Erm there is a VERY long list of compounds found out in the environment
that you can do in vitro tests on and get antiviral activity. This doesnt
mean simply eating the source will deliver enough to the target, or that
in vivo stuff carries on the promise. This is equally true of a long list
of synthetics too. Now once one nucleoside analgoue was found to work its
hardly surprising that a bunch of others have since got through as well,
but step away from that and SP303 was one compound that nearly made it.
Like quercetin its a natural bioflavonoid, it got to Phase II clinical
trial and then got dropped - IIRC thats as far as resiquimod got and that
was a VERY interesting compound.

The compound cited by your treatise has a publication record thats
ongoing...so overlooked it not a reasonable statement - its being looked
at. However that whole flavonoid range of compounds is an area people look
at....i've seem a fair number of posters, several papers my previous boss
has had to review have been on that sort of compound, its an area thats
been driven close to licensing (which is rare for anything).
You might want to take a look at
Cos P. Vanden Berghe D. De Bruyne T. Vlietinck AJ.
Plant substances as antiviral agents: An update (1997-2001).
Current Organic Chemistry. Vol. 7(12)(pp 1163-1180), 2003

Which is a sizeable review (and there are others so its not the exclusive
text). Note that review focuses of things from natural sources targettign
HSV and HIV....as they are the big areas.

Given quercetin is not the only compound of its class, and others have
been advanced further perhaps you could consider its reasonable to suggest
that its not the best of its type rather than its been overlooked.

I cite the following evidence that this might be the case
Lee J-H. Kim Y-S. Lee C-K. Lee H-K. Han S-S.
Antiviral activity of some flavonoids on herpes simplex viruses.
Korean Journal of Pharmacognosy. Vol. 30(1)(pp 34-39), 1999.
The abstract says;
To search for less toxic antiherpetic agents, the inhibitory effects of
twelve kinds of flavonoids including chrysin, quercetin, quercitrin,
rutin, fisetin, gossypin, kaempferol, morin, naringenin, naringin,
hesperetin and hesperidin on the plaque formation of herpes simplex virus
[snip technical details and hop to results]
cultured in medium containing flavonoids. Naringenin showed the the most
potent antiviral activity against HSV-1 with selectivity index (SI) of
19.1 and hesperetin showed the most potent antiviral activity against
HSV-2 with SI of 9.8. These results suggest that some flavonoids may be a
potential therapeutic agent for the treatment and prevention of herpes
simplex virus infections.

This indicates that while there is plenty of work saying quercetin works,
it does list other compounds in the group that are better.

Either way your source is not exactly compelling as its sloppy....

To state this which is sloppy as this is best described as an
alphaherpesvirus feature not one common to the entire family suggests a
poor grasp or explanation of the basic biology, espceically when you can't
claim alphaherpesvirus context since it talks about EBV a few lines later
in the same paragraph. Its mixing up all sorts bits of info and putting
them out messily which is not great when you are trying to deal with
something thats quite a bit beyond basic virus biology.

It makes this crass error, indicating the author cannot even check out the
most basic of virus biology.

...and this is incredibly sloppy way to describe or say cold viruses...if
its adeno, just say adeno, if it includes other cold viruses (eg corona,
rhino- etc) say that and make it convincing. It cites papers prior to the
SARS outbreak and prior (more importantly) to the identification of the
agent of that outbreak as evidence of activity against said virus and the
papers it cites as evidence, well the first is fine but it only looked at
HSV1, Polio, para-flu and RSV - not the coronavirus that was pulled out of
SARS (or even any coronavirus that would suggest it might). Oh and the
Pharmazie paper doesnt mention viruses in the title or abstract so without
further explaination as to what evidence its citing is either irrelevant
or at best requires context as to why its a suppoorting piece of evidence.
You need to cite correctly (that's something drilled into me and any
referee's report will nail you hard if you mess up)

Getting back to the main topic....quercetin. Its a flavonoid, it is active
against HSv and other viruses. In HSV it appears to hit the viral protein
kinase as one target. Its being looked at (there's about 5000 papers on it
to date, though only about 20 or so cross check with viruses
specifically). These are up to the recent past so I think overlooked is
not a fair assessment...especially given that korean paper I cited and the
existence of SP303 which suggest there are better ones in the class to use
and look at,....thats lowered priority after assessment, not the ignoring
that 'overlooked' suggests.

Keep looking at flavonoids....very active compounds. Don't get bogged down
with just one though....there's a lot of them so take the broader view of
the class as a whole.

Tim
--
When playing rugby, its not the winning that counts, but the taking apart
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