Toward bioluminescence in the near-infrared region: Tuning the emission wavelength of firefly luciferin analogues by allyl substitution

Abstract The synthesis and bioluminescence of allyl-substituted luciferin derivatives as substrates for firefly luciferase are reported. The allylation of luciferins induced bathochromic shift (15–40 nm) of the bioluminescence emission. Upon combination with other chemical modifications for bioluminescence wavelength tuning, novel red emitting luciferin analogues were obtained with emission maxima at 685 and 690 nm.