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dc.contributor.authorWang, Z.J.en_US
dc.contributor.authorLin, S.M.en_US
dc.contributor.authorHu, M.L.en_US
dc.description.abstractHypericin and pseudohypericin are the two major dianthrones of St John's wort (SJW, Hypericum perforatum) that are reported to have antidepressant and antiviral effects. In this study we used methanol extracts of five commercial SJW products to determine the two congeners using a modified reverse phase HPLC method with gradient elution. One SJW product is specified by the manufacturer to contain 340 mug hypericin per tablet (170 mg extract), while the other four products are specified to contain 900 mug hypericin per tablet (300 mg); none of the products is claimed to contain pseudohypericin. Our results showed that the actual contents of hypericin in these products ranged from 1.7 to 38.5% of the claimed amounts. However, the amounts of pseudohypericin were in general much higher than those of hypericin. When hypericin and pseudohypericin were combined as total hypericin, the four products that supposedly contain 900 mug per tablet were found to contain 26, 484, 587 and 615 mug total hypericin per tablet, or 2.9, 53.8, 65.2 and 68.3% of the claimed hypericin contents respectively. The product which supposedly contains 340 mug hypericin per tablet was found to contain 388 mug total hypericin per tablet, or 114% of the claimed hypericin content. The relatively low hypericin contents measured in these products are not a result of losses during extraction, because the two congeners had high recoveries (93.7 and 94.3% for hypericin and pseudohypericin respectively) when added before methanolic extraction to an SJW product with known amounts of the two congeners. Thus our results show that the commercial SJW products vary greatly in their amounts of total hypericin and that pseudohypericin, rather than hypericin, is the major hypericin in these products. (C) 2004 Society of Chemical Industry.en_US
dc.relationJournal of the Science of Food and Agricultureen_US
dc.relation.ispartofseriesJournal of the Science of Food and Agriculture, Volume 84, Issue 5, Page(s) 395-397.en_US
dc.subjectSt John's worten_US
dc.titleContents of hypericin and pseudohypericin in five commercial products of St John's wort (Hypericum perforatum)en_US
dc.typeJournal Articlezh_TW
Appears in Collections:食品暨應用生物科技學系


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