Supercritical CO2 Extraction of Flavonoids from Apocynum venetum and Its Antimicrobial Activity
In order to solve the problem of waste of flavonoids in Apocynum venetum fibers by traditional degumming process, the Apocynum venetum fibers were pretreated by supercritical degumming, and the effective components of flavonoids were extracted by supercritical CO2. Four main factors affecting the extraction of flavonoids in Apocynum venetum were studied and analyzed. Then the extracts were analyzed by high performance liquid chromatography and antimicrobial experiments. The results showed that the co-solvent mainly affected the polarity of supercritical fluid. With the increase of co-solvent content, the extraction efficiency of flavonoids increased. However, when the co-solvent content was too high, excessive water could easily cause blockage of extraction pipeline and decrease the extraction efficiency of flavonoids. The extraction efficiency of flavonoids was higher at 45 and 20 MPa, and higher or lower pressure and temperature would affect the extraction efficiency of flavonoids. With the increase of supercritical CO2 flow rate, the extraction rate of flavonoids increases gradually, but the requirement for extraction equipment is higher. Flavonoids in Apocynum venetum have good antimicrobial effect, which is one of the reasons why Apocynum venetum fiber has antimicrobial properties.
Keywords: Apocynum venetum phloem fiber, supercritical CO2 extraction of flavonoids