Monday, March 18, 2013

Monday's Molecule #200

This is the 200th Monday's Molecule. I started this series back on November 13, 2006. Today's molecule is a repeat of that first one. Let's see if readers in 2013 can do better than those in 2006! The last "Monday's Molecule" was puromycin [Monday's Molecule #199]. The winners were Bell Gunn and River Jiang. River needs to contact me by email to set up a lunch date. I'm going to try and treat all the previous winners this week so if I owe you a lunch you should get in touch right away to collect.

The mystery molecule is an aldohexose. There are 16 different aldohexoses. The structures and names of 8 of them are show below in order to help you out.

This is a tough one. You have to know several carbohydrate naming conventions and you have to understand Fischer projections. Good luck.

Post your answer as a comment. I'll hold off releasing any comments for 24 hours. The first one with the correct answer wins. I will only post mostly correct answers to avoid embarrassment. The winner will be treated to a free lunch.

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.)

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.

Winners will have to contact me by email to arrange a lunch date. Please try and beat the regular winners. Most of them live far away and I'll never get to take them to lunch. This makes me sad.

Comments are now open.

UPDATE: The correct answer is L-gulose. In addition to understanding the rules of Fischer Projections you need to remember that the D- and L- enantiomers are mirror images of each other. See Better Biochemistry: Fischer Projections for an explanation. The winner is Bill Gunn (again).

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)
Nov. 28: Philip Rodger
Dec. 5: 凌嘉誠 (Alex Ling)
Dec. 12: Bill Chaney
Dec. 19: Joseph C. Somody
Jan. 9: Dima Klenchin
Jan. 23: David Schuller
Jan. 30: Peter Monaghan
Feb. 7: Thomas Ferraro, Charles Motraghi
Feb. 13: Joseph C. Somody
March 5: Albi Celaj
March 12: Bill Chaney, Raul A. Félix de Sousa
March 19: no winner
March 26: John Runnels, Raul A. Félix de Sousa
April 2: Sean Ridout
April 9: no winner
April 16: Raul A. Félix de Sousa
April 23: Dima Klenchin, Deena Allan
April 30: Sean Ridout
May 7: Matt McFarlane
May 14: no winner
May 21: no winner
May 29: Mike Hamilton, Dmitri Tchigvintsev
June 4: Bill Chaney, Matt McFarlane
June 18: Raul A. Félix de Sousa
June 25: Raul A. Félix de Sousa
July 2: Raul A. Félix de Sousa
July 16: Sean Ridout, William Grecia
July 23: Raul A. Félix de Sousa
July 30: Bill Chaney and Raul A. Félix de Sousa
Aug. 7: Raul A. Félix de Sousa
Aug. 13: Matt McFarlane
Aug. 20: Stephen Spiro
Aug. 27: Raul A. Félix de Sousa
Sept. 3: Matt McFarlane
Sept. 10: Matt Talarico
Sept. 17: no winner
Sept. 24: Mikkel Rasmussen
Oct. 1: John Runnels
Oct. 8: Raúl Mancera
Oct. 15: Raul A. Félix de Sousa
Oct. 22: Mikkel Rasmussen
Nov. 12: Seth Kasowitz, Bill Gunn
Nov. 19: Michael Rasmussen
Dec. 4: Paul Clapham, Jacob Troth
Dec. 10: Jacob Troth
Dec. 17: Bill Chaney, Dima Klenchin, Bill Gunn
Jan. 14: Evey Salara
Jan. 21: Piotr Gasiorowski
March 11: Bill Gunn, River Jiang
March 18: Bill Gunn


  1. L-Gulose, and I give up on what bad things it does to certain cells.

  2. Its L-gulose. As for the mechanism of toxicity, my guess is it might be converted into an analogue of D-fructose which messes with glycolysis.

  3. Man, I can't believe I got it wrong 6-ish years ago. I actually remembered which aldohexose it was because it was one of the weird sounding ones: L-gulose.

    I also double checked by finding the post, so I cheated a little. Incidentally, who is the all-time winner?

    1. I don't know who has won the most times. It's possibly 凌嘉誠, but Dima Klenchin and Bill Chaney have also won lots of times.