Synthesis of Privileged Scaffolds by Using Diversity‐Oriented Synthesis

An elegant reagent‐controlled strategy has been developed for the generation of a diverse range of biologically active scaffolds from a chiral bicyclic lactam. Reduction of the chiral lactam with LAH or alkylation with LHMDS to trigger different cyclization reactions have been shown to generate privileged scaffolds, such as pyrrolidines, indolines, and cyclotryptamines. Their amenability to substitution allows us to create various compound libraries by using these scaffolds. In silico studies were used to estimate the drug‐like properties of these compounds. Selected compounds were subjected to anticancer screening by using three different cell lines. In addition, all these compounds were subjected to antibacterial screening to gauge the spectrum of biological activity that was conferred by our DOS methodology. Gratifyingly, with no additional iterative cycles, our method directly generated anticancer compounds with potency at low nanomolar concentrations, as represented by spiroindoline 14 .     

Electron paramagnetic resonance and optical absorption studies of manganese ions doped in polyvinyl(alcohol) complexed with polyethylene glycol polymer films

Electron paramagnetic resonance (EPR), optical absorption, and infrared spectral studies have been carried out on Mn²⁺ ions doped in poly(vinyl alcohol) (PVA) complexed with polyethylene glycol (PEG) films prepared by solution cast technique. The EPR spectra of 0.25?mol% Mn²⁺ ions doped polymer complex (PVA+PEG) at room temperature exhibit sextet hyperfine structure (hfs), centered at g????1.99. The spin?CHamiltonian parameter values indicate that the ground state of Mn²⁺ ion is d⁵ and the site symmetry around Mn²⁺ ions in tetragonally distorted octahedral site. The spin concentration participating in the resonance is measured as a function of temperature and it is observed that it obeys Boltzmann??s law. The paramagnetic susceptibility (??) is calculated from the EPR data at various temperatures (93?C333?K) and it obeys the Curie?CWeiss law. The optical absorption spectra exhibits two bands which are assigned to ⁶A_1g (S)??⁴A_1g (G) or ⁴E_g (G) and ⁶A_1g (S)??⁴T_2g (G) transitions. The infrared spectrum exhibits few bands due to the presence of O?CH, C?CH, and C=C groups.     

New Synthesis of Analogues of the Antihypertensive Active Pharmaceutical Ingredient Irbesartan

A simple and new synthetic approach to various analogues of Irbesartan is described.     

Regeneration of levulinic acid from loaded-organic phase: equilibrium,kinetic studies and process economics

Regeneration of carboxylic acids from the loaded-organic phase is an essential step to complete the reactive extraction process. A study on the regeneration of levulinic acid from loaded-organic phase (methyl isobutyl ketone + tri-n-octylamine + acid) was carried out using various techniques including NaOH, temperature swing, diluent swing, and tri-methylamine methods. Equilibrium data obtained show that among all the methods, the recovery of acid is the highest for the tri-methylamine method when the molar ratio of tri-methylamine to levulinic acid concentrations is greater than 1. Kinetic studies performed for the tri-methylamine method showed that there are no changes in the specific rate of extraction with changes in stirrer speed rate and phase volume ratio (V _aq/V _org), and the overall order of reaction is 1.5. Based on the effects of stirrer speed and phase volume ratio on the specific rate of extraction, the reaction was concluded to occur in the fast regime. Also, about 80% of acid was recovered by the evaporation of tri-methylamine phase at 104–140 °C. A detailed economic evaluation for the recovery of levulinic acid using reactive extraction for a feed rate of 2 m³ h^?1 shows that the payback period for recovering capital investment is 0.49 years.     

Alkaline earth zinc borate glasses doped with Cu2+ ions studied by EPR,optical and IR techniques

Copper ions incorporated into alkaline earth zinc borate glasses 10RO + 30ZnO + 60B₂O₃ (R = Mg, Ca and Sr) and 10SrO + (30 ? x)ZnO + 60B₂O₃ + xCuO (x = 0, 0.1, 0.3, 0.5, and 0.7 wt.%) were characterized by electron paramagnetic resonance (EPR), optical absorption and FTIR techniques. The EPR spectra of all the glass samples exhibit resonance signals characteristic of Cu²⁺ ions. The values of spin-Hamiltonian parameters indicate that the Cu²⁺ ions in alkaline earth zinc borate glasses were present in octahedral sites with tetragonal distortion. The spin concentration (N) participating in resonance was calculated as a function of temperature for strontium zinc borate (SrZB) glass sample containing 0.7 wt.% of Cu²⁺ ions and the activation energy was calculated. From the EPR data, the paramagnetic susceptibility (χ) was calculated at different temperatures and the Curie constant was evaluated from the 1/χ-T graph. The optical absorption spectra of these samples show only one absorption band. The optical band gap energies (E_g) and Urbach energy (ΔE) are calculated from their ultraviolet edges. The FTIR studies show different stretching and bending vibrations of alkaline earth zinc borate glasses.     

Synthesis and Anticancer Activity of Oxadiazole Incorporated Ellipticine Derivatives

Russian Journal of General Chemistry - A series of ellipticine derivatives 8a–8j containing oxadiazole structural block are synthesized and evaluated for their anticancer activity on human...     

Green synthesis and anticancer activity of tetrahydrodipyrazolo[3,4-b:4′,3′-e]pyridines catalyzed by phospho sulfonic acid

Biologically portent/significant tetrahydrodipyrazolo[3,4-b:4′,3′-e]pyridines are synthesized by an efficient green synthesis of various aldehydes with 3-methyl-1H-pyrazol-5(4H)-one in ammonium acetate using phospho sulfonic acid as a solid catalyst under microwave-assisted interaction under solvent-free conditions at 70°C. This methodology is easy to handle and get good to excellent yields. Later the potential in vitro antiproliferation of the titled compounds is evaluated. Among all the titled compounds, 4s and 4t showed the most potent anticancer potentiality on the used cancer cell lines of SK-BR-3 and HeLa (IC₅₀ = 10.70 ± 0.27 and 12.58 ± 0.38, and 19.38 ± 0.32 and 21.55 ± 0.41 μg/mL for SK-BR-3 cells lines and HeLa cells lines, respectively), which were comparable to the positive control.