The influence of cobalt(II) and tin(II) chloride on regioselectivity and kinetics of phenylselenocyclization of 6-methyl-hept-5-en-2-ol.

The reaction of the Δ-alkenols with PhSeX can follow three possible reaction pathways: two pathways lead to the formation of two regioisomeric cyclic ether products through the process of intramolecular cyclization, while the third represents the addition of the reagent to the double bond of an alkenol. As there are relatively few literature data on the kinetics of these reactions, we have chosen 6-methyl-hept-5-en-2-ol as a substrate of interest in order to obtain valuable results that will enable better understanding of the mechanism of phenylselenoetherification reactions. 6-Methyl-hept-5-en-2-ol is a particularly interesting model-substrate due to its substitution pattern of functional groups involved in the cyclization process.

Synthesis, crystal and solution structures and antimicrobial screening of palladium(II) complexes with 2-(phenylselanylmethyl)oxolane and 2-(phenylselanylmethyl)oxane as ligands.

Two novel Pd(II) complexes with 2-(phenylselanylmethyl)oxolane and 2-(phenylselanylmethyl)oxane as ligands were synthesized. The crystal and molecular structure of the complexes has been determined by single crystal X-ray diffraction. It turned out for both complexes that the two ligands are coordinated to Pd via Se atoms in a trans-fashion and the other two trans-positions are occupied by Cl ions.

Antioxidative and antiproliferative evaluation of 2-(phenylselenomethyl)tetrahydrofuran and 2-(phenylselenomethyl)tetrahydropyran.

Purpose: To determine the antioxidant and antiproliferative influence of 2-(phenylselenomethyl)tetrahydrofuran (1a) and 2-(phenylselenomethyl)tetrahydropyran (2a) on colon cancer cell line HCT-116 and breast cancer cell line MDA-MB-231.

Methods: Cell viability was monitored in a dose-dependent manner using MTT assay. The concentration of superoxide anion radical (O2 •(-)) was determined spectrophotometrically.

Kinetic and mechanistic studies of base-catalyzed phenylselenoetherification of (Z)- and (E)-hex-4-en-1-ols.

The mechanism of phenylselenoetherification of (Z)- and (E)-hex-4-en-1-ols using some bases (triethylamine, pyridine, quinoline, 2,2'-bipyridine) as catalysts and some solvents [tetrahydrofuran (THF) and CCl4] as reaction media was examined through studies of kinetics of the cyclization by UV-vis spectrophotometry. It was demonstrated that the intramolecular cyclization is facilitated in the presence of bases as a result of the hydrogen bond between the base and the alkenol's OH group. The rate constants in the base-catalyzed reactions are remarkably influenced by the bulkiness and basicity of the base used and the nature of the considered nitrogen donors.

Mechanistic investigation of the base-promoted cycloselenoetherification of pent-4-en-1-ol.

The mechanism of phenylselenoetherification of pent-4-en-1-ol using some bases (pyridine, triethylamine, quinoline, 2,2'-bipyridine) as catalyst was examined through studies of kinetics of the cyclization, by UV-VIS spectrophotometry. It was demonstrated that the intramolecular cyclization is facilitated in the presence of bases caused by the hydrogen bond between base and alkenol's OH-group. The obtained values for rate constants have shown that the reaction with triethylamine is the fastest one.

Effects of cisplatin and other Pt(II) complexes on spontaneous motility of isolated human oviduct.

The toxicity of platinum(II) ion could be significantly modified by coordination with some organic compounds. In our study, the cytotoxicity and the influence of platinum(II) complexes, such as cisplatin, cis-[PtCl(2)(NH(3))(2)], [PtCl(2)(SMC)] and [PtCl(2)(DMSO)(2)] (where SMC is S-methyl-l-cysteine and DMSO is dimethyl sulphoxide) on spontaneous motility of isolated human fallopian tubes were investigated. Cisplatin showed potent pro-apoptotic effects on peripheral blood mononuclear cells (PBMC).

Studies of interactions between platinum(II) complexes and some biologically relevant molecules.

The reactions of Pt(II) complexes, cis-[Pt(NH3)2Cl2], [Pt(terpy)Cl]+, [Pt(terpy)(S-cys)]2+, and [Pt(terpy)(N7-guo)]2+, where terpy=2,2':6',2''-terpyridine, S-cys=L-cysteine, and N7-guo=guanosine, with some biologically relevant ligands such as guanosine-5'-monophosphate (5'-GMP), L-cysteine, glutathione (GSH) and some strong sulfur-containing nucleophiles such as diethyldithiocarbamate (dedtc), thiosulfate (sts), and thiourea (tu), were studied in aqueous 0.1 M Hepes at pH of 7.4 using UV-vis, stopped-flow spectrophotometry, and 1H NMR spectroscopy.