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Biomedical subjects

J H Perrin

Publications and source records attributed to J H Perrin.

At least 73 records · Page 4Linked to original sources
PubMed1976

A reversed-phase thin-layer chromotographic method for the determination of relative partition coefficients of very lipophilic compounds.

A reversed-phase thin-layer chromatographic method has been developed for the determination of partition coefficients. A support phase has been chosen, following investigation of the lack of adsorptive properties, which has a minimal effect on the pH of the buffer system. A stationary phase has been chosen to give deltaRm values of the same magnitude as Hansch pi values for a series of phenothiazines. The method can be applied to molecules of a wide range of lipophilicity following preliminary investigations of suitable phase-volume ratios and of the pH and composition of the binary mobile phase, providing adsorption on the support phase is excluded.

Adsorption↗
PubMed1976

Comparison of graphical and computerized methods for calculating binding parameters for two strongly bound drugs to human serum albumin.

The determination of drug-protein binding parameters (n's and K's) can lead to important information on the required therapeutic dosage regimen and possible clinical complications associated with competitive displacement of one drug by a concurrently administered agent. Graphical and computer estimates of the data are often incorrectly formulated, and and seldom are adequate data obtained at low binding ratios. Commonly used graphical procedures, inadequately formulated computer methods, and a statistically correct computer method were used to compare results obtained from a circular dichroic examination of dicumarol-human serum albumin and fenoprofen-human serum albumin interactions. Literature binding constants for dicumarol-albumin range from 1 X 10(5) to 30 times that figure, and it is shown here that a wide range in parameter estimates may be obtained depending on the method of data analysis. The parameter estimates in the case of fenoprofen-albumin are even more variable.

Binding Sites↗
PubMed1976

Effect of chain length on critical micelle formation and protein binding of quaternary ammonium compounds.

The micelle formation tendency (log 1/CMC)) of a series of alkyldimethylbenzylammonium compounds is shown to be linearly dependent on the alky chain length, indicating no curling of the side chain up to C19. Protein binding of these charged molecules on the primary binding site for sulfaethiodole is shown to be parabolically dependent on the chain length with an optimal chain length around C16.

Binding Sites↗
PubMed1975

Preliminary investigations of intrinsic and extrinsic optical activity as purity criterion for human serum albumins.

Induced circular dichroism measurements were made to follow the binding of four acidic drugs to two lots of crystalline and two lots of fraction V human serum albumins. The magnitude of the induced circular dichroism varied with all lots of albumin, suggesting a strong sensitivity of the phenomenon to small changes in purity or secondary structure of the albumins. The circular dichroism of the albumins themselves showed much less variation. The more classical analytical techniques of UV absorption, measurement of absorption following methyl orange binding, gel electrophoresis, and ultracentrifugation were also performed on the albumins for comparison.

Blood Protein Electrophoresis↗