ULTRAVIOLET ABSORPTION SPECTRA 195 



be regarded as the sura of the absorption of the phloroglucinol nucleus and 

 the polyphenoUc residue. Catechins generally have absorption maxima 

 in the region 2700-2800 A (e = 1000-3000). Secondary maxima may 

 appear about 2150 2200 A (Bradfield and Penney, 1948; Morton and 

 Sawires, 1940; Klingstedt, 1922). 



REFERENCES 



Arnold, W., and J. R. Oppenheimer (1950) Internal conversion in the photosynthetic 



mechanism of bhie-green algae. J. Gen. Physiol., 33: 423-435. 

 Aronoff, S. (1940) Some structural interpretations of flavone spectra. J. Org. 



Chem., 5: 561-571. 

 Bayliss, N. S. (1948) A "metallic" model for the spectra of conjugated polyenes. 



J. Chem. Phys., 16: 287-292. 

 (1950) The effect of the electrostatic polarization of the solvent on electronic 



absorption spectra in solution. J. Chem. Phys., 18: 292-296. 

 Bowen, E. J. (1946) The chemical aspects of light. 2d ed., Oxford University Press, 



London. 



(1950) Light absorption and photochemistry. Quart. Revs. London, 4: 



236-250. 



Bradfield, \. E., and M. Penney (1948) The catechins of green tea. Part II. J. 

 Chem. Soc, 2249-2254. 



Braude, E. A. (1945) Ultra-violet light absorption and the structure of organic com- 

 pounds. Ann. Repts. on Progr. Chem. (Chem. Soc. London), 42: 105-130. 



(1950) Studies on light absorption. Part IX. The relation between absorp- 

 tion intensities and molecular dimensions and its application to the electronic 

 spectra of polyenes and polycyclic benzenoid hydrocarbons. J. Chem. Soc, 

 379-384. 



Brink, N. G., D. E. Wolf, E. Kaczka, E. L. Rickes, F. R. Koniuszy, T. R. Wood, and 

 K. Folkers (1949) Vitamin Bj.. IV. Further characterization of vitamin B12. 

 J. Am. Chem. Soc, 71: 1854-1856. 



Brockman, J. A., Jr., J. V. Pierce, E. L. R. Stokstad, H. P. Broquist, and T. H. Jukes 

 (1950) Some characteristics of a crystalline compound derived from vitamin 

 B12. J. Am. Chem. Soc, 72: 1042. 



Erode, W. R. (1943) Chemical spectroscopy. 2d ed., John Wiley & Sons, Inc., New 

 York. 



— (1946) The absorption spectra of vitamins, hormones, and enzymes. Ad- 

 vances in Enzymol., 4: 269-311. 



(1949) The presentation of absorption spectra data. J. Opt. Soc Amer., 



39: 1022-1031. 

 Butenandt, A., H. Friedrich-Freksa, S. Hartwig, and G. Scheibe (1942) Beitrag zur 



Feinstruktur des Tabakmosaik Virus. Hoppe-Seyler's Z. physiol. Chem., 274: 



276-284. 

 Cain, C. K., M. F. Mallette, and E. C. Taylor, Jr. (1948) Pyrimido[4,5-6]pyrazines 



(pteridines). III. Pteridinemono- and -dicarboxylic acids. J. Am. Chem. 



Soc, 70: 3026-3029. 

 Caspersson, T. (1950) Cell growth and cell function, a cytochemical study. W. W. 



Norton & Company, Inc., New York. 

 Cavalieri, L. F., and A. Bendich (1950) The ultraviolet alhsorpl ion spectra of 



pyrimidiues and purines. J. Am. Chem. Soc, 72: 2587-2594. 

 Chako, N. Q. (1934) Absorption of light in organic compound.s. J. Chem. Phys., 



2: 644-653. 



