Pharmaceutical quality of hypericum extracts.

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. 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.