Resveratrol is a natural phytoalexin, which has attracted widespread attention due to its anti-cancer, antioxidant, anti-inflammatory, lipid-lowering, cell aging, and cardiovascular disease prevention and treatment effects. However, the content of resveratrol in natural plants is relatively low, and with the increase in its demand, its extraction and synthesis technology has gradually gained attention.
How to extract resveratrol?
Extracting Resveratrol from Plants
Natural resveratrol is a secondary metabolite produced by plants under external stimulation and is synthesized from phenyl propionic acid through the shikimic acid pathway. At present, resveratrol has been found in 21 families, 31 genera, and 72 species. Common methods for resveratrol extraction include traditional solvent extraction, ultrasonic extraction, microwave-assisted method, enzymatic hydrolysis, and CO2 supercritical extraction, etc.
1. Traditional solvent extraction method
In the solvent extraction method, the water extraction method is the most simple and feasible, but for resveratrol, because it is insoluble in water and weakly polar, it usually needs to be extracted with an organic solvent. The study found that the extraction rate of ethyl acetate to resveratrol was high, reaching 80%, which is currently considered the best extraction solvent for resveratrol.
2. Ultrasonic extraction method
Ultrasonic extraction is a physical crushing process, which uses ultrasonic waves to generate high-speed, strong cavitation and stirring to destroy the cell wall structure of plant medicinal materials. It is released, directly into the solvent and mixed thoroughly to improve extraction efficiency.
The optimal ultrasonic extraction process conditions are: extraction temperature 70 ℃, action time 30 min, liquid-solid mass ratio 40, ethanol concentration 65% for extraction, and extraction is performed twice.
3. Microwave-assisted method
The microwave-assisted method is a potential green extraction and separation technology, which is widely used in the extraction of various natural active ingredients.
The optimized extraction conditions were as follows: microwave power 360 W, microwave time 120 s, extraction material-to-liquid ratio 1 g: 25 mL, and extraction agent volume concentration 80%.
4. Enzymatic hydrolysis
Due to the low content of resveratrol in nature, the extraction object needs to be biotransformed before extraction, for example, the resveratrol extract and resveratrol polymer derivatives in the sample are converted into resveratrol by enzymatic hydrolysis Petrol can greatly improve the extraction rate of resveratrol.
The optimal conditions for the extraction of resveratrol by enzymatic hydrolysis were as follows: the enzyme type was cellulase, the enzyme dosage was 0.6%, the enzymatic hydrolysis pH = 5.0, the enzymatic hydrolysis temperature was 50 %, the enzymatic hydrolysis time was 36 h, and the sample after enzymatic hydrolysis was added 8 times the amount of 80% ethanol, 85 ° C (the liquid is slightly boiling) for 3 extractions, 2h each time.
5 .CO₂ supercritical extraction
Supercritical fluid extraction technology is a new type of extraction method with high time efficiency and high extraction rate.
The optimal extraction process was as follows: P = 25 MPa, T = 50 t, AOT concentration of 0.05 mol/L, and extraction times of 3 times.
E-mail: medical@ysgcn.com
