Firefly Luciferin 



Bernard L. Strehler 



Department of Biochemistry (Fels Fund) 



University of Chicago, Chicago, IlHnois 



In the course of the early work on luminescence of firefly extracts 

 (McElroy and Strehler, 1949) one of the factors which was demon- 

 strated to be necessary for hght production, in addition to ATP, mag- 

 nesium ion, and oxygen, was a compound which we termed "firefly 

 luciferin." Subsequently, some of the properties of this compound 

 were described (Strehler and McElroy, 1949). Further physical and 

 chemical studies were undertaken independently by Dr. McElroy at 

 the Johns Hopkins University and by the author at the Oak Ridge 

 National Laboratory. The results presented here represent work soon 

 to be published jointly with Dr. McElroy (Strehler and McElroy, 

 1954), and Mr. John Sites (Strehler and Sites, 1954) of the stable 

 isotopes division, Oak Ridge. 



The luciferin used in these experiments was isolated by two dif- 

 ferent procedures, one involving partition chromatography on a Celite 

 column with water as a stationary phase and butanol-chloroform as 

 the moving phase. The other involved chromatography on a Dowex 

 50 column and adsorption and elution from a fuller's earth column. 

 The materials prepared in these two ways appeared to be identical 

 in both the ultraviolet and infrared regions of the spectrum. Elemen- 

 tary analysis (qualitative) indicated the presence of sulfur and nitro- 

 gen and the absence of phosphorus. The material is soluble in polar 

 organic solvents and water at neutral pH and partitions into ether 

 from strongly acid aqueous solution. 



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