Enhancing the zircon yield through the addition of calcium phosphates into ZrO-SiO binary systems: synthesis and structural, morphological, mechanical and analysis.

The crystallization of ZrSiO is generally accomplished by the addition of mineralizers into ZrO-SiO binary oxides. The current investigation aimed to investigate the effect of adding calcium phosphates into ZrO-SiO binary oxides on the yield of ZrSiO. The concentration of calcium phosphate additions were varied to obtain ZrSiO that fetches improved mechanical and biological properties for application in hard tissue replacements.

The Rise and Fall of Chloroquine/Hydroxychloroquine as Compassionate Therapy of COVID-19.

The emergence and rapid spread of novel coronavirus disease (COVID-19) has posed a serious challenge to global public health in 2020. The speed of this viral spread together with the high mortality rate has caused an unprecedented public health crisis. With no antivirals or vaccines available for the treatment of COVID-19, the medical community is presently exploring repositioning of clinically approved drugs for COVID-19.

Mutational analysis of structural proteins of SARS-CoV-2.

SARS-CoV-2 transmissibility is higher than that of other human coronaviruses; therefore, it poses a threat to the populated communities. We investigated mutations among envelope (E), membrane (M), and spike (S) proteins from different isolates of SARS-CoV-2 and plausible signaling influenced by mutated virus in a host. We procured updated protein sequences from the NCBI virus database.

An Update on Antiviral Therapy Against SARS-CoV-2: How Far Have We Come?

COVID-19 pandemic has spread worldwide at an exponential rate affecting millions of people instantaneously. Currently, various drugs are under investigation to treat an enormously increasing number of COVID-19 patients. This dreadful situation clearly demands an efficient strategy to quickly identify drugs for the successful treatment of COVID-19.

Bax/Tubulin/Epithelial-Mesenchymal Pathways Determine the Efficacy of Silybin Analog HM015k in Colorectal Cancer Cell Growth and Metastasis.

The inhibition of apoptosis, disruption of cellular microtubule dynamics, and over-activation of the epithelial mesenchymal transition (EMT), are involved in the progression, metastasis, and resistance of colorectal cancer (CRC) to chemotherapy. Therefore, the design of a molecule that can target these pathways could be an effective strategy to reverse CRC progression and metastasis. In this study, twelve novel silybin derivatives, HM015a-HM015k (15a-15k) and compound 17, were screened for cytotoxicity in CRC cell lines.

Blocking oestradiol synthesis pathways with potent and selective coumarin derivatives.

A comprehensive set of 3-phenylcoumarin analogues with polar substituents was synthesised for blocking oestradiol synthesis by 17-β-hydroxysteroid dehydrogenase 1 (HSD1) in the latter part of the sulphatase pathway. Five analogues produced ≥62% HSD1 inhibition at 5 µM and, furthermore, three of them produced ≥68% inhibition at 1 µM. A docking-based structure-activity relationship analysis was done to determine the molecular basis of the inhibition and the cross-reactivity of the analogues was tested against oestrogen receptor, aromatase, cytochrome P450 1A2, and monoamine oxidases.

Structure-Activity Relationship Analysis of 3-Phenylcoumarin-Based Monoamine Oxidase B Inhibitors.

Monoamine oxidase B (MAO-B) catalyzes deamination of monoamines such as neurotransmitters dopamine and norepinephrine. Accordingly, small-molecule MAO-B inhibitors potentially alleviate the symptoms of dopamine-linked neuropathologies such as depression or Parkinson's disease. Coumarin with a functionalized 3-phenyl ring system is a promising scaffold for building potent MAO-B inhibitors.

HM015k, a Novel Silybin Derivative, Multi-Targets Metastatic Ovarian Cancer Cells and Is Safe in Zebrafish Toxicity Studies.

This study was designed to determine the mechanisms by which the novel silybin derivative, (E)-3-(3-(benzyloxy) phenyl)-1-(4-hydroxyphenyl)prop-2-en-1-one ( or ), produces its anticancer efficacy in ovarian cancer cells. Compound induced apoptosis in ovarian cancer cells in a time-dependent manner by significantly upregulating the expression of Bax and Bak and downregulating the expression of Bcl-2. Interestingly, induced the cleavage of Bax p21 into its more efficacious cleaved form, Bax p18.

Design and discovery of silybin analogues as antiproliferative compounds using a ring disjunctive - Based, natural product lead optimization approach.

The present study reports the synthesis and anticancer activity evaluation of twelve novel silybin analogues designed using a ring disjunctive-based natural product lead (RDNPL) optimization approach. All twelve compounds were tested against a panel of cancer cells (i.e.

Inhibition of Aβ(1-42)Oligomerization, Fibrillization and Acetylcholinesterase Activity by Some Anti-Inflammatory Drugs: An in vitro Study.

Background: Number of contradictory reports are available on the effects of antiinflammatory drugs on Alzheimer's disease (AD) including beneficial, adverse and stage dependent effects. We provide insights of the effects exerted by some anti-inflammatory drugs on the chemistry of AD.

Methods: Three different doses of dexamethasone (0.

Identification of estrogen receptor α ligands with virtual screening techniques.

Utilization of computer-aided molecular discovery methods in virtual screening (VS) is a cost-effective approach to identify novel bioactive small molecules. Unfortunately, no universal VS strategy can guarantee high hit rates for all biological targets, but each target requires distinct, fine-tuned solutions. Here, we have studied in retrospective manner the effectiveness and usefulness of common pharmacophore hypothesis, molecular docking and negative image-based screening as potential VS tools for a widely applied drug discovery target, estrogen receptor α (ERα).

Impact of Substituents in Tumor Uptake and Fluorescence Imaging Ability of Near-Infrared Cyanine-like Dyes.

This report presents a simple strategy to introduce various functionalities in a cyanine dye (bis-indole-N-butylsulfonate-polymethine bearing a fused cyclic chloro-cyclohexene ring structure), and assess the impact of these substitutions in tumor uptake, retention and imaging. The results obtained from the structural activity relationship (SAR) study demonstrate that certain structural features introduced in the cyanine dye moiety make a remarkable difference in tumor avidity. Among the compounds investigated, the symmetrical CDs containing an amino-phenyl thioether group attached to a cyclohexene ring system and the two N-butyl linkers with terminal sulfonate groups in benzoindole moieties exhibited excellent tumor imaging ability in BALB/c mice bearing Colon26 tumors.

Advances in chalcones with anticancer activities.

Chalcones are naturally occurring compounds exhibiting broad spectrum biological activities including anticancer activity through multiple mechanisms. Literature on anticancer chalcones highlights the employment of three pronged strategies, namely; structural manipulation of both aryl rings, replacement of aryl rings with heteroaryl scaffolds, molecular hybridization through conjugation with other pharmacologically interesting scaffolds for enhancement of anticancer properties. Methoxy substitutions on both the aryl rings (A and B) of the chalcones, depending upon their positions in the aryl rings appear to influence anticancer and other activities.

Study on gluco-regulatory potential of glimepiride sulfonamide using in silico, in vitro and in vivo approaches.

Glimepiride sulfonamide (GS) is a drug intermediate to synthesize glimepiride (antidiabetic drug). We hypothesized that GS exerts gluco-regulatory effect because GS is comprised of the structural components of dipeptidyl peptidase-IV (DPP-IV) inhibitors sitagliptin and DPP-728and glimepiride (sulfonylurea based antidiabetic drug).We analyzed the drug-likeness and docking efficiency of GS with DPP-IV using in silico tools.

6H-Indolo[2,3-b]quinoxalines: DNA and protein interacting scaffold for pharmacological activities.

6H-Indolo[2,3-b]quinoxaline, a planar fused heterocyclic compound exhibits a wide variety of pharmacological activities. The mechanism of pharmacological action exerted by these compounds is predominantly DNA intercalation. The thermal stability of the intercalated complex (DNA and 6H-indolo[2,3-b]quinoxaline derivatives) is an important parameter for the elucidation of anticancer, antiviral and other activities.

Analogue-based design, synthesis and docking of non-steroidal anti-inflammatory agents. Part 2: methyl sulfanyl/methyl sulfonyl substituted 2,3-diaryl-2,3-dihydro-1H-quinazolin-4-ones.

A series of methyl sulfanyl/methyl sufonyl substituted 2,3-diaryl-2,3-dihydro-1H-quinazolin-4-one were designed using analogue-based design, scaffold hopping and shape similarity matching. The designed compounds were synthesized in 2-3 steps with simple chemistry and screened by ovine cyclooxygenases (COXs) inhibitory assay and carrageenan-induced rat paw edema assay. Among the screened compounds, two compounds exhibited 100% cyclooxygenase-2 (COX-2) inhibitory potency without showing cycloxygenase-1 (COX-1) inhibition at 20 μM.

DPP-IV inhibitory potential of naringin: an in silico, in vitro and in vivo study.

The incretin based therapies are an emerging class of antidiabetic drugs, with two categories: one is glucagone like peptide-1 (GLP-1) agonists and the other one is dipeptidyl peptidase (CD26; DPP-IV) inhibitors. However, in the DPP-IV inhibitors category only few compounds are commercially available and also have some undesirable effects. Therefore, in the present work we tried to explore a naturally occurring compound naringin for its potential DPP-IV inhibition and antidiabetic potential.

Analogue-based design, synthesis and molecular docking analysis of 2,3-diaryl quinazolinones as non-ulcerogenic anti-inflammatory agents.

In our effort to identify potent gastric sparing anti-inflammatory agents, a series of methyl sulfanyl/methyl sulfonyl substituted 2,3-diaryl quinazolinones were designed by analogue-based design strategy and synthesized for biological evaluation. Subsequently, the compounds were evaluated for both cyclooxygenase inhibitions by ovine COX assay and carrageenan-induced rat paw edema assay. All the methyl sulfonyl substituted quinazolinones were exhibited promising anti-inflammatory activity.

QSAR investigations on benzylideneamino and phenyliminomethyl scaffolds for selective COX-2 inhibiton: a Hansch approach.

Cyclooxygenase inhibitory and selectivity profile of a combined series of thirty one aryl sulphonamide compounds possessing 4-benzylideneamino or 4-phenyliminomethyl scaffolds were subjected to QSAR study using Hansch approach. The compounds in the selected series were characterized using classical aromatic substituent constants like hydrophobicity (pi), molar refractivity (MR), Hammett electronic (sigma), electronic field effect (F), resonance effect (R), and some indicator variables encoding molecular group contributions. Statistically significant QSAR models were generated using multiple regression analysis and cross-validation tools.

Binding of matrix metalloproteinase inhibitors to extracellular matrix: 3D-QSAR analysis.

Binding to the extracellular matrix, one of the most abundant human protein complexes, significantly affects drug disposition. Specifically, the interactions with extracellular matrix determine the free concentrations of small molecules acting in tissues, including signaling peptides, inhibitors of tissue remodeling enzymes such as matrix metalloproteinases, and other drug candidates. The nature of extracellular matrix binding was elucidated for 63 matrix metalloproteinase inhibitors, for which the association constants to an extracellular matrix mimic were reported here.

Drug-membrane interactions studied in phospholipid monolayers adsorbed on nonporous alkylated microspheres.

Characterization of interactions with phospholipids is an integral part of the in vitro profiling of drug candidates because of the roles the interactions play in tissue accumulation and passive diffusion. Currently used test systems may inadequately emulate the bilayer core solvation properties (immobilized artificial membranes [IAM]), suffer from potentially slow transport of some chemicals (liposomes in free or immobilized forms), and require a tedious separation (if used for free liposomes). Here the authors introduce a well-defined system overcoming these drawbacks: nonporous octadecylsilica particles coated with a self-assembled phospholipid monolayer.

Quantitative structure-activity relationship analysis of 2,3-diaryl indoles as selective cyclooxygenase-2 inhibitors.

Quantitative structure-activity relationship (QSAR) studies have been performed on a combined series of 2-sulfonylphenyl-3-phenyl-indoles and 2-phenyl-3-sulfonylphenyl-indoles with a common 2,3 vicinal diaryl indole scaffold, recently reported as selective COX-2 inhibitors. This study is aimed to throw light on this, special class of diaryl heterocyclic family of selective COX-2 inhibitors. A preliminary Fujita-Ban analysis on 32 compounds provided valuable insights about the role of different substituents R1 and R2 around the 2,3 vicinal diaryl rings and R3, at position-5 of the central indole moiety in explaining their in vitro COX-2 inhibitory activity.

First QSAR report on FSH receptor antagonistic activity: quantitative investigations on physico-chemical and structural features among 6-amino-4-phenyltetrahydroquinoline derivatives.

A quantitative attempt has been made to correlate the structure-activity relationship (SAR) among the recently reported 6-amino-4-phenyltetrahydroquinoline derivatives as antagonists for the Gs-protein-coupled human follicle-stimulating hormone (FSH) receptor. The compounds used for the present study have been reported to show high antagonistic efficacy in vitro using a CHO-hFSHR(luc) assay. Our QSAR investigations revealed a hydrophobic type of interactions between these ligands and the FSH receptor, hence confirming the presence of a lipophilic pocket on the active site of the target structure.

QSAR analyses of conformationally restricted 1,5-diaryl pyrazoles as selective COX-2 inhibitors: application of connection table representation of ligands.

As a part of our continuing efforts in discerning the structural and physicochemical requirements for selective COX-2 over COX-1 inhibition among the fused pyrazole ring systems, herein we report the QSAR analyses of the title compounds. The conformational flexibility of the title compounds was examined using a simple connection table representation. The conformational investigation was aided by calculating a connection table parameter called fraction of rotable bonds, b_rotR encompassing the number of rotable bonds and b_count, the number of bonds including implicit hydrogens of each ligand.

QSAR studies on structurally similar 2-(4-methanesulfonylphenyl)pyran-4-ones as selective COX-2 inhibitors: a Hansch approach.

QSAR analysis based on classical Hansch approach was adopted on two recently reported novel series of 2-phenylpyran-4-ones as selective cyclooxygenase-2 (COX-2) inhibitors. The 6-methyl derivatives of title compounds bifurcate as 3-phenoxypyran-4-ones (subset A) and 3-phenylpyran-4-ones (subset B) among series 1. Series 2 consists of 5-chloro derivatives of title compounds.