Some species make this molecule for a very special reason. Identify the molecule using the common name and the IUPAC name. You must also say why it's important for some species.
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. The winner will be treated to a free lunch with a famous Nobel Laureate, or with me if the Nobel Laureate isn't available.
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.
UPDATE: The molecule is taurocholate (2-{[(3α,5β,7α,12α)-3,7,12-trihydroxy-24-oxocholan-24-yl]amino}ethanesulfonate). Taurocholate is a bile salt in mammals. This week's winners are Bill Chaney and Raul A. Félix de Sousa.
Winners
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