<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

(SoNS) School of Natural Sciences

Natural products are the source of innumerable pharmaceutical drug candidates and also form an important aspect of herbal remedies. They are also a source of various bioactive compounds. Herein we have leveraged the structural attributes of several natural products in building a library of architecturally diverse chiral molecules by harnessing R-tryptophan as the chiral auxiliary. It is converted to its corresponding methyl ester 1 which in turn provided a bevy of 1-aryl-tetrahydro-β-carbolines 2a-d, which were then converted to chiral compounds via a diversity oriented synthetic strategy (DOS). In general, intermolecular and intramolecular ring rearrangements facilitated the formation of the final compounds. Four different classes of molecules with distinct architectures were generated, adding up to nearly twenty-two individual molecules. Phenotypic screening of a representative section of the library revealed two molecules that selectively inhibit MCF7 breast cancer cells with IC50 of ∼5 μg mL-1 potency. © 2017 The Royal Society of Chemistry.

Chemistry

Fulltext

Organic and Biomolecular Chemistry

A diversity oriented synthesis of natural product inspired molecular libraries

A novel nanocomposite consisting of π-conjugated 2-aminoterephthalic acid (ATA) coated iron oxide (Fe3O4) nanoparticles and reduced graphene oxide (RGO) has been synthesized using a facile combination of wet-chemistry and low-power sonication. The ATA-Fe3O4/RGO nanocomposites exhibited a high specific capacitance of the order of 576 F g−1; significantly higher than that of pristine Fe3O4 (132 F g−1) and RGO (60 F g−1) counterparts, indicative of a synergistic effect between the ATA-Fe3O4 and RGO components. Furthermore, the maximum energy storage density was calculated to be 75 W h kg−1 (at a current density of 6 A g−1). The charging-discharging analysis showed promising long-term stability with nearly 86\% retention of the capacitance after 5000 cycles. The superior capacitive behaviour of these ATA-Fe3O4/RGO nanocomposites is attributed to the synergistic effect of the π-conjugated ATA coating on Fe3O4 which enhances the pseudo-capacitive charge transfer process of Fe3O4 and works in conjunction with the surface functional groups (such as carboxylic, amino and amide) present on the RGO surface, providing enhanced double layer capacitance. Thus, the current system exploits the advantages of both the double layer capacitors and pseudocapacitors in a hybrid structure. © The Royal Society of Chemistry.

Physics

RSC Advances

Novel π-conjugated iron oxide/reduced graphene oxide nanocomposites for high performance electrochemical supercapacitors

Molecular couplings between DNA and water together with the accompanying processes of energy exchange are mapped via the ultrafast response of DNA backbone vibrations after OH stretch excitation of the water shell. Native salmon testes DNA is studied in femtosecond pump-probe experiments under conditions of full hydration and at a reduced hydration level with two water layers around the double helix. Independent of their local hydration patterns, all backbone vibrations in the frequency range from 940 to 1120 cm-1 display a quasi-instantaneous reshaping of the spectral envelopes of their fundamental absorption bands upon excitation of the water shell. The subsequent reshaping kinetics encompass a one-picosecond component, reflecting the formation of a hot ground state of the water shell, and a slower contribution on a time scale of tens of picoseconds. Such results are benchmarked by measurements with resonant excitation of the backbone modes, resulting in distinctly different absorption changes. We assign the fast changes of DNA absorption after OH stretch excitation to structural changes in the water shell which couple to DNA through the local electric fields. The second slower process is attributed to a flow of excess energy from the water shell into DNA, establishing a common heated ground state in the molecular ensemble. This interpretation is supported by theoretical calculations of the electric fields exerted by the water shell at different temperatures. © 2017 Author(s).

World University root node

Structural Dynamics

Molecular couplings and energy exchange between DNA and water mapped by femtosecond infrared spectroscopy of backbone vibrations

Drug toxicity is a long-standing concern of modern medicine. A typical anti-pain/fever drug paracetamol often causes hepatotoxicity due to peroxynitrite ONOO−. Conventional blood tests fail to offer real-time unambiguous visualization of such hepatotoxicity in vivo. Here we report a luminescent approach to evaluate acute hepatotoxicity in vivo by chromophore-conjugated upconversion nanoparticles. Upon injection, these nanoprobes mainly accumulate in the liver and the luminescence of nanoparticles remains suppressed owing to energy transfer to the chromophore. ONOO− can readily bleach the chromophore and thus recover the luminescence, the presence of ONOO− in the liver leads to fast restoring of the near-infrared emission. Taking advantages of the high tissue-penetration capability of near-infrared excitation/emission, these nanoprobes achieve real-time monitoring of hepatotoxicity in living animals, thereby providing a convenient screening strategy for assessing hepatotoxicity of synthetic drugs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Angewandte Chemie - International Edition

Real-Time In Vivo Hepatotoxicity Monitoring through Chromophore-Conjugated Photon-Upconverting Nanoprobes

The ordered hexagonal perovskite Ba2CuTeO6 hosts weakly coupled S=12 spin ladders produced by an orbital ordering of Cu2+. The magnetic susceptibility $\chi$(T) of Ba2CuTeO6 is well described by that expected for isolated spin ladders with exchange coupling of J≈86K but shows a deviation from the expected thermally activated behavior at low temperatures below T∗≈25K. An anomaly in $\chi$(T), indicative of magnetic ordering, is observed at Tmag=16K. No clear signature of long-range ordering, however, is captured so far in NMR 1/T1, specific heat or neutron diffraction measurements at and below Tmag. The marginal magnetic transition, indicative of strong quantum fluctuations, is evidence that Ba2CuTeO6 is in very close proximity to a quantum critical point between magnetically ordered and spin-gapped phases controlled by interladder couplings.

Physical Review B

S= 12 quantum critical spin ladders produced by orbital ordering in Ba2CuTeO6

In India, the rice root knot nematode, Meloidogyne graminicola is the dominant species infecting rice-wheat cropping system due to its broad host range and ability of causing potential yield loss. It has become an emerging problem in the nurseries and upland rice. Second stage juveniles (J2s) penetrate the roots closely behind the root tip; migrate to vascular cylinder turning it into multinucleated giant cells, by endomitosis and cell hypertrophy characterized by hook shaped galls. In the present study, 33 direct seeded rice (DSR) genotypes of Asian rice (Oryza sativa) were evaluated for resistance against rice root-knot nematode, M. graminicola on the basis of root-knot index and multiplication factor. Out of the total 33 rice cvs, 6 cultivars had less than10 galls/ plant and of these, cv. NDR-97 exhibited a strong resistant response with least number of galls (1.5galls/plant) and remaining are moderately and highly susceptible. The most and least susceptible cultivars were selected for further histopathological and differential gene expression studies. © 2017, Nematological Society of India. All rights reserved.

Life Sciences

Indian Journal of Nematology

Evaluation of resistance in direct seeded rice (Oryza sativa L.) against Meloidogyne graminicola

Deinococcus indicus strain DR1, a red-pigmented, arsenic- and radiation-resistant bacterium, was isolated from a water sample of the Dadri wetland, Uttar Pradesh, India. Here, we report a draft genome sequence of this strain, which may provide useful information regarding the genes and pathways involved in heavy-metal bioremediation. © 2017 Chauhan et al.

Genome Announcements

Draft genome sequence of Deinococcus indicus DR1, a novel strain isolated from a freshwater wetland

In order to understand, clarify and provide confirmations in the contexts of the prevalent confusions concerning Li-storage in graphenic carbon (viz. the reduced dimensional scale of graphitic carbon), electrochemical lithiation/delithiation has been performed with CVD-grown fairly pristine well-ordered few-layer graphene films (FLG; ∼7 layers; as a model material). Chronopotentiograms and cyclic voltammograms recorded with the FLG present distinct features corresponding to the transformation between different Li-GICs (i.e., 'staging') below 0.3 V against Li/Li+, thus confirming that 'classical' Li-intercalation does occur even at such reduced dimensional (nano)scale. Nevertheless, even in this lower potential window (our main focus here), Li-storage in FLG involves contributions from both diffusion- and surface-controlled mechanisms. The Li-capacities recorded with FLG just within this lower potential window, and also upon subtracting any possible contribution from the Cu current collector, were still ∼3-4 times greater than those obtained with similarly grown thicker bulk graphite films (TBG: ∼450 nm; Li-capacity recorded: ∼380 mA h g-1). Contrary to the usual belief, the excess Li-capacity of FLG cannot be explained by the presence of extrinsic/intrinsic defects, which are nearly negligible in the FLG films under consideration. Simulation of Li-storage in graphene via DFT indicated that the excess capacity (after formation of the LiC6 configuration) is associated with additional stable Li-storage on the outer graphene surfaces in the forms of more than one Li-layer (but different from Li-plating) and segregation close to the 'stepped' (exposed) edges of the inner graphene layers (but not exactly at the edge sites). Overall, such predicted Li-storage mechanisms are in agreement with the experimentally observed contributions from both 'classical' Li-intercalation and surface-controlled processes (even at potentials below 0.3 V), which primarily account for the excess Li-capacities recorded with graphenic carbon. © 2017 The Royal Society of Chemistry.

Journal of Materials Chemistry A

Understanding the Li-storage in few layers graphene with respect to bulk graphite: Experimental, analytical and computational study

Bioisosteric modification of known fucosidase inhibitors A and B, resulted in three new types of molecules, 4b, 5c and 6a (belonging to furopyridinedione, thiohydantoin and hydantoin chemotypes) that could potentially bind to α-l-fucosidase (bovine kidney origin). Molecular docking revealed and compared the putative binding interaction between 4b, 5c and 6a with A and B against the active site of a homology model of α-l-fucosidase. Based on this initial investigation, design and synthesis of a library of small molecules based on furopyridinedione, thiohydantoin and hydantoin, followed by their in vitro screening against α-l-fucosidase (bovine kidney origin) generated a potent inhibitor (compound 4e) with IC50 of ∼0.7 μM. Compound 4e possessed no cytotoxic properties when tested against healthy mammalian COS-1 cells. Reaction kinetics study suggested it to be a mixed inhibitor. Finally compounds 4a, b, e and f, bearing the furopyridinedione motif also exhibited substantial inhibition of the proliferation of MCF 7 breast cancer cells. © The Royal Society of Chemistry.

Bioisosteric modification of known fucosidase inhibitors to discover a novel inhibitor of α-l-fucosidase

An efficient solvent free Pd(pCH2S)2dba catalyzed green-chemical strategy for the synthesis of diaryl disulfides from aryl thiols in moderate to excellent yield is reported. Variety of diaryl disulfides were synthesized. The catalyst is recyclable up to four cycles. © 2016 Elsevier Ltd