Molecule of the Day

I hadn’t heard of this one before today: Mutagen X.


Mutagen X is apparently a byproduct of water chlorination, which isn’t so surprising – chloroform (CHCl3) can occur in chlorinated water. This MX stuff is much worse, apparently. Anyone know the immediate source of the carbon?


  1. #1 John
    November 9, 2007

    As with chloroform, the carbon source is usually humic acids.

  2. #2 markmier
    November 9, 2007

    I’m a water engineer (BS in Chem Eng, MS in Environmental Eng). I’m not sure, but I would guess that the carbon comes from humic or fulvic acids, i.e. NOM (natural organic matter) that is naturally present in surface water, and occasionally groundwater. It’s not a single simple molecule, it’s a whole family of complex organic soup. I personally haven’t heard of Mutagen X, though there are all kinds of disinfection byproducts (DBPs) out there. Chloroform is the most common. THMs (trihalomethanes, of which chloroform is obviously one) and HAAs (haloacetic acids) are the ones that are regulated by the SDWA (safe drinking water act). Is that enough TLAs for you? (three letter acronyms)

  3. #3 Molecule of the Day
    November 9, 2007

    Yeah, I’ve read the “humic acid” explanation, and maybe I’m showing my ignorance, but can’t we do a little better? Five-membered lactenones always remind me of ascorbate. Anyone have any idea what the real precursor is? It can’t be that diverse a range of substrates for transformation by what amounts to chlorine radical.

  4. #4 Renan
    November 10, 2007

    This would be a good theme for a science-fiction story, IMHO…

  5. #5 Cranberry
    November 12, 2007

    Looks like the carbon could have come from an isoprene, but those can come from practically anywhere.

  6. #6 joeylawn
    November 12, 2007

    I remember the story in Peru where they were worried about trihalomethanes causing cancer in drinking water. So they stopped chlorinating the water for a while, and many died from water-borne bacterial diseases. I’d rather drink THM’s than, say, cryptosporidium, etc.

  7. #7 Uncle Al
    November 13, 2007

    Compare Mutagen X, structure and steric bulk, with that of Vioxx,

    A little lab work toward the intersection would be interesting. Furanones can be scccharide degradation products. To what does Splenda pyrolyze at cooking, baking, and crust-browning temps?

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