Supercritical carbon dioxide and co-solvent extractions of estradiol and progesterone from antler velvet

Supercritical carbon dioxide in the presence of co-solvent was used for extraction of the active sex hormones (including estradiol and progesterone) from antler velvet. The effects of ethanol concentration, flow rate of co-solvent, extraction pressure, temperature and extraction time on the extraction yield and content of sex hormones were studied, and a optimal condition was obtained. The qualitative–quantitative analysis of components in extract was determined by radioimmunoassay analysis (RIA), high performance liquid chromatography (HPLC) and thin layer chromatographic (TLC). Three biological bases and five phospholipids in the SFE extract were identified according to their chromatographic behavior and spectral characteristics. The major components were uracil (Ur), hypoxanthine (HX), uridine (U) and p-hydroxybenzaldehyde (PHBD), sphingomyelin (SPH), phophatidylcholine (PC), phosphatidylethanolamine (PE), lysophophatidylcholine (LPC) and lysophophatidylethanolamine (LPE). The experimental results showed that, when the co-solvent was 75% ethanol, the extraction pressure was 30 MPa, the temperature was 35 °C, the extraction time was 30 min, the consumption of CO2 was 15 L/g at the flow rate of 2.0 L/min, the mean yield and content of estradiol were 87.67 pg/g and 1224.10 pg/g, respectively, while the mean yield and content of progesterone were 25.66 ng/g and 354.06 ng/g, respectively. Under these conditions, the percentages of main analytes were increased, and the recovery of estradiol and progesterone was above 88%.