Discussion 



The Infrared Spectrum of Anderson's Luciferin 



Dr. Mason: In Figs. 8 and 9 are depicted infrared spectra of Cypri- 

 dina luciferin prepared by the method of Anderson. To obtain these 

 spectra dry flakes of amorphous luciferin were placed between rock 

 salt surfaces and absorption was measured by manual adjustment of 

 wavelength setting and null point with a Beckman infrared spectro- 



WAVE NUMBERS IN cm"' 

 4000 3000 2000 1500 12 50 1000 



2 



40 



6.0 8.0 100 



WAVELENGTH IN MICRONS 



Fig. 8. 



12 



14.0 



meter. Strong bands occur at 3250, 2800, 1680, 1630 and 1510 cm-^. The 

 absorption of infrared energy in the 2700 to 3100 cm"^ (Fig. 9) region 

 by a luciferin film was measured by Dr. R. C. Gore of the American 

 Cyanimid Company, Stamford. Using a lithium fluoride prism, ab- 

 sorption bands were found at 2860, 2920, 2960 and 3060 cm-^ It was 

 the comparison of these results with the published spectra of proteins 

 and polypeptides that led to the inference that the peptide bond is 

 present in Anderson's preparations of Cypridina luciferin. As it seems 

 evident from Dr. Tsuji's new work that Anderson's luciferin may yet 

 be of a low order of homogeneity, these spectra are being ofiFered as a 

 physical characterization of the material obtained at that stage and as 



157 



