Supercritical CO2 fluid has low polarity, which makes it difficult to extract components with greater polarity. Adding an entrainer can improve the solvent effect of the supercritical fluid, thereby increasing the extraction rate.
For example, by adding a suitable entrainer to supercritical CO2 fluid, a specific Lewis acid-base interaction force (such as hydrogen bond, complexation, etc.) can be formed between the alkaloid and the entrainer, thereby reducing the activation energy during desorption It finally overcomes the restriction of the matrix to the alkaloids, which enhances the solubility and selectivity of supercritical CO2 fluid to alkaloids, thereby increasing the extraction rate.
Ued supercritical CO2 to extract fat-soluble substances in sophora flavescens, detected the yield of matrine, and studied the parameters such as pressure, temperature and time in the supercritical extraction process, and finally compared with the direct solvent extraction method.
A comparison is made and it is found that the matrine yield is higher under the conditions of pressure 12-18 MPa, temperature 60-75 ℃, and extraction time 2 h, and the average yield of matrine total alkaloids obtained by supercritical CO2 extraction is higher than the direct solvent extraction method is 72% higher.
Used supercritical extraction technology to extract quinolizidine in Sophora flavescens, and used L9(3)4 orthogonal test to optimize the optimal extraction conditions for factors such as temperature, pressure and volume flow.
The pressure is 25 MPa, the temperature is 50 ℃, the volume flow of CO2 is 2 L/min, and the time is 30 min.
Under these conditions, three alkaloids such as matrine, oxysophocarpine and oxymatrine are extracted. The quality scores were 95.6%, 95.8%, and 99.6% respectively.
[Alias] Bitter bone, Sichuan ginseng, ox ginseng, earth bone, wild locust root.
[Source] It is the root of the leguminous plant Sophora flavescens Ait.
Subshrub. The root is terete with yellow skin. The stems and branches have irregular longitudinal grooves and are covered with yellow fine hairs when they are young. Singular pinnate compound leaves, alternate, with linear stipules underneath, with 5 to 21 leaflets, ovate-elliptic to oblong-lanceolate, apex round or obtuse, base round or broadly cuneate, entire. The raceme is terminal, short-haired, linear bracts, yellowish white flowers, butterfly-shaped corolla, 10 stamens, filaments free, only the base is healed, 1 pistil, upper ovary. The pods are linear, with a long beak at the apex, and do not crack when mature. The seeds are constricted and nearly spherical.
Harvesting and processing
Harvest in spring and autumn, preferably in autumn. After digging out the roots, remove the roots and fibrous roots, wash the sediment, and dry. Fresh roots are sliced and dried, called Sophora flavescens slices.
Cylindrical, 10 to 30 cm long, 1 to 2 cm in diameter. The surface is gray-brown or brown-yellow, with obvious longitudinal wrinkles. The cork is very thin, brown-yellow or gray-brown, most of which are ruptured and curled outwards, easily peeling off and showing yellow smooth skin. The quality is hard, not easy to break, and the broken surface is thick and fibrous. The cross section is yellow-white with obvious cambium. The air is pungent and the taste is extremely bitter. Sophora flavescens slices are obliquely cut thin slices with different shapes and sizes, oblique round or oblong, 2.5 cm long, 1 to 1.5 cm wide, and 2 to 5 mm thick. The quality is hard, the cut surface is pale yellow and white, there are ring-shaped annual rings, and the xylem is made of radial lines.