Galactomannans and arabinans from seeds of Caesalpiniaceae

Schizolobium parahybae and S. amazonicum seeds yielded galactomannans with identical 3.0:1 Man:Gal ratios and with the same D-galactose distribution along the main chain. Although the galactomannan from seeds of Cassia fastuosa showed the same Man:Gal ratio, its line structure differed significantly from that of the two Schizolobium species as shown by the analysis of cligosaccharides (DP 2 to 6) obtained by partial acid hydrolysis. Seed coats of S. parahybae and S. amazonicum furnished similar unusual neutral linear alpha-L-arabinofuranan (1-->5) linked, as determined by methylation analysis, optical rotation and C-13 NMR spectroscopy. On the other hand, C. fastuosa seed coats furnished two acidic arabinans. These results in terms of using galactomannans and arabinans in chemotyping, support the suggestion of Rizzini that S. parahybae and S. amazonicum are not different species. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.