78 



INTRODUCTION TO IMAIUNOCHEMICAL SPECIFICITY 



D-galactose, lactose, melibiose, L-arabinose, and D-fucose) also all had 

 the same configuration at carbons 3 and 4. Here, too, the hydroxyl 

 groups at carbons 3 and 4 are at the same side of the ring, but are 

 pointing up, which is just the opposite of that found in the sugars 

 inhibiting Lotus (Fig. 6-3). 



CH2OH 



H,OH 



^ W OH 



D-Galoctose 



CH2OH 



H.OH 

 3H H/' 



^^H NHCOCH3 



A/-Acefyl- D-galactosamine 



H,OH 



Fig. 6-3. Hawortli formulas of sugars inhibiting the anti-(A-|-B) of Sophora 

 japonica. (Redrawn from Kriipe, 1956). 



Alakela (1957), who made a much more extensive study of plant 

 agglutinins and their inhibition reactions, suggested that monosac- 

 charides fall into four classes with respect to their specific inhibiting 

 activity for plant agglutinins and that this is based on their configura- 

 tion at carbons 3 and 4 (Fig. 6-4). 



