UPDATE: The original structure was missing a methyl group at the bottom right. This has now been corrected.
Identify the molecule—the common name will do but make sure you get it right because there are quite a few similar molecules. 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.
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 a gibberellin-like molecule. It was intended to be gibberellin GA1 but I left off a methyl group. This is similar to Monday's Molecule #102 (gibberellin GA3). Defects in one of the genes for gibberellin GA1 synthesis gave rise to the tall/short phenotype studied by Gregor Mendel [Mendel's Stem Length Gene (Le)]. Gibberellin GA1 was one of the molecules synthesized by Elias James Corey, winner of the Nobel Prize in Chemistry 1990. The winner this week is Albi Celaj.
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