4-(2-Ethyl­phen­yl)-1-(2-oxoindolin-3-yl­idene)thio­semicarbazide

The title compound, C17H16N4OS, is stabilized in the form of a two-dimensional polymeric network due to inter­molecular N—H⋯S and N—H⋯O hydrogen bonds. An intra­molecular N—H⋯N hydrogen bond forms an S(5) ring, whereas inter­actions of the N—H⋯O and C—H⋯S types complete S(6) ring motifs. π–π inter­actions with a centroid–centroid distance of 3.6514 (10) Å are found between the ethyl-substituted benzene ring and the heterocyclic ring of the isatin derivative

Synthesis of 2-{[5-(aralkyl/aryl)-1,3,4-oxadiazol-2- yl]sulfanyl}-N-(4-methyl-1,3-thiazol-2-yl)acetamides: Novel bi-heterocycles as potential therapeutic agents

Purpose: To evaluate the therapeutic potential of new bi-heterocycles  containing a 1,3-thiazole and 1,3,4-oxadiazole in the skeleton against Alzheimer's disease and diabetes, supported by in-silico study. Methods: The synthesis was initiated by the reaction of 4-methyl- 1,3-thiazol-2-amine (1) with bromoacetyl bromide (2) in aqueous basic medium to obtain an electrophile,2-bromo-N-(4-methyl-1,3- thiazol- 2-yl)acetamide (3). In parallel reactions, a series of carboxylic acids, 4a-r, were converted through a sequence of three steps, into respective 1,3,4-oxadiazole heterocyclic cores, 7a-r, to utilize as nucleophiles. Finally, the designed molecules, 8a-r, were synthesized by coupling 7a-r individually with 3 in an aprotic polar solvent. The structures of these bi-heterocycles were elucidated by infrared (IR), electron ionization-mass spectrometry (EI-MS), proton nuclear magnetic resonance (1H-NMR) and carbon nuclear magnetic resonance (13C-NMR). To evaluate their enzyme inhibitory potential, 8a-r were screened against acetylcholinesterase (AChE), but brine shrimp lethality bioassay.Results: The most active compound against AChE was 8l with half-maximal inhibitory concentration (IC50) of 17.25 ± 0.07 μM. Against BChE, the highest inhibitory effect was shown by 8k (56.23 ± 0.09 μM). Compound 8f (161.26 ± 0.23μM) was recognized as a fairly good inhibitor of urease. In view of its inhibition of α-glucosidase, 8o (57.35 ± 0.17μM) was considered a potential therapeutic agent.Conclusion: The results indicate that some of the synthesized products with low toxicity exhibit notable enzyme inhibitory activity against selected enzymes compared with the reference drug, and therefore, are of potential therapeutic interestKeywords: 4-Methyl-1,3-thiazol-2-amine,1,3,4-Oxadiazole,  Cholinesterases, α-Glucosidase, Urease, Brine shrim

4-(2-Fluoro­phen­yl)-1-(2-oxoindolin-3-yl­idene)thio­semicarbazide

The title compound, C15H11FN4OS, is almost planar, the dihedral angle between the aromatic ring systems being 5.00 (13)°. The conformation is stabilized by intra­molecular N—H⋯N and N—H⋯O hydrogen bonds, which generate S(5) and S(6) rings, respectively. N—H⋯F and C—H⋯S inter­actions also occur. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds occur, generating R 2 2(8) loops

1-(2-Oxoindolin-3-yl­idene)-4-[2-(trifluoro­meth­oxy)phen­yl]thio­semi­carbazide

The crystal structure of the title compound, C16H11F3N4O2S, is stabilized in the form of polymeric chains by N—H⋯O inter­actions. In the mol­ecular structure, two S(5) ring motifs are formed by intra­molecular N—H⋯N and N—H⋯O hydrogen bonding and two S(6) rings are present due to N—H⋯O and C—H⋯S inter­actions. π–π inter­actions are present with distances of 3.2735 (17), 3.563 (2) and 3.664 (4)/3.688 (3) Å between the centroids of the heterocyclic rings, between the centroids of the heterocyclic ring and trifluoro­meth­oxy-substituted phenyl ring, and between the centroids of the trifluoro­meth­oxy-substituted phenyl rings, respectively. The trifluoro­meth­oxy­phenyl group is disordered over two sites with an occupancy ratio of 0.642 (10):0.358 (10)

Analysis of Newtonian heating and higher-order chemical reaction on a Maxwell nanofluid in a rotating frame with gyrotactic microorganisms and variable heat source/sink

The goal of this study is to investigate the rotating Maxwell nanoliquid flow incorporating gyrotactic microbes with Newtonian heating and irregular heat source sink. The motion of the flow is induced due to linearly unidirectional elongated surface. The uniqueness of the flow is enhanced by the inclusion of additional phenomenon of higher order chemical reaction incorporated with Darcy Forchheimer flow, Fourier and Fick law. Numerical solution of the formulated problem is developed via bvp4c function in MATLAB. The influence of the embroiled parameters on the flow distribution is demonstrated through various graphs and tables. It is noticed that fluid velocity declines on incrementing the rotation parameter. An upsurge in thermal field is portrayed on augmenting the Newtonian heating. Comparative analysis of the results of the proposed model with previous published research is included which confirms the validity of the current model

Dynamics of multipartite quantum correlations under decoherence

Quantum discord is an optimal resource for the quantification of classical and non-classical correlations as compared to other related measures. Geometric measure of quantum discord is another measure of quantum correlations. Recently, the geometric quantum discord for multipartite states has been introduced by Jianwei Xu [arxiv:quant/ph.1205.0330]. Motivated from the recent study [Ann. Phys. 327 (2012) 851] for the bipartite systems, I have investigated global quantum discord (QD) and geometric quantum discord (GQD) under the influence of external environments for different multipartite states. Werner-GHZ type three-qubit and six-qubit states are considered in inertial and non-inertial settings. The dynamics of QD and GQD is investigated under amplitude damping, phase damping, depolarizing and flipping channels. It is seen that the quantum discord vanishes for p>0.75 in case of three-qubit GHZ states and for p>0.5 for six qubit GHZ states. This implies that multipartite states are more fragile to decoherence for higher values of N. Surprisingly, a rapid sudden death of discord occurs in case of phase flip channel. However, for bit flip channel, no sudden death happens for the six-qubit states. On the other hand, depolarizing channel heavily influences the QD and GQD as compared to the amplitude damping channel. It means that the depolarizing channel has the most destructive influence on the discords for multipartite states. From the perspective of accelerated observers, it is seen that effect of environment on QD and GQD is much stronger than that of the acceleration of non-inertial frames. The degradation of QD and GQD happens due to Unruh effect. Furthermore, QD exhibits more robustness than GQD when the multipartite systems are exposed to environment.Comment: 15 pages, 4 figures, 4 table

Synthesis of cephradine metal complexes and its anti-bacterial evaluation

Cephradine belongs to the first generation cephalosporin having a broad range of anti-bacterial activities. In the present work, Cephradine wasreacted with different metal salts. These metal salts were Iron, Copper, Cobalt and Nickel salts. All the complexes of Cephradine metals were synthesized at room temperature using a mechanical vibrator. The reactions yielded the coordinated complexes within 5-10 min with improved product yield. The synthesized complexes were analyzed for their antibacterial power using disc diffused assay. All the Cephradine complexes showed powerful antibacterial activity. The Co, Cu, Ni and Sn complexes showed good antibacterial activities 18.5 mm by Cu complexes against S. typhi, 17 mm against B. subtillus 16.5 mm against S. aureus, 16 mm against S. coccus. Similarly Sn complexes exhibited 17 mm zone of inhibition against S. coccus and 15.5 mm against B. subtillus. Cobalt and Ni complexes also shed significant inhibition activities against bacterial pathogenic bacterial strains. The study is of particular importance and new, using mechanical vibrator for the first time. The product yield is also comparatively good with short reaction time