Page 27 - phytotherapy_ EBOOK_2025

St. John's Wort

Hypericum consists of the dried aerial parts of Hypericum perforatum, family
Hypericaceae.
Commercial extracts are standardized on their naphthodianthrone content, expressed as
hypericin.
Major Chemical Constituents
Hypericum contains a variety of constituents with biological activity.
Anthraquinones: Principally hypericin and pseudohypericin; also iso-hypericin and
emodin-anthrone.
Prenylated phloroglucinol derivatives: Hyperforin, adhyperforin and furohyperforin.
These phloroglucinol derivatives represent the main constituents of the plant’s lipophilic
extract and are regarded as the key bioactive compounds responsible for its antibacterial
and antidepressant effects. However, they are highly susceptible to oxidation and chemical
degradation.
Flavonoids:
Kaempferol, luteolin and quercetin, quercitrin, isoquercitrin and hyperoside. The
biflavonoid amentoflavone is confined principally to the flowers.

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