Asymmetric synthesis of (6R)-4-hydroxy-6-substituted-δ-lactones

A novel approach for the asymmetric synthesis of (6R)-4-hydroxy-6-substituted-δ-lactones has been achieved using asymmetric reduction of a prochiral ketone in the presence of (S)-(?)-diphenyl-prolinol/borane as a key step. The enantiomeric purity of the products was determined by chiral GC.     

The present and future of e-waste plastics recycling

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Identification of molecular fingerprints of phenylindole derivatives as cytotoxic agents: a multi-QSAR approach

Phenylindole is reported to be an interesting scaffold having promising cytotoxic activities and can overcome the cancer drug resistance possibly via binding to the colchicine binding site of tubulin. In order to find out the molecular fingerprints for the better cytotoxic activity of phenylindole derivatives, multiple validated chemometric modeling approaches namely hologram QSAR (HQSAR), Bayesian classification model, and pharmacophore mapping analyses were applied into a dataset of 102 phenylindole derivatives. The final HQSAR model shows good statistical significance (Q²?=?0.760; R²_Train?=?0.868; R²_Test?=?0.660), and the best pharmacophore hypothesis has the highest regression coefficient value (r?=?0.975) and the lowest RMS value of 0.679. Moreover, the Bayesian model is also statistically validated and robust to discriminate the cytotoxic and non-cytotoxic phenylindoles. These studies suggest that the amine group should be unsubstituted for retaining higher cytotoxicity. The pharmacophore mapping and Bayesian classification study suggest the importance of 2-phenyl group as a ring aromatic feature conducive to cytotoxicity. The steric and hydrophobic effect of long chain linear alkyl group has a positive influence on cytotoxicity as evidenced by the multi-QSAR study. Therefore, this multi-QSAR modeling reported here is beneficial in designing potential phenylindole cytotoxic agents in future.     

A rapid and green method for expedient multicomponent synthesis of N-substituted decahydroacridine-1,8-diones as potential antimicrobial agents

Research on Chemical Intermediates - An efficient, green, high yielding, and quick method for the synthesis of N-substituted decahydroacridine-1,8-diones was achieved by multicomponent reaction...     

Synthesis,in vitro cytotoxicity,and molecular docking study of novel 3,4-dihydroisoquinolin-1(2H)-one based piperlongumine analogues

With the aim of expanding the scope of SAR on piperlongumine (PL), a naturally occurring anticancer molecule, we have designed a novel hybrid molecule bearing 3,4-dihydroisoquinolin-1(2H)-one and trans-cinnamic acids. The structure, based on hybridization strategy, is used for hybridization of naturally occurring scaffolds. We have synthesized 14 hybrid molecules by coupling 3,4-dihydroisoquinolin-1(2H)-one core with cinnamic acids using the mix anhydride approach. The newly synthesized inhibitors were evaluated for cell viability against breast cancer MCF-7 and cervical cancer HeLa cell lines. Furthermore, the active compounds were screened for their potential in breast cancer MDA-MB-231, cervical cancer C33A cell lines, prostate cancer DU-145, PC-3, and normal VERO cells. From the series, compound 10g was seen to inhibit MCF-7 cell growth significantly with GI₅₀ < 0.1 μM along with growth inhibition in MDA-MB-231 (GI₅₀ = 20 μM) and C33A (GI₅₀ = 3.2 μM). While the inhibitor 10i inhibits MCF-7 breast cancer cell growth GI₅₀ = 3.42 μM along with inhibition of cell growth in MDA-MB-231 (GI₅₀ = 30 μM), HeLa (GI₅₀ = 7.67 μM), C33A (GI₅₀ = 13 μM), DU-145 (GI₅₀ = 6.45 μM), PC-3 (GI₅₀ = 8.68 μM), and VERO (GI₅₀ = 2.93 μM), respectively. Furthermore, molecular docking study demonstrated these compounds could bind tightly to the colchicine domain of tubulin through a network of favorable steric and electrostatic interactions and thus act as a tubulin polymerization inhibitor.     

Substrate dependent properties of electrodeposited EuTe thin films

In electrodeposition, substrate besides providing mechanical support to the electrodeposit, affects significantly the structural and morphological properties of a film. Electrodeposition and characterization of EuTe thin films onto different substrates such as stainless steel (SS), titanium (Ti), copper (Cu), fluorine-doped tin oxide (F:SnO₂) covered glasses have been described. The deposition potentials have been estimated from the polarization curves. The reaction mechanism is proposed for the formation of EuTe electrodeposits. Preparative parameters such as deposition potential, current density, and deposition time are studied. The films have been characterized by X-ray diffraction, scanning electron microscopy (SEM), atomic force microscopy (AFM) and energy dispersive analysis by X-rays (EDAX) techniques. The electrodeposited EuTe films are polycrystalline on all the substrates with same cubic crystal structure. The SEM studies reveal that the surface morphology is different for the substrates studied. However, no cracks have been observed in the SEM micrographs. The AFM images show large spherical grains supporting the polycrystalline nature of the samples. The EDAX analysis shows that the EuTe films are nearly stoichiometric, slightly rich in tellurium.     

Green access to novel spiro pyranopyrazole derivatives

A catalyst-free multicomponent reaction (MCR) capable of affording a wide range of novel spiro pyranopyrazole derivatives from pyrazolone in situ formed from acetylenic esters with hydrazine hydrate at room temperature with isatin and malononitrile is reported. A plausible mechanism is suggested. Catalyst-free conditions along with green solvent system make the process ecofriendly as well as economical. Simple reaction conditions and easy work-up procedure that resulted into simple isolation and purification of products by non-chromatographic methods, that is, by simple recrystallization from methanol as well as novelty are the significant advantages of the present protocol.     

A simple method for measuring the size of metal nanoclusters in solution

The connection between quantum size effects and the surface plasmon resonance of metal nanoclusters is introduced and the pros and cons of in situ and ex situ cluster analysis methods are outlined. A new method for estimating the size of nanoclusters is presented. This method combines core/shell cluster synthesis, UV-visible spectroscopy, and Mie theory. The core/shell approach enables the estimation of metal cluster sizes directly from the UV-visible spectra, even for transition metal nanoclusters such as Pd that have no distinct surface-plasmon peak in UV-visible region. Pd/Au and Au/Pd core/shell clusters as well as Au-Pd alloy clusters are synthesized and used as test cases for simulations and spectroscopic measurements. The results of the simulations and UV-visible spectroscopy experiments are validated with transmission electron microscopy.     

A Molecular Shuttle Driven by Fullerene Radical‐Anion Recognition

We describe a electrochemically driven molecular shuttle, in which shuttling takes place by means of fullerene radical‐anion recognition that results in a very low operation potential (E_1/2=?0.580 V vs. decamethylferrocene). This has been achieved by introducing positive charges on the macrocycle, which strengthen the existing π–π interactions between the macrocycle and the electrogenerated fullerene radical anion by means of an electrostatic component. In addition, the synthesis of such a molecular shuttle has been accomplished by developing a new synthetic approach that exploits the controlled translocation of the macrocycle as a selective protecting group.