Talk:Hypericin

message: The statement, "Hypericin may inhibit reuptake of dopamine β-hydroxylase, leading to increased dopamine levels," seems to be misleading and potentialy inacurate. Dopamine β-hydroxylase is an enzyme that converts dopamine into norepinephrine, so one could deduce that increased levels of dopamine β-hydroxylase resulting from its reuptake would not lead to increased levels of dopamine, but rather reduced levels of dopamine and increased levels of norepinephrine. Mike19772007 20:57, 19 July 2007 (UTC)
replies: text: It is written "Hypericin may inhibit the action of the enzyme dopamine β-hydroxylase, leading to increased dopamine levels, although thus possibly decreasing norepinephrine and epinephrine" 
Dopamine beta-hydroxylase converts dopamine to norepinephrine. If the enzyme is inhibited and no other mechanism compensates for it dopamine levels should increase. Where is the contradiction? -- 16:20, 30 April 2008 (UTC)
thread_title:  Dopamine β-hydroxylase 

message: Does hypericin cause monoamine oxidase inhibition? I've seen a few sources which state one should limit tyramine (which MAO cleans up) intake when using St. John's Wort, of which hypericin is a key ingredient. 20.137.18.50 (talk) 15:32, 30 April 2008 (UTC)
thread_title:  MAOI? 

message: I am trying to withdraw from a high dose of Venlafaxine and Hypericin has been mentioned as helpful in mitigating the symptoms.  However, I have no idea what level of dosage is recommended or for how long it should be taken.  If anyone out there knows, perhaps they could add it to the Hypericin entry?  —Preceding unsigned comment added by Coinnich (talk • contribs) 08:27, 11 November 2008 (UTC)
thread_title:  Use of Hypericin in SSRI / SSNRI Withdrawal 

message: Not all facts are appropriately cited. The first two sentences of the last paragraph need citations. This article could use more references.
The first sentence could be arranged differently "which, together with hyperforin, is one of the principal active constituents..." It would make more sense to say "which, together with hyperforin, are the principal active constituents of Hypericum..."
I also believe that St. John's wort other naphtodianthrone, pseudohypericin, should be added because that is the only other naphthodianthrone and it is found in concentrations 2-4 times higher than hypericin in most extracts.
Appropriate subheadings could make the article more clear and easy to read for example: Occurrence and Mechanism of Action.  More background knowledge such as where hypericins are found on the plant and their therapeutic effects etc. could be added for expansion of this article. 
The biosynthesis of hypericins is in the polyketide pathway where an octaketide chain  goes through processes of  cylizations and decarboxylations form emodin anthrone which are believed to be the precursors of hypericin.  Oxidization reactions yield protoforms which then are converted into hypericin and pseudohypericin.  Theses reactions are photosensitive and take place under exposure to light and using the enzyme Hyp-1.
[1] Karioti A, Bilia AR (2010) Hypericins as potential leads for new therapeutics. Int J Mol Sci 11:562-594
[2] Falk H (1999) From the photosensitizer hypericin to the photoreceptorstentorian—the chemistry of phenanthroperylene quinines. AngewChem Int Ed 38:3116–3136
[3] Bais HP, Vepachedu R, Lawrence CB, Stermitz FR, Vivanco JM (2003)Molecular and biochemical characterization of an enzyme responsible for the formation of hypericin in St. John’s wort(Hypericum perforatum L.). J Biol Chem 278:32413–32422
[4] Michalska K, Fernades H, Sikorski M, Jaskolski M (2010) Crystal structure of Hyp-1, a St. John’s wort protein implicated in the biosynthesis of hypericin. J Struct Biol 169:161–171
[5] Zobayed SMA, Afreen F, Goto E, Kozai T (2006) Plant-environment interactions: accumulation of hypericin in dark glands of Hypericum perforatum. Ann Bot 98:793–804
[6] Murthy, Hosakatte Niranjana et al. “Hypericins: Biotechnological Production from Cell and Organ Cultures.” Applied Microbiology and Biotechnology 98.22 (2014): 9187–9198. PubMed. Web.
Hm952211 (talk) 20:35, 21 October 2015 (UTC)
thread_title:  Citations/Grammar/Additions 

message: PubChem prefers to call a dimerized-anthracene–like tautomer hypericin instead.  Are they less reliable than our source for the infobox, which appears to be the Merck Index?  
If PubChem is more reliable, then we certainly ought to change the infobox PubChem code.  In that case, ought we also change the other entries in the infobox to match?  
If it isn't more reliable, should we mention the existence of other major tautomers in the article body?  
(Feel free to only answer a subset of the above.)  Bernanke's Crossbow (talk) 08:36, 17 May 2023 (UTC)
thread_title:  Wrong tautomer?