Study On The Processes Of Supercritical CO₂ Extraction And Ultrafiltration Concentration For Separating Active Components From Antler Velvet

Antler velvet, as a kind of traditional Chinese medicine, has long been recognized as one of the most effective and powerful invigorants for strengthening the kidney, sexual-reinforcing and pro-longing life. Many substances from antler velvet were identified and claimed to contain active components. Among these components, some biological bases(e.g. hypoxanthine), steroidal compounds, phospholipid and cholesterol have inhibitory effect on monoamine oxidase(MAO); insulin-like growth factor-1(IGF-1), which can promote the body's growth and development, has special effect on diabetes mellitus and its complications. Therefore, it is important to extract and separate active components from antler velvet by advanced separation technology for promoting the modernization of Chinese traditional medicine production.Based on the previous research results in our laboratory and the idea of comprehensive utilization, supercritical CO₂ extraction of MAO inhibitor was firstly investigated with antler velvet freeze-dried powder as raw material. The optimum results show that the extraction yield can reach 3.92% under pressure of 35MPa and temperature of 35℃.The extracts of antler velvet obtaind by supercritical fluid (EAS) inhibit MAO-B activity in an apparently dose-dependent manner. The activity of MAO-B and MAO-A were inhibited up to 94.87% and 18.92% respectively at 238.15mg/L EAS phosphate solution, which shows that EAS has certain inhibition selectivity on MAO.The chemical composition of EAS was analyzed by GC-MS. The analytical results show that there are 29 kinds of important active components in EAS, including saturated fatty acids, unsaturated fatty acids, steroids and cholesterol.Ultrasonic extraction was further used to extract IGF-1 and protein from the residues of SFE. The experimental results show that the extraction yields from residues can reach a higher degree under pressure of 35MPa and temperature not exceeding 40℃. The extraction yields of IGF-1 and protein from residue can reach 20.86μg/g and 130.73mg/g respectively at the optimal condition. The extraction yields of IGF-1 and protein with ultrasonic extraction from SFE residue are higher than those from antler velvet freeze-dried powder directly.Polyethersulfone (PES) membrane and modified PES membrane were used for further concentration. The effect of MWCO, pressure, pH and concentration rate on IGF-1 ultrafiltration process was investigated, and the optimal conditions were obtained. The recovery rate of IGF-1 and protein can reach 68.32% and 69.20% respectively by PES membrane, while the recovery rate of IGF-1 and protein can reach 57.17% and 87.43% respectively by modified PES membrane.Different methods were employed to clean membrane. The results show that membrane immersed in 4‰NaOH-1‰NaClO solution for 24h is the appropriate cleaning method, in which PES membrane water flux recovery rate can reach 98.65% and modified PES membrane water flux recovery rate can reach 93.75%.