Study and Discussion on the Extraction Process of Schisandra Extract

Hugan Tablets have the effects of soothing the liver and regulating qi, strengthening the spleen and promoting digestion, and lowering serum alanine aminotransferase. They have significant therapeutic effects on chronic hepatitis, viral hepatitis, persistent hepatitis, and early-stage cirrhosis. This product was originally a variety listed in the ministerial and provincial standards, and was later included in the 1995 edition of the Chinese Pharmacopoeia. Its testing items added "determination of schisandrin B content," but no provisions were made for the extraction process of Schisandra extract. If the Schisandra extract is still extracted according to the original material process, the extraction of schisandrin B would be unreliable. For this reason, based on the properties of schisandrin B, we designed tests to extract Schisandra extract using the same method with different concentrations of ethanol and using the same concentration of ethanol with different methods. Compared with the original method, the extraction was more complete. Experiments proved that the 95% ethanol percolation method for extracting Schisandra extract is a relatively ideal production process.

1 Materials, instruments and reagents

1.1 Medicinal material: Schisandra chinensis (place of origin: Liaoning). After drying, it was crushed into a fine powder.

1.2 Instrument: SP-8810-HPLC, detection wavelength 254 nm.

1.3 Reagent: schisandrin B (China National Institute of Biological Products).

2 Test methods, procedures and results

2.1 Equal amounts of Schisandra chinensis fine powder were taken and reflux-extracted twice with 75%, 80%, and 95% ethanol respectively. For the first extraction, 4 times the amount of ethanol was added and refluxed for 3 h; for the second extraction, 3 times the amount of ethanol was added and refluxed for 2 h. The two extraction liquids were combined, ethanol was recovered under reduced pressure, and then concentrated under normal pressure to a thick extract, with a relative volume mass of about 1.028. Two concentrations of thick extract were weighed respectively, and the content was determined according to the method under the content determination item for Hugan Tablets in Part 1 of the 1995 edition of the Chinese Pharmacopoeia. The results are as follows.

For Schisandra extract extracted with 75% ethanol, the schisandrin B content was 0.242%; for Schisandra extract extracted with 80% ethanol, the schisandrin B content was 0.268%; for Schisandra extract extracted with 95% ethanol, the schisandrin B content was 0.317%.

2.2 One portion of Schisandra powder was percolated with 6 times the amount of 95% ethanol, at a percolation rate of 3-4 ml/min. The ethanol was recovered and concentrated to a thick extract, with a relative volume mass of about 1.028. Two thick extracts obtained by different methods were respectively taken, and the content was determined according to the content determination item for Hugan Tablets in Part 1 of the Chinese Pharmacopoeia. The results were:

The Schisandra extract extracted by the 95% ethanol percolation method contained 0.328% schisandrin B.

3 Discussion

3.1 Since the 1995 edition of the Chinese Pharmacopoeia does not specify the extraction method for Schisandra extract, and the process methods in the original ministerial and provincial standards all used 75% ethanol reflux extraction for Schisandra extract. Experiments proved that when 95% ethanol is used to extract Schisandra extract, the content of schisandrin B is the highest. Because schisandrin B is a fat-soluble component, increasing the ethanol concentration is beneficial for more complete extraction of schisandrin B.

3.2 The structure of schisandrin B contains an oxygen ring. Long-term heating reflux extraction will destroy its active components, reducing the extracted content. Therefore, the percolation method was compared with the reflux method. Extraction by the percolation method is more complete, can reduce damage to the active components, and increases the content.

3.3 The Pharmacopoeia does not specify the place of origin of Schisandra. Since Schisandra sphenanthera does not contain schisandrin B, only Schisandra chinensis can be used for Hugan Tablets.

3.4 The 95% ethanol percolation method for extracting Schisandra extract is the optimal extraction condition for producing Hugan Tablets.