Structure elucidation of Keroplatus (Diptera:Keroplatidae) fungus gnat oxyluciferin

Bioluminescence of insects is a well-known natural phenomenon in the focus of interest of scientific research. While the mechanisms of bioluminescence in Coleoptera have been extensively studied, there is a lack of information about the chemistry of light emission in Diptera species. Here we report the Keroplatus spp. oxyluciferin structure elucidation and identification as 3-hydroxykynurenic acid. Additionally, the present study provides the first direct evidence of the relationship between the bioluminescent systems of Orfelia and Keroplatus. However, the properties of the putative Orfelia oxyluciferin suggest that the light emission mechanisms are not identical.