Photo- and X-ray Induced Cytotoxicity of CeF3-YF3-TbF3 Nanoparticle-Polyvinylpyrrolidone-"Radachlorin" Composites for Combined Photodynamic Therapy.

The Ce0.5Y0.35Tb0.15F3 nanoparticles with a CeF3 hexagonal structure were synthesized using the co-precipitation technique. The average nanoparticle diameter was 14 ± 1 nm. The luminescence decay curves of the Ce0.5Y0.35Tb0.15F3 nanoparticles (λem = 541 nm, 5D4-7F5 transition of Tb3+) conjugated with Radachlorin using polyvinylpyrrolidone coating as well as without Radachlorin were detected. Efficient nonradiative energy transfer from Tb3+ to the Radachlorin was demonstrated. The maximum energy transfer coefficients for the nanoparticles conjugated with Radachlorin via polyvinylpyrrolidone and without the coating were 82% and 55%, respectively. The average distance between the nanoparticle surface and Radachlorin was R0 = 4.5 nm. The best results for X-ray-induced cytotoxicity were observed for the NP-PVP-Rch sample at the lowest Rch concentration. In particular, after X-ray irradiation, the survival of A549 human lung carcinoma cells decreased by ~12%.

6aH-Benzo[α]fluorene: NMR evidence of the unexpected product of the reaction of butyryl chloride with 1,2-diphenylacetylene.

The reaction of butyryl chloride with ethynylbenzene in the presence of AlCl3 afforded a mixture of the Z/E-isomers of 1-chloro-2-phenylhex-1-en-3-one. 1,2-Diphenylethyne under these conditions gave a novel polycarbocycle core, 6aH-benzo[a]fluorene. The chemical structure of 11-chloro-5,6-diphenyl-6a-propyl-6aH-benzo[a]fluorene was established by means of IE-MS, 1 H, 13 C NMR, COSY, HSQC, HMBC, and 2D INADEQUATE technique.

Synthesis of 5-(trifluoroacetyl)imidazoles from Bromoenones and Benzimidamides via Aza-Michael Initiated Ring Closure Reaction.

INTRODUCTION: A simple method for the preparation of 5-(trifluoroacetyl)imidazoles was elaborated. METHODS: The reaction of trifluoromethyl(α-bromoalkenyl)ketones with benzimidamides was employed to afford the target heterocycles in good yields. RESULTS: The assembly of imidazole core proceeds via aza-Michael adduct formation followed by intramolecular nucleophilic substitution and spontaneous aromatization as an oxidation sequence. CONCLUSION: The yields of target imidazoles can be improved by the use of soft oxidizing agents.

Selenium Dihalides Click Chemistry: Highly Efficient Stereoselective Addition to Alkynes and Evaluation of Glutathione Peroxidase-Like Activity of Bis(E-2-halovinyl) Selenides.

Highly efficient stereoselective syntheses of novel bis(E-2-chlorovinyl) selenides and bis(E-2-bromovinyl) selenides in quantitative yields by reactions of selenium dichloride and dibromide with alkynes were developed. The reactions proceeded at room temperature as anti-addition giving products exclusively with (E)-stereochemistry. The glutathione peroxidase-like activity of the obtained products was estimated and compounds with high activity were found. The influence of substituents in the products on their glutathione peroxidase-like activity was discussed.

A Regioselective Synthesis of Novel Functionalized Organochalcogen Compounds by Chalcogenocyclofunctionalization Reactions Based on Chalcogen Halides and Natural Products.

The regioselective synthesis of novel functionalized condensed organochalcogen compounds by chalcogenocyclofunctionalization reactions based on chalcogen halides and the natural products thymol and carvacrol has been developed. The reactions of selenium dibromide with allyl thymol and allyl carvacrol proceeded in methylene chloride at room temperature in the presence of NaHCO3 affording bis[(7-isopropyl-4-methyl-2,3-dihydro-1-benzofuran-2-yl)methyl] and bis[(4-isopropyl-7-methyl-2,3-dihydro-1-benzofuran-2-yl)methyl] selenides in 90-92% yield. Similar sulfides were obtained in 70-72% yields by the reaction of sulfur dichloride in chloroform under reflux. Trihalotellanes containing the same organic moieties were synthesized from allyl thymol, allyl carvacrol and tellurium tetrachloride or tetrabromide in quantitative yields. Corresponding functionalized ditellurides were prepared in 91-92% yields by the reduction of the trichlorotellanes with sodium metabisulfite in two-phase solvent system. The comparison of reactivity of sulfur, selenium and tellurium halides in chalcogenocyclofunctionalization and distinguishing features of each reaction were discussed.

Natural Compounds and Their Structural Analogs in Regio- and Stereoselective Synthesis of New Families of Water-Soluble 2H,3H-[1,3]thia- and -Selenazolo[3,2-a]pyridin-4-ium Heterocycles by Annulation Reactions.

It has been found that both eugenol and isoeugenol derivatives reacted with 2-pyridinesulfenyl and 2-pyridineselenenyl halides in a regioselective mode affording products with opposite regiochemistry. Synthesis of new families of 2H,3H-[1,3]thia- and -selenazolo[3,2-a]pyridin-4-ium heterocycles has been developed by annulation reactions of 2-pyridinechalcogenyl halides with natural compounds (eugenol, isoeugenol, methyl eugenol, methyl isoeugenol, acetyl eugenol, trans-anethole) and their structural analogs. The influence of the substrate structure and the nature of halogen on the product yields are studied. The 2-pyridinesulfenyl and 2-pyridineselenenyl chlorides are more efficient reagents compared to corresponding bromides. The obtained condensed heterocycles are novel water-soluble functionalized compounds with promising biological activity.