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A regio- and stereoselective method for the synthesis of N-unsubstituted 3-aryl-4-(trifluoromethyl)-4H-spiro[chromeno[3,4-c]-pyrrolidine-1,3'-oxindoles] in 24–79% yields, based on the three-component reaction of 3-nitro-2-(trifluoromethyl)-2H-chromenes with azomethine ylides generated in situ from benzylamines and isatins by refluxing in CH2Cl2 for 24 h has been developed. 3-Phenyl-4-(trifluoromethyl)-4H-spiro[chromeno[3,4-c]pyrrolidine-1,3'-oxindoles] were obtained in 36–71% yields via the three-component reaction of 3-nitro-2-(trifluoromethyl)-2H-chromene, isatins, and L-phenylglycine proceeding in EtOH at 60°C for 5 h. The resulting compounds exhibited cytotoxic activity against human cervical cancer HeLa cells in the micromolar concentration range.

The crystal structures of four new chiral [1,2,3]triazolo[5,1-b][1,3,4]thiadiazines are described, namely, ethyl 5′-benzoyl-5′H,7′H-spiro[cyclohexane-1,6′-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine]-3′-carboxylate, C19H22N4O3S, ethyl 5′-(4-methoxybenzoyl)-5′H,7′H-spiro[cyclohexane-1,6′-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine]-3′-carboxylate, C20H24N4O4S, ethyl 6,6-dimethyl-5-(4-methylbenzoyl)-6,7-dihydro-5H-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine-3-carboxylate, C17H20N4O3S, and ethyl 5-benzoyl-6-(4-methoxyphenyl)-6,7-dihydro-5H-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine-3-carboxylate, C21H20N4O4S. The crystallographic data and cell activities of these four compounds and of the structures of three previously reported similar compounds, namely, ethyl 5′-(4-methylbenzoyl)-5′H,7′H-spiro[cyclopentane-1,6′-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine]-3′-carboxylate, C19H22N4O3S, ethyl 5′-(4-methoxybenzoyl)-5′H,7′H-spiro[cyclopentane-1,6′-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine]-3′-carboxylate, C19H22N4O4S, and ethyl 6-methyl-5-(4-methylbenzoyl)-6-phenyl-6,7-dihydro-5H-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine-3-carboxylate, C22H22N4O3S, are contrasted and compared. For both crystallization and an MTT assay, racemic mixtures of the corresponding [1,2,3]triazolo[5,1-b][1,3,4]thiadiazines were used. The main manner of molecular packing in these compounds is the organization of either enantiomeric pairs or dimers. In both cases, the formation of two three-centre hydrogen bonds can be detected resulting from intramolecular N—H...O and intermolecular N—H...O or N—H...N interactions. Molecules of different enantiomeric forms can also form chains through N—H...O hydrogen bonds or form layers between which only weak hydrophobic contacts exist. Unlike other [1,2,3]triazolo[5,1-b][1,3,4]thiadiazines, ethyl 5′-benzoyl-5′H,7′H-spiro[cyclohexane-1,6′-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine]-3′-carboxylate contains molecules of only the (R)-enantiomer; moreover, the N—H group does not participate in any significant intermolecular interactions. Molecular mechanics methods (force field OPLS3e) and the DFT B3LYP/6-31G+(d,p) method show that the compound forming enantiomeric pairsviaweak N—H...N hydrogen bonds is subject to greater distortion of the geometry under the influence of the intermolecular interactions in the crystal. For intramolecular N—H...O and S...O interactions, an analysis of the noncovalent interactions (NCIs) was carried out. The cellular activities of the compounds were tested by evaluating their antiproliferative effect against two normal human cell lines and two cancer cell lines in terms of half-maximum inhibitory concentration (IC50). Some derivatives have been found to be very effective in inhibiting the growth of Hela cells at nanomolar and submicromolar concentrations with minimal cytotoxicity in relation to normal cells.

The alkylation of 6-(polyfluoro)alkyl-2-thiouracils with 4-bromobutyl acetate in refluxing acetonitrile in the presence of K2CO3 proceeds regioselectively to give S, O-disubstituted pyrimidines as the major products and S,N-isomers as the minor ones, whereas the use of 2-bromoacetophenone as an alkylating agent results in the formation of the S,O-isomer. 6-Trifluoromethyl-2-thiouracil and 2-(2-oxo-2-phenylethylthio)-4-(2-oxo-2-phenylethoxy)-6-trifluoromethyl-pyrimidine exhibited marked tuberculostatic activity. 6-Trifluoromethyl-2-thiouracil did not exert a significant cytotoxic effect on the HeLa cell culture and human dermal fibroblasts.

A one-pot three-component reaction of azomethine ylides generated in situ from isatins and sarcosine with 3-nitro-2-(trifluoromethyl)-2H-chromenes in i-PrOH at 55–60 °C leads to the kinetically controlled products – exo-spiro[chromeno[3,4-c]pyrrolidine-3,3′-oxindoles]. When this reaction is carried out in 1,4-dioxane under reflux, the thermodynamically controlled endo-spiro[chromeno[3,4-c]pyrrolidine-1,3′-oxindoles] are preferably formed. The isomerization of the kinetic products in DMSO solution at different temperatures has been studied by NMR spectroscopy and the stepwise mechanism of reversible [3+2] cycloaddition has been confirmed. The cytotoxic activity of some CF3-substituted spiro[chromeno[3,4-c]pyrrolidine-oxindoles] against the HeLa cell line was evaluated by the MTT test.

For the culture of normal and transformed fibroblasts, the differential effect of two nanoclusters (Мо72Fe30, Мо132) has been shown. The Мо72Fe30 nanocluster is nontoxic to normal fibroblasts, while the Мо132 cluster shows toxicity to normal and transformed fibroblasts. An analysis of the ultrastructure of the cells under the influence of the nanoclusters has demonstrated the specificity of the changes. The dermal fibroblasts are more resistant to the action of Мо72Fe30; the Мо132 cluster causes extensive disorders in the membrane organelles both in normal and transformed fibroblasts. The results confirm the possibility of applying the Мо72Fe30 nanocluster in biomedicine and the use of the Мо132 nanocluster in oncology.

Interactions of bimodal (fluorescent and magnetic) nanoparticles with HeLa cells were studied. The nanoparticles, characterized by high magnetic moment and relaxing capacity, exhibited fluorescence sufficient for their use as labels in confocal microscopy and flow cytometry. Penetration of these nanoparticles into the cell depended on their surface charge: positively charged nanoparticles of this structure penetrated inside, while negatively charged particles were not found in the cells.

Hybrid nanoparticles based on Fe3O4 and CdS combining magnetic and luminescence properties were synthesized. The possibility of visualization of various cells by 3-mercaptopropylsilane-modified CdS nanoparticles and hybrid nanoparticles based on them using a confocal microscope was demonstrated. The synthesized materials did not show a clear-cut cytotoxicity.

This study presents the synthesis and optical properties of a new class of bright green-yellow fluorescent dyes with potential applications in bioimaging. A facile synthetic route via the chelation of aryl(hetaryl)aminoacryloylthiophene scaffolds with a BF2 fragment is presented. The photophysical properties of the dyes are attributed to the nature and position of electron-donating and electron-withdrawing substituents. Upon coordination to a BF2 fragment, characteristic emission was observed, with λem ranging from 503 to 543 nm and quantum yields of 0.14-0.42. Compared with parent aryl(hetaryl)aminoacryloylthiophenes, a significant red shift in absorption (up to 480 nm in solution) and emission (up to 543 nm in solution and 610 nm in the solid state) and high chemical stability and photostability were observed. The electron-accepting character of the substituents on the terminal aromatic ring or replacing this fragment with pyridine or pyrazine moieties resulted in increased quantum yields. To gain insight into the electronic structures and optical properties, quantum mechanical calculations were performed. The results of (TD-)DFT calculations supported the structural and spectroscopic data and showed the features of electronic distribution in the frontier molecular orbitals and active electrophilic and nucleophilic sites in the compounds investigated. Synthesized BF2 complexes are promising dyes for cell imaging and flow cytometry owing to their ready penetration and accumulation in cells.