Structural analysis of an impurity of the drug landiolol.

In a course of development and preparation of landiolol (1a), a known ultra-short-acting β-blocker, process quality control by HPLC and LC-MS analysis consistently showed an impurity peak ranging from 0.05% to 0.15 % and exhibiting a molecular mass m/z 887.

Synthesis of glycyrrhetinic acid derivatives for the treatment of metabolic diseases.

The effect of glycyrrhetinic acid (GA) and GA-derivatives towards 11beta-hydroxysteroid dehydrogenase (11beta-HSD) was investigated. Novel compounds with modifications at positions C-3, C-11 and C-29 of the GA skeleton were prepared. Single crystal X-ray diffraction data of selected substances are reported and discussed.

Efficient synthesis of glycyrrhetinic acid glycoside/glucuronide derivatives using silver zeolite as promoter.

3-O-Glycopyranosides of glycyrrhetinic acid have been synthesized in good to high yields and excellent stereoselectivity using glycosyl bromide donors and silver zeolite as promoter. In addition to the preparation of glycosides containing beta-linked glucosyl, 2-deoxy-2-trichloroacetamido-glucosyl, galactosyl, cellobiosyl and lactosyl residues, also the deactivated acetylated methyl glucopyranosyluronate bromide donor could be coupled to triterpene aglycon ester derivatives in good yields. The ester protecting group located at C-30 of the oleanolic acid scaffold exerted an influence on the overall yield, with the methylester-protected glycosyl acceptor giving better yields compared to the allyl, benzyl as well as diphenylmethyl ester aglycon.

Evaluation of acid-base disorders in dairy cows using principal component analysis and empiric equations.

Acid-base disorders were studied in two groups of dairy cows. According to conventional interpretation in the 1st group of dairy cows (n = 10) the results of the acid-base parameters indicated respiratory alkalosis and in the 2nd group (n = 10) metabolic acidosis. The data of the two groups were examined using principal component analysis.

[Functional liver disorder in relation to decreased titratable acidity of milk].

The internal environment of 17 dairy cows was observed by help of 23 variables of metabolic profile in blood and milk at lowered titratable acidity of milk (Tab. I) Average values of the observed variables were compared with reference values in a histogramme (Fig. 1).