Chemistry

<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

Natural products from medicinal plants have always attracted a lot of attention due to their diverse and interesting therapeutic properties. We have employed the principles of green chemistry involving isomerization, coupling and condensation reaction to synthesize a class of compounds derived from eugenol, a naturally occurring bioactive phytophenol. The compounds were characterized structurally by 1 H-, 13 C-NMR, FT-IR spectroscopy and mass spectrometry analysis. The purity of compounds was detected by HPLC. The synthesized compounds exhibited anti-cancer activity. A 10–12-fold enhancement in efficiency of drug molecules (~ 1 µM) was observed when delivered with graphene oxide (GO) as a nanovehicle. Our data suggest cell death via apoptosis in a dose-dependent manner due to increase in calcium levels in specific cancer cell lines. Interestingly, the benzoxazine derivatives of eugenol with GO nanoparticle exhibited enhanced therapeutic potential in cancer cells. In addition to anti-cancer effect, we also observed significant role of these derivatives on parasite suggesting its multi-pharmacological capability. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.

Life Sciences

(SoNS) School of Natural Sciences

Molecular and Cellular Biochemistry

Integrative natural medicine inspired graphene nanovehicle-benzoxazine derivatives as potent therapy for cancer

Organelle-targeted photosensitizers (PSs) having luminescence properties are potential theranostic agents for simultaneous luminescence imaging and photodynamic therapy. Herein, we report a water-soluble luminescent cyclometalated IrIII complex, Ir-Bp-Ly, as a lysosome-targeted theranostic probe. Ir-Bp-Ly exhibits exceptional photophysical properties, with good triplet-state quantum yield (0.90), singlet oxygen generation quantum yield (0.71 at pH 4), and long lifetime (1.47 μs). Interestingly, Ir-Bp-Ly localizes mostly in lysosomes due to the presence of morpholine units, suggesting its potential use as a lyso-tracker. Ir-Bp-Ly displays a notable PDT effect in C6 glioma cells, efficiently generating reactive oxygen species owing to close proximity between the energy levels of its triplet state and those of molecular oxygen (3O2). The mechanism of cell death has been studied through caspase-3/7 and flow cytometry analyses, which clearly established the apoptotic pathway. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

World University root node

Chemistry - A European Journal

A Cyclometalated IrIII Complex as a Lysosome-Targeted Photodynamic Therapeutic Agent for Integrated Imaging and Therapy in Cancer Cells

Immunotargeting ability of antibodies may show significant difference between in vitro and in vivo. To select antibody leads with high affinity and specificity, it is necessary to perform in vivo validation of antibody candidates following in vitro antibody screening. Herein, a robust in vivo validation of anti-tetraspanin-8 antibody candidates against human colon cancer using ratiometric quantification method is reported. The validation is performed on a single mouse and analyzed by multiplexed surface-enhanced Raman scattering using ultrasensitive and near infrared (NIR)-active surface-enhanced resonance Raman scattering nanoprobes (NIR-SERRS dots). The NIR-SERRS dots are composed of NIR-active labels and Au/Ag hollow-shell assembled silica nanospheres. A 93% of NIR-SERRS dots is detectable at a single-particle level and signal intensity is 100-fold stronger than that from nonresonant molecule-labeled spherical Au NPs (80 nm). The result of SERRS-based antibody validation is comparable to that of the conventional method using single-photon-emission computed tomography. The NIR-SERRS-based strategy is an alternate validation method which provides cost-effective and accurate multiplexing measurements for antibody-based drug development. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Advanced Healthcare Materials

Ultrasensitive NIR-SERRS Probes with Multiplexed Ratiometric Quantification for In Vivo Antibody Leads Validation

A catalyst consisting of titanium oxide encapsulated cuprous iodide nanoparticles was prepared via a sol-gel method using inexpensive raw materials and was harnessed successfully in the oxidative amidation of alkynes via an environmentally benign and sustainable protocol. The mechanism of action of this transformation was thoroughly discussed. The robustness of the catalyst was elucidated by the synthesis of diverse analogues of α-ketoarylamide from a variety of electron rich and poor substrates via a simple procedure in moderate to high yields, with no generation of toxic by-products, in good recyclability up to five cycles, under solvent free and aerobic conditions. The chemical nature, morphology and loading of the CuI@TiO2 nanocatalyst were investigated by TEM, SEM, XPS, EDX, powder XRD, BET, TGA and ICP-MS. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.

Fulltext

New Journal of Chemistry

Aerobic oxidative amidation of alkynes using titanium oxide encapsulated cuprous iodide nanoparticles (CuI@TiO2)

Ligand- and solvent-free catalytic conditions that harness a nanostructured–CuI catalyst encapsulated in TiO2 has been reported for C2-amination of azoles (benzothiazole, benzoxazole and thiazole). The reaction is highly regioselective. The catalyst is robust, inexpensive and can be recycled up to four times. This strategy was further used for the synthesis of a small molecule with anti-HIV and anti-tumor properties. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

European Journal of Organic Chemistry

Solid Supported Nano Structured Cu-Catalyst for Solvent/Ligand Free C2 Amination of Azoles

Presence of cyclobutane rings in bioactive natural products makes them a popular synthetic target. Most common strategy for synthesizing cyclobutanes is [2+2] cycloaddition, which is usually facilitated by using ultraviolet radiation and catalysts. Herein we report the design and synthesis of densely functionalized cyclobutanes by alleviating these drawbacks and using sunlight. Further, we identified the putative mechanism of the transformation based on kinetic, fluorescence and crystallographic studies and evaluated biological activities of the products against MCF7 cell lines. The rational design of the olefinic substrates was based on their UV–vis spectra. The generic aspect of the reaction was elucidated by the syntheses of diverse analogs of cyclobutanes. Further, crystal structures and UV–vis spectra of the olefinic partners assisted us in rationalizing the stereoselectivity of the heterodimers. We believe this energy-efficient mild approach will provide a substantial contribution to the existing repertoire of strategies to regio- and stereoselectively access cyclobutanes. © 2018 Elsevier Ltd

Tetrahedron

Harnessing sun for catalyst and sensitizer free regio- and stereo-selective [2+2] cycloaddition

The authors regret Mr. Rahul Agarwal has been missed from the author list. Mr. Rahul Agarwal should have been cited as the third author of this article and his affiliation is: Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Dadri, Chithera, Gautam Budh Nagar, Uttar Pradesh 201314, India. The corrected order of authors and affiliations are shown above. The authors would like to apologise for any inconvenience caused. © 2018 Elsevier Ltd

Bioorganic and Medicinal Chemistry

Corrigendum to ‘Design, synthesis and in vitro study of densely functionalized oxindoles as potent α-glucosidase inhibitors’ (Bioorganic &amp; Medicinal Chemistry (2018) 26(18) (4996–5005), (S0968089618308472) (10.1016/j.bmc.2018.08.022))

<p>A facile cobalt(III) catalyzed C–H activation of arenes with substituted (benz)imidazoles as directing groups (DG) is reported. The strategy was utilized for the synthesis of polyheteroarenes when appropriate substrates were treated with diarylacetylenes as the coupling partner. The desired compounds were synthesized in moderate to excellent yield. A putative reaction mechanism is proposed. The final compounds revealed photoluminescence properties. © 2018 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim</p>

(Benz)Imidazole-Directed Cobalt(III)-Catalyzed C–H Activation of Arenes: A Facile Strategy to Access Polyheteroarenes by Oxidative Annulation

Elastic fibers are present in a variety of tissues and are responsible for their resilience. Until now, no optical contrast agent in the near-infrared (NIR) wavelength range of 700–900 nm has been reported for the imaging of elastic fibers. Here, we report the discovery of a NIR zwitterionic elastin probe ElaNIR (elastin NIR) through fluorescent-image-based screening. The probe was successfully applied for in vitro, ex vivo, and in vivo imaging by various imaging modalities. Age-related elastin differences shown by in vivo fluorescent and photoacoustic imaging indicated that ElaNIR can be a potentially convenient tool for uncovering changes of elastin in live models. Technological advancement of microscopic imaging has spurred the development of molecular probes for the detection of biologically and environmentally important analytes. Among fluorescent imaging tools, near-infrared (NIR) fluorescent molecules have been popular for in vivo imaging because of their ability to penetrate tissue deeper with reduced scattering and autofluorescence. Here, we report the discovery of the NIR zwitterionic elastin probe ElaNIR. We found that ElaNIR showed selective binding for elastin, such as those in the aorta, lungs, and skin. ElaNIR also allowed visualization and quantification of elastin levels in young and old mice, which reflect age-dependent changes of elastin in vivo. This makes ElaNIR a unique chemical tool for monitoring changes of elastin in tissue or animal models and provides new opportunities to study the effects of chemical compounds on elastin levels in biological processes. The near-infrared zwitterionic elastin probe ElaNIR for in vivo imaging of elastin structures was found through fluorescent-image-based screening. ElaNIR is well suited for in vitro, ex vivo, and in vivo imaging of elastin and also allows visualization and quantification of elastin levels in young and old mice, which reflect age-dependent changes of elastin in vivo. © 2018 Elsevier Inc.