22 



CARBOHYDRATES 



TABLE 1. STRUCTURES AND OCCURRENCE OF SOME OLIGOSACCHARIDES 



Gentiobiose: 6-0-/3-D-glucopyranosyl-D-glucose (various glycosides) 



CH2OH 



CH2 



Ho>| — Y H^^ — Y 



OH OH 



Melibiose: 6-O-Q-D-galactopyranosyl-D-glucose (Fraxinus spp. ) 



^9H2 

 ^1/ 



OH 



Sucrose: a-D-glucopyranosyl- /3-D-fructofuranoside (throughout the plant kingdom) 



CHjOH 



CH2OH 



Trehalose: a-D-glucopyranosyl-a-D-glucopyranoside (Selaginella lepidophylla) 



