Hypericum perforatum biflavone from

Hypericum perforatum (Clusiaceae), commonly known as SJW, is used in many countries for the treatment of mild-to-moderate forms of depression. Several clinical studies provide evidence that SJW is as effective as conventional synthetic antidepressants (46-51). From a phytochemical point of view, H. perforatum belongs to one of the best-investigated medicinal plants. A series of bioactive compounds have been detected in the crude material, namely phenylpropanes, flavonol derivatives, biflavones, proanthocyani-dins, xanthones, phloroglucinols, some amino acids, naphthodianthrones, and essential oil constituents (Fig. 3) (52-54). 

Michler, H. Laakmann, G. Wagner, H., Development of an LC-MS method for simultaneous quantitation of amentoflavone and biapigenin, the minor and major biflavones from Hypericum perforatum L., in human... 

H.perforatum, 13, II8-biapigenin 46 as the major, and 13 , II8-biapigenin (= amentoflavone) 47 as minor components [87, 88]. There were some assumptions that biflavones could contribute to the antidepressant activity of St. John s Wort, however their significance remains unclear [7]. Of the xanthones, a very typical class of compounds in the Guttiferae family, only two have been reported to occur in H. perforatum [89, 90]. The xanthonolignoid kielcorin 48 was isolated and identified by Nielsen and Arends from root materials of this and several other Hypericum species [91]. In aerial parts of H. perforatum, a trace amount of 1,3,6,7-tetrahydroxyxanthone 49 was found by Berghofer [86]. 

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