Synthesis of enamines and their bromination

Enamines represent an important class of reactive intermediates in organic synthesis. They are frequently used as a potential building block to access several types of heterocyclic ring systems and biologically active analogues. Realizing the wide spectrum of usage of enamines, there is a quest for the development of simple and high yielding process. The aim of the present work is to synthesize various enamines from the azeotropic removal of water by refluxing an amine with 1, 3-diketone in ethanol. Bromination of these enamines is also carried out in presence of NBS/MeOH in solid support K-10 at α –positio

Synthesis, Spectroscopic and Crystal Structure Analysis of 2-(4-Fluorobenzyl)-6-(4-Methoxyphenyl)Imidazo[2,1-B][1,3,4]Thiadiazole and its Morpholinomethyl Derivative

The preparation of 2-(4-fluorobenzyl)-6-(4-methoxyphenyl)-5-morpholin-1-ylmethyl imidazo[2,1-b][1,3,4]thiadiazole via the intermediate 2-(4-fluorobenzyl)-6-(4-methoxyphenyl)Imidazo[2,1-b][1,3,4] thiadiazole is described. Elemental analysis, IR spectrum, 1H NMR and X-ray crystal structure analyses were carried out to determine the compositions and molecular structures of the two compounds. The crystal packing exhibits intermolecular C–H?O, C–H?N, C–H?F and π–π stacking interactions leading to the formation of the supramolecular network

Digital Audio Watermarking using EMD for Voice Message Encryption with Added Security

Several accurate watermarking methods for image watermarking have being suggested and implemented to secure various forms of digital data, images and videos however, very few algorithms are proposed for audio watermarking. This is also because human audio system has dynamic range which is wider in comparison with human vision system. In this paper, a new audio watermarking algorithm for voice message encryption based on Empirical Mode Decomposition (EMD) is introduced. The audio signal is divided into frames and each frame is then decomposed adaptively, by EMD, into intrinsic oscillatory components called Intrinsic Mode Functions (IMFs). The watermark, which is the secret message that is to be sent, along with the synchronization codes are embedded into the extrema of the last IMF, a low frequency mode stable under different attacks and preserving the perceptual quality of the host signal. Based on exhaustive simulations, we show the robustness of the hidden watermark for audio compression, false decryption, re-quantization, resampling. The comparison analysis shows that our method has better performance than other steganography schemes recently reported

Synthesis, spectroscopic and crystal structure analysis of 2-amino-5,5-dimethyl-7-oxo-4,5,6,7-tetrahydro-1-benzothiophene-3-carbonitrile and-3-carboxamide

The preparation of 2-amino-5,5-dimethyl-7-oxo-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxamide via the intermediate 2-amino-5,5-dimethyl-7-oxo-4,5,6,7-tetrahydro-1-benzothiophene-3-carbonitrile is described, along with details of the crystal structure analysis of both compounds

Pharmacokinetics and pharmacodynamics of famotidine and ranitidine in critically ill children

To characterize and compare acid suppression (pharmacodynamics) and pharmacokinetics of IV famotidine and ranitidine in critically ill children at risk for stress gastritis. Single‐blind, randomized study in PICU patients 6 months to 18 years requiring mechanical ventilation with continuous gastric pH monitoring, randomized to IV famotidine 12 mg/m 2 or ranitidine 60 mg/m 2 when gastric pH 1 hour with serial blood sampling following first dose. Twenty‐four children randomized to either famotidine (n = 12) or ranitidine (n = 12). Sixteen out of twenty‐four completed both PK and PD study arms (7/12 famotidine; 4.7 ± 3.4 years; 9/12 ranitidine; 6.6 ± 4.7 years; p  = 0.38). Time to gastric pH 4.0 and total time pH above 4.0 similar with no difference in pH at 6 and 12 hours ( p  > 0.2). No difference between drugs in clearance, volume of distribution and half‐life ( p  > 0.05). Ratio of AUC pH to AUC drug concentration 0–12 hours after first dose was significantly greater for famotidine (0.06849 ± 0.01460 SD) than ranitidine (0.02453 ± 0.01448; p  < 0.001) demonstrating greater potency of famotidine. pH lowering efficacy of both drugs is similar. Greater potency of famotidine may offer clinical advantage due to lower drug exposure and less frequent dosing to achieve same pH lowering effect.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102678/1/jcph219.pd

In silico docking analysis of piperine with cyclooxygenases

The structure of 1-[5-(1,3-benzodioxol- 5-yl)-1-oxo-2,4- pentadienyl]piperidine (Piperine), C17H19O3N, a versatile bioactive molecule has been redetermined at 100(2) K by X-ray crystallography to explore their potential utilization in inhibition of prostaglandin release. The crystal structure is stabilized by weak nonclassical intermolecular C-H…O hydrogen bonds and also intermolecular C-H…π interactions. The crystallographic coordinates of the compound were extrapolated to docking studies to elucidate the action of piperine against the enzymes, cyclooxygenases (COX-1 and COX-2) involved in biosynthesis of prostaglandin release. Using AutoDock suite, piperine was docked at the binding site of COX-1 and COX-2 enzyme and a strong affinity (-9.06kcal/mol, Ki =227.73nM and -8.77kcal/mol, Ki = 375.62nM, respectively) was formed by Hydrogen bonds and hydrophobic interactions. These results suggest that piperine can be a promising lead for the development of COX family inhibitors

Synthesis, Spectroscopy and Crystal Structure of 2‐Ethyl‐6‐(4‐nitrophenyl)imidazo[2,1‐b] [1,3,4]thiadiazole‐5‐carbaldehyde.

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Synthesis, spectroscopic and crystal structure analysis of a compound with pharmocophoric substituent: 2-cyclohexyl-6-(2-oxo-2H-chromen-3-yl)- imidazo[2,1-b] [1,3,4]thiadiazole-5-carbaldehyde

Imidazo[2,1-b][1,3,4] thiadiazole derivatives are significant for their various pharmacological properties. This paper reports the synthesis and structure of one of them, 2-cyclohexyl-6-(2-oxo-2H-chromen-3-yl)imidazo[2,1-b][1,3,4]thiadiazole-5-carbaldehyde. The compound crystallizes in the monoclinic space group P21/c with a=17.316(3)Å, b=6.5420(9)Å, c =17.056(3)Å, β=112.909(2)°, V=1779.7(4)Å3, z=4. The, Imidazo[2,1-b][1,3,4] thiadiazole and the coumarin ring systems are each planar but inclined at an angle of 48.14(2)° towards each other. The crystal structure is stabilized by C–H … O interactions

Quantitative Analysis of NF-κB Transactivation Specificity Using a Yeast-Based Functional Assay

The NF-κB transcription factor family plays a central role in innate immunity and inflammation processes and is frequently dysregulated in cancer. We developed an NF-κB functional assay in yeast to investigate the following issues: transactivation specificity of NF-κB proteins acting as homodimers or heterodimers; correlation between transactivation capacity and in vitro DNA binding measurements; impact of co-expressed interacting proteins or of small molecule inhibitors on NF-κB-dependent transactivation. Full-length p65 and p50 cDNAs were cloned into centromeric expression vectors under inducible GAL1 promoter in order to vary their expression levels. Since p50 lacks a transactivation domain (TAD), a chimeric construct containing the TAD derived from p65 was also generated (p50TAD) to address its binding and transactivation potential. The p50TAD and p65 had distinct transactivation specificities towards seventeen different κB response elements (κB-REs) where single nucleotide changes could greatly impact transactivation. For four κB-REs, results in yeast were predictive of transactivation potential measured in the human MCF7 cell lines treated with the NF-κB activator TNFα. Transactivation results in yeast correlated only partially with in vitro measured DNA binding affinities, suggesting that features other than strength of interaction with naked DNA affect transactivation, although factors such as chromatin context are kept constant in our isogenic yeast assay. The small molecules BAY11-7082 and ethyl-pyruvate as well as expressed IkBα protein acted as NF-κB inhibitors in yeast, more strongly towards p65. Thus, the yeast-based system can recapitulate NF-κB features found in human cells, thereby providing opportunities to address various NF-κB functions, interactions and chemical modulators