Choleic acids

Experiments on the mode of action of hexyl resorcinol as an anthelmintic

1. Hexyl resorcinol penetrates readily into Ascaris lumbricoides var. suis through the cuticle.

2. The rate of penetration is roughly proportional to the concentration of the drug in the medium, and is not significantly affected by changes of pH. or oxygen tension and the presence of a number of other substances, including other drugs and certain nutrient substances.

3. The rate of penetration is greatly decreased by gastric mucin and certain concentrations of bile salts and soaps.

4. The rate of penetration of the drug is increased by certain concentrations of sodium oleate.

Light-scattering studies on bile acid salts II: pattern of self-association of sodium deoxycholate, sodium taurodeoxycholate, and sodium glycodeoxycholate in aqueous electrolyte solutions

The pattern of self-association of the bile salts sodium deoxycholate, sodium glycodeoxycholate, and sodium taurodeoxycholate was investigated in aqueous electrolyte solutions by the light-scattering technique. The turbidity of the bile salt solutions was obtained over the concentration range of 0-20 mg/ml at 25 degrees. These data were analyzed according to a monomer-micellar equilibrium model and a stepwise association model. Comparison of the light-scattering data with these models suggests that the monomer-micellar model may be inappropriate. Analysis of the data according to the stepwise association model suggests that the dihydroxy bile salts associate to form dimers, trimers, and tetramers in addition to a larger aggregate which varies in size depending on the degree of conjugation of the bile salt.