Mantosh K. Sinha
University of Pittsburgh
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Publication
Featured researches published by Mantosh K. Sinha.
Angewandte Chemie | 2012
Kareem Khoury; Mantosh K. Sinha; Tadamichi Nagashima; Eberhardt Herdtweck; Alexander Dömling
A truly 4-component reaction! In analogy to a galaxy consisting of millions of stars a multicomponent reaction scaffold can result in millions of compound variations. The MCR of α-amino acids, oxocomponents, isocyanides and primary or secondary amines is such a high-number high-diversity reaction providing an enormous potential for drug discovery or catalyst screening.
Organic and Biomolecular Chemistry | 2013
Mantosh K. Sinha; Kareem Khoury; Eberhardt Herdtweck; Alexander Dömling
Efficient access to a large chemical space based on new scaffolds with defined 3D conformations and highly variable in the side chains is needed to find novel functional materials. Four heterocyclic scaffolds based on a four component Ugi reaction of α-amino acids, oxo components, isocyanides and primary or secondary amines suitably functionalized are described. A handful of examples are described for each scaffold.
Chemistry: A European Journal | 2012
Mantosh K. Sinha; Ofer Reany; Maayan Yefet; Mark Botoshansky; Ehud Keinan
Bistable rotaxanes are important design elements of molecular devices for a broad range of applications, such as controlled drug release, molecular rotary motors, and chemical sensors. The host-guest complexes of cucurbit[6]uril and 1,4-bis(alkylaminomethyl)benzene were found to exhibit two stable binding modes with an unexpectedly high barrier between them. Their structural and dynamic properties, kinetic and thermodynamic parameters, as well as different chemical reactivity towards the azide-alkyne [3+2] cycloaddition reaction (click chemistry), were discovered by NMR spectroscopy, X-ray crystallography, and isothermal titration microcalorimetry. The highly stable 2:1 complex, which is formed at room temperature, was found to be a kinetic product, which may be converted to the thermodynamic 1:1 complex upon prolonged heating to 100 °C. The latter is a very stable rotaxane despite the fact that it lacks bulky end groups.
Chemistry: A European Journal | 2010
Mantosh K. Sinha; Ofer Reany; Galit Parvari; Ananta Karmakar; Ehud Keinan
4-Aminobipyridine derivatives form strong inclusion complexes with cucurbit[6]uril, exhibiting remarkably large enhancements in fluorescence intensity and quantum yields. The remarkable complexation-induced pK(a) shift (DeltapK(a)=3.3) highlights the strong charge-dipole interaction upon binding. The reversible binding phenomenon can be used for the design of switchable beacons that can be incorporated into cascades of binding networks. This concept is demonstrated herein by three different applications: 1) a switchable fluorescent beacon for chemical sensing of transition metals and other ligands; 2) direct measurement of binding constants between cucurbit[6]uril and various nonfluorescent guest molecules; and 3) quantitative monitoring of biocatalytic reactions and determination of their kinetic parameters. The latter application is illustrated by the hydrolysis of an amide catalyzed by penicillin G acylase and by the elimination reaction of a beta-cabamoyloxy ketone catalyzed by aldolase antibody 38C2.
Journal of Organic Chemistry | 2008
Irina Ben Shir; Sanjita Sasmal; Tom Mejuch; Mantosh K. Sinha; Moshe Kapon; Ehud Keinan
Low-barrier molecular rotary motors having rotaxane architecture can be constructed using a cucurbituril host and a polyyne guest serving as stator and rotator, respectively. The repulsive interaction between these components is supported by molecular mechanics calculations with model systems and experimentally verified by X-ray crystallography with several synthetic host-guest complexes, all suggesting that the diyne rod floats at the center of the macrocyclic host with no apparent van der Waals contacts between them. Further support for these interactions is suggested by microcalorimetry measurements.
Chemistry: A European Journal | 2013
Mantosh K. Sinha; Kareem Khoury; Eberhardt Herdtweck; Alexander Dömling
Subsequent mild cyclization of aromatic substrates by Pictet-Spengler condensation stereoselectively gave new tricyclic compounds. Examples are described in decent yields over two steps in one pot, and a crystal structure is also presented to support the proposed structures.
Regenerative Biomaterials | 2015
Mantosh K. Sinha; Jin Gao; Chelsea E.T. Stowell; Yadong Wang
Injectable thermal gels are a useful tool for drug delivery and tissue engineering. However, most thermal gels do not solidify rapidly at body temperature (37°C). We addressed this by synthesizing a thermo-sensitive, rapidly biodegrading hydrogel. Our hydrogel, poly(ethylene glycol)-co-poly(propanol serinate hexamethylene urethane) (EPSHU), is an ABA block copolymer comprising A, methoxy poly ethylene glycol group and B, poly (propanol L-serinate hexamethylene urethane). EPSHU was characterized by gel permeation chromatography for molecular weight and 1H NMR and Fourier transformed infrared for structure. Rheological studies measured the phase transition temperature. In vitro degradation in cholesterol esterase and in Dulbeccos phosphate buffered saline (DPBS) was tracked using the average molecular weight measured by gel permeation chromatography. LIVE/DEAD and resazurin reduction assays performed on NIH 3T3 fibroblasts exposed to EPSHU extracts demonstrated no cytotoxicity. Subcutaneous implantation into BALB/cJ mice indicated good biocompatibility in vivo. The biodegradability and biocompatibility of EPSHU together make it a promising candidate for drug delivery applications that demand carrier gel degradation within months.
Organic Letters | 2004
Sanjita Sasmal; Mantosh K. Sinha; Ehud Keinan
Chemistry: A European Journal | 2004
Hongna Han; Mantosh K. Sinha; Lawrence J. D'Souza; Ehud Keinan; Subhash C. Sinha
Advanced Functional Materials | 2017
Abhinav P. Acharya; Mantosh K. Sinha; Michelle L. Ratay; Xiaochu Ding; Stephen C. Balmert; Creg J. Workman; Yadong Wang; Dario A. A. Vignali; Steven R. Little