Hypericin is a substance isolated from a medicinal herb Hypericum perforatum, commonly known as St. John’s Wort. Hypericin belongs to group of compound known as napthodianthrones. Hypericin is a secondary plant metabolite of St.John’s Wort and the amount of Hypericin strongly depend upon the source of the plant material. Initially Hypericin was considered to be the antidepressant principle of Hypericum perforatum, but according to latest research Hyperforin has emerged as antidepressant principle of the herb. Hypericin is used as standard for identification of genuine plant material and thus has importance from quality control point of view. The standardization of Hypericum perforatum is now based on both hypericin and hyperforin content. The herb must contain 0.3% of hypericin.
Singh, Amrit Pal
"Hypericin: A Napthodianthrone from Hypericum perforatum,"
1, Article 42.
Available at: http://opensiuc.lib.siu.edu/ebl/vol2005/iss1/42