Newly synthesized derivatives of β-cyclodextrin, mono(6-deoxy-6-(1-1,2,3-triazo-4-yl)-1-propane-3-O-(4-methoxyphenyl))β-cyclodextrin (1) and mono(6-deoxy-6thio(1-propane-3-O-(4-methoxyphenyl))) β-cyclodextrin (2) were designed to be receptors of the anticancer drug doxorubicin, which could potentially decrease the adverse effects of the drug during treatment. In both aqueous and aqueous dimethyl sulfoxide (DMSO) solutions, doxorubicin forms an inclusion complex with the new cyclodextrin derivatives with formation constants of K(s) = 2.3 × 10(4) and K(s) = 3.2 × 10(5) M(-1) for cyclodextrins 1 and 2, respectively. The stabilities of the complexes are 2-3 orders of magnitude greater than those with native β-cyclodextrin, and the flexibility of the linker of the side group of the cyclodextrins contributes to this stability. In a hydrogen-bond-accepting solvent, such as pure DMSO, an association that includes hydrogen bonding and chloride ions is favored over the binding of doxorubicin in the cavity of the cyclodextrin derivative. This contrasts with an aqueous medium in which a strong inclusion complex is formed. Cyclic voltammetry, UV-vis, (1)H NMR, and molecular modeling studies of solutions in DMSO and of solutions in water/DMSO demonstrated that the two different modes of intermolecular interaction between doxorubicin and the cyclodextrin derivative depended on the solvent system being utilized.

The gold electrode is functionalized by sequential self-assembly of a monolayer of the title thiolated cyclodextrin with and without dopamine included in the cavities. The structure of a-cyclodextrin modified gold electrode is carefully characterized using STM and AFM. Surface complexation of dopamine is examined and its association constant is evaluated. Chemical reactions accompanying the electrode process of dopamine, which interfere in the electrochemical dopamine determination, are described and the conditions to avoid them are proposed. Dopamine incorporated in the a-cyclodextrin sites anchored to the electrode surface was found to provide electrochemical contact of the electrode with the solution-resident dopamine. Dopamine present in the a-cyclodextrin cavities has different properties compared to dopamine in the bulk buffer solution and can act as a mediator for the dopamine molecules diffusing to the electrode. This unique mediation effect leads to improvement of the sensitivity of dopamine determination using the a-cyclodextrin modified electrode and a procedure for the determination of dopamine in large excess of ascorbate is proposed.

Mono-and hepta-antennated C-6 branched glycosylthioureido-cyclomaltoheptaose derivatives have been prepared efficiently by reaction, at ambient temperature, of b-d-glycopyranosyl isothiocyanates in the glucopyranose, cellobiose, and lactose series with either 6 I -amino-6 I -deoxycyclomaltoheptaose in pyridine or heptakis(6-amino-6-deoxy)cyclomaltoheptaose in water ± acetone at pH 8. The reverse strategy, which involves the corresponding glycosylamines as nucleophiles in reaction with cyclomaltoheptaose isothiocyanates, proved less satisfactory resulting in a number of by-products which hampered the purification step. The synthetic scheme was extended to alkyl and aryl isothiocyanate, electrophiles which as functional groups are of interest for the elaboration of dendritic wedges and the modification of the interaction and inclusion properties of cyclodextrins.

The compressed sensing NMR (CS-NMR) is an approach to processing of nonuniformly sampled NMR data. Its idea is to introduce minimal l(p) -norm (0 < p ≤ 1) constraint to a penalty function used in a reconstruction algorithm. Here, we demonstrate that 2D CS-NMR spectra allow the full spectral assignment of near-symmetric β-cyclodextrin derivatives (mono-modified at the C6 position). The application of CS-NMR ensures experimental time saving and the resolution improvement, necessary because of very low chemical shift dispersion. In the overnight experimental time, the set of properly resolved 2D NMR spectra required for the unambiguous assignment of mono(6-deoxy-6-(1-1,2,3-triazo-4-yl)-1-propane-3-O-(phenyl)) β-cyclodextrin was obtained. The highly resolved HSQC spectrum was reconstructed from 5.12% of the data. Moreover, reconstructed 2D HSQC-TOCSY spectrum yielded information about the correlations within one sugar unit, and 2D HSQC-NOESY technique allowed the sequential assignment of the glucosidic units.