Thursday, January 17, 2008

Gerty Cori Biochemist on USA Stamp

Biochemist Gerty Cori is going to be on a new USA stamp to be issued in March. Cori and her husband won the Nobel Prize in 1947 for their work on glycogen metabolism [Nobel Laureates: Carl Ferdinand Cori and Gerty Theresa Cori].

One of the key intermediates in this pathway is the Cori ester [Monday's Molecule #25]. That's the molecule pictured on the stamp. Unfortunately, there's a mistake in the structure. How many can spot it? Why didn't they ask a biochemist to check the design?

UPDATE: Here's the correct structure.
The error was first discovered by a reader of Chemical & Engineering News [Going postal over structural errors]. Here's how C&EN describes the mistake ...
It is a sad state of affairs, because it was precisely the isolation of glucose-1-phosphate, and discovery of the so-called Cori ester, that garnered Cori the Nobel Prize. "Long-dead carbohydrate chemists would roll over in their graves to see this structure after all the effort they made to get it right," one sugar chemist wrote in an e-mail to Newscripts.

The glitch made us rather glum, despondent even, as we considered the squandered opportunity to serve some first-class carbohydrates to the American public. For alas, the suboptimal stamps have already been printed and are still scheduled for release in early March, despite the error.

[Hat Tip: Living the Scientific Life]


  1. Perhaps somebody "artistic", but not very chemical, thought it would look better if they moved it off her shoulder a bit?

  2. If it was the beta-D-glucose-1-phosphate anomer, it'd be sticking in her nose!

  3. can someone explain the mistake? On the picture it's alpha-D-glucose-1-phosphate. Not the beta. I thought the Cori ester was the alpha? And they haven't got the counterion in the phosphate formula - does that count as the mistake?
    I'm not a biochemist :) please enlighten me

  4. Hint, anon- are you quite sure that's really a phosophester bond in that picture?

  5. The chair conformation is almost certainly the most stable conformation. They got that part correct.

    However, the stability of the version shown depends on it being the β anomer. The structure on the stamp is the α anomer as Dunbar noted and this is likely to be less stable.

    On the other hand, the real Cori ester is the α anomer as anonymous says. It's made by a mutase reaction with α-D -glucose -6-phosphate as substrate and the subsequent activated glucose (UDP-glucose) is the α anomer.

    The error is the phosphate group. The bond should be to the first oxygen atom and not the second one.

    While it may seem to be a trivial error, the fact remains that it is an error and should have been corrected. The publication of a stamp that gets it wrong does not enhance the reputation of the USA.

  6. aha! thanks very much for pointing that one out.

  7. Larry, while you are correct there's is a literal error, I think you are wrong to criticize it. Anyone with the knowledge to interpret that structure (i.e. anyone who has ever taken an ochem class) will recognize that phosphate group as being slightly askew. People without the knowledge to interpret the structure are not harmed because I have yet to meet someone who learned sugar structures from US stamps. Sometimes the aesthetics do take precedence over literal correctness.

    This reminds me of a biochem professor of mine with not-so-great handwriting. When he drew structures on the board quickly, sometimes his Hs would look like Ns because the horizontal bar in the H would slant a little. This was never a serious problem because it was always evident what the meaning was from the context of the structure. The same applies here. The stamp is a tribute, not a textbook diagram.

  8. matt says,

    Anyone with the knowledge to interpret that structure (i.e. anyone who has ever taken an ochem class) will recognize that phosphate group as being slightly askew.

    And they will wonder why in the world a country like America can't get it right on their stamps.

    Face it matt, if it was some primitive third world country Americans would probably be happy to point out how stupid they are to get such a simple structure wrong on their stamp.

    If it were a Canadian stamp I'd be very embarrassed.

  9. that is just dumb with a capitle K