Coelenterazine h,2-Deoxycoelenterazine

2,8-Dibenzyl-6-(4-hydroxyphenyl)imidazo[1,2-a]pyrazin-3(7H)-one

Coelenterazine h is a coelenteramide derivative that is used as a substrate for bioluminescence signal. It is an effective activator of the light-producing enzyme, luciferase, and has been used to study calcium-dependent regulatory pathways. Coelenterazine h is also able to activate the proteases in cell culture that are involved in the release of intracellular ATP, which can be detected with a chemiluminescent reaction. Coelenterazine h has been shown to be less sensitive than luciferin for detection of bioluminescence signal, but has greater analytical sensitivity for ATP levels.

Coelenterazine is a luciferin, a light-emitting biomolecule that serves as a substrate for luciferases or as a constituent of photoproteins, including aequorin. Coelenterazine can be used to reconstitute the aequorin complex both in vivo and in vitro, emitting blue light when bound to calcium ions. Coelenterazine h is a synthetic derivative of native coelenterazine that exhibits 16-fold higher luminescence intensity (emission maximum ~466 nm; half-total time of 0.6-1.2 sec) than native coelenterazine. Aequorin complexes reconstituted with coelenterazine h are reported to be more sensitive to calcium ions than those employing the native constituent, providing a useful indicator for small changes in Ca2+ concentrations.

Coelenterazine H is a synthetic derivative of coelenterazine (a light-emitting biomolecule).