. bartayresiana against LPS-induced RAW 264.7 macrophages and to explore potential molecular pathways associated with this anti-inflammatory effects. Fucoidan was first isolated and purified from D. bartayresiana, and then, MTT assay was used to determine the effect of fucoidan on cell viability. Its effects on reactive oxygen species (ROS) formation and apoptosis were also studied using the ROS assay and acridine orange/ethidium bromide fluorescence labelling, respectively. Molecular docking and molecular dynamics simulation studies were performed on target proteins NF-κB and TNF-α to identify the route implicated in these inflammatory events. It was observed that fucoidan reduced LPS-induced inflammation in RAW 264.7 cells. Fucoidan also decreased the LPS-stimulated ROS surge and was found to induce apoptosis in the cells. Molecular docking and molecular dynamics simulation studies revealed that fucoidan’s potent anti-inflammatory action was achieved by obstructing the NF-κB signalling pathway. These findings were particularly noteworthy and novel because fucoidan isolated from D. bartayresiana had not previously been shown to have anti-inflammatory properties in RAW 264.7 cells or to exert its activity by obstructing the NF-κB signalling pathway. Conclusively, these findings proposed fucoidan as a potential pharmaceutical drug for inflammation-related diseases.
Various targets, such as estrogen receptor (ER), mammalian target ofrapamycin(mTOR), epidermal growth factor receptor (EGFR), androgen receptor (AR) andpoly adenosine diphosphate-ribose polymerase (PARP), are focused on the treatment of breast cancer. In this study, in silico tools such as pharmacophore modeling, 3D QSAR study, molecular docking, binding free energy determination and molecular dynamics were executed on a series of pyrazolopyrimidines derivatives. The pharmacophore modeling of forty-one anticancer derivatives was generated, and atom-based 3D QSAR was applied. Molecular docking, dynamics, binding energy and high-throughput virtual screening (HTVS) were conducted by the software Schrodinger. The best five featured pharmacophore hypotheses AHRRR_1 with a maximum survival score of 5.533 was subjected to rigorous scoring function analysis and 3D QSAR studies. Docking studies and binding free energy were carried out on 41 inhibitors for their anti-breast cancer activity against human estrogen, progesterone receptor, EGFR kinase and mammalian target of rapamycin mTOR. Molecular dynamics simulation of the docked complex-34/4WKQ validated the stability of this complex. HTVS was performed to determine the virtual hits with the best-fitted model AHRRR_1. New EGFR kinase inhibitors were designed based on the active compound templates. Molecular docking was carried out on virtual hits, and newly designed compounds and dynamics studies revealed that the binding modes obtained after MD simulation were more or less similar to that acquired post docking mode. Promiscuity assessments demonstrated that designed compounds would be specific rather than a promiscuous one. Based on these findings, we have designed four novel compounds as anti-breast inhibitors, with potent binding affinity and desirable ADME properties.
Recent advances in hardware and software algorithms have led to the rise of data-driven approaches for designing therapeutic modalities. One of the major causes of human mortality is diabetes. Thus, there is a tremendous opportunity for research into effective antidiabetic designs. Therefore, in this study, we used machine learning-based small molecule design. We used various chemoinformatic and binary fingerprint techniques on small molecules to construct multiple models for alpha-amylase inhibitors. Among these models, the top models were used for ensemble-based machine learning predictions on libraries of organic molecules supplemented with synthetic scaffolds that could be used as antidiabetic agents. Further, involved identifying 10 promising molecules from computational studies and determining their inhibitory effects on alpha-amylase. These molecules were synthesised and thoroughly analysed to assess their biological inhibitory properties. Then, thermodynamic simulations were conducted to determine the stability and affinity of experimentally active molecules. The research results showcased the top 10 ML models recorded impressive statistics with an average model score of 0.8216, Pearson-r value of 0.827 and external validation yielding a Q2 value of 0.835, proving their reliability and accuracy. Ten derivatives of benzothiophene dioxolane was prime research focus due to computational predictions. The biological inhibitory assay of synthesised molecules showed that small molecules with ID ALC5 and ALC6 exhibited inhibitory efficiencies (IC50) of 2.1 ± 0.14 µM and 5.71 ± 0.02 µM against alpha-amylase enzyme, whereas other molecules showed moderate inhibition. In conclusion, the positive results of the experiment indicate that researchers should explore machine learning-driven design.Communicated by Ramaswamy H. Sarma.
Aims The rich ethnomedicinal practices of Dakshina Kannada have received considerable attention, and many treatment methods have been documented. This work aimed to explore the traditional medicinal plants originating from Dakshina Kannada for their anti-SARS-CoV-2 activity by employing in silico methodologies. Methods Virtual screening of Dakshina Kannada's plants was conducted, which are known for their antiviral activities. Potent plants were shortlisted as Tinospora cordifolia, Nyctanthes arbortristis, Bacopa monnieri, Bombax ceiba, and Curcuma longa based on molecular docking scores. Among these, the active plant Tinospora cordifolia possessed the most potent phytochemicals. Molecular dynamics (MD) simulation and MM/GBSA calculations have been performed on cordifolioside A, syringin, and cordioside. Results Initially, the selected plants were docked into the active site of SARS-CoV-2 protein. MD simulations were performed to investigate the various conformations and validate the docking results, revealing that cordifolioside A and syringin were more stable than cordioside. The stability of the phytoconstituents in complex with SARS-CoV-2 protein was steady throughout the 100 ns simulation time. Finally, the binding free energies were calculated using the MM/GBSA method. The pharmacophore model has confirmed the hydrogen bond interactions, and PASS prediction determined their antiviral activities. Conclusion Thus, the present study identified the most potent plant from Dakshina Kannada against the SARS-CoV-2 virus as Tinospora cordifolia with powerful phytochemicals (cordifolioside A, syringin and cordioside). Furthermore, in vitro and in vivo experiments are needed to provide experimental data to develop anti-SARS-CoV-2 drugs.
Insulin administered orally has a limited therapeutic profile due to factors such as digestion enzymes, pH, temperature, and acidic conditions in the gastrointestinal tract. Type 1 diabetes patients are typically restricted to use intradermal insulin injections to manage their blood sugar levels as oral administration is not available. Research has shown that polymers could enhance the oral bioavailability of therapeutic biologicals, but traditional methods for developing suitable polymers are time-consuming and resource-intensive. Although computational formulations can be used to identify the best polymers more quickly. The true potential of biological formulations has not been fully explored due to a lack of benchmarking studies. Therefore, molecular modelling techniques were used as a case study in this research to determine which polymer is most compatible among five natural biodegradable polymers to address insulin stability. Specially, molecular dynamics simulations were conducted in order to compare insulin-polymer mixtures at different pH levels and temperatures. Hormonal peptide morphological properties were analyzed in body and storage conditions to assess stability of insulin with and without polymers. According to our computational simulations and energetic analyses, polymer cyclodextrin and chitosan maintain insulin stability the most effectively, while alginate and pectin are less effective relatively. Overall, this study contributes valuable insight into the role of biopolymers in stabilizing hormonal peptides in biological and storage conditions. A study such as this could have a significant impact on the development of new drug delivery systems and encourage scientists to utilize them in the formulation of biologicals.
Researchers are investigating the medicinal properties of herbal plants throughout the world, which often leads to the discovery of novel plants and their chemicals for prophylactic needs of humans. Natural phytochemicals continue to be sought as alternative treatments for various diseases because of their non-toxic and therapeutic properties. In recent years, computational phytochemistry has enabled large-scale screening of phytochemicals, enabling researchers to pursue a wide range of therapeutic research alternatives to traditional ethnopharmacology. We propose to identify an anti-diabetic plant by computational screening on Indian herbal plants in conjunction with experimental characterization and biological validation. The methodology involves the creation of an in-house Indian herbal plant database. Molecular docking is used to screen against alpha amylase for anti-diabetic prophylaxis. Cassia angustifolia was chosen because its phytochemicals are able to bind to alpha amylase. Plants were experimentally extracted, botanically studied and their biological activity was evaluated. Further, the use of molecular dynamics was then applied to pinpoint the phytochemicals responsible for the affinity of alpha amylase. Results in the phytochemical analysis of the extracts revealed strong presence of alkaloids, flavonoids and cardiac glycosides. Moreover, alpha amylase biological activity with C. angustifolia extracts of chloroform, hexane and ethyl acetate demonstrated activity of 3.26, 8.01 and 30.33 µg/ml validating computational predictions. In conclusion, this study developed, validated computational predictions of identifying potential anti-diabetic plants 'Cassia angustifolia' from house herbal databases. Hope this study shall inspire explore plant therapeutic repurposing using computational methods of drug discovery.Communicated by Ramaswamy H. Sarma.
The unprecedented global pandemic of COVID-19 has created a daunting scenario urging an immediate generation of therapeutic strategy. Interventions to curb the spread of viral infection primarily include setting targets against the virus. Here in this study we target S protein to obstruct the viral attachment and entry and also the M pro to prevent the viral replication. For this purpose, the interaction of S protein and M pro with phytocompounds, sanguinarine and eugenol, and their derivatives were studied using computational tools. Docking studies gave evidence that 8-hydroxydihydrosanguinarine (8-HDS), a derivative of sanguinarine, showed maximum binding affinity with both the targets. The binding energies of the ligand with S protein and M pro scored to be Delta Gb -9.4 Kcal/mol and Delta Gb -10.3 Kcal/mol, respectively. MD simulation studies depict that the phytocompound could effectively cause structural perturbations in the targets which would affect their functions. 8-Hydroxydihydrosanguinarine distorts the alpha-helix in the secondary structure of M pro and RBD site of S protein. Protein-protein interaction study in presence of 8-hydroxydihydrosanguinarine also corroborate the above findings which indicate that this polyphenol interferes in the coupling of S protein and ACE2. The alterations in protonation of M pro suggest that the protein structure undergoes significant structural changes at neutral pH. ADME property of 8-hydroxydihydrosanguinarine indicates this could be a potential drug. This makes the phyto-alkaloid a possible therapeutic molecule for anti COVID-19 drug design.
Background: Lung cancer is alarmingly increasing and therapies targeting receptors such as human epidermal growth factor have been found to be emerging in treating lung cancer. Many studies report azetidinone bearing compounds to be cytotoxic. This work aims to prove the anti-lung cancer action of synthesized azetidinones that are through epidermal growth factor receptor (EGFR) inhibition. Materials and Methods: Novel azetidinone derivatives were synthesized from Schiff bases; molecular docking analyzed the interactions with EGFR, and pharmacophore modeling revealed the features responsible for the possible interactions. Moreover, the compounds with good docking scores were selected for anti-lung cancer study by MTT assay. Results: The compounds 4c, 5a, and 6c have scored better docking scores with indole hydrazide, napthoic hydrazide, and 4-chloro hydrazide groups, respectively. At 250 μM, the tested azetidinones, 4c, 5a, and 5d, exhibited the highest activity against lung cancer cells in contrast with the standard. The pharmacophore modeling predicted the groups responsible for the formation of hydrogen bonding. Conclusion: In this work, the synthesized azetidinones were screened for their anticancer activities and EGFR interaction. Moreover, it confirms that it could effectively inhibit the EGFR receptors in lung cancer cells and can act as potential anticancer leads and might consider for the future studies.
Dual TK inhibitors have shown significant clinical effects against many tumors, but with unmanageable side effects. Design approach and selectivity of these inhibitors plays substantial role in their potency and side-effects. Understanding the homology of binding sites in targeted receptors, and involvement of signaling proteins after the inhibition might help in producing less toxic but effective inhibitors. Herein, we designed benzylideneindolon-2-one derivatives based on homology modeling in binding sites of VEGFR-2 and EGFR receptors as dual-inhibitor potent anticancer compounds with high selectivity. The benzylideneindolon-2-one derivatives were found to possess conformational switch in form of oxindole, substituted at 2-benzimidazole. Within synthesized compounds, 5b was found most active in in-vitro enzyme inhibition assay against VEGFR-2 and EGFR with highest IC50 value of 6.81 +/- 2.55 and 13.04 +/- 4.07 nM, respectively. Interestingly, cytotoxicity studies revealed selective toxicity of compound 5b against proliferation of A-431 cell lines (over expressed VEGFR-2 and EGFR) with GI(50) value of 0.9 +/- 0.66 mu M. However, the compounds showed mild to moderate activity in all other cancer cell line in the range of 0.2-100 mu M. Further mode of action studies by flow cytometry and western blot on A-431 indicated that they work via apoptosis at S-phase following Bcl/Bax pathway, and cell migration via MMP9. 5b not only suppressed tumor growth but also improved vandetanib associated with weight loss toxicity. Moreover, 5b was found safer than sunitinib and erlotinib with LD50 of 500 mg/kg body weight. These results propose 5b as potential anti-tumor drug with safer profile of conventional inhibitors of VEGFR-2 and EGFR for solid tumors.
The unprecedented global pandemic of COVID-19 has created a daunting scenario urging an immediate generation of therapeutic strategy. Viral inhibitory potential of Pyridone ring containing analogues was already accounted for several infectious viruses and suggested for being significant in case of present COVID-19. Thus, pyridone ring containing 8-HDS is subjected for its inhibitory prospective in the present study for SARS-CoV2. Methods: Here in this study we target S protein to obstruct the viral attachment and entry and also the M pro to prevent the viral replication. For this purpose, the interaction of S protein and M pro with phytocompounds, sanguinarine and eugenol, and their derivatives were studied using computational tools. Results: It is evident from the docking studies that 8-Hydroxydihydrosanguinarine, a derivative of sanguinarine, exhibits maximum binding affinity with both the targets. The binding energies of the ligand with S protein and M pro scored to be ΔGb-9.4 Kcal/mol and ΔGb-10.3 Kcal/mol respectively. MD simulation studies depict that the phytocompound could effectively cause structural perturbations in the targets which would affect their functions. 8-Hydroxydihydrosanguinarine distorts the α-helix in the secondary structure of M pro and RBD site of S protein. Protein-protein interaction study in presence of 8-hydroxydihydrosanguinarine (8-HDS) also corroborates the above findings which indicate that this polyphenol interferes in the coupling of S Protein and ACE2. The alterations in protonation of M pro suggest that the protein structure undergoes significant structural changes at neutral pH. ADME (Physicochemical, Lipophilicity, Water Solubility, Pharmacokinetics, Drug-likeness) property of 8-HDS suggests that this could be a potential drug. Conclusions: Our research via computational tools establishes that 8-HDS can be an efficient inhibitor in blocking viral infection. This makes the phyto-alkaloid a possible therapeutic molecule for anti COVID-19 drug design. Thus it can prove to be a potential molecule in therapeutic drug development against COVID-19.
Two series of fluorinated chalcones containing morpholine and imidazole-based compounds (f1-f8) were synthesized and evaluated for recombinant human monoamine oxidase (MAO)-A and -B as well as acetylcholinesterase inhibitory activities. Our results indicate that morpholine containing chalcones are highly selective MAO-B inhibitors having reversibility properties. All the imidazole-based fluorinated chalcones showed weak MAO inhibitions in both isoforms. Among the tested compounds, (2E)-3-(3-fluorophenyl)-1-[4-(morpholin-4-yl)phenyl]prop-2-en-1-one (f2) showed potent inhibitory activity for recombinant human MAO-B (IC50 = 0.087 μM) with a high selectivity index (SI) of 517.2. In the recovery experiments using dialysis, the residual activity of MAO-B inhibited by f2 was close to that with the reversible reference inhibitor. Inhibition assays revealed that the Ki values of f1 and f2 for MAO-B were 0.027 and 0.020 μM, respectively, with competitive patterns. All the morpholine-based compounds (f1-f4) showed moderate inhibition toward acetylcholinesterase with IC50 values ranging between 24 and 54 μM. All morpholine-containing compounds exhibit good blood-brain barrier permeation in the PAMPA method. The rational approach regarding the highly selective MAO-B inhibitor f2 was further ascertained by induced fit docking and molecular dynamics simulation studies.
Background & objectives: Malaria has remained a global health problem despite the effective control and treatment measures. In the backdrop of drug resistance, developing novel hybrid molecules targeting the sexual stages (gametocytes) of the human malaria parasite Plasmodium falciparum is of great significance. Recently, chalcone- based polyphenols have generated a great interest in the malaria research community worldwide due to their ease of synthesis and significant biological activity. The primary objective of this study was to investigate the interaction of a newly synthesized quinoline-appended chalcone derivative (ADMQ) with gametocyte specific proteins, Pfg 27 and Pfs 25 and explore its in vitro gametocytocidal potential. Methods: The characterization of ligand-protein interactions at the atomistic level was done by a simulation strategy that combines molecular docking and molecular dynamics (MD) simulation in a coherent workflow. The X-ray crystal structure of Pfg 27 was retrieved from protein data bank and Pfs 25 was built using the Iterative Threading ASSembly Refinement (I-TASSER) server. The detailed interaction of both ADMQ and a known gametocytocidal agent, methylene blue (MB) (used as a positive control) with gametocyte proteins Pfg 27 and Pfs 25 was studied with a 50 ns explicit MD simulation. The ligand binding pose in terms of glide score, molecular mechanics-generalized born surface area (MM-GBSA) binding energies, protein-ligand root-mean-square-deviation (RMSD) and secondary structure elements (SSE) changes were analyzed accordingly. The direct effect of ADMQ on structural integrity of P. falciparum gametocytes was also examined using in vitro microscopy. Results: The analogous Glide score and MM-GBSA free energy of binding indicated stable interactions for both ADMQ and MB harboured in the active site of targeted gametocyte proteins, Pfg 27 and Pfs 25, separately. Explicit MD simulation by Desmond software package indicated similar distinguishable conformational changes in the active site of target polypeptide chain due to the specific accommodation of ADMQ molecule. The simulation also manifested comparable mechanistic profile in terms of protein-ligand RMSD and changes in secondary structure elements (SSE). Further, ADMQ treatment was found to adversely affect the structural integrity of gametocytes, which resulted in appearance of vesicles protruding from the gametocytes. Interpretation & conclusion: The consolidated in silico molecular modeling and in vitro study described herein may give an insight into the interaction patterns of quinoline-chalcone hybrids with critical gametocyte proteins in the mosquito. This study will possibly pave the way for further exploration of similar heterocyclic quinoline-chalcone hybrids to open up new avenues in drug candidate development against P. falciparum gametocytes.
The principal intent of this work is to explore whether the site-specific binding of a newly synthesized quinoline-appended anthracenyl chalcone, (E)-3-(anthracen-10-yl)-1-(6,8-dibromo-2-methylquinolin-3-yl)prop-2-en-1-one (ADMQ), with an extracellular protein of the human circulatory system, human serum albumin (HSA), can control the rotamerization of its sole tryptophan residue, Trp-214. With this aim, we have systematically studied the binding affinity, interactions, and localization pattern of the title compound inside the specific binding domain of the transport protein and any conformation alteration caused therein. Multiple spectroscopic experiments substantiated by an in silico molecular modeling exercise provide evidence for the binding of the guest ADMQ in the hydrophobic domain of HSA, which is primarily constituted by residues Trp-214, Arg-218, Arg-222, Asp-451, and Tyr-452. Rotationally restricted ADMQ prefers to reside in Sudlow site I (subdomain IIA) of HSA in close proximity (2.45 nm) to the intrinsic fluorophore Trp-214 and is interestingly found to control its vital rotamerization process. The driving force for this rotational interconversion is predominantly found to be governed by the direct interaction of ADMQ with Trp-214. However, the role of induced conformational perturbation in the biomacromolecule itself upon ADMQ adoption cannot be ruled out completely, as indicated by circular dichroism, 3D fluorescence, root-mean-square deviation, root-mean-square fluctuation, and secondary structure element observations. The comprehensive spectroscopic study outlined herein provides important information on the biophysical interaction of a chalcone-based potential therapeutic candidate with a carrier protein, exemplifying its utility in having a regulatory effect on the microconformations of Trp-214.
Twenty novel 2-thioxo-1, 3-thiazolidin-4-one derivatives (5a-5t) were synthesized and evaluated for their antitubercular activity. The structure of the compounds was confirmed by IR, NMR and Mass Spectroscopy methods. In addition, single-crystal X-ray diffraction was performed for compound 5a. All the synthesized compounds were screened for their in-vitro antimycobacterial activity against MTB (H37RV, ATCC No: 27294) by Alamar Blue assay method. Compounds 5r, 5k, 5t displayed most potent in-vitro activity with MICs of 0.05, 0.1, 0.2 mu g/ml concentrations respectively which are comparatively potent than the standards. Molecular docking and dynamics simulations were performed to find out the plausible mechanism of the titled compounds. (C) 2017 Elsevier B.V. All rights reserved.
Bioactive peptide research has experienced considerable therapeutic interest owing to varied physiological functions, efficacy in excretion, and tolerability of peptides. Colostrum is a rich natural source of bioactive peptides with many properties elucidated such as anti-thrombotic, anti-hypertensive, opioid, immunomodulatory, etc. In this study, a variant peptide derived from β-lactoglobulin from buffalo colostrum was evaluated for the anti-ophidian property by targeting snake venom metalloproteinases. These are responsible for rapid local tissue damages that develop after snakebite such as edema, hemorrhage, myonecrosis, and extracellular matrix degradation. The peptide identified by LC-MS/MS effectively neutralized hemorrhagic activity of the Echis carinatus venom in a dose-dependent manner. Histological examinations revealed that the peptide mitigated basement membrane degradation and accumulation of inflammatory leucocytes at the venom-injected site. Inhibition of proteolytic activity was evidenced in both casein and gelatin zymograms. Also, inhibition of fibrinolytic and fibrinogenolytic activities was seen. The UV-visible spectral study implicated Zn2+ chelation, which was further confirmed by molecular docking and dynamic studies by assessing molecular interactions, thus implicating the probable mechanism for inhibition of venom-induced proteolytic and hemorrhagic activities. The present investigation establishes newer vista for the BLG-col peptide with anti-ophidian efficacy as a promising candidate for therapeutic interventions.
Transient interactions between cancer stem cells and components of the tumor microenvironment initiate various signaling pathways crucial for carcinogenesis. Predominant hyaluronan (HA) receptor, CD44 is structurally and functionally one of the most variable cell surface receptors having the potential to generate a diverse repertory of CD44 isoforms by alternative splicing of variant exons and post-translational modifications. A structurally distinctive variant of CD44, CD44v10, has an inevitable role in malignant progression, invasion, and metastasis. This can be attributed to the binding of HA with CD44v10, which demonstrates a completely different behavioral pattern as compared to the other spliced variants of CD44 molecule. Absence of a comprehensively predicted crystal structure of human CD44s and CD44v10 is an impediment in understanding the resultant structural alterations caused by the binding of HA. Thus, in this study, we aim to predict the CD44s and CD44v10 structures to their closest native confirmation and study the HA binding-induced structural perturbations using homology modeling, molecular docking, and MD simulation approach. The results depicted that modeled 3D structures of CD44s and CD44v10 isoforms were found to be stable throughout MD simulations; however, a substantial decrease was observed in the binding affinity of HA with CD44v10 (−5.355 kcal/mol) as compared to CD44s. Furthermore, loss and gain of several H-bonds and hydrophobic interactions in CD44v10–HA complex during the simulation process not only elucidated the reason for decreased binding affinity for HA but also prompted toward the plausible role of HA-induced structural perturbations in occurrence and progression of carcinogenesis.
The usefulness of heterocyclic chalcone derivative as a therapeutic target in controlling hypertension and its site specific binding interaction with model transport protein to get a clear picture about its delivery mechanism.
The present study embodies the detail DNA binding interaction of a potential bioactive quinoline appended chalcone derivative (E)-3-(anthracen-10-yl)-1-(6,8-dibromo-2-methylquinolin-3-yl)prop-2-en-1-one (ADMQ) with calf thymus DNA (ctDNA) and its consequences by UV-Vis absorption, steady state fluorescence spectroscopy, fluorescence anisotropy, circular dichromism, helix melting, agarose gel electrophoresis, molecular docking, Induced Fit Docking (IFD) and molecular dynamics (MD) simulation. The UV-Vis absorption and fluorescence study reveal that the molecule undergoes considerable interaction with the nucleic acid. The control KI quenching experiment shows the lesser accessibility of ADMQ molecule to the ionic quencher (I-) in presence of ctDNA as compared to the bulk aqueous phase. Insignificant change in helix melting temperature as well as in circular dichromism (CD) spectra points toward non-covalent groove binding interaction. The moderate rotational confinement of this chalcone derivative (anisotropy = 0.106) trapped in the nucleic acid environment, the comparative displacement assay with well-known minor groove binder Hoechst 33258 and intercalator Ethidium Bromide establishes the minor groove binding interactions of the probe molecule. Molecular docking, IFD and MD simulation reveal that the DNA undergoes prominent morphological changes in terms of helix unwinding and bending to accommodate ADMQ in a crescent shape at an angle of 110 in a sequence specific manner. During interaction, ADMQ rigidifies and bends the sugar phosphate backbone of the nucleic acid and thereby shortens its overall length by 3.02 angstrom. Agarose gel electrophoresis experiment with plasmid pBR 322 reveals that the groove binded ADMQ result in a concentration dependent cleavage of plasmid DNA into its supercoiled and nicked circular form. The consolidated spectroscopic research described herein provides quantitative insight into the interaction of a heterocyclic chalcone derivative with relevant target nucleic acid, which may be useful for the future research on chalcone based therapeutic agents. (C) 2015 Elsevier B.V. All rights reserved.
The serendipitous discovery of the anticancer drug cisplatin cemented medicinal inorganic chemistry as an independent discipline in 1960s. DNA and protein kinases are one of the major intracellular targets of many anticancer drugs. It is thus highly desirable to develop metal complexes, either by interacting with DNA or to target alternative cellular machinery such as protein kinases to provide a more effective means of monitoring disease progression. In this study we report the synthesis and characterization of few novel Cu(II) and Zn(II) Knoevenagel condensed metallointercalators incorporating phthalic acid. The intercalation behavior of the complexes with DNA is confirmed by spectral and analytical experiments. Due to the promising performance of DNA interaction efficacy of Cu(II) complexes 1-4, their in vitro and in vivo anticancer properties are explored on various cancerous cell lines which reveal that they exhibit substantial anticancer activity without affecting the normal cells. It is found that the complex 1 induces apoptosis in Hep G2 cells. Theoretically, DFT is used to optimize the Cu(II) complexes 1-4 to explore their quantum mechanical properties and to carry out affinity studies against cyclin dependant kinase 2 (CDK2) to understand atomic level interactions. Further, the complex-receptor stability is confirmed by molecular dynamics.
Cancer remains one of the major contributors to human mortality and a hazard to human growth. The search for a new treatment continues unabated. Aurora kinases play an important role in cell cycle, and thus a potential target for the treatment of cancer. In the present work, we aim to discover potential leads against aurora kinase using various rational methods of drug discovery. The available crystal complexes of AKs were analyzed for their interactions and quantified with glide-extra precision (XP) docking. About 20 crystal pdb were selected from the protein databank based on the resolution factor, R-factor and R-value. And after docking with the native ligands, the RMSD value was calculated, wherein the protein with the least RMSD was found to be 3UOK which was further used for our screening of small molecules from the in-house database by molecular docking. Fragments which were found to possess the best interactions were considered for the synthesis with characterization, and biological activity was carried out against breast cancer and colorectal cancer cell lines to assess the inhibitory capability of synthesized compounds. Molecule with the molecular id IS2 i.e. (3E)-3-(5-fluoro-2-oxo-1,2-dihydro-3H-indol-3-ylidene)-2H chromene-2,4(3H)-dione was found to possess inhibitory activity with an IC50 of 1.324 nM and 5.785 µM for breast cell line and colorectal cell line studies, respectively.