Monday, November 28, 2011

Monday's Molecule #151

This is a very complicated molecule so I'm not going to ask for the IUPAC name. You can win with the common name but be sure to get it right!

This molecule has played a very important role in elucidating some basic concepts in molecular biology but its structure is rarely shown in 21st century biochemistry textbooks.

Post your answer in the comments. I'll hold off releasing any comments for 24 hours. The first one with the correct answer wins. I will only post correct answers to avoid embarrassment.

There could be two winners. If the first correct answer isn't from an undergraduate student then I'll select a second winner from those undergraduates who post the correct answer. You will need to identify yourself as an undergraduate in order to win. (Put "undergraduate" at the bottom of your comment.) Every undergraduate who posts a correct answer will have their names entered in a Christmas draw. The winner gets a free autographed copy of my book! (One entry per week. If you post a correct answer every week you will have ten chances to win.)

Some past winners are from distant lands so their chances of taking up my offer of a free lunch are slim. (That's why I can afford to do this!)

In order to win you must post your correct name. Anonymous and pseudoanonymous commenters can't win the free lunch.

UPDATE: The molecule is rifampicin, an inhibitor of bacterial RNA polymerase. The winner is Philip Rodger. Congratulations Philip, please send me an email message so we can arrange lunch.

Nov. 2009: Jason Oakley, Alex Ling
Oct. 17: Bill Chaney, Roger Fan
Oct. 24: DK
Oct. 31: Joseph C. Somody
Nov. 7: Jason Oakley
Nov. 15: Thomas Ferraro, Vipulan Vigneswaran
Nov. 21: Vipulan Vigneswaran (honorary mention to Raul A. Félix de Sousa)


  1. My real name: Philip Rodger

    Undergrad. :)

  2. Raul A. Félix de Sousa (, November 28, 2011 9:28:00 AM

    So easy, that's rifampicin, or isoniazid, or pyrazinamide, or better, (7S,9E,11S,12R,13S,14R,15R,16R,17S,18S,19E,21Z)-2,15,17,27,29-pentahydroxy-11-methoxy-3,7,12,14,16,18,22-heptamethyl-26-{(E)-[(4-methylpiperazin-1-yl)imino]methyl}-6,23-dioxo-8,30-dioxa-24-azatetracyclo[,7.05,28]triaconta-1(28),2,4,9,19,21,25(29),26-octaen-13-yl acetate

  3. I'm going to go with Rifampicin. T'was a harder one this time, had to google the numbers of constituent atoms to home in on :)

    Anyway, not a graduate student and from a distant land so the dinner must go to another deserving individual.

  4. Oops, I'm sorry, it's just Rifampicin (or it's IUPAC name), and not isoniazid or pyrazinamide. When I googled it, I was directed to the Wikipedia page containing a fixed drug combination of these three compounds and hurryiedly added the others as if they were synonyms.

  5. Rt. Hon. Alex Ling

    Reminded me of amanitin, so it was pretty easy to google RNA polymerase inhibitors. I should really get to these posts earlier.

  6. Rifampicin

    Best wishes,

    Bill Chaney

  7. Hi Larry

    antibiotic Rifampicin


    Glyn Tompkinson
    Not an undergrad

  8. Name: Rt. Hon. Alex Ling
    Molecule: Rifampicin

    Looked like amanitin, so I just googled RNA polymerase inhibitors. I wonder if there is some basis for structural convergence?

  9. I think it's rifampicin! I'm a grad student in southern Ontario but I don't make it up to Toronto often.. so you are probably off the hook for lunch again (if I'm actually the winner of course!).

  10. Looked like amanitin, so I just googled RNA polymerase inhibitors.

    Yep, exactly the same here.

  11. ooohhhh I found an easy way to solve these Monday Molecules. Feel free to not publish this comment, although I suspect some people have already thought of it.

    So, Google has a new search that allows search by image.

  12. an easy way to solve these Monday Molecules

    probably the easiest way to defeat search with the image is for Larry to draw the structure(s) by hand. Then scan or take a snapshot (even a cell phone will suffice). Then search engine will start looking for sparsely-filled hand-drawn images ignoring the chemical structure.

  13. Or just draw the structure in ChemDraw and export it yourself