@article { ISI:000264991100040, title = {Mass transfer and solubility of CO and H-2 in ionic liquid. case of [Bmim][PF6] with gas-inducing stirrer reactor}, journal = {Industrial \& Engineering Chemistry Research}, volume = {48}, number = {8}, year = {2009}, month = {APR}, pages = {4075-4082}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Since the past decade, ionic liquids have gained significant importance as alternative solvents for catalysis applications. Many of the reactions evaluated in ionic liquids employ gases as substrates, and therefore it is important to know their solubility and mass transfer characteristics. This work reports for the first time both the solubility and volumetric gas-liquid mass transfer coefficient k(La) for hydrogen and carbon monoxide in 1-n-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF6]) at three temperatures (293, 323, and 373 K) in relevance to hydroformylation reaction. The experimental data on the volumetric gas-liquid mass transfer coefficient are described by a dimensionless correlation for the bench-scale stirred tanks with gas-inducing impeller. k(La) values have also been evaluated for different [Bmim][PF6]-decane emulsions at 373 K.

}, issn = {0888-5885}, doi = {10.1021/ie801584p}, author = {Sharma, Amit and Julcour, Carine and Kelkar, Ashutosh A. and Deshpande, Raj Madhukar and Delmas, Henri} } @article { ISI:000283463600060, title = {Hydroformylation of 1-octene using [Bmim][PF6]-decane biphasic media and rhodium complex catalyst: thermodynamic properties and kinetic study}, journal = {Industrial \& Engineering Chemistry Research}, volume = {49}, number = {21}, year = {2010}, note = {21st International Symposium on Chemical Reaction Engineering (ISCRE 21), Philadelphia, PA, JUN 13-16, 2010}, month = {NOV}, pages = {10698-10706}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

A chemical reaction engineering approach is reported to investigate the biphasic hydroformylation of I-octene using [bmim][PF6] ionic liquid. It is based both on a process parameter investigation (temperature, concentrations, and pressures) and a thermodynamic study of the reaction medium (gas liquid and liquid liquid equilibria). Initial rate data show complex behavior with respect to operating parameters and are best described by a rate equation based on a mechanistic model. Complete reaction scheme including isomerization is then modeled accounting from the time dependent concentration of the organic substrates measured in organic phase and recalculated in ionic liquid phase from liquid liquid equilibria.

}, issn = {0888-5885}, doi = {10.1021/ie100222k}, author = {Sharma, Amit and Lebigue, Carine Julcour and Deshpande, Raj Madhukar and Kelkar, Ashutosh A. and Delmas, Henri} } @article { ISI:000325039100047, title = {Ultrasound promoted efficient and green protocol for the expeditious synthesis of 1, 4 disubstituted 1, 2, 3-triazoles using Cu(II) doped clay as catalyst}, journal = {Applied Clay Science}, volume = {80-81}, year = {2013}, month = {AUG}, pages = {351-357}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Cu(II) doped clay catalyst has been prepared by an easy technique from inexpensive starting materials and investigated for the one pot synthesis of 1, 4-disubstituted 1, 2, 3-triazoles via Huisgen [3 + 2] cycloaddition under ultrasonic irradiation at room temperature. The catalyst is highly active, selective, and stable and can be reused several times. The prepared catalyst has been characterized by XRD, BET-SA, H-2-TPR, SEM and XPS techniques. This transformation is fast, efficient and does not require nitrogen atmosphere or anoxic conditions and additive. (C) 2013 Elsevier B.V. All rights reserved.

}, keywords = {Catalyst support, Copper catalyst, Crystallization, selectivity, Sustainability}, issn = {0169-1317}, doi = {10.1016/j.clay.2013.06.030}, author = {Dar, Bashir Ahmad and Bhowmik, Amrita and Sharma, Amit and Sharma, Parduman R. and Lazar, Anish and Singh, A. P. and Sharma, Meena and Singh, Baldev} } @article {44618, title = {Specific stereoisomeric conformations determine the drug potency of cladosporin scaffold against malarial parasite}, journal = {Journal of Medicinal Chemistry}, volume = {61}, year = {2018}, month = {JUL}, pages = {5664-5678}, abstract = {

The dependence of drug potency on diastereomeric configurations is a key facet. Using a novel general divergent synthetic route for a three-chiral center antimalarial natural product cladosporin, we built its complete library of stereoisomers (cladologs) and assessed their inhibitory potential using parasite-, enzyme-, and structure-based assays. We show that potency is manifest via tetrahyropyran ring conformations that are housed in the ribose binding pocket of parasite lysyl tRNA synthetase (KRS). Strikingly, drug potency between top and worst enantiomers varied 500-fold, and structures of KRS-cladolog complexes reveal that alterations at C3 and C10 are detrimental to drug potency whereas changes at C3 are sensed by rotameric flipping of glutamate 332. Given that scores of antimalarial and anti-infective drugs contain chiral centers, this work provides a new foundation for focusing on inhibitor stereochemistry as a facet of antimicrobial drug development.

}, issn = {0022-2623}, doi = {10.1021/acs.jmedchem.8b00565}, author = {Das, Pronay and Babbar, Palak and Malhotra, Nipun and Sharma, Manmohan and Jachak, Goraknath R. and Gonnade, Rajesh G. and Shanmugam, Dhanasekaran and Harlos, Karl and Yogavel, Manickam and Sharma, Amit and Reddy, D. Srinivasa} } @article {47457, title = {Design, synthesis, and structural analysis of cladosporin-based inhibitors of malaria parasites}, journal = {ACS Infectious Diseases}, volume = {7}, year = {2021}, month = {JUL}, pages = {1777{\textendash}1794}, type = {Article}, abstract = {

Here we have described a systematic structure activity relationship (SAR) of a set of compounds inspired from cladosporin, a tool compound that targets parasite (Plasmodium falciparum) lysyl tRNA synthetase (KRS). Four sets of analogues, synthesized based on point changes in the chemical scaffold of cladosporin and other logical modifications and hybridizations, were assessed using high throughput enzymatic and parasitic assays along with\ in vitro\ pharmacokinetics. Co-crystallization of the most potent compound in our series (CL-2) with\ PfKRS revealed its structural basis of enzymatic binding and potency. Further, we report that\ CL-2\ has performed better than cladosporin in terms of metabolic stability. It thus represents a new lead for further optimization toward the development of antimalarial drugs. Collectively, along with a lead compound, the series offers insights on how even the slightest chemical modification might play an important role in enhancing or decreasing the potency of a chemical scaffold.

}, doi = {10.1021/acsinfecdis.1c00092}, author = {Babbar, Palak and Das, Pronay and Manickam, Yogavel and Mankad, Yash and Yadav, Swati and Parvez, Suhel and Sharma, Amit and Reddy, Srinivasa} } @article {48375, title = {Profiling of metabolic alterations in mice infected with malaria parasites via high-resolution metabolomics}, journal = {Molecular and Biochemical Parasitology}, volume = {252}, year = {2022}, month = {NOV}, pages = {111525}, type = {Article}, abstract = {

Background: Malaria infection can result in distinct clinical outcomes from asymptomatic to severe. The association between patho-physiological changes and molecular changes in the host, and their correlation with severity of malaria progression is not fully understood. Methods: In this study, we addressed mass spectrometry-based temporal profiling of serum metabolite levels from mice infected with Plasmodium berhgei (strain ANKA). Results: We show global perturbations and identify changes in specific metabolites in correlation with disease progression. While metabolome-wide changes were apparent in late-stage malaria, a subset of metabolites exhibited highly correlated changes with disease progression. These metabolites changed early on following infection and either continued or maintained the change as mice developed severe disease. Some of these have the potential to be sentinel metabolites for severe malaria. Moreover, glycolytic metabolites, purine nucleotide precursors, tryptophan and its bioactive derivatives were many fold decreased in late-stage disease. Interestingly, uric acid, a metabolic waste reported to be elevated in severe human malaria, increased with disease progression, and subsequently appears to be detoxified into allantoin. This detoxification mechanism is absent in humans as they lack the enzyme uricase. Conclusions: We have identified candidate marker metabolites that may be of relevance in the context of human malaria.

}, keywords = {Host response, Infectious diseases, malaria, metabolite, Plasmodium}, issn = {0166-6851}, doi = {10.1016/j.molbiopara.2022.111525}, author = {Chhibber-Goel, Jyoti and Shukla, Anurag and Shanmugam, Dhanasekaran and Sharma, Amit} }