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131.
Dr. Abshar Hasan Dr. Kyueui Lee Dr. Kunal Tewari Prof. Lalit M. Pandey Prof. Phillip B. Messersmith Prof. Karen Faulds Dr. Michelle Maclean Dr. King Hang Aaron Lau 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(26):5789-5793
Microbial surface attachment negatively impacts a wide range of devices from water purification membranes to biomedical implants. Mimics of antimicrobial peptides (AMPs) constituted from poly(N-substituted glycine) „peptoids“ are of great interest as they resist proteolysis and can inhibit a wide spectrum of microbes. We investigate how terminal modification of a peptoid AMP-mimic and its surface immobilization affect antimicrobial activity. We also demonstrate a convenient surface modification strategy for enabling alkyne–azide „click“ coupling on amino-functionalized surfaces. Our results verified that the N- and C-terminal peptoid structures are not required for antimicrobial activity. Moreover, our peptoid immobilization density and choice of PEG tether resulted in a „volumetric“ spatial separation between AMPs that, compared to past studies, enabled the highest AMP surface activity relative to bacterial attachment. Our analysis suggests the importance of spatial flexibility for membrane activity and that AMP separation may be a controlling parameter for optimizing surface anti-biofouling. 相似文献
132.
Alam Noor Sharma K. K. Pandey K. M. 《Journal of Thermal Analysis and Calorimetry》2020,140(5):2485-2495
Journal of Thermal Analysis and Calorimetry - The objective of present research work is to investigate the combustion flame acceleration and performance of pulse detonation engine (PDE). The PDE... 相似文献
133.
Narayan D. Chaurasiya Jacob Midiwo Pankaj Pandey Regina N. Bwire Robert J. Doerksen Ilias Muhammad Babu L. Tekwani 《Molecules (Basel, Switzerland)》2020,25(22)
A set of structurally related O-methylated flavonoid natural products isolated from Senecio roseiflorus (1), Polygonum senegalense (2 and 3), Bhaphia macrocalyx (4), Gardenia ternifolia (5), and Psiadia punctulata (6) plant species were characterized for their interaction with human monoamine oxidases (MAO-A and -B) in vitro. Compounds 1, 2, and 5 showed selective inhibition of MAO-A, while 4 and 6 showed selective inhibition of MAO-B. Compound 3 showed ~2-fold selectivity towards inhibition of MAO-A. Binding of compounds 1–3 and 5 with MAO-A, and compounds 3 and 6 with MAO-B was reversible and not time-independent. The analysis of enzyme-inhibition kinetics suggested a reversible-competitive mechanism for inhibition of MAO-A by 1 and 3, while a partially-reversible mixed-type inhibition by 5. Similarly, enzyme inhibition-kinetics analysis with compounds 3, 4, and 6, suggested a competitive reversible inhibition of MAO-B. The molecular docking study suggested that 1 selectively interacts with the active-site of human MAO-A near N5 of FAD. The calculated binding free energies of the O-methylated flavonoids (1 and 4–6) and chalcones (2 and 3) to MAO-A matched closely with the trend in the experimental IC50′s. Analysis of the binding free-energies suggested better interaction of 4 and 6 with MAO-B than with MAO-A. The natural O-methylated flavonoid (1) with highly potent inhibition (IC50 33 nM; Ki 37.9 nM) and >292 fold selectivity against human MAO-A (vs. MAO-B) provides a new drug lead for the treatment of neurological disorders. 相似文献
134.
Bedadyuti Vedvyas Pati Asit Ghosh Komal Yadav Shyam Kumar Banjare Shalini Pandey Upakarasamy Lourderaj Ponneri C. Ravikumar 《Chemical science》2022,13(9):2692
The stereoselective synthesis of 1,3-enynes from 1,3-diynes is demonstrated by palladium-catalyzed selective C–C bond cleavage of cyclopropanol. Exclusive formation of mono-alkenylated adducts was achieved by eliminating the possibility of di-functionalization with high stereoselectivity. Indeed, this protocol worked very well with electronically and sterically diverse substrates. Several studies, including deuterium labeling experiments and intermolecular competitive experiments, were carried out to understand the mechanistic details. The atomic-level mechanism followed in the catalytic process was also validated using DFT calculations, and the rate-controlling states in the catalytic cycle were identified. Furthermore, preliminary mechanistic investigations with radical scavengers revealed the non-involvement of the radical pathway in this transformation.Palladium-catalyzed tandem activation and functionalization of readily accessible cyclopropanols have been demonstrated to access valuable conjugated enynes from 1,3-diynes with high stereo-selectivity. 相似文献
135.
Zeenat Zara Deepti Mishra Saurabh Kumar Pandey Eva Csefalvay Fatemeh Fadaei Babak Minofar David eha 《Molecules (Basel, Switzerland)》2022,27(1)
The effect of aqueous solutions of selected ionic liquids solutions on Ideonella sakaiensis PETase with bis(2-hydroxyethyl) terephthalate (BHET) substrate were studied by means of molecular dynamics simulations in order to identify the possible effect of ionic liquids on the structure and dynamics of enzymatic Polyethylene terephthalate (PET) hydrolysis. The use of specific ionic liquids can potentially enhance the enzymatic hydrolyses of PET where these ionic liquids are known to partially dissolve PET. The aqueous solution of cholinium phosphate were found to have the smallest effect of the structure of PETase, and its interaction with (BHET) as substrate was comparable to that with the pure water. Thus, the cholinium phosphate was identified as possible candidate as ionic liquid co-solvent to study the enzymatic hydrolyses of PET. 相似文献
136.
137.
Divakar Vishwanath Swamy S. Girimanchanaika Dukanya Dukanya Shobith Rangappa Ji-Rui Yang Vijay Pandey Peter E. Lobie Basappa Basappa 《Molecules (Basel, Switzerland)》2022,27(3)
Novel PARP inhibitors with selective mode-of-action have been approved for clinical use. Herein, oxadiazole based ligands that are predicted to target PARP-1 have been synthesized and screened for the loss of cell viability in mammary carcinoma cells, wherein seven compounds were observed to possess significant IC50 values in the range of 1.4 to 25 µM. Furthermore, compound 5u, inhibited the viability of MCF-7 cells with an IC50 value of 1.4µM, when compared to Olaparib (IC50 = 3.2 µM). Compound 5s also decreased cell viability in MCF-7 and MDA-MB-231 cells with IC50 values of 15.3 and 19.2 µM, respectively. Treatment of MCF-7 cells with compounds 5u and 5s produced PARP cleavage, H2AX phosphorylation and CASPASE-3 activation comparable to that observed with Olaparib. Compounds 5u and 5s also decreased foci-formation and 3D Matrigel growth of MCF-7 cells equivalent to or greater than that observed with Olaparib. Finally, in silico analysis demonstrated binding of compound 5s towardsthe catalytic site of PARP-1, indicating that these novel oxadiazoles synthesized herein may serve as exemplars for the development of new therapeutics in cancer. 相似文献
138.
139.
U. Pandey A. Mukherjee G. Samuel S. Banerjee H. D. Sarma M. Venkatesh 《Journal of Radioanalytical and Nuclear Chemistry》2008,275(2):243-246
Lanreotide, a somatostatin analogue, was radioiodinated with 125I to explore the possibility of using 123I labeled lanreotide as a diagnostic radiopharmaceutical for tumors overexpressing somatostatin (SST) receptors. Radioiodination
was carried out with 125I using chloramine T as the oxidant. The labeling yield was >90%. Characterization of 125I-Lanreotide was carried out by paper electrophoresis as well as HPLC. 125I-Lanreotide was purified by chromatography using a C18 Sep-Pak column. Radiochemical purity of the purified 125I-Lanreotide thus obtained was >99%. Significant tumor uptake of 125I-Lanreotide was observed in C57BL/6 mice bearing melanoma. 相似文献
140.
R. Raman Ashok Kumar Kapoor Shiv Kumar Akhilesh Pandey 《Journal of Electronic Materials》2009,38(10):2046-2051
Colloidal silver is observed to affect the transmittance of p-type Cd1−y
Zn
y
Te (CZT) single-crystal substrate material at room temperature. The optical transmittance spectra have been analyzed in the
near-infrared (NIR) and mid-infrared (MIR) regions. The transmittance characteristics of CZT showed significant reduction
in absorption due to split-off valance band transitions in the NIR region and intervalence band absorption in the MIR region
upon coating CZT substrates with silver paste. This reduction in absorption has been explained to be due to the compensation
of the acceptor defects (native and foreign). Silver atoms incorporated from the silver coating help in compensation of these
defects. A similar effect on transmittance characteristics of mercury cadmium telluride (MCT) epilayers grown on CZT substrates
after coating silver paste on the CZT substrate side was also observed. An improvement in the transmittance of CZT substrates
after the application of silver paste was observed. A similar improvement in transmittance is usually achieved by annealing
the substrates in a Cd/Zn atmosphere. The results are explained by considering the formation of neutral complexes of acceptors
(cadmium vacancies) and the interstitial silver. This study also points to the important conclusion that silver paste on CZT
should be applied with caution for measurement purposes since it diffuses even at room temperature and modifies the optical
characteristics. 相似文献