The affinity, relative to cortisol (l), of 17a-and 21-esters and 17a, 2l-diesters of cortisol for the glucocorticoid receptor of rat thymus cytosol was determined by a competitive binding assay which used [3H] dexamethasone. Esterification of the 21-hydroxy group of cortisol caused a loss of relative affinity to 0.046 for acetate and 0.32 for valerate. Esterfication of the l7a- hydroxy group resulted in an increase in relative affinity to 1.14 for acetate, 12.4 for ...
![[2-[(8S,9S,10R,11S,13S,14S,17R)-11,17-dihydroxy-10,13-dimethyl-3-oxo-2,6,7,8,9,11,12,14,15,16-decahydro-1H-cyclopenta[a]phenanthren-17-yl]-2-oxoethyl] pentanoate Structure](https://image.chemsrc.com/caspic/235/6678-00-8.png)