Stabilization of platinum(II) hydrides by tri-t-butylarsine; facile syntheses of stable trans-PtH2[As(t-Bu)3]2 and trans-PtHX[As(t-Bu)3]2 complexes

trans-PtH₂[As(t-Bu)₃]₂ was prepared in very good yield by afacile reaction of K₂PtC1₄ with As(t-Bu)₃ in alkaline ethanol. Treatment of trans-PtH₂[As(t-Bu)₃]₂ with CF₃CO₂H or HCI afforded trans-PtH(O₂CCF₃)[As(t-Bu)₃]₂ or trans-PtHCl[As(t-Bu)₃]₂. respectively, in almost quantitative yield.     

Probing metabolic alterations in breast cancer in response to molecular inhibitors with Raman spectroscopy and validated with mass spectrometry

Rapid and accurate response to targeted therapies is critical to differentiate tumors that are resistant to treatment early in the regimen. In this work, we demonstrate a rapid, noninvasive, and label-free approach to evaluate treatment response to molecular inhibitors in breast cancer (BC) cells with Raman spectroscopy (RS). Metabolic reprogramming in BC was probed with RS and multivariate analysis was applied to classify the cells into responsive or nonresponsive groups as a function of drug dosage, drug type, and cell type. Metabolites identified with RS were then validated with mass spectrometry (MS). We treated triple-negative BC cells with Trametinib, an inhibitor of the extracellular-signal-regulated kinase (ERK) pathway. Changes measured with both RS and MS corresponding to membrane phospholipids, amino acids, lipids and fatty acids indicated that these BC cells were responsive to treatment. Comparatively, minimal metabolic changes were observed post-treatment with Alpelisib, an inhibitor of the mammalian target of rapamycin (mTOR) pathway, indicating treatment resistance. These findings were corroborated with cell viability assay and immunoblotting. We also showed estrogen receptor-positive MCF-7 cells were nonresponsive to Trametinib with minimal metabolic and viability changes. Our findings support that oncometabolites identified with RS will ultimately enable rapid drug screening in patients ensuring patients receive the most effective treatment at the earliest time point.

Rapid and accurate response to targeted therapies is critical to differentiate tumors that are resistant to treatment early in the regimen.     

Synthesis of 1-(5-phenyl-2H-tetrazol-2-ylacetyl)-4-substituted thiosemicarbazides as possible antiinflammatory agents

A series of 1-(5-phenyl-2H-tetrazol-2-ylacetyl)-4-substituted thiosemicarbazids were prepared as possible antiinflammatory agents. Their antiproteolytic activity was reported.     

Synthesis of polyhydroquinoline derivatives through unsymmetric Hantzsch reaction using organocatalysts

A novel and green approach for efficient and rapid synthesis of polyhydroquinoline derivatives via unsymmetric Hantzsch reaction using organocatalysts at room temperature was reported. The process is a simple, environmentally friendly, rapid, and high yielding reaction for the synthesis of polyhydroquinoline derivatives. The catalytic efficiency of various small organocatalysts such as l-proline, trans-4-hydroxy-l-proline, l-thiaproline, dl-phenylglycine, and (−)-cinchonidine was studied under aqueous, organic, and solvent free conditions.     

Organic phase conversion of bulk (wurtzite) ZnO to nanophase (wurtzite and zinc blende) ZnO

We describe the all-organic phase conversion of bulk commercial ZnO in the wurtzite modification to sub-30 nm ZnO that we find to be partially in the zinc blende [, a=4.568(3) Å] modification. The conversion involves refluxing ZnO in 2,4-pentanedione (acetylacetone) at 413 K to form the zinc 2,4-pentanedionate, which is decomposed by heating at 573 K in an appropriate high-temperature solvent such as dibenzylether to form nanophase ZnO. This nanophase, partially zinc blende ZnO can also be obtained in a single step by heating commercial zinc 2,4-pentanedionate in refluxing dibenzylether. Thermodiffractometry suggests that the conversion of zinc blende ZnO to wurtzite ZnO commences near 650 K.     

Some compounds of iron(III) with bidentate bases

Summary The iron(III) compound, FeCl(OH)(MeCO₂) · MeCO₂H · 0.5 H₂O, (1), interacts with the sample bidentate ligand, 2,2-bipyridyl (bipy), to form an aduct, Fe₂Cl₂(OH)₂(MeCO₂)₂ · (bipy). By the loss of protons, anthranilic (anthH) and salicylic (salH₂) acids behave as uninegative charged ligands to give FeCl(anth)₂ · H₂O and FcCl(salH)₂ · H₂O, respectively. The former decomposes on heatingin vacuo to form Fe₂O(anth)₄ while the latter yields Fe₂O(sal)₂. Acetylacetone (acacH) and 8-hydroxyquinoline (quinH) give FeCl(acac)₂ and FeCl(quin)₂ · (quinH). The latter desolvates at 140°/10^–4 torr to form FeCl(quin)₂. l.r. spectra, thermal decomposition, molar conductance and magnetic susceptibility studies at room temperature have been used to characterize these compounds.     

Molecular simulation study of effect of molecular association on vapor-liquid interfacial properties

Vapor-liquid interfacial properties of square-well associating fluids are studied via transition-matrix Monte Carlo simulation. Results for one-site and two-site association models are presented. Coexistence properties, surface tension, cluster distribution, density profile, and orientation profile are presented. Molecular association affects the interfacial properties and cluster fractions more than it affects the bulk densities. We observe that the surface tension exhibits a maximum with respect to association strength. This behavior is in agreement with the recent study of Peery and Evans for one site system using a square-gradient approach.     

Heterogeneous colorimetric sensor for mercuric salts

A novel chemical sensor for the colorimetric detection of mercuric salts is described. The sensor is based on a mesoporous nanocrystalline TiO2 film sensitised with a ruthenium dye; immersion of this film in an aqueous solution of Hg2+ results in a rapid colorimetric response, with both a high selectivity and a sub-micromolar sensitivity.     

A mild and practical method for the regioselective synthesis of N-acylated 3,4-dihydropyrimidin-2-ones. New acyl transfer reagents

The treatment of 3,4-dihydropyrimidin-2-ones with n-BuLi at −78 °C, followed by quenching with various electrophiles furnished N3-substituted derivatives, regioselectively. Further, N1,N3-diacyl derivatives were found to transfer N1-acyl groups to nucleophilic sites.     

Molecular simulation study of the effect of pressure on the vapor-liquid interface of the square-well fluid

We examine a model system to study the effect of pressure on the surface tension of a vapor-liquid interface. The system is a two-component mixture of spheres interacting with the square-well (A-A) and hard-sphere (B-B) potentials and with unlike (A-B) interactions ranging (for different cases) from hard sphere to strongly attractive square well. The bulk-phase and interfacial properties are measured by molecular dynamics simulation for coexisting vapor-liquid phases for various mixture compositions, pressures, and temperatures. The variation of the surface tension with pressure compares well to values given by surface-excess formulas derived from thermodynamic considerations. We find that surface tension increases with pressure only for the case of an inert solute (hard-sphere A-B interactions) and that the presence of A-B attractions strongly promotes a decrease of surface tension with pressure. An examination of density and composition profiles is made to explain these effects in terms of surface-adsorption arguments.