[Glycine determination according to the European Pharmacopoeia]. / Zur Kenntnis des Glycinnachweises des Europäischen Arzneibuchs.

The treatment of an aqueous solution of glycine with hypochlorite yields formaldehyde and glyoxylic acid. After acidification and removing formaldehyde by boiling glyoxylic acid reacts with resorcinol to the lactone of bis-2,4-dihydroxyphenyl acetic acid. Under alkaline conditions the lactone is oxidized to the violet oxonol anion and subsequently, after hydrolysis of the lactone, to the yellow fluorescent carboxylate anion.

Microionization constants: novel approach for the determination of the zwitterionic equilibrium of hydroxyphenylalkylamines by photometric titration.

The record of the formation of the phenolate and the zwitterionic form in the course of titration by photometry makes it possible to estimate the tautomeric equilibrium, K(Z), between the zwitterionic and the uncharged form of an ampholyte, provided that (1) the absorptivity of the phenolate and the zwitterionic form are identical and (2) the absorptivities of both forms are distinct from the absorptivities of the protonated and the uncharged form. The relation between the absorbance and K(Z), the degree of titration and the degree of overlapping of the basic and the acid ionization constant is given.

High-performance liquid chromatographic determination of pholedrine in human serum using ion-pair extraction and amperometric detection.

The method for the quantitation of pholedrine in human serum involves extraction of the sample with benzene utilizing an ion-pairing reagent, bis(2-ethylhexyl)phosphoric acid, and re-extraction into diluted phosphoric acid. Analysis is carried out on a ODS reversed-phase column with heptanesulfonate as the ion-pairing reagent. The procedure allows quantitation at the lower nanogram level and is useful for pharmacokinetic investigations.

Modified radioimmunoassay for pimozide.

Tritium labelled pimozide, the tracer in Michiels' RIA of pimozide, can be substituted for a derivative of pimozide with tritium labelled tag, prepared in a more convenient way than the original tracer. In the synthesis of the immunogen the conjugation rate is optimized to be 12 to 13.

Radioimmunoassay for the determination of pholedrine.

A radioimmunoassay for the determination of free pholedrine at the lower nanogram level was developed. The sulfate conjugate cross-reacts and has to be separated before the assay procedure in plasma.

Phospholipase A2 inhibition by alkylbenzoylacrylic acids.

3-(4-Alkylbenzoyl)acrylic acids (ABAAs) were synthesized by acylation of alkylbenzenes with maleic anhydride and then screened in vitro for inhibition of phospholipase A2 (PLA2) from snake venom and from porcine pancreas. The inhibitory potency of ABAAs increased with the length of the alkyl residues resulting in IC50 values of between 10(-7) and 10(-4) mol/L. The most potent inhibitors of the snake venom PLA2 were the 4-(n)-hexadecyl and octadecyl (OBAA) derivatives. Kinetic experiments referred to a time-dependent inhibitory reaction. Irreversibility was examined by dilution and dialysis. A molar ratio of inactivation of OBAA of nearly 20 was estimated. Double reciprocal replots of the apparent inactivation constants to the concentration of OBAA gave a (pseudo) first order rate constant of inactivation of 2.3 min-1. For the dissociation constant of the enzyme-inhibitor intermediate, a value of 6 x 10(-6) mol/L was obtained. On the other hand, the PLA2 from porcine pancreas seemed hardly to be inhibited by ABAAs. The present data are discussed in relation to the proposed model for PLA2 inactivation by manoalide. In human PMNs leukotriene B4 and 5-HETE production was essentially reduced. In human platelets the thrombin-induced TxA2 production was reduced. Since these effects disappeared after addition of arachidonic acid, these findings refer to a PLA2 inhibition. The immunologically induced bronchospasm in guinea pigs was significantly and dose-dependently inhibited by OBAA. This indicates that ABAAs might be useful in treating allergic diseases, such as asthma, eczema, allergic shock and others.

[The stability of hydrochlorothiazide and cyclopenthiazide in various dosage forms. 3. Stability of hydrochlorothiazide injection solutions]. / Untersuchungen zur Stabilität von Hydrochlorothiazid und Cyclopenthiazid in unterschiedlichen Arzneiformen. 3. Mitteilung1: Stabilität von Hydrochlorothiazid-Injektionslösungen I.

Studies of the stability of hydrochlorothiazide (1) in N-methylacetamide prove that a temperature dependent equilibrium is found in the isothermic short-term test as well as in the longterm stability test. Whereas the kinetic reaction evaluation after Arrhenius doesn't allow a forecast, the 25 degrees C-values, extrapolated after the Van't Hoff-equation, were confirmed using the long-term test. By adding the decomposition product aminodisulfamide (2) the hydrolysis is restricted.

[The affinity of aromatic fluoride derivatives of phenothiazine neuroleptics to spiroperidol binding sites of dopamine receptors by the radioligand technic in vitro]. / Untersuchungen zur Affinität kernfluorierter Derivate von Phenothiazin-Neuroleptica zur 3H-Spiroperidol-Bindungsstelle des Dopaminrezeptors mittels Radioligandtechnik in vitro.

By introduction of fluorine into the position 7 of butaperazine, chlorpromazine, methoxypromazine, perphenazine, prochlorperazine or into the position 3 of promazine derivatives are obtained with higher affinities for the 3H-spiroperidol binding site of the dopamine receptor compared with the corresponding substances free of fluorine.

[Pharmaceutic and biopharmaceutic evaluation of acetylaminonitropropoxybenzene (Falimint). A Biotransformation of the active agent]. / Zur pharmazeutischen und biopharmazeutischen Begutachtung von Acetylaminonitropropoxybenzolum (Falimint). 4. Mitteilung: Biotransformation des Wirkstoffes.

2-Acetamino-4-nitropropoxybenzene is metabolized almost completely. Till now in urine of man seven components have been detected. The main way of metabolism is the oxidation of the propoxy group to a carboxyl group. Also the deacetylated compound of this acid has been found to a certain extent. A further metabolite is supposed to be oxidized in the side chain in another way. In a higher extent dealkylation to 2-acetamino-4-nitrophenol takes place which is eliminated probably in conjugation with glucuronic acid. Free 2-acetamino-4-nitrophenol and 2-amino-4-nitrophenol respectively are only detectable in traces. Deacetylation of 2-amino-4-nitropropoxybenzene takes place only in a very small extent. Till now metabolites with reduced nitro group haven't been found.