Cocrystal formation, crystal structure, solubility and permeability studies for novel 1,2,4-thiadiazole derivative as a potent neuroprotector.

The cocrystallization approach has been applied to modify the poor solubility profile of the biologically active 1,2,4-thiadiazole derivative (TDZ). Extensive cocrystal screening with a library of coformers resulted in formation of a new solid form of TDZ with vanillic acid in a 1:1 molar ratio. The cocrystalline phase was identified and characterized by thermal and diffraction analyses including single-crystal X-ray diffraction.

Thermostability of photosystem I trimers and monomers from the cyanobacterium Thermosynechococcus elongatus.

The performance of solar energy conversion into alternative energy sources in artificial systems highly depends on the thermostability of photosystem I (PSI) complexes Terasaki et al. (2007), Iwuchukwu et al. (2010), Kothe et al.

Selective Na(+)/K(+) effects on the formation of α-cyclodextrin complexes with aromatic carboxylic acids: competition for the guest.

We investigated the effects of K(+) and Na(+) ions on the formation of α-cyclodextrin complexes with ionized aromatic carboxylic acids. Using solution calorimetry and (1)H NMR, we performed the thermodynamic and structural investigation of α-cyclodextrin complex formation with benzoic and nicotinic acids in different aqueous solutions containing K(+) and Na(+) ions as well as in pure water. The experiments show that the addition of sodium ions to solution leads to a decrease in the binding constants of the carboxylic acids with α-cyclodextrin as compared to pure water and solutions containing potassium ions.

Investigation of the pH-dependent complex formation between beta-cyclodextrin and dipeptide enantiomers by capillary electrophoresis and calorimetry.

The effect of pH on complex formation between beta-CD and the enantiomers of the dipeptides Ala-Phe, Ala-Tyr and Asp-PheOMe was investigated at 298.15 K by CE and calorimetry. Beta-CD displayed a higher enantioselectivity toward the protonated peptides compared to their zwitterionic forms.

Interactions of beta- and hydroxypropyl-beta-cyclodextrin with some purine alkaloids: thermodynamic study.

The effect of native and hydroxypropylated beta-cyclodextrin on the solubility and activity of some purine alkaloids was examined. For this purpose, the solubility of purine alkaloids in pure water and in aqueous solutions of mentioned beta-cyclodextrins was determined at 298.15 K.

Study on complex formation of biologically active pyridine derivatives with cyclodextrins by capillary electrophoresis.

The capillary electrophoretic separation of the pyridine derivatives pyridoxine, pyridoxal, nicotinamide, nicotinic acid and isonicotinic acid in phosphate buffer using cyclodextrins as buffer additives was studied at pH 2.0 and 3.5.

P700+- and 3P700-induced quenching of the fluorescence at 760 nm in trimeric Photosystem I complexes from the cyanobacterium Arthrospira platensis.

The 5 K absorption spectrum of Photosystem I (PS I) trimers from Arthrospira platensis (old name: Spirulina platensis) exhibits long-wavelength antenna (exciton) states absorbing at 707 nm (called C707) and at 740 nm (called C740). The lowest energy state (C740) fluoresces around 760 nm (F760) at low temperature. The analysis of the spectral properties (peak position and line width) of the lowest energy transition (C740) as a function of temperature within the linear electron-phonon approximation indicates a large optical reorganization energy of approximately 110 cm(-1) and a broad inhomogeneous site distribution characterized by a line width of approximately 115 cm(-1).