Chiral micellar electrokinetic chromatography with laser-induced fluorescence detection (chiral-MEKC-LIF) was used to investigate D- and L-amino acid contents in cerebrospinal fluid (CSF) samples related to different Alzheimer disease (AD) stages. CSF samples were taken from (i) control subjects (S1 pool), (ii) subjects showing a mild cognitive impairment who remained stable (S2 pool), (iii) subjects showing an mild cognitive impairment that progressed to AD (S3 pool) and (iv) subjects diagnosed with AD (S4 pool). The optimized procedure only needed 10 μL of CSF and it included sample cleaning, derivatization with FITC and chiral-MEKC-LIF separation. Eighteen standard amino acids were baseline separated with efficiencies up to 703,000 plates/m, high sensitivity (LODs in the nM range) and good resolution (values ranging from 2.6 to 9.5). Using this method, L-Arg, L-Leu, L-Gln, γ-aminobutyric acid, L-Ser, D-Ser, L-Ala, Gly, L-Lys, L-Glu and L-Asp were detected in all the CSF samples. S3 and S4 samples (i.e. AD subjects) showed significant lower amounts of L-Arg L-Lys, L-Glu and L-Asp compared to the non-AD S1 and S2 samples, showing in the S4 group the lowest amounts of L-Arg L-Lys, L-Glu and L-Asp. Moreover, γ-aminobutyric acid was significantly higher in AD subjects with the highest amount also found for S4. No significant differences were observed for the rest of amino acids including D-Ser. Based on the obtained chiral-MEKC-LIF data, it was possible to correctly classify all the samples into the four groups. These results demonstrate that the use of enantioselective procedures as the one developed in this work can provide some new light on the investigations of AD, including the discovery of new biomarkers related to different stages of AD.

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The enantiomers of ketoprofen were separated by capillary electrophoresis using the (2,3,6-tri-O-methyl)-derivatives of α-, β-, and γ-cyclodextrin (CyD) as chiral selectors. The affinity pattern of the ketoprofen enantiomers toward these CyDs changed depending on their cavity size. Thus, with hexakis (2,3,6-tri-O-methyl)-α-CyD and heptakis (2,3,6-tri-O-methyl)-β-CyD, the R enantiomer of the drug migrated first, whereas the enantiomer migration order was reversed in the presence of octakis(2,3,6-tri-O-methyl)-γ-CyD. The change in the migration order was rationalized on the basis of changes in the structure of the complexes between the ketoprofen enantiomers and the chiral selectors as derived from nuclear magnetic resonance spectroscopy experiments.

New silicon-organic polyepoxides containing epoxy side groups attached to their main chains have been synthesised by hydride addition (hydrosilylation) of dihydrosiloxanes with the diallyl ether of an epoxidised glycerol group situated at the tertiary carbon atom. General features of the reaction were studied and its kinetic rate constants and reaction order determined. The relative reactivities of various dihydridesiloxanes in the hydrosilylation reaction were determined. The modification of the polyepoxides introduced chelates containing Cu, Ni, Mn and Co atoms into the main chain. The composition and structure of the synthesised polymers were established from elemental, IR and NMR spectral analyses and from DSC, DTA and TGA data. It was established that the glass transition temperature (Tg) and thermo-oxidative stability of the chelate-containing polymers considerably exceeded those of the unmodified polyepoxides.