This was a tough one to crack! Only 3 signals in proton NMR spectrum, and, thanks to X-ray, we could see more. But now we finally know how exactly these polychaeta worms glow to mate each other. Check out our new paper about Odontosyllis luciferin on PNAS website.
Figure from PNAS website. O. undecimdonta worms and components of its bioluminescence system. (A) The fireworm in daylight and in the dark. (B) Light emission of lyophilized worms in water. (C) NMR tube with the purified oxyluciferin (Green), visible light. (D) Fluorescence of Green, UV light. (E) NMR tube with the purified product of nonenzymatic oxidation of luciferin (Pink), visible light.