Hypericin

From Wikipedia, the free encyclopedia
Hypericin[1]
Identifiers
CAS number 548-04-9 YesY
PubChem 5281051
ChemSpider 4444511 YesY
UNII 7V2F1075HD YesY
ChEBI CHEBI:5835 YesY
ChEMBL CHEMBL286494 YesY
Jmol-3D images Image 1
Properties
Molecular formula C30H16O8
Molar mass 504.44 g mol−1
Appearance Blue-black solid
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Hypericin is a naphthodianthrone, a red-colored anthraquinone-derivative, which, together with hyperforin, is one of the principal active constituents of Hypericum (Saint John's wort).[2][3] Hypericin is believed to act as an antibiotic, antiviral[2] and non-specific kinase inhibitor. Hypericin may inhibit the action of the enzyme dopamine β-hydroxylase, leading to increased dopamine levels, although thus possibly decreasing norepinephrine and epinephrine.

It was initially believed that the anti-depressant pharmacological activity of hypericin was due to inhibition of monoamine oxidase enzyme. The crude extract of Hypericum is a weak inhibitor of MAO-A and MAO-B. Isolated hypericin does not display this activity, but does have some affinity for NMDA receptors. This points in the direction that other constituents are responsible for the MAOI effect. The current belief is that the mechanism of antidepressant activity is due to the inhibition of reuptake of certain neurotransmitters.[2]

The large chromophore system in the molecule means that it can cause photosensitivity when ingested beyond threshold amounts.[citation needed] Photosensitivity is often seen in animals that have been allowed to graze on St. John's Wort. Because hypericin accumulates preferentially in cancerous tissues, it is also used as an indicator of cancerous cells. In addition, hypericin is under research as an agent in photodynamic therapy, whereby a biochemical is absorbed by an organism to be later activated with spectrum-specific light from specialized lamps or laser sources, for therapeutic purposes. The antibacterial and antiviral effects of hypericin are also believed to arise from its ability for photo-oxidation of cells and viral particles.[2]

Hypericin derives from polyketides cyclisation.[4][5]

References

  1. Merck Index, 11th Edition, 4799
  2. 2.0 2.1 2.2 2.3 Pharmacognosy of St. John's Wort
  3. Oubre, Alondra (1991). "Hypericin: the active ingredient in Saint John’s Wort". Archived from the original on September 28, 2007. Retrieved September 18, 2006. 
  4. Loren W. Walker (1999). A Review of the Hypothetical Biogenesis and Regulation of Hypericin synthesis via the Polyketide Pathway in Hypericum perforatum and Experimental Methods Proposed to Evaluate the Hypothesis. 
  5. Christian Hertweck (2009). "Polyketide Biosynthesis". Angew. Chem. Int. Ed. 48: 4688–4716. doi:10.1002/anie.200806121. 
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