after a 30-min incubation at 37 degrees c in serum , percentage of hydrolysis for acetyloxy , propionyloxy , butyryloxy , pivaloyloxy and octanoyloxy esters of hpr is 41 , 20 , 7.5 , 1.9 and 1.5 , respectively .
C0020291
hydrolysis
C1337105
hpr