Search

Here, we present a detailed investigation on the interaction of 4-chloro-7-nitro-1,2,3-benzoxadiazole (NBD) embedded olanzapine derivative (OLA-NBD) with a model transport protein, human serum albumin (HSA). The thermodynamic parameters, Δ

Among the different types of polymeric vehicles, (PLGA) is biodegradable and has emerged as promising tool for the delivery of cancer therapeutics. The salient features of PLGA micro carriers include prolonged circulation time, increased tumor localization and biodegradability and effectiveness of the therapeutics. We have synthesized PLGA microspheres where curcumin can be loaded and thereby increases its bioavailability. The cytotoxicity of curcumin (PLGA@CCM) microspheres was evaluated on triple negative breast cancer (TNBC) cell lines. They were found to induce apoptosis by perturbing the mitochondrial membrane potential. PLGA@CCM@FA induces apoptosis in human triple negative breast cancer cells by up-regulating Cleaved caspase-3 and down regutes p-AKT. The in-vivo study in BALB/C mice model exhibited more tumor regression in case of PLGA@CCM@FA microspheres. Our results suggests that these microspheres can be an effective vehicle for delivery of hydrophobic drugs to the folate over expressed cancer cells.

We report a novel phenazine-embedded fluorescent probe (2-[2-(pyridin-2-ylmethoxy)-phenyl]-1H-imidazo[4,5-b]phenazine, PIP), which upon complexation with Cu(II)-ion-forming [(PIP)CuII(Cl)] becomes ...

Fluorescence spectroscopy is a significant bio-analytical technique for specific detection of nitric oxide (NO) and for broadcasting the in vitro and in vivo biological activities of this gasotransmitter. Herein, a benzo-coumarin embedded smart molecular probe (BCM) is employed for NO sensing through detailed fluorescence studies in purely aqueous medium. All the spectroscopic analysis and literature reports clearly validate the mechanistic insight of this sensing strategy i.e., the initial formation of 1,2,3,4-oxatriazole on treatment of the probe with NO which finally converted to its carboxylic acid derivative. This oxatriazole formation results in a drastic enhancement in fluoroscence intensity due to the photoinduced electron transfer (PET) effect. The kinetic investigation unveils the second and first-order dependency on [NO] and [BCM] respectively. The very low detection limit (16 nM), high fluorescence enhancement (123 fold) in aqueous medium and good formation constant (Kf = (4.33 ± 0.48) × 104 M−1) along with pH invariability, non-cytotoxicity, biocompatibility and cell permeability make this probe a very effective one for tracking NO intracellularly.

We introduce herein, a novel copper complex-based fluorescent probe [CuII(DQ468)Cl]+ that exhibits a significant fluorescence turn-on response towards nitroxyl (HNO) with high selectivity over other biological reactive oxygen, nitrogen and sulfur species, including nitric oxide (NO). A smart strategy, involving HNO-induced reduction of paramagnetic [CuII(DQ468)Cl]+ to diamagnetic [CuI(DQ468)]+ with concomitant fluorescence enhancement via a PET mechanism is focused here. This reduction-based strategy was also supported by X-band EPR response and mass spectroscopy. The metal free probe (DQ468) showed high affinity towards Cu2+ to form [CuII(DQ468)Cl]+ with a 0.091 μM detection limit, which subsequently enabled the detection of HNO in an organo-aqueous medium at biological pH (7.4) in the green wavelength region (λem = 543 nm) with a LOD of 0.41 μM. The ground-state geometries of DQ468, [CuII(DQ468)Cl]+ and [CuI(DQ468)]+ were optimized by DFT calculations, which revealed that the central metal ion in [CuII(DQ468)Cl]+ is in a distorted tetrahedral geometry with the C1 point group. Additionally, the negligible cytotoxicity and good biocompatibility make the developed probe useful for the in vitro detection of HNO.

A Cu(II) based sensor (1) prepared by the complexation between (quinolin-8-ylamino)-acetic acid hydrazide (L2) and Cu2+ ions has been developed for a highly sensitive and selective recognition of HNO and S2− over other biologically abundant anions with prominent enhancement in absorption and emission intensities. The sensor (1) shows weak fluorescence due to ET (electron transfer) but upon addition of HNO and S2− a large enhancement in the fluorescence intensity (F.I.) was observed over other possible competitive anions on the basis of reduction of Cu(II) to Cu(I) and formation of CuS, respectively. The 1 : 1 complexation was characterized by mass spectrometry (MS), elemental analysis and Job's plot. The corresponding Kf value was evaluated to be (4.934 ± 0.05) × 104 M−1 for Cu2+ from UV-Vis absorption titration. Quantum yields of L2 and [Cu-L2 + S2−] and [Cu-L2 + HNO] complexes in acetonitrile (CH3CN) are found to be 0.107, 0.09 and 0.07, respectively, using quinine sulphate as the standard.

Tuning of the photoluminescence of graphene quantum dots (GQDs) through modulation of the bandgap and chemical doping is important for the GQDs use in optoelectronic devices. Herein, tuning of dual properties, i.e., wettability (hydrophilic to hydrophobic) and photoluminescence, of graphene quantum dots is demonstrated. We synthesized graphene quantum dots (GQDs) and alkylated graphene quantum dots (C12-GQDs) by simple chemical exfoliation (top-down technique) of graphite nanopowder. The synthesized GQDs are highly hydrophilic due to the presence of oxygenated functional moieties. We successfully functionalized the synthesized GQDs covalently with dodecyl amine (DDA) and simultaneously reduced them with glycine to render hydrophobicity on the GQD surface. Herein, glycine plays a dual role as a chemical functionalizer and reducing agent. All the characterizations of GQDs and C12-GQDs were carried out by UV-visible absorption spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, dynamic light scattering, Raman spectroscopy, and contact angle analysis. Interestingly, after covalent modification, we also observed the tuning of photoluminescence (from green to blue) of GQDs. Thus, we can easily tune the dual properties, i.e., wettability and photoluminescence, of GQDs by simple covalent modification with long-chain alkyl (–C12H27) groups.

A series of novel carbamo(dithioperoxo)thioate derivatives have been prepared in excellent yield using a significantly fast, one-pot three component reaction and experimented for their potential as anti-filarial agents against model filarial nematode Setaria cervi. Among 23 compounds (4a-w) evaluated for the anti-filarial activities, five compounds (4a, 4b, 4c, 4d and 4h) have shown promising anti-proliferative effects on the juvenile stage microfilariae (mf) as well as in adults in a time and dose dependent manner. Compound 4a was found most active against oocytes, mf and adult nematods as well as non-cytotoxic to the normal cells. It has been established that the anti-filarial activity of the compounds were observed due to the involvement of reactive oxygen species (ROS) and apoptosis. Several biochemical and microscopic experiments have been carried out to establish the fact that both intrinsic and extrinsic pathways of apoptosis contribute to the compound 4a mediated death phenomenon of the filarial nematodes.

Intracellular survival of Leishmania donovani demands rapid production of host ATP for its sustenance. However, gradual decrease in intracellular ATP in spite of increased glycolysis suggested ATP efflux during infection. Accordingly, extracellular ATP showed an increase and pannexin-1 was found to be the major ATP exporter in infected condition. Extracellular ATP also showed a gradual decrease after initial increase and analysing cell surface ATP-degrading enzymes revealed induction of the ectonucleotidases, CD39 and CD73. Ectonucleotidase mediated ATP degradation led to increased extracellular adenosine (eADO) and inhibiting CD39 and CD73 in infected cells decreased adenosine concentration and parasite survival, documenting importance of adenosine in infection. Inhibiting adenosine uptake by cells did not affect parasite survival implicating eADO might exert its effect through receptor-mediated signaling. Leishmania indeed induced expression of adenosine receptors A2AR and A2BR, both being important for anti-inflammatory responses. Treating infected BALB/c mice with CD39 and CD73 inhibitors resulted in decreased parasite burden and increased host-favourable cytokine production. Collectively, these observations indicate that infection-induced ATP is exported and after converting into adenosine exerts receptor-mediated signaling for propagating infection.

A series of C-glycosylated cinnamoylfuran derivatives were synthesized in excellent yield from free sugars. The C-glycosylated furan derivatives were prepared under aqueous reaction conditions. The anticancer potentials of the synthesized compounds were evaluated on the basis of their comparative cytotoxic effects on cancer cells (MCF-7 and HeLa) and normal cells (NKE). Among 28 compounds evaluated for their cytotoxic effects on cancer cells, three compounds (compounds 8, 24 and 28) were shown to have significant cytotoxic effects on MCF-7 and HeLa cell lines and comparatively less toxicity against normal NKE cell line. Based on its selectivity index, compound 24 was considered the most promising anticancer agent amongst the above three compounds. Further biochemical studies with compound 24 showed that both intrinsic and extrinsic pathways of apoptosis contribute to compound 24 mediated cytotoxicity.

The active fraction and/or compounds of Calendula officinalis responsible for wound healing are not known yet. In this work we studied the molecular target of C. officinalis hydroethanol extract (CEE) and its active fraction (water fraction of hydroethanol extract, WCEE) on primary human dermal fibroblasts (HDF). In vivo, CEE or WCEE were topically applied on excisional wounds of BALB/c mice and the rate of wound contraction and immunohistological studies were carried out. We found that CEE and only its WCEE significantly stimulated the proliferation as well as the migration of HDF cells. Also they up-regulate the expression of connective tissue growth factor (CTGF) and α-smooth muscle actin (α-SMA) in vitro. In vivo, CEE or WCEE treated mice groups showed faster wound healing and increased expression of CTGF and α-SMA compared to placebo control group. The increased expression of both the proteins during granulation phase of wound repair demonstrated the potential role of C. officinalis in wound healing. In addition, HPLC-ESI MS analysis of the active water fraction revealed the presence of two major compounds, rutin and quercetin-3-O-glucoside. Thus, our results showed that C. officinalis potentiated wound healing by stimulating the expression of CTGF and α-SMA and further we identified active compounds. Copyright © 2016 John Wiley & Sons, Ltd.

Among the different types of biomaterials, natural excipients gum acacia (GA) is economic and has the potential for controlled drug delivery. We have synthesized GA microspheres by co-precipitation method and characterized them by XRD, FESEM, 1H NMR, FTIR, UV visible spectra and DLS. Despite its potential anti-cancer activity, solubility of curcumin is very low rendering its limit in application. We have used GA microspheres where curcumin can be loaded comfortably and thereby increases its bioavailability. The cytotoxicity of curcumin encapsulated GA microspheres was evaluated on triple negative breast cancer cell lines. They were found to induce apoptosis by perturbing the mitochondrial membrane potential. Folic acid was conjugated to curcumin encapsulated GA microspheres, for delivering it specifically to the cancer cells. The in-vivo study in BALB/C mice model exhibited more tumor regression in case of folic acid targeted curcumin encapsulated GA microsphere. Our results implicates that these microspheres can be an effective therapeutic agent to folate receptors over expressing cancer cells.

SUMMARY Prolonged and strenuous exercise has been proposed as a possible source of male-factor infertility. Forced intensive swimming has also been identified as one source of a dysfunctional male reproduction system. The present study evaluated the possible protective role of α-lipoic acid and N-acetylcysteine (NAC) on intensive swimming-induced germ-cell depletion in adult male rats. Forced exhaustive swimming of 1 hr/day, 6 days/week for 8 consecutive weeks resulted in a significant (P

Lymphatic filariasis, affecting around 120 million people in 80 countries worldwide, is an extremely painful disease and caused permanent and long term disability. Owing to its alarming prevalence there is immediate need for development of new therapeutics. A series of trans-stilbene derivatives were synthesized using aqueous reaction condition showing potential as antifilarial agents demonstrated in vitro. MTT reduction assay and dye exclusion test were performed to evaluate the micro and macrofilaricidal potential of these compounds. Amid 20 trans-stilbene derivatives together with Resveratrol (RSV), a multifunctional natural product was screened; nine compounds (28, 29, 33, 35, 36, 38, 39, 41 and 42) have showed promising micro and macrofilaricidal activities and four of them (28, 39, 41 and 42) showed better effectiveness than RSV. In the treated parasites apoptosis was established by DNA laddering, in situ DNA fragmentation and FACS analysis. The generation of ROS in the treated parasites was indicated by the depletion in the level of GSH, GR and GST activity and elevation of SOD, catalase, GPx activity and superoxide anion and H2O2 level. Along with the ROS generation and oxidative stress, the decreased expression of anti-apoptotic ced-9 gene and increased expression of nematode specific pro-apoptotic genes, egl-1, ced-4 and ced-3 at the level of transcription and translation level; the up-regulation of caspase-3 activity and involvement of caspase-8,9,3, cytochrome-c and PARP were also observed and which denotes the probable existence of both extrinsic and intrinsic pathways apoptosis in parasitic nematodes. This observation is reported first time and thus it confirmed the mode of action and effectiveness of the compounds. Further, the comparative bioavailability–pharmacokinetics studies showed that compound 28 possesses comparable properties with Ivermectin. This study will certainly intensify our understanding of the pharmacological importance of trans-stilbenes as an anti-filarial agent.

A coordination terpolymerization strategy is introduced to alter the connectivity within layers of a pillared-layer coordination polymer. Assembling two different dicarboxylate linkers around a metal cluster in the layer suppresses interpenetration while enabling formation of a rectangular 2D grid structure.

Design and synthesis of porous solids employing both reversible coordination chemistry and reversible covalent bond formation is described. The combination of two different linkage modes in a single material presents a link between two distinct classes of porous materials as exemplified by metal-organic frameworks (MOFs) and covalent organic frameworks (COFs). This strategy, in addition to being a compelling material-discovery method, also offers a platform for developing a fundamental understanding of the factors influencing the competing modes of assembly. We also demonstrate that even temporary formation of reversible connections between components may be leveraged to make new phases thus offering design routes to polymorphic frameworks. Moreover, this approach has the striking potential of providing a rich landscape of structurally complex materials from commercially available or readily accessible feedstocks.

The two-dimensional assembly of multicarboxylated arenes is explored at the liquid-graphite interface using scanning tunneling microscopy. Symmetry variations were introduced via phenylene spacer addition and the influence of these perturbations on the formation of hydrogen-bonded motifs from an alkanoic acid solvent is observed. This work demonstrates the importance of symmetry in 2D crystal formation and draws possible links of this behavior to prediction of coordination modes in three-dimensional coordination polymers.

Incorporation of three distinct linkers with identical functionality in a coordination copolymer is accomplished in materials designated UMCM-10, -11, and -12. Uniaxial lattice expansion, achieved in these highly porous and non-interpenetrated materials, is utilized in size-selective guest incorporation.