[ 41 ] 



V. 



THE CONSTITUTION OF CATECHIN— Paet I. 



By JAMES J. DRUMM, M.Sc, 

 University College, Dublin. 



[Bead May 28. Publislied July 17, 1923.] 



Although a great many papers have already appeared on the subject of the 

 eateehins, the constitution of these bodies has not yet been finally settled. 

 Hitherto the most thoroughly investigated representative of the class has 

 been the principal catechin of Gambir catechu. In the present paper also a 

 few further derivatives of this catechin are described, the preparation and 

 properties of which place the structure of the parent molecule in a new 

 light. 



Without attempting a detailed account of the literature of the subject, it 

 may be stated that A. G. Perkin (Jour. Chem. Soc, 1905, 84, p. 87) made the 

 first real attempt to establish a structural formula (i) for catechin. 



O , .OH 



CH-/ \oH 



CHOH 



Perkin's formula (i) represents catecliin as a derivative of chromane, and 

 therefore also of oy-diphenylpropane. 



Perkin (Jour. Chem. Soc. 1897, Ixxi, p. 1138) has pointed out that tliere is 

 a close relationship between the nuclear groups of tannins and those of the 

 flavone dyes which occur associated with the tannins in many plants. Thus, 

 quercitin occurs associated with catechin in Gambir catechu, and both contain 

 the catechol and phloroglucinol nuclei. 



liyan and Walsh (Proc. Eoyal Dublin Society, 1916, xv, p. 114) suggest 

 that the flavone dyes and authocyanidins are formed in plants from the more 

 widely distributed phlobatannins. Freudenberg (Ber. d. Deutsch. Chem. 

 Soc, Ges., 1920, liii, 1420) shares this view, and considers it extremely 

 unlikely that the structure of the eateehins should strongly deviate from the 



R.I. A. PROC, VOL. i:XXVI, SECT. B, [A] 



