On the plasma protein binding of 16-acetyl-gitoxin.

The plasma protein binding of 16-acetyl-gitoxin (16-AG) was estimated in comparison with that of digoxin by the use of equilibrium dialysis, ultracentrifugation, and gel filtration techniques. Depending on temperature, the binding of 16-AG reached values between 81 and 90%. Calculations of the reaction enthalpy and entropy show that hydrophobic interaction results. The corresponding values of digoxin amount to 13 and 15%.