Mature fruit of Chorisia speciosa yield an exudate (E-I) following mechanic
al injury. The polysaccharide contains rhamnose, arabinose, xylose, mannose
, glucose, galactose and glucuronic acid in molar ratios of 20:11:1:3:2:40:
23. The main chain of the structure is composed by P-galactopyranosyl units
linked (1 --> 3) and (1 --> 6) as indicated by NMR spectra and methylation
data. Arabinosef and rhamnose are terminal residues. In order to compare E
-I with the polysaccharides from the fruit mesocarp, the latter was submitt
ed to different extractions. The water fraction contains rhamnose, arabinos
e, xylose, mannose, glucose, galactose and uronic acid in molar ratios of 1
8:4:1:2:3:44:28. It was treated with CTAB yielding a precipitate which was
decomplexed with NaCl, giving four fractions. The fraction obtained using 0
.15 M NaCl had a quantitative composition similar that of E-I. (C) 1999 Els
evier Science B.V. All rights reserved.