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Small molecules that contain the (TFMO) moiety were reported to specifically inhibit the class-IIa histone deacetylases (HDACs), an important target in cancer and the disorders of the central nervous system (CNS). However, radiolabeling methods to incorporate the [18F]fluoride into the TFMO moiety are lacking. Herein, we report a novel late-stage incorporation of [18F]fluoride into the TFMO moiety in a single radiochemical step. In this approach the bromodifluoromethyl-1,2,4-oxadiazole was converted into [18F]TFMO via no-carrier-added bromine-[18F]fluoride exchange in a single step, thus producing the PET tracers with acceptable radiochemical yield (3–5%), high radiochemical purity (> 98%) and moderate molar activity of 0.33–0.49 GBq/umol (8.9–13.4 mCi/umol). We validated the utility of the novel radiochemical design by the radiosynthesis of [18F]TMP195, which is a known TFMO containing potent inhibitor of class-IIa HDACs. [ABSTRACT FROM AUTHOR]

A novel ionic liquid microemulsion composed of 1-octyl-3-methylimidazolium bis ((trifluoromethyl)sulfonyl)imide ([Omim]NTf, an ionic liquid), water, surfactant 1-hexadecyl-3-methylimidazolium bromide ([Cmim]Br, an ionic liquid), and cosurfactant n-butyl alcohol was prepared in our study. Pseudo-ternary phase diagram, conductivity measurement, and dynamic light scattering (DLS) analysis identified the microregion of microemulsion and confirmed the formation of water-in-ionic liquid (W/IL) region. Starch nanoparticles were prepared in the W/IL microemulsion with epichlorohydrin as cross-linker. Fourier transform infrared spectroscopy and X-ray diffraction characterized the structure of starch nanoparticles and demonstrated that cross-linking reaction happened among starch molecules. Scanning electron microscopy intuitively revealed that starch nanoparticles were spherical granules with smooth surface and fine dispersibility. Also, starch nanoparticles with a mean diameter of 93.2 nm and relatively concentrated size distribution were confirmed by DLS. [ABSTRACT FROM AUTHOR]

Amphiphilic substances, surfactants, are in common use to enhance the aqueous solubility of organic compounds. Solubilization of 3-{3,5-bis (trifluoromethyl)phenyl}quinoline was investigated by employing spectrophotometry, light scattering and tensiometry in micellar solutions of nonionic surfactants {dimethyldodecylamine-N-oxide, DDAO; polyoxyethylene(23)lauryl ether, Brij35; and polyoxyethylene(04)lauryl ether, Brij30}, a cationic surfactant (dodecyltrimethyl-ammonium bromide, DTAB), anionic surfactants (sodium dodecylbenzenesulfonate, SDBS; sodium dodecyl sulfate, SDS), and a zwitterionic surfactant (N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate, DDAPS). It is noted that the solubility of the title compound 3-{3,5-bis (trifluoromethyl)phenyl}quinoline increased linearly with the increase in surfactant concentration irrespective of the type of surfactant. This is due to association of the title compound with surfactants. The molar solubilization ratio (MSR), micelle-water partition coefficient ( K), and the Gibbs energy of solubilization ( $$ \Delta G_{\text{S}}^{\text{o}} $$ ) of the title compound in the micelles were determined and correlated with each other. The nonionic surfactant DDAO showed the highest solubilization capacity. The order of degree of solubility among nonionic, cationic, and anionic surfactants for 3-{3,5-bis (trifluoromethyl)phenyl}quinoline is DDAO > DDAPS > SDBS > DTAB > SDS > Brij35 > Brij30. This comparative study can be used to select an appropriate medium for the title compound's solubilization, where the nonionic surfactants DDAO, Brij35 and Brij30 would be more beneficial due to their minimal protein binding and retention of their micellar form even after large dilution in blood owing to their very low critical micellar concentration values. The light scattering study indicated that the hydrodynamic radius of the blank and drug-loaded surfactants remained the same within experimental error. [ABSTRACT FROM AUTHOR]

The reactions of acetone, 2,2,2-trifluoroacetone and hexafluoroacetone in methanesulfonic (MSA) and triflic acids (TFSA) with benzene have been studied at M06-2X/6-311+G(d,p) level using cluster-continuum model, where the carbonyl group is explicitly solvated by acid molecules. The introduction of a trifluoromethyl group into the ketone structure reduces the activation energy of the tetrahedral intermediates formation due to an increase of the electrophilicity of the carbonyl group and raises the activation and the reaction energies of the C-O bond cleavage in formed carbinol due to the destabilization of the corresponding carbocation. The introduction of the second trifluoromethyl group inhibits the hydroxyalkylation reaction due to a very strong increase of the reaction and activation energies of the C-O bond cleavage which becomes the rate determining step. The most important catalytic effect of TFSA compared to MSA is not the protonation of the ketone carbonyl, but the reduction of the activation and reaction energies of the carbinol C-O bond cleavage due to better protosolvation properties. Even for TFSA no complete proton transfer to carbonyl oxygen has been observed for free ketones. Therefore, the protonation energies of free ketones cannot be considered as a measure of ketone reactivity in the hydroxyalkylation reaction. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]