Ionic liquid mediated synthesis and in vitro mechanistic exploration of polycyclic cage-like heterocyclic hybrid

A three-component, [3 + 2]-cycloaddition/annulation domino protocol is described for the synthesis in excellent yield of a polycyclic cage-like heterocyclic hybrid (PCHH) that comprises various advantaged structural units viz., α,β-unsaturated ketone moiety, 4-pyridinone and pyrroloisoquinoline in a cage-like framework. The antitumor activity of PCHH on human breast (MCF7), colon (HCT116), cervical (JURKAT) and lung (NCI-H460) malignant cell lines inhibited the propagation of all cell lines. This hybrid molecule displayed increased broad-spectrum anticancer activity with higher doses of PCHH. Furthermore, the compound induced 45.21% of early apoptosis and 46.32% of late apoptosis in the Jurkat cancer cell line. Cell cycle analysis showed that this cage-like compound caused cell cycle arrest of Jurkat cells at the S phase and sub G0/G1 phase. Additionally, it led to increased DNA fragmentation and mitochondrial membrane permeabilization through activation of caspase-3 enzyme. Present investigation demonstrates the specific cytotoxic activity of the cage-like compound and the induction of apoptosis through the intrinsic pathway of Jurkat cells.     

Antimicrobial effects of vanillin-based pyridyl-benzylidene-5-fluoroindolins

In this study, the antimicrobial effect and DNA gyrase inhibitor potential of vanillin-based pyridyl–substituted fluoro-indolines were evaluated. These compounds are synthesized and established through green-chemistry approaches. The inhibition effect on both DNA gyrase A and B was evaluated in silico and in vitro. Agar well diffusion method–based antimicrobial activity against Gram-ve Pseudomonas aeruginosa (MTCC 424) and Escherichia coli (MTCC 443), Gram+ve Streptococcus pyogenes (MTCC 442) and Staphylococcus aureus (MTCC 96), and a clinical isolate of Candida albicans (Fungi) was evaluated. The cytotoxicity of the compounds was assessed over macrophages using the MTT assay. In the results, the target compounds exhibited a broad-spectrum antimicrobial activity against both bacterial types and fungal.     

Synthesis,spectral characterization,C?C coupling,oxidation reactions and antibacterial activities of new ruthenium(III) Schiff base complexes

A new series of hexa‐coordinated stable Ru(III) Schiff base complexes of the type [RuX(EPh₃)(L)] (where X = Cl/Br; E = P/As; L = tetradentate N₂O₂ donor Schiff ligands) have been synthesized and characterized by elemental analysis, magnetic susceptibility measurement, FT‐IR, UV–vis, ¹³C{¹H}‐NMR, ESR spectra, electrochemical and powder X‐ray diffraction pattern studies. The selective oxidation of alcohols to their corresponding carbonyl compounds occurred in the presence of N‐methylmorpholin‐N‐oxide (NMO), H₂O₂ and O₂ atmosphere at ambient temperature as co‐oxidants and C? C coupling reactions. Further, these new Schiff base ligands and their Ru(III) complexes were also screened for their antibacterial activity against K. pneumoniae, Shigella sp., M. luteus, E. coli and S. typhi. Copyright © 2010 John Wiley & Sons, Ltd.     

The use of two nematic solvents in the determination of molecular structure of systems providing deceptively simple spectra

The use of two liquid crystals as solvents in the determination of molecular structure has been demonstrated for systems which do not provide structural information from studies in a single solvent owing to the fact that the spectra are deceptively simple, with the result that all the spectral parameters cannot be derived with reasonable precision. The specific system studied was 2-(p-bromophenyl)-4,6-dichloropyrimidine, for which relative inter-proton discances have been determined from the proton NMR spectra in two nematic solvents.     

Development and validation of a HPLC method for quantification of rivastigmine in rat urine and identification of a novel metabolite in urine by LC‐MS/MS

A sensitive, specific and accurate HPLC method for the quantification of rivastigmine (RSM) in rat urine was developed and validated. The method involves the simple liquid–liquid extraction of RSM and pyridostigmine as an internal standard (IS) from rat urine with tertiary methyl butyl ether. The chromatographic separation of RSM and IS was achieved with 20 mm ammonium acetate buffer (pH 6.5) and acetonitrile (65:35, v/v) delivered at flow‐rate of 1 mL/min on a Kromasil KR‐100. The method was in linear range from 50 to 5000 ng/mL. The validation was done as per FDA guidelines and the results met the acceptance criteria. The method was successfully applied for the quantification of RSM in rat urine. Besides method validation, we have identified two metabolites of RSM in urine. Both the metabolites were characterized by HPLC‐PDA and LC‐MS/MS and it was found that one metabolite is novel. Copyright © 2010 John Wiley & Sons, Ltd.     

High-Performance Thin-Layer Chromatographic Analysis of Bicalutamide in Bulk Drug and Liposomes

JPC – Journal of Planar Chromatography – Modern TLC - A sensitive, accurate, precise, and specific high-performance thinlayer chromatographic (HPTLC) method for analysis of bicalutamide...     

Effects of <Emphasis Type="Italic">A.marina</Emphasis>-Derived Isoquercitrin on TNF-Related Apoptosis-Inducing Ligand Receptor (TRAIL-R) Expression and Apoptosis Induction in Cervical Cancer Cells

TNF-related apoptosis-inducing ligand (TRAIL) is an anticancer agent, which has greater apoptosis inducing capacity, but most of the cancer cells become resistant to TRAIL-induced apoptosis. The combined treatment of TRAIL with natural products could restore the cancer cell sensitivity to recombinant human TRAIL (rhTRAIL) protein and might enhance the TNF-related apoptosis-inducing ligand receptor (TRAIL-R) expression. This investigation was aimed to isolate flavonoids from leaves of Avicennia marina and evaluate their potential for sensitization of rhTRAIL in human cervical cancer cells (SiHa). The methanolic extract of A.marina leaves were purified and structure was elucidated as isoquercitrin by NMR and LC-MS analysis. Isolated isoquercitrin showed cytotoxicity against SiHa cell line at IC₅₀ of 980 μM. Messenger RNA (mRNA) expression of TRAIL-Rs was quantified by qRT-PCR, combination of isoquercitrin, and/or rhTRAIL increased TRAIL-R1 and TRAIL-R2 gene expression by 7 folds and 4 folds, respectively. Also, FACS assay revealed that combined treatment has increased the early apoptosis up to 7.24%. In the present study, we found that isoquercitrin enhances the mRNA expression of TRAIL-Rs, but the percentage of apoptosis was meager, possibly due to the influence of other anti-apoptotic proteins.     

Synthesis, structural and magnetic properties of spin ladder compound Ca1−xCoxCu2O3

MCu₂O₃ (M=Ca and Co) system has two-leg spin ladder structure similar to that of the prototype SrCu₂O₃ system except that the rungs are buckled with an angle of 123° and 105° for CaCu₂O₃ and CoCu₂O₃ compounds, respectively. We have synthesized powder samples of (Ca_1−xCo_x)Cu₂O₃ (x=0.00-1.00) by the solid state reaction method and their structural and magnetic properties have been investigated. All the synthesized compounds crystallize in orthorhombic structure with space group Pmmn. Lattice parameters of (Ca_1−xCo_x)Cu₂O₃ decrease with the increase in Co content. DC magnetic susceptibility χ(T) results of the end products CaCu₂O₃ and CoCu₂O₃ show antiferromagnetic transition (T_N) at 27 and 215 K, respectively. Co doping into (Ca_1−xCo_x)Cu₂O₃ enhances its T_N systematically with increasing Co concentration. The χ(T) of CoCu₂O₃ shows a broad transition with the peak temperature around 215 K and it was found to be field independent up to 90 kOe. The ambiguity concerning the transition was ruled out by recording the temperature dependent X-ray diffraction pattern on CoCu₂O₃ system, which indicated that there is no structural transition in the investigated temperature range of 115-300 K. Further, specific heat measurement on CoCu₂O₃ confirms the magnetic phase transition by the appearance of a sharp peak at 215 K.     

A Novel Synthesis and Characterization of Titanium Superoxide and its Application in Organic Oxidative Processes

A novel, exceptionally stable titanium superoxide radical ion was prepared and its structure determined by FTIR, ESR, Raman spectroscopy, X-ray diffraction, thermogravimetric/differential thermal analysis and elemental analysis. This heterogeneous catalyst has been found to be effective for the selective oxidation of aromatic amines and phenols to the corresponding nitro aromatics and p-quinones, respectively. In addition, this non-toxic, inexpensive and reusable catalyst has also been used in aminobromination of olefins, which proceed to give the 1, 2-bromoaminated anti-Markovnikov product. A brief account of these results is summarized in this review.