Supercritical fluid extracts active ingredients of herbal medicine
At present, the supercritical fluid extraction technology can be used for the extraction and separation of the effective ingredients of single Chinese medicine and the extraction and separation of the effective ingredients of compound Chinese medicine preparations.
In particular, the extraction of single-flavored Chinese medicine is more extensive, mainly including the extraction of volatile oils, alkaloids, flavonoids, quinones, coumarins, lignans, saponins, polysaccharides, etc.
How many effective ingredients can CO2 extract from herbal medicines?
Volatile oil is the most suitable component for CO2 supercritical extraction. The boiling point of the volatile oil is low, the relative molecular mass and polarity are small, and most of the volatile oil is unstable because of its unstable nature. It is easy to use conventional co-water distillation or steam distillation. Causes the oxidative decomposition of volatile oil. The use of supercritical CO2 extraction, the extraction temperature is low, can avoid the oxidative decomposition of the effective components in the volatile oil.
Alkaloids mostly exist in plants in the form of organic acid salts, inorganic acid salts, esters, glycosides, etc. The solubility of supercritical CO2 fluid is low, so it is generally necessary to pretreat them with alkaline reagents first, and appropriate Entrainers such as methanol, ethanol, acetone, chloroform, etc. improve its solubility.
Several commonly used extraction methods for flavonoids include alcohol extraction, alkaline water extraction and hot water extraction, and supercritical fluid extraction is a very efficient extraction technology.
Quinone compounds are more polar, so when supercritical CO2 extraction is used, higher pressure is often required, and appropriate entrainers, such as ethanol solutions of different concentrations, are also required. In addition, when supercritical CO2 is used to extract the main components of saponins such as ginseng, platycodon, licorice, etc., because saponins are composed of saponins, sugars, uronic acid or other organic acids, they are generally soluble in water and also have strong polarity. Therefore, it is also necessary to add an entrainer or increase the pressure to increase its yield.
What is the process of CO2 extraction of herbal medicines?
How does CO2 extract unsaturated fatty acid?
Wang Kai et al used supercritical extraction to extract the unsaturated fatty acids in taurus, and investigated the effects of pressure, temperature and time on the extraction process, and finally determined that the optimal conditions were pressure 250 bar, temperature 40 ℃, and time 120 The volume flow rate of CO2 is 8 mL/min, and the extract is systematically studied by GC-MS combined technology. The mass fraction of each component is determined by the peak area normalization method, of which 30.72% of linoleic acid , Sitosterone 17.46%.
How does CO2 extract coumarins?
Chen et al used supercritical fluid to extract coumarins from Angelica sinensis and Angelica dahurica. They determined that the optimal process conditions were pressure 30 MPa, temperature 50 ℃, volume flow rate 25 L/h, extraction time 2 h, and the highest extraction rate.
How does CO2 extract animal medicine?
The SFE technology has been widely used in the extraction of active ingredients from botanicals, and there have been certain studies in the extraction of animal medicines.
Zhou Ran et al used supercritical fluid to extract the effective ingredients in velvet antler, and compared the extracts with 75% ethanol and methanol reflux extracts for their antioxidant activities. They found that the supercritical velvet antler extracts were resistant to free radical damage to protein and nucleic acid. The effect of ability is significantly higher than the other two methods of extracts.
How does CO2 extract pomegranate leaves?
Wang Hua uses supercritical extraction technology to extract total phenols from pomegranate leaves.
Due to the polarity of pomegranate leaf total phenols and the low solubility in supercritical fluid CO2, it is necessary to add a small amount of entrainer in the supercritical fluid system to change the phase behavior of the supercritical fluid system to adjust the polarity of the solvent,it improves the solubility of solvents.
The experiment finally determined that the best extraction conditions were 100 g of pomegranate leaf material with 250 mL of ethanol, extraction pressure of 25 MPa, temperature of 60 ℃, and extraction time of 120 min.
According to this process, the yield of the crude extract of total phenols from pomegranate leaves is 0.172 8%, and the mass fraction of total phenols from pomegranate leaves is 42.61%.