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JPC – Journal of Planar Chromatography – Modern TLC - A high-performance thin-layer chromatographic (HPTLC) method has been established for simultaneous analysis of eugenol and piperine... 相似文献
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Dr. Kartik Maity Karabi Nath Dr. Michael A. Sinnwell Dr. Radha Kishan Motkuri Dr. Praveen K. Thallapally Prof. Kumar Biradha 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(64):14500-14505
The deliberate construction of isoreticular eea-metal–organic frameworks (MOFs) ( Cu-eea-1 , Cu-eea-2 and Cu-eea-3 ) and rtl-MOFs ( Co-rtl-1 and Co-rtl-2 ) has been accomplished based on the ligand-to-axial pillaring of supermolecular building layers. The use of different metal ions resulted in two types of supermolecular building layers (SBLs): Kagome (kgm) and square lattices (sql) which further interconnect to form anticipated 3D-MOFs. The isoreticular expansion of (3,6)-connected Cu-MOFs has been achieved with desired eea-topology based on kgm building layers. In addition, two (3,6)-connected Co-rtl-MOFs were also successfully constructed based on sql building layers. The Cu-eea-MOFs were shown to act as hydrogen storage materials with appreciable amount of hydrogen uptake abilities. Moreover Cu-eea-MOFs have also exhibited remarkable CO2 capture ability at ambient condition compared to nitrogen and methane, due to the presence of amide functionalities. 相似文献
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A series of novel 3-amino-4,5-dihydro-6-methyl-4-oxo-N-aryl-1H-pyrazolo[4,3-c]pyridine-7-carboxamide have been synthesized starting from various oxoketene dithioacetals. The cyclocondensation reaction of 2-(bis(methylthio)methylene)-3-oxo-N-arylbutanamide 2a–w with cyanoacetamide using NaOiPr as base under reflux condition afforded novel highly functionalized pyridone 3a–w derivatives. Further, [3?+?2] cyclocondensation reaction of pyridones with hydrazine in the presence of alcohol was yielded pyrazolopyridones (23 nos) 4a–w with excellent yields. All newly synthesized compounds were evaluated for in vitro anti-HIV activity using MTT method. Most of these compounds have showed moderate to potent activity against HIV-1 (IIIB) and HIV-2 (ROD) strains with an IC50 ranging from >18 IC50[µg/ml] to <100 IC50[µg/ml]. Among them, compounds 4j and 4v were identified as the most promising compound for both types of HIV strains. (IC50?=?18?µg/ml). Three compounds 4l, 4m, and 4p have been found potent anti-HIV 1 and 2 activity against MT-4 cells. 相似文献
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Aditya Kulkarni Selvakumar Arumugam Maria Francis Pulikanti Guruprasad Reddy Ekta Nag Sai Manoj N. V. T. Gorantla Dr. Kartik Chandra Mondal Dr. Sudipta Roy 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(1):200-206
Cyclic alkyl(amino) carbene (cAAC)-supported, structurally diverse alkali metal-phosphinidenides 2 – 5 of general formula ((cAAC)P-M)n(THF)x [ 2 : M=K, n=2, x=4; 3 : M=K, n=6, x=2; 4 : M=K, n=4, x=4; 5 : M=Na, n=3, x=1] have been synthesized by the reduction of cAAC-stabilized chloro-phosphinidene cAAC=P-Cl ( 1 ) utilizing metallic K or KC8 and Na-naphthalenide as reducing agents. Complexes 2 – 5 have been structurally characterized in solid state by NMR studies and single crystal X-ray diffraction. The proposed mechanism for the electron transfer process has been well-supported by cyclic voltammetry (CV) studies and Density Functional Theory (DFT) calculations. The solid state oligomerization process has been observed to be largely dependent on the ionic radii of alkali metal ions, steric bulk of cAAC ligands and solvation/de-solvation/recombination of the dimeric unit [(cAAC)P-M(THF)x]2. 相似文献
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Kartik Sau 《Ionics》2016,22(12):2379-2385
Molecular dynamics (MD) study of Na+ transport in Na2Ni2TeO6 is performed systematically with varying strength of Na+–Na+ short range repulsions to understand the physical principle governing ion transport mechanism. Na+ diffusion is enhanced by nearly an order of magnitude with reduced Na+–Na+ short range repulsion within the studied range. A similar behavior is also observed in other systems, e.g., AgI and Na2Zn2TeO6, where mobile ions are located closely. The Na+ ion occupancy in Na2Ni2TeO6 shows a significant shift from Na1 to Na2 sites gaining some degree of correlation. The study also emphasizes how mobile ion size influences the ionic diffusion. The fresh insight such as microscopic migration pathways, energy barriers, and jumping mechanism of Na+ are derived from the study. 相似文献
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Recognition of Artificial Nucleobases by E. coli Purine Nucleoside Phosphorylase versus its Ser90Ala Mutant in the Synthesis of Base‐Modified Nucleosides
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Dr. Ilja V. Fateev Maria I. Kharitonova Konstantin V. Antonov Dr. Irina D. Konstantinova Dr. Vasily N. Stepanenko Dr. Roman S. Esipov Prof. Frank Seela Dr. Kartik W. Temburnikar Prof. Katherine L. Seley‐Radtke Vladimir A. Stepchenko Dr. Yuri A. Sokolov Prof. Anatoly I. Miroshnikov Prof. Igor A. Mikhailopulo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(38):13401-13419
A wide range of natural purine analogues was used as probe to assess the mechanism of recognition by the wild‐type (WT) E. coli purine nucleoside phosphorylase (PNP) versus its Ser90Ala mutant. The results were analyzed from viewpoint of the role of the Ser90 residue and the structural features of the bases. It was found that the Ser90 residue of the PNP 1) plays an important role in the binding and activation of 8‐aza‐7‐deazapurines in the synthesis of their nucleosides, 2) participates in the binding of α‐D ‐pentofuranose‐1‐phosphates at the catalytic site of the PNP, and 3) catalyzes the dephosphorylation of intermediary formed 2‐deoxy‐α‐D ‐ribofuranose‐1‐phosphate in the trans‐2‐deoxyribosylation reaction. 5‐Aza‐7‐deazaguanine manifested excellent substrate activity for both enzymes, 8‐amino‐7‐thiaguanine and 2‐aminobenzothiazole showed no substrate activity for both enzymes. On the contrary, the 2‐amino derivatives of benzimidazole and benzoxazole are substrates and are converted into the N1‐ and unusual N2‐glycosides, respectively. 9‐Deaza‐5‐iodoxanthine showed moderate inhibitory activity of the WT E. coli PNP, whereas 9‐deazaxanthine and its 2′‐deoxyriboside are weak inhibitors. 相似文献
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Sai Manoj N. V. T. Gorantla Dr. Sudip Pan Prof. Dr. Kartik Chandra Mondal Prof. Dr. Gernot Frenking 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(62):14211-14220
Quantum chemical studies using density functional theory and ab initio methods have been carried out for the molecules L-C3-L with L=PPh3 ( 1 ), NHCMe ( 2 , NHC=N-heterocyclic carbene), and cAACMe ( 3 , cAAC=cyclic (alkyl)(amino) carbene). The calculations predict that 1 and 2 have equilibrium geometries where the ligands are bonded with rather acute bonding angles at the linear C3 moiety. The phosphine adduct 1 has a synclinal (gauche) conformation whereas 2 exhibits a trans conformation of the ligands. In contrast, the compound 3 possesses a nearly linear arrangement of the carbene ligands at the C3 fragment. The bond dissociation energies of the ligands have the order 1 < 2 < 3 . The bonding analysis using charge and energy decomposition methods suggests that 3 is best described as a cumulene with electron-sharing double bonds between neutral fragments (cAACMe)2 and C3 in the respective electronic quintet state yielding (cAACMe)=C3=(cAACMe). In contrast, 1 and 2 possess electron-sharing and dative bonds between positively charged ligands [(PPh3)2]+ or [(NHCMe)2]+ and negatively charged [C3]− fragments in the respective doublet state. 相似文献
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We have investigated the magnetic behavior of ball-milled fine particles of well-known Kondo lattices, CeAu2Si2, CePd2Si2 and CeAl2, by magnetization and heat-capacity studies in order to understand the magnetic behavior when the particle size is reduced. These compounds have been known to order antiferromagnetically in the bulk form near () 10, 10 and 3.8 K respectively. We find that the features due to magnetic ordering get suppressed to temperatures below 1.8 K in the case of fine particles of ternary alloys, though trivalence of Ce as inferred from the effective moment remains unchanged. In contrast to this, in CeAl2, there appears to be a marginal enhancement of , when the particle size is reduced to less than a micron. These results can be consistently understood by proposing that these compounds move toward left in the Doniach magnetic phase-diagram, for instance, due to relatively more 4f-localization, as the particle size is reduced. 相似文献