Synthesis of Cobalt Bis(Dicarbollide)—Curcumin Conjugates for Potential Use in Boron Neutron Capture Therapy

A series of novel cobalt bis(dicarbollide)—curcumin conjugates were synthesized. Two conjugates were obtained through the nucleophilic ring-opening reaction of the 1,4-dioxane and tetrahydropyran derivatives of cobalt bis(dicarbollide) with the OH group of curcumin, and using two equiv. of the oxonium derivatives, two other conjugates containing two cobalt bis(dicarbollide) units per molecule were obtained. In contrast to curcumin, the conjugates obtained were found to be non-cytotoxic against both tumor and normal cell lines. The analysis of the intracellular accumulation of the conjugates by flow cytometry showed that all cobalt bis(dicarbollide)—curcumin conjugates entered HCT116 colorectal carcinoma cells in a time-dependent manner. New non-cytotoxic conjugates contain a large amount of boron atoms in the biomolecule and can potentially be used for further biological research into boron neutron capture therapy (BNCT).     

New bifunctional amphiphilic oxyethylimidazolium derivatives of calix[4]arene containing alkynyl/azide fragments: regularities of aggregation and polymerization under azide/alkyne cycloaddition conditions

Russian Chemical Bulletin - New bifunctional amphiphilic oxyethylimidazolium derivatives of calix[4]arene with terminal alkynyl or azide fragments in the polar moiety of the molecule were...     

Synthesis and antiproliferative evaluation of glucosylated pyrazole analogs of K252c

Pyrazole analogs of the staurosporine aglycon K252c were recently described as potent inhibitors of the three Pim protein kinase isoforms. To evaluate the impact of the introduction of a sugar moiety on the biological activities of this heterocyclic scaffold, four new glucosylated pyrazole analogs of K252c were synthesized. Their biological evaluation demonstrated that most active compounds 11 and 19 substituted by a β-d-glucosyl moiety at N12 or N13 positions exhibited antiproliferative activities toward HCT116 cells.     

Synthesis of pyrrolidines,pyrrolines, and pyrroles

As compounds of potential physiological activity, new sulfamide derivatives, Schiffs bases derived from N-arylpyrrolines, are obtained by reacting sulfanilamide, 2-(p-aminobenzenesulfamide) thiazole, 2-(p-aminobenzenesulfamido)-pyrimidine, and 1-phenyl-3-ethyl-4-methyl-5-(p-aminobenzenesulfamido) pyrazole with -(2-chloroethyl)--chlorocrotonaldehyde.For Part XIV see [1].     

Reaction of 3,4-Dichloro-5-methoxyfuran-2(5H)-one with 1,2-Organylbis(diphenylphosphines)

The reactions of 3,4-dichloro-5-methoxyfuran-2(5H)-one with 1,2-ethylenebis(diphenylphosphine) and 4,5-bis(diphenylphosphinyl)-2-phenylpyridazin-3(2H)-one involve substitution of both chlorine atoms with ³-P atoms to form unstable diphosphonium bicyclic salts which in the course of the reaction undergo an unusual fragmentation to give finally mono- and tricyclic diphosphoniacyclohexane structures.     

Initiation of free-radical polymerization of acetylene monomers with molecular chlorine at low temperatures

The reactions of molecular chlorine with phenylacetylene (PA) and para-diethinylbenzene (p-DEB) at low temperatures (77–210 K) were studied by electronic paramagnetic resonance (EPR), size exclusion chromatography, double bond analysis (DBA), calorimetry, and UV, visible, and IR spectroscopy. The low-temperature (100–210 K) reactions of molecular chlorine without high-energy chemical (HEC) effects formed radicals capable of oligomerizations and polymerizations. A readily soluble polymer para-diethinylbenzene having no spatial cross-linkages (but possibly having a branched structure) was obtained. Polymerization occurred in direct contact with chlorine. It accelerated near the melting point (T _m) of chlorine and proceeded vigorously along with chlorination at T _m = 172 K. The occurrence of low-temperature polymerization without HEC treatment points to the high reactivity of the reagents. From the viewpoint of applications, low-temperature oligomerization or polymerization of monomers with molecular chlorine can afford oligomers or polymers with definite properties, which cannot be obtained by other initiation procedures.     

Molecular characteristics and hydrodynamic behavior of polyelectrolyte-surfactant complexes in chloroform

Molecular characteristics of polyelectrolyte complexes of the ultrahigh-molecular-weight poly-(N,N-dimethyl-N-benzyl-N-methacryloyloxyethyl)ammonium chloride with oppositely charged surfactants in chloroform were studied by centrifugal sedimentation and viscometry. The effect of oil-soluble surfactants on the hydrodynamic properties of the complexes was examined.     

Tris(Trimethylsilyl)Phosphine in Reaction with Bis(Phenylenedioxa)Chlorophosphorane. The Way to Phosphoranylphosphines

Abstract

Tris(trimethy1silyl)phosphine (1) is the key reagent in the synthesis of one- and two-coordinated phosphorus compounds. Its characteristic features are extreme reactivity, high nucleophility of phosphorus atom and the P-Si bonds lability. The interaction of phosphine (1) with bis(catecho1)chlorophosphome (2) has been studied by dynamic ³¹P NMR method. On the reagents ratio 1:1 at first the nucleophilic substitution of chlorine occurs leading to formation of phosphome (3) with P^III-P^v bond (σ_P(III) -117.0, σ^P(V) 17.4 ppm, ¹J_pp 305.0 Hz) which converts then into more stable 2-(trimethylsiloxyphenyloxy)-4,5-bem- 1,3,2-dioxaphospholane (4).