Methyl 2-[(tert-Butoxycarbonyl)amino]-3-hydroxy-3-phenylpropanoate: Synthesis of Erythro (±) Isomer by Reduction and Threo (±) Isomer by Inversion Method

Russian Journal of General Chemistry - We report an efficient protocol for synthesis of methyl 2-[(tert-butoxycarbonyl) amino]-3-hydroxy-3-phenylpropanoate (Erythro (±)) by simple reduction...     

Analytical study for oblique wave interaction with a submerged horizontal perforated plate near a partially reflecting vertical wall

Meccanica - A novel iterative analytical solution is developed to study the oblique wave interaction with a horizontally submerged perforated plate near a partially reflecting vertical wall. The...     

α,α-Dibromoketone precursors in the synthesis of some new thiazole derivatives: Thiazol-2-yl hydrazonobutanoates,thiazol-2-yl pyrazole-4-carboxylates and acids

In the present study, α,α-dibromoacetophenones are used as efficient precursors for the facile synthesis of several new hydrazonothiazoles, ethyl 3-((4-arylthiazol-2-yl)hydrazono)butanoates, which undergo Vilsmeier-Haack cyclization to obtain thiazolylpyrazole esters, ethyl 3-methyl-1-(4-arylthiazol-2-yl)-1H-pyrazole-4-carbxylates, basic hydrolysis of which gives the corresponding acids, 3-methyl-1-(4-arylthiazol-2-yl)-1H-pyrazole-4-carbxylic acids. All these compounds are tested for antibacterial activity against Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis; Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa and antifungal activity against Saccharomyces cerevisiae and Candida albicans.     

Recent Advances and Developments of in vitro Evaluation of Heterocyclic Moieties on Cancer Cell Lines

Besides worthy development in cancer therapy, cancer is still one of the leading causes of death, worldwide. The future burden of cancer will probably be even larger because people are adopting poor lifestyles with poor diet, frequently smoking and less physical activity. The effective anticancer drugs having efficacy and selectivity with low toxicity is still a challenge for the scientific fraternity. The advances in the cancer study have its origin on the availability of different types of experimental model systems that review the various forms of this disease. Cell lines emerge as a feasible alternative for anticancer activities, being at the same time easy to manipulate and molecularly characterize. Heterocycles are key structural components of many of the anti‐cancer drugs available on the market today. Indeed, of the novel molecular anti‐cancer agents approved by the FDA between 2010 and 2017, almost two‐thirds contained heterocyclic rings within their structures. This review summarizes and provides updated literature on heterocyclic compounds using various cancer cell lines reported during the period of 2014–2017 together with the structure‐activity relationships.     

Residence time distribution measurements in an ethyl acetate reactor using radiotracer technique

Journal of Radioanalytical and Nuclear Chemistry - In the present study, residence time distribution measurements were carried out in an industrial-scale ethyl acetate reactors using Bromine-82 as...     

Redox-Reversible 2D Metal–Organic Framework Nanosheets (MONs) Based on the Hydroquinone/Quinone Couple

2D metal–organic nanosheets (MONs), akin to graphene, have aroused immense contemporary interest. In our quest to develop functional 2D MONs based on organic linkers designed de novo, we reasoned that benzene-tetrabenzoic acid, which has been exploited tremendously in the construction of pillared metal–organic frameworks (MOFs), could be maneuvered readily to access redox-active MONs based on the benzoquinone/hydroquinone redox couple. Herein, we show that the self-assembly of 2,3,5,6-tetrakis(p-carboxyphenyl)hydroquinone H₄BTA with Zn(NO₃)₂ does lead to 2D metal–organic nanosheets that stack down the y axis, affording a layered Zn MOF. Although the crystals of the latter do not exhibit a discernible chemically induced redox switching behavior, the 2D MONs accessed by ultrasound-induced liquid-phase exfoliation (UILPE) lend themselves to a facile redox switching behavior. Treatment of a dispersion of the 2D MONs in methanol with phenyliodine(III) diacetate (PIDA) results in the oxidation of the hydroquinone core to benzoquinone. Remarkably, the latter can be reverted to the former by treatment with ascorbic acid as a reducing agent; indeed, the redox process can be made out by the naked eye. The results constitute the first example of chemically induced redox switching of 2D MONs. In view of emergent applications of 2D materials in general and MONs in particular, for example, improvement of the performance of membranes in separations by doping with MONs, the redox-switchable property may lead to the development of unique materials with heretofore unexplored potential.     

Vertical Sediment Concentration Distribution in High-Concentrated Flows:An Analytical Solution Using Homotopy Analysis Method

Transport of suspended sediment in open channel flow has an enormous impact on real life situations,viz. control and management of reservoir sedimentation, geomorphic evolution such as dunes, rivers, and coastlines etc. Transport entails advection and diffusion. Turbulent diffusion is governed by the concept of Fick’s law, which is based on the molecular diffusion theory, and the equation that represents the distribution of sediment concentration is the advection-diffusion equation. The study uses the existing governing equation which considers different phases for solid and fluid, and then couples the two phases. To deal with high-concentrated flow, sediment and turbulent diffusion coefficients are taken to be different from each other. The effect of hindered settling on sediment particles is incorporated in the governing equation, which makes the equation highly non-linear. This study derives an explicit closed-form analytical solution to the generalized one-dimensional diffusion equation representing the vertical sediment concentration distribution with an arbitrary turbulent diffusion coefficient profile. The solution is obtained by Homotopy Analysis Method, which does not rely on the small parameters present in the equation. Finally, the solution is validated by comparing it with the implicit solution and the numerical solution. A relevant set of laboratory data is selected to check the applicability of the model, and a close agreement shows the potential of the model in the context of application to high-concentrated sediment-laden open channel flow.     

Design and Synthesis of New Aryloxy‐linked Dimeric 1,2,3‐Triazoles via Click Chemistry Approach: Biological Evaluation and Molecular Docking Study

A quest for more potent new antitubercular agents has prompted to design and synthesize aryloxy‐linked dimeric 1,2,3‐triazoles ( 4a – j ), from azides ( 2a‐e ) and bis(prop‐2‐yn‐1‐yloxy)benzene ( 3a – b ) on 1,3‐dipolar cycloaddition reaction via copper (I)‐catalyzed click chemistry approach with good to better yields. The titled compounds ( 4a – j ) were designed using molecular hybridization approach by assembling various bioactive pharmacophoric fragments in a single molecular framework. All the synthesized compounds have been screened for their in vitro antitubercular, antifungal, and antioxidant activities against their respective strains. Among them, 4h and 4i show the highest antifungal activity, whereas compounds 4h , 4i , and 4j have revealed promising antitubercular activity against their respective strains. In addition to this, most of the synthesized compounds were found as potent antifungal and antioxidant agents. A significant network of bonded and non‐bonded interactions stabilized these molecules into the active site of fungal CYP51 that is realized from the obtained well‐placed docking poses and the associated thermodynamic interactions with the enzyme. The synthesized compounds have also been analyzed for absorption, distribution, metabolism, and excretion properties.