Synthesis and Antibacterial Activity Studies of the Conjugates of Curcumin with -Dodecaborate and Cobalt Bis(Dicarbollide) Boron Clusters.

A series of novel conjugates of cobalt bis(dicarbollide) and -dodecaborate with curcumin were synthesized by copper(I)-catalyzed azide-alkyne cycloaddition. These conjugates were tested for antibacterial activity. It was shown that all derivatives are active when exposed to ATCC 10702 and are not active against Gram-negative microorganisms and at the maximum studied concentration of 1000 mg/L.

Synthesis and Structure of -Carboranyl Azide and Its "Click" Reactions.

Novel zwitter-ionic -carboranyl azide 9-N(CH)MeN--7,8-CBH was prepared by the reaction of 9-Cl(CH)MeN--7,8-CBH with NaN. The solid-state molecular structure of -carboranyl azide was determined by single-crystal X-ray diffraction. 9-N(CH)MeN--7,8-CBH was used for the copper(I)-catalyzed azide-alkyne cycloaddition with phenylacetylene, alkynyl-3β-cholesterol and cobalt/iron bis(dicarbollide) terminal alkynes to form the target 1,2,3-triazoles.

Effects of Linkers on the Development of Liposomal Formulation of Cholesterol Conjugated Cobalt Bis(dicarbollides).

Boron neutron capture therapy (BNCT) remains an important treatment arm for cancer patients with locally invasive malignant tumors. This therapy needs a significant amount of boron to deposit in cancer tissues selectively, sparing other healthy organs. Most of the liposomes contain water-soluble polyhedral boron salts stay in the core of the liposomes and have low encapsulation efficiency.

Boron-Containing Lipids and Liposomes: New Conjugates of Cholesterol with Polyhedral Boron Hydrides.

A series of boron-containing lipids were prepared by reactions of cyclic oxonium derivatives of polyhedron boranes and metallacarboranes (closo-dodecaborate anion, cobalt and iron bis(dicarbollides)) with amine and carboxylic acids which are derived from cholesterol. Stable liposomal formulations, on the basis of synthesized boron-containing lipids, hydrogenated soybean l-α-phosphatidylcholine and (HSPC) 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG) as excipients, were prepared and then characterized by dynamic light scattering (DLS) that revealed the formation of particles to be smaller than 200 nm in diameter. The resulting liposomal formulations showed moderate to excellent loading and entrapment efficiency, thus justifying the design of the compounds to fit in the lipid bilayer and ensuring ease of in vivo use for future application.

Fast flip-flop of halogenated cobalt bis(dicarbollide) anion in a lipid bilayer membrane.

Transmembrane translocation (flip-flop) of cobalt bis(dicarbollide) (COSAN) anions, elicited by application of a voltage-jump across the lipid bilayer membrane, manifested itself in monoexponential electrical current transients in the microsecond time scale. Halogenation of COSAN led to multi-fold acceleration of the flip-flop, the effect increasing with the molecular weight of the halogens. The exception was a fluorinated analog which exhibited slowing of the translocation kinetics.

Molecular conductors with a 8-hydroxy cobalt bis(dicarbollide) anion.

Molecular conductors based on the 8-hydroxy cobalt bis(dicarbollide) anion, (TMTTF)[8-HO-3,3'-Co(1,2-C2B9H10)(1',2'-C2B9H11)] (1), (BMDT-TTF)[8-HO-3,3'-Co(1,2-C2B9H10) (1',2'-C2B9H11)] (2), and (BEDT-TTF)[8-HO-3,3'-Co(1,2-C2B9H10)(1',2'-C2B9H11)] (3), were synthesized, and their crystal structures and electrical conductivities were determined. Compounds 2 and 3 are isostructural to the corresponding radical-cation salts of the parent cobalt bis(dicarbollide). All of the radical-cation salts prepared were found to be semiconductors.