224 THE CARBOHYDRATES 



CH CH 



^\ /\ 



CHO . CH = CH . C C CH .OH CH C . OH 



I II I II I 



CH C CH CHjs— C C.OCH3 



CO CH 



I 

 OCH3 



The above formula is closely related to that assigned to 

 Gambier-catechin by Freudenberg,* and lends support to the 

 view that lignin may be related to the tannins. 



Lignin Isolated by the Action of Alkali. 



A study of the lignin of flax isolated by heating with 

 8-12 per cent caustic soda for six to ten hours at 140-160°, led 

 Powell and Whittaker f to compare the resulting product 

 with that isolated from various woods including pine, spruce, 

 ash, birch, and poplar ; they conclude that jute lignin is 

 essentially different from flax lignin, to which they assign the 

 formula C45H48O10 which differs considerably from Klason's 

 formula, CaoHaoOe, for pine lignin. Flax lignin has four 

 methoxyl groups, and five hydroxyl groups capable of acety- 

 lation, three of which are phenolic. To the parent hydroxyl 

 compound free from CH3 or COCH3 groups, they assign the 

 name lignol, C41H40O16, and the formula — 



C3eH3„04(CO)2CHO(OH), 



Powell and Whittaker disagree with Hagglund's | state- 

 ment that lignin contains 5 per cent of a furfural yielding 

 carbohydrate as an integral part of the molecule ; purified 

 lignin contained only 0-3 per cent pentosan and still further 

 purification gave no furfural at all. 



Beckmann, Liesche, and Lehmann § in an investigation 

 upon the lignin content of winter rye straw, used a 2 per cent 

 aqueous alcoholic solution of caustic soda acting in the cold 



* Freudenberg : " Ber. deut. chem. Gesells.," 1920, 53, 1416. 



t Powell and Whittaker : " J. Chem. Soc," 1924, 125, 337 ; 1925. 

 127, 132. 



X Hagglund : " Cellulosechemie." 1923, 4, 73. 



§ Beckmann, Liesche, and Lehmann: " Zeit. angew. Chem.," 1921, 

 34» 285. 



