Bioluminescence activity of Latia luciferin analogs

Latia luciferin analogs were synthesized and their bioluminescence activities were measured. The Latia luciferase was found to recognize strictly the 2,6,6-trimethylcyclohexene ring moiety in the luciferin structure. While the enol ether analogs exhibited no bioluminescence activity, the corresponding enol acetate analog possessed 60% activity compared to natural luciferin having an enol formate structure, implying that the initial step of the light producing reaction is an enzymatic hydrolysis to yield the corresponding enolate anion.