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How Not to Do It

Phthalate: A Natural Product? Sure ‘Bout That?

In case anyone missed it, a commenter on this post unearthed a really extraordinary find in the chemical literature. Here’s an obscure isolation paper, from an obscure Chinese journal, reporting on a profoundly boring list of marine natural products.
What’s so great, you ask? Well, take a look at the list. Dum de dum. . .hold on a minute, bis(2-ethylhexyl) phthalate? From Streptomyces, you say? When it’s one of the most common plasticizers in the world, a bulk industrial chemical that, well, notoriously leaches out of labware under solvent exposure? Sure thing, guys. Sure thing.

19 comments on “Phthalate: A Natural Product? Sure ‘Bout That?”

  1. chemgeek says:

    so you’re saying marine animals have learned to make plastics???
    Damn you Darwin!!!!!

  2. Chris says:

    Sorry, I’m not a chem person, but the wiki article claims that it can be found in the blood of ~25% of pregnant women. Does this mean they are ingesting this stuff? If so, does this imply that Streptomyces is consuming this stuff from somewhere else, and then spitting it back out?

  3. RB Woodweird says:

    Reminds me of the person in my grad school group who spent a long time isolating the products of a multistep synthesis and sent samples off to the regional NIH MS facility for analysis. The major isolate was phthalate and the minor one was hydrocortisone. (He had been using a skin rash cream.)

  4. JAB says:

    A common mistake. Mostly it comes from labware, but it certainly can be found in smaller amounts in the environment. I isolated it when working on Cannabis as a grad student, I remember rejecting a meeting abstract claiming it as a natural product a number of years later…….it’s one of those defects of corporate memory things that doesn’t always get passed on. Same as cardiac glycosides for cancer, but that’s another rant.

  5. Brian Baldridge says:

    I think Derek’s point is that even if the compound was indeed found in the places specified and not by contamination of the assay, classifying it as “natural” is a bit of a stretch.

  6. RandDChemist says:

    What a novel way to bump up the compound count.
    I’m filing a patent immediately on the biosynthesis of plastics by Streptomyces. Surely I will receive a grant and accolades for my work. Surely.
    Don’t anyone try to steal this treasure from me. Bwahahaha!

  7. RTW says:

    35 years ago in while taking Instramental Analysis, my Professor related two very interesting stores similar to this with regards process plant water analysis.
    The first had to do with water coming out of a plant into the sewage treatment plant. Had high levels of said plasticizers coming to the treatment plant from a large production facility. But Said plant couldn’t provide a means as to how these got there beciase none of their processes would result in these being made or utilized. Analysis showed the new water lines brought to the plant to be made out new HDPE plastic I believe. Analysis of the water coming into the plant showed high levels of the plasticizers.
    Send example had a similar situation. Seems there was paper plant that took water in from Lake Superior to use treated it and discharged it back out into the same lake. This paper mill had people up in arms all over the place and I remember when I was in Jr High (12 years old) the science class wrote letters to the company asking them to stop polluting the lake with asbestos.
    A few years later at the university again in instrumental analysis class the professor tells us the whole story. Seems the amount of asbestos coming into the plant from the lake was actually at a high level than going out, so actually the paper mill was cleaning Lake Superior of asbestos and not polluting it with it!!!
    This was a LONG time ago and our instrumental methods have become much more sensitive I am sure since that time. So researchers really need to look at the whole.

  8. To anyone performing positive mode ESI-mass spec, you are virtually guaranteed to see a peak at m/z 391, which is due to bis(2-ethylhexyl) phthalate. My first foray into bioanalytical chemistry was developing methods for the analysis of phthalates while at the CDC. I was stunned by how prevalent these compounds are in the environment. We gave up trying to quantify the parent compounds and started focusing on the mono-ester forms, which are the primary metabolites formed via CYP-450 metabolism. Even then, you have to be really careful to make sure that your method doesn’t convert the parent compound to the mono-ester.

  9. Cellbio says:

    I also worked on Cannabis as a grad student, listened to music on it, played ultimate frisbee on it, and about everything else except smooth talk the ladies. Somehow the word dude doesn’t fit into those conversations with great effect.

  10. Handles says:

    Glad you all liked that abstract 🙂
    Unfortunately, theres nothing extraordinary about it, theres plenty more like it in the literature. My PhD supervisor came back from a natural products conference in Thailand once, where some poor grad student had proudly announced his isolation of phthalates, and suffered more immediate criticism.
    Heres perhaps a better example, notable for its concise abstract:

  11. rogi says:

    I will sleep better tonight knowing that all of the jobs which have been outsourced (including my own)will be handled by skilled and studied chemists who will bring, at substantial savings for pharmacutical companies, cutting edge research based on the paradigm set forth by CRO organizations in third world countries.

  12. geezer says:

    I think source of the data, some “obsure Chinese journal” sums it up. No peer review.

  13. HelicalZz says:

    Doesn’t this mean it can now be sold as a neutraceutical?
    Zz (tongue firmly in cheek)

  14. Mark Nelson says:

    Now that phthalates are deemed natural products it is only a matter of time before they become GRAS and further assaults on human development and reproduction escalate.
    The purported antibacterial triclosan was found in marine sponges and reported in the literature, although they isolated only micrograms.
    And of course, the makers of fine organo-persisters and halogenated molecules felt vindicated that such a useless compounds was found in nature. Good reason to spread it all over the earth now.

  15. DENNY says:

    Wouldn’t it be strange if the chemists reporting the work weren’t idiots, and 2-EHP actually WAS a natural product? No, its not possible, since the majority here firmly reject it. Majority determines truth, nicht wahr?

  16. Mark Nelson says:

    If I could get the journal Zhong Yao Cai we could scope this out and see how this was isolated and analyzed and controlled for. My company cancelled the subscription because our private jets needed new leather seats, and who could be caught dead in tattered vinyl?
    But you are right on, Denny, you never know what nature is going to produce and weirder things have been known to happen.

  17. Hap says:

    “If you see hoofprints, think horses, not zebras.”
    Since phthalates are everywhere, assuming that your bugs are making them (rather than your isolation or human sources in the environment put them there) is a pretty strong assertion – if you make a strong claim, you ought to have strong data to support it. One example of such data would be feeding experiments (if you give the bugs 13C labeled precursors, and they actually make the phthalates, then the phthalates should also be 13C labeled, which would tell you if the bugs were making them). Without that kind of data, why do you expect people to believe their claims?

  18. bikinmike3 says:

    It’s been done. Babu & Wu, Science of the Total Environment, 2010, 4949-4975.
    There is very compelling evidence for biosynthesis of PEs, including several that are not commercial products, such as bis(2-ethylbutyl) phthalate.

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