Pharmaceutical quality of hypericum extracts

AU: Wagner-H; Bladt-S

AD: Institute fur Pharmazeutische Biologie der Universitat Munchen, Germany.

SO: J-Geriatr-Psychiatry-Neurol. 1994 Oct; 7 Suppl 1: S65-8

Summary

• Hypericum extracts contain at least ten constituents or groups of components that may contribute to the pharmacological effects. It is not yet possible to correlate the antidepressive mode of action with specific constituents; therefore, the pharmaceutical quality of the extracts was characterized on the basis of typical leading substances and especially the hypericins.
• The red-colored hypericins have been found in very few other plants, while most other ingredients are found in many other plants.
• The hypericins also have a photodynamic effect, and sometimes they do not occur until the crude drug has been processed and exposed to light. The concentration of hypericins (mainly hypericine and pseudohypericin) in buds and flowers can vary between 0.06% and 0.75%. A minimum content of 0.04% total hypericin is required for commercial qualities.
• For the analysis and improvement of the production procedure, the content of hypericin and pseudohypericin was measured experimentally. The drug material was extracted with different solvents and the yield was analyzed for each kind of solvent, its concentration and extraction temperature. Optimal yields were obtained with 80% methanol at temperatures of 80 degrees C.

Table 9 shows the percentages of hypericin and pseudohypericin obtained with different extract solutions.

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