On the mechanism of the generation of 5-oxy-2,3-dihydroimidazo[1,2-a]pyrazin-3-ones by the direct variable-temperature NMR method: a variable-temperature study
Unstable hydroperoxide of coelenterazine (Oplophorus luciferin) analog has been synthesized by the reaction of coelenterazine analog with polymer-bound Rose Bengal via photooxygenation. This compound may be a key intermediate model in the bioluminescence of aequorin and the chemiluminescence of coelenterazine.
The structure of yellow compound from aequorin was revised by means of synthesis of stable analogs having tert-butyl group at the 2-position of the imidazopyrazinone chromophore. Comparing their absorption spectra concluded that the yellow compound should have the 5-oxo structure instead of having hydroxy group at 2 position as reported previously.