clearly_not_atara
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Bemotrizinol — the sunscreen FDA won't let us have
http://en.wikipedia.org/wiki/Bemotrizinol
3,5-Bis-(3-(2-ethylhexyl)-oxyphenol-6-yl)-p-methoxyphenyl-s-triazine is a potent and highly photostable UV-absorbing dye that has
made it into sunscreens in Europe, Japan and recently Canada but lags on US shelves due to regulatory capture and a desire to feminize the US
population:
"Unlike some other organic sunscreen actives, it shows no estrogenic effects in vitro."
Okay, I'm just kidding about that last part. The truth is probably just that nobody's paid attention to who's running the FDA since 9/11 (never forget
9/11, but feel free to forget all of our founding values) and the foxes (drug firms) run the henhouse.
But the photostability is the really interesting thing about this stuff, because it radically decreases the chance of being converted into nasty
byproducts. Also, some people claim it even doesn't burn as much as ketone-quinone sunscreens, although I'll wait until I try it.
Anyway, it's rare that I see such a perfect candidate for a synthesis challenge. It's probably within reach of the determined experimenter:
cyanuric chloride, resorcinol, 2-ethylhexanol are somewhat accessible and not horribly dangerous to work with. And the molecule is cool! Worth making,
novel, possible, not interesting to LE, etc.
So, what kind of prize can I offer? I haven't decided. The challenge, quite simply, is to make it.
[Edited on 04-20-1969 by clearly_not_atara]
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Texium
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What will be the terms of the challenge? Must it be from OTC starting materials, or just first to have a writeup from whatever they’re able to get
their hands on?
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clearly_not_atara
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Hm, that is a good question. You cannot buy:
3,5-bis(3-(2-ethylhexyloxy)phenol-6-yl)-chloro-s-triazine (assuming it exists at all?)
3,5-dichloro-p-methoxyphenyl-s-triazine
3-(2-ethylhexyloxy)-phenol
bemotrizinol, itself
protected derivatives of the above; derivatives of the above exchanging hydroxy for amino/alkoxy/formyl/halogen groups; derivatives of the above
exchanging chloro for other halogens; other similar subterfuge
I.e. only "reasonably normal" commodity chemicals are allowed, not obvious "checkpoint" molecules. You may, however, purchase a sample of the above
compounds to use for comparison, if desired. Performing the synthesis of 2-ethylhexanol from butyraldehyde is not required but would be
impressive.
[Edited on 27-5-2021 by clearly_not_atara]
[Edited on 04-20-1969 by clearly_not_atara]
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Newton2.0
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Doesn't its photostability increase the likelihood that it is an environmentally persistent pain-in-the-butt, not unlike the extremely persistent
fluorinated carbon compounds? At some point these things do need to break down. I wonder if this is the reason why it is banned. Who knows?
Also, I would venture a guess that the reason many of these don't show estrogenic effects has to do with the lack of nine-carbon compounds
incorporated into the structure. It is widely known that these mimic estrogens and is actually something that frightens the hell out of me considering
their ubiquity.
[Edited on 27-5-2021 by Newton2.0]
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unionised
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Quote: Originally posted by Newton2.0  |
Also, I would venture a guess that the reason many of these don't show estrogenic effects has to do with the lack of nine-carbon compounds
incorporated into the structure.
[Edited on 27-5-2021 by Newton2.0] |
would you like to expand on that?
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Newton2.0
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"What are NPEs?
Nonylphenol ethoxylates comprise a subclass of alkylphenol ethoxylates. Alkylphenol
ethoxylates begin with an alkylphenol, which consists of phenol (a benzene ring with a hydroxyl
group) that is bonded to an alkyl group. Alkyl groups are chains of carbon atoms (straight or
branched) attached to hydrogen atoms. Alkylphenols are named according to the length of the
alkyl chain –thus, nonylphenol contains a nonyl chain of nine carbons, and octylphenol contains
an octyl chain of eight carbons. Alkylphenols are distinguished among themselves by the
location of the alkyl group relative to the hydroxyl group.
Nonylphenol is ethoxylated by inserting ethylene oxide. The degree of ethoxylation –the
number of ethylene oxide molecules added– is indicated by a number, so NPE-4 would include
four ethylene oxide groups. However, the term NPE-4 also applies to branched molecules as
well as straight chains, so there are actually many different chemicals with the same name.
NP and NPEs are toxic and estrogenic.
The term “nonylphenol ethoxylates” refers to a large group of chemicals that vary in
chemical structure and toxicological effects. However, they all share common degradation
products –nonylphenols and the short chain NPEs– that are more toxic and have similar effects.
Since the less toxic NPEs have short biodegradation half-lives, and their metabolites are longer
lived, consideration of toxicology and ecotoxicology focuses mostly on NP and the short-chain
NPEs (NP-1 and NP-2), which are persistent, bioaccumulative, and extremely toxic to aquatic
organisms.4 NP and other alkylphenols are potent xenoestrogens, causing hormonal responses
at concentrations as low as 1 femtomole to 10 picomoles per liter (10-15 to 10-11 moles per liter),
exceeding the potency of estradiol.5"
Basically, my understanding is that there are some surfactants that are very similar to the pharmacophore of estrogens. Perhaps the omission of these
NPs and NPEs, both branched and unbranched, are why these would be safer alternatives to the existing options. We currently are having some troubles
due to the absurd levels of these compounds in our water which may lead to higher incidences of cancers and the accelerated onset of puberty in
children.
I took this from https://www.beyondpesticides.org/assets/media/documents/BP.c...
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clearly_not_atara
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| Quote: Originally posted by Newton2.0 | | Doesn't its photostability increase the likelihood that it is an environmentally persistent pain-in-the-butt, not unlike the extremely persistent
fluorinated carbon compounds? At some point these things do need to break down. I wonder if this is the reason why it is banned. Who knows?
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Bluntly no; plenty of photo-unstable things do not break down when they get into (dark) ground water; plenty of photostable things do break down by
other means; being exposed to bright sunlight on the surface of human skin is just not a very good model for environmental degradation.
Plus, the US FDA has never really cared about ecotoxicity; look at all of the other drug runoff in sewage etc for examples. EU with their various
Green Parties would be far more likely to care.
[Edited on 04-20-1969 by clearly_not_atara]
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Newton2.0
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I was thinking more along the lines of it being a persistent pollutant aboveground, but I can see what you mean.
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Newton2.0
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I wish the FDA cared about ecotoxicity. It astounds me how much damage is done to the environment because we irresponsibly produce a product with
blatant disregard for its safe disposal.
I am actually very interested in learning more about bemotrizinol as I am pretty worried about the risks of commonly available sunscreens. Does
anyone else get freaked out by sunscreen pre-burning your skin?
Seems like a cool proj!
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dicyanin
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There is another one, bisoctrizole, which also lacks estrogenic effects. But it is also not allowed for use in the USA. It is approved in the EU.
https://en.wikipedia.org/wiki/Bisoctrizole
Ashby J, Tinwell H, Plautz J, Twomey K, Lefevre PA (December 2001). "Lack of binding to isolated estrogen or androgen receptors, and inactivity in the
immature rat uterotrophic assay, of the ultraviolet sunscreen filters Tinosorb M-active and Tinosorb S". Regul Toxicol Pharmacol. 34 (3):
287–91.
doi:10.1006/rtph.2001.1511
^ they tested both bemotrizinol and bisoctrizole
sic transit gloria mundi
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