Determination of acid dissociation constants, enthalpy, entropy and Gibbs free energy of the baricitinib by the UV-metric and pH-metric analysis.

Baricitinib is a drug used for the treatment of rheumatoid arthritis. It is a selective and reversible inhibitor of Janus kinases 1 and 2, which play an important role in signalling the pro-inflammatory pathway activated in autoimmune disorders such as rheumatoid arthritis. The pH-spectrophotometric and pH-potentiometric titrations allowed the measurement of three or four successive dissociation constants of Baricitinib.

The dissociation constants of the cytostatic bosutinib by nonlinear least-squares regression of multiwavelength spectrophotometric and potentiometric pH-titration data.

Potentiometric and spectrophotometric pH-titration of the multiprotic cytostatics bosutinib for dissociation constants determination were compared. Bosutinib treats patients with positive chronic myeloid leukemia. Bosutinib exhibits four protonatable sites in a pH range from 2 to 11, where two pK are well separated (ΔpK>3), while the other two are near dissociation constants.

Reliability of dissociation constants and resolution capability of SQUAD(84) and SPECFIT/32 in the regression of multiwavelength spectrophotometric pH-titration data.

The resolving power of multicomponent spectral analysis and the computation reliability of the stability constants and molar absorptivities determined for five variously protonated anions of physostigmine salicylate by the SQUAD(84) and SPECFIT/32 programs has been examined with the use of simulated and experimental spectra containing overlapping spectral bands. The reliability of the dissociation constants of drug was proven with goodness-of-fit tests and by examining the influence of pre-selected noise level s(inst)(A) in synthetic spectra regarding the precision s(pK) and also accuracy of the estimated dissociation constants. Precision was examined as the linear regression model s(pK)=β(0)+β(1)s(inst)(A).

Biological protection of the main cereals against fungal specific diseases.

Our field experiments showed that the use of Czech biopreparations (Supresivit, Ibefungin and Polyversum) based on the following microorganisms: Trichoderma harzianum, Bacillus subtilts and Pythium oligandrum applied as the seed treatment, the spray on the plants and like the mixture with mineral fertilizers (NPK, ammonium sulphate) lead namely after the seed-treatment and after the application as the mixture with mineral fertilizers to the increasing of the yield about 3-5 % (spring barley, winter wheat). This increasing was given by depression of soil-borne phytopathogenic fungi of the genera: Fusarium, Drechslera (Helminthosporium), Pseudocercosporella (Tapesia), Gaeumannomyces, and partially Rhynchosporium. The number of the fungi on plant rests were also influenced.

Multiparametric curve fitting-XII Resolution capability of two programs for analysing multicomponent spectra, squad(84) and psequad(83).

The resolving power of multicomponent spectra analysis and the computation reliability of the stability constants and molar absorptivities determined for nine variously protonated anions of three sulphonephthaleins and an impurity, by analysis of data for a mixture by programs SQUAD(84) and PSEQUAD(83), has been examined by use of synthetic and experimentally measured spectra containing severely overlapping spectral bands. The model mixture of Bromocresol Green, Phenol Red, Thymol Blue and azoxine as impurity, with five yellow, three blue and one red species in the pH range from 2 to 10, was used to examine the influence of precision of spectral data and of use of the spectra of the individual components, on the precision and accuracy of the estimated parameters when the chemical model is known. An efficient computation strategy has been found and both programs were shown to lead to the same values and reliability of the parametric estimates.