Investigation of redox mechanism and DNA binding of novel 2-(x-nitrophenyl)-5-nitrobenzimidazole (x = 2, 3 and 4).

The present study describes the investigation of the binding modes of potential anti-cancerous nitrophenyl derivatives of 2-(x-nitrophenyl)-5-nitrobenzimidazole with calf thymus DNA. The -2-(x-nitrophenyl)-5-nitrobenzimidazoles under investigation differ only in position x of nitro group in nitrophenyl substituent relative to benzimidazole moiety leading to 1-NPNB (x = 2), 2-NPNB (x = 3) and 3-NPNB (x = 4). The DFT calculations predicted that derivatives were electrochemically reducible which was then confirmed by cyclic voltammetry.

Design, synthesis, in-vitro thymidine phosphorylase inhibition, in-vivo antiangiogenic and in-silico studies of C-6 substituted dihydropyrimidines.

Thymidine phosphorylase (TP) is an angiogenic enzyme. It plays an important role in angiogenesis, tumour growth, invasion and metastasis. In current research work, we study the effect of structural modification of dihydropyrimidine-2-ones (DHPM-2-ones) on TP inhibition.

Microwave-assisted green synthesis of superparamagnetic nanoparticles using fruit peel extracts: surface engineering, T 2 relaxometry, and photodynamic treatment potential.

Superparamagnetic iron oxide nanoparticles (SPIONs) have the potential to be used as multimodal imaging and cancer therapy agents due to their excellent magnetism and ability to generate reactive oxygen species when exposed to light. We report the synthesis of highly biocompatible SPIONs through a facile green approach using fruit peel extracts as the biogenic reductant. This green synthesis protocol involves the stabilization of SPIONs through coordination of different phytochemicals.

Structure based medicinal chemistry-driven strategy to design substituted dihydropyrimidines as potential antileishmanial agents.

In an attempt to explore novel and more potent antileishmanial compounds to diversify the current inhibitors, we pursued a medicinal chemistry-driven strategy to synthesize novel scaffolds with common pharmacophoric features of dihydropyrimidine and chalcone as current investigational antileishmanial compounds. Based on the reported X-ray structure of Pteridine reductase 1 (PTR1) from Leishmania major, we have designed a number of dihydropyrimidine-based derivatives to make specific interactions in PTR1 active site. Our lead compound 8i has shown potent in vitro antileishmanial activity against promastigotes of L.

Synthesis, in vitro and computational studies of 1,4-disubstituted 1,2,3-triazoles as potential α-glucosidase inhibitors.

1,4-Disubstituted-1,2,3-triazoles were synthesized by Cu(I) catalyzed click reaction, where the azides, with electron donating and electron withdrawing groups acted as 1,3-dipoles and 1-ethynyl-1-cyclohexanol served as the terminal alkyne. These synthesized triazoles were subjected to enzymatic assay which showed promising activity against α-glucosidase; 1-(2-cyano-4-nitrophenyl)-4-(1-hydroxycyclohexyl)-1H-1,2,3-triazole 3m being the most active members of the library. Molecular docking studies of these triazoles with the homology-modeled α-glucosidase protein were also performed to delineate ligand-protein interactions at molecular level which suggested that Phe157, Arg312 and His279 are the major interacting residues in the biding site of the protein and may have a significant role in the inhibition of enzyme's function.

Dual inhibition of the α-glucosidase and butyrylcholinesterase studied by molecular field topology analysis.

A striking dual inhibition of enzymes α-glucosidase and butyrylcholinesterase by small drug-like molecules, including 1,4-disubstituted-1,2,3-triazoles, chalcones, and benzothiazepines, was rationalized with the help of Molecular Field Topology Analysis, a 3D QSAR technique similar to CoMFA. A common pharmacophore supported the concept of a link existing between type-2 diabetes mellitus and Alzheimer's disease. These findings will be instrumental for rational design of drug candidates for both of these conditions.

Bioisosteric approach in designing new monastrol derivatives: an investigation on their ADMET prediction using in silico derived parameters.

Medicinal chemists are facing an increasing challenge to deliver safer and more effective medicines. An appropriate balance between drug-like properties such as solubility, permeability, metabolic stability, efficacy and toxicity is one of the most challenging problems during lead optimization of a potential drug candidate. Insoluble and impermeable compounds can result in erroneous biological data and unreliable SAR in enzyme and cell-based assays.

Brine shrimp lethality assay 'an effective prescreen': microwave-assisted synthesis, BSL toxicity and 3DQSAR studies-based designing, docking and antitumor evaluation of potent chalcones.

Context: In the course of searching potential antitumor agents from a library of chalcones synthesized under microwave irradiations, the brine shrimp lethality (BSL) assay and a 3D structure-activity relationship (3DQSAR) studies were followed by the antitumor evaluation of most potent analogues.

Objective: The objective of the current study was to effectively use the BSL assay for the identification of potential cytotoxic analogues from a set of compounds.

Methods: We applied the comparative molecular field analysis (CoMFA) and devised 3DQSAR on 33 synthesized chalcones leading to prediction of five related compounds with improved activity.

Structure based virtual screening-driven identification of monastrol as a potent urease inhibitor.

Virtual screening uses computer based methods to discover new ligands on the basis of biological structures. Among all virtual screening methods structure based docking has received considerable attention. In an attempt to identify new ligands as urease inhibitors, structure-based virtual screening (SBVS) of an in-house database of 10,000 organic compounds was carried out.

Synthesis, in vitro antibacterial and antifungal activity of some n-acetylated and non-acetylated pyrazolines.

Fourteen new N-acetylated and non-acetylated pyrazoline derivatives were synthesized by reacting chalcones with hydrazine in the presence of absolute ethanol however reaction was carried out in the presence of glacial acetic acid to afford N-acetylated pyrazolines. The chemical structures of the synthesized pyrazolines were confirmed by FTIR, (1)HNMR, (13)CNMR and mass spectroscopic data. The pyrazolines (1-14) were screened for antibacterial activity against ten bacterial strains using seven Gram-positive and three Gram-negative bacteria and antifungal activity against Aspergillus flavus, Aspergillus niger and Aspergillus pterus.

Similarity analysis, synthesis, and bioassay of antibacterial cyclic peptidomimetics.

The chemical similarity of antibacterial cyclic peptides and peptidomimetics was studied in order to identify new promising cyclic scaffolds. A large descriptor space coupled with cluster analysis was employed to digitize known antibacterial structures and to gauge the potential of new peptidomimetic macrocycles, which were conveniently synthesized by acylbenzotriazole methodology. Some of the synthesized compounds were tested against an array of microorganisms and showed antibacterial activity against Bordetella bronchistepica, Micrococcus luteus, and Salmonella typhimurium.

Microwave-assisted synthesis and bioevaluation of some semicarbazones.

In continuation to our efforts in finding potential therapeutic agents, a variety of biologically significant semicarbazones were synthesized by the reaction of different carbonyl compounds with phenyl semicarbazides through microwave irradiation. Initially, 18 semicarbazones were studied for their antimicrobial, antitumor, and antioxidant potential. None of the tested compounds showed any antibacterial activity; however, some compounds showed significant antifungal activity.

Synthesis, characterization, anti-inflammatory and in vitro antimicrobial activity of some novel alkyl/aryl substituted tertiary alcohols.

The synthesis of some novel alkyl/aryl substituted tertiary alcohols was accomplished in two steps. The synthetic route involves preparation of Grignard reagents by treating alkyl/aryl bromides with magnesium turnings in dry ether. Then substituted chalcones were reacted with the Grignard reagents to afford alkyl/aryl substituted tertiary alcohols 1-10.

In silico modeling of the specific inhibitory potential of thiophene-2,3-dihydro-1,5-benzothiazepine against BChE in the formation of beta-amyloid plaques associated with Alzheimer's disease.

Background: Alzheimer's disease, known to be associated with the gradual loss of memory, is characterized by low concentration of acetylcholine in the hippocampus and cortex part of the brain. Inhibition of acetylcholinesterase has successfully been used as a drug target to treat Alzheimer's disease but drug resistance shown by butyrylcholinesterase remains a matter of concern in treating Alzheimer's disease. Apart from the many other reasons for Alzheimer's disease, its association with the genesis of fibrils by beta-amyloid plaques is closely related to the increased activity of butyrylcholinesterase.

Redox behavior of anticancer chalcone on a glassy carbon electrode and evaluation of its interaction parameters with DNA.

The interaction of anticancer chalcone [AMC, 1-(4'-aminophenyl)-3-(4-N,N-dimethylphenyl)-2-propen-1-one] with DNA has been explored using electrochemical, spectroscopic and viscometric techniques. A shift in peak potential and decrease in peak current were observed in cyclic voltammetry and hypochromism accompanied with bathochromic shift were noticed in UV-Vis absorption spectroscopy. These findings were taken as evidence for AMC -DNA intercalation.

Solid-phase synthesis and biological evaluation of a parallel library of 2,3-dihydro-1,5-benzothiazepines.

Solid-phase synthesis of a parallel library of 3'-hydroxy-2,3-dihydrobenzothiazepines has been carried out through [4+3] annulation of alpha,beta-unsaturated ketones with aminothiophenol, using Wang resin as solid support. The synthesized compounds were evaluated for their potential as antibacterial, tumor inhibitors as well as acetyl- and butyrylcholinesterase inhibitors. None of the compounds showed any significant antibacterial activity.

In silico studies of urease inhibitors to explore ligand-enzyme interactions.

In continuation of our previous study on the urease inhibition by a number of chalcones, 2,3-dihydro-1,5-benzothiazepines and 2,3,4,5-tetrahydro-1,5-benzothiazepines, FlexX docking has been exploited to get a deeper insight into the mechanism of their inhibitory action. A comparison of the IC(50) values of the active compounds reveals that, of the three classes of compounds studied, 2,3-dihydro-1,5-benzothiazepines were the most potent urease inhibitors. An in silico examination of these compounds showed that the activity is related to the interaction of ligand with the nickel metallocentre, its interaction with two amino acid residues, Asp224 and Cys322, in addition to the orientation of rings A and B in the catalytic core of the enzyme.

Structural insight into the inhibition of acetylcholinesterase by 2,3,4, 5-tetrahydro-1, 5-benzothiazepines.

Benzothiazepines 1-3 inhibited acetylcholinesterase (AChE; EC 3.1.1.

Combinatorial synthesis, lead identification, and antitumor study of a chalcone-based positional-scanning library.

A 175-member chalcone library was designed and synthesized from seven differently substituted acetophenones (A(1)-A(7)) and 25 differently substituted aryl or heteroaryl aldehydes (B(1)-B(25)). Potential lead compounds were identified by deconvolution of a two-dimensional library matrix via positional scanning, and the members of the most-active sub-libraries were synthesized and screened against crown-gall tumors with the aid of the potato-disc assay. The resulting hits gave rise to significant antitumor activities, with no antibacterial effect on the tumor-producing bacterium Agrobacterium tumefaciens.

Syntheses and biological activities of chalcone and 1,5-benzothiazepine derivatives: promising new free-radical scavengers, and esterase, urease, and alpha-glucosidase inhibitors.

A series of 2,4-diaryl-2,3,4,5-tetrahydro- (36-40) and 2,4-diaryl-2,3-dihydro-1,5-benzothiazepines (25-35) have been synthesized from the corresponding chalcones 1-24. Both the benzothiazepines and chalcones were evaluated as DPPH free-radical scavengers and as inhibitors of cholinesterases, urease, and alpha-glucosidase. Compounds 2, 5, 6, 7, 10, 13, 18, 21, 36a, 37a, 37b, and 39a showed significant cholinesterase inhibiting activities.

Combinatorial synthesis and antibacterial evaluation of an indexed chalcone library.

A 120-membered chalcone library has been designed and prepared from six differently substituted acetophenones (A1-A6) and 20 benzaldehydes (B1-B20). The library was subjected to biological studies targeted against six bacterial strains. For the identification of the most-active member(s) of the library, the so-called indexed or positional-scanning method was applied.

Electron ionization fragmentation mechanisms of different substituted 2,3-dihydro- and 2,3,4,5-tetrahydro-1,5-benzothiazepines.

The electron ionization induced fragmentations of ten biologically significant 2,3-dihydro-1,5-benzothiazepines and the corresponding 2,3,4,5-tetrahydro-1,5-benzothiazepines have been studied by low- and high-resolution mass spectrometry. The fragmentations follow a general pattern, the details of which are discussed with respect to the nature and position of the substituent in the aromatic ring. The dihydro- and tetrahydro-1,5-benzothiazepines both undergo fragmentation through four routes (A-D).

Derivatives of 4-(2-hydroxylphenyl)-2-phenyl-2,3-dihydro-1,5-benzothiazepine.

In the structures of 2-(4-chlorophenyl)-4-(2-hydroxyphenyl)-2,3-dihydro-1,5-benzothiazepine, C(21)H(16)ClNOS, 4-(2-hydroxyphenyl)-2-(4-tolyl)-2,3-dihydro-1,5-benzothiazepine, C(22)H(19)NOS, and 4-(2-hydroxyphenyl)-2-(3-methoxyphenyl)-2,3-dihydro-1,5-benzothiazepine, C(22)H(19)NO(2)S, the central seven-membered heterocyclic rings adopt twist-boat conformations in which the N atoms are involved in strong intramolecular hydrogen bonds with the hydroxyl H atoms, resulting in six-membered rings.