3 RESULTS AND DISCUSSION
3.1 SC-CO2 and co-solvent extraction of estradiol
and progesterone
The structures of estradiol and progesterone are
shown in Fig. 2. In our previously study, pure SC-CO2
was first used to investigate the possibility of extracting
estradiol and progesterone from antler velvet.
However, non-polar CO2 can not easily extract polar
estradiol and progesterone from antler velvet.