Abstract: Polysaccharides isolated from seeds of fenugreek(Trigonella foenum-graecum),China honeylocust (Gleditsia sinensis), smalleaf honeylocust (G. microphyllfa) and tara (Caesalpinia spinosa) are composed of D-galactose and D-mannose, which are similar to galactomannan from guar gum. Structural studies are performed by GC, ¹HNMR and ¹³CNMR. All galactomannans possess molecules having main chains consisted of (1→4)-linked β-D-mannose residues, with different proportions of side chains consisted of single α-D-galactose residue linked to the main chain by (1→6)-bond. Ratios of galactose to mannose of the above polysaccharides are 1:1.2, 1:2.5, 1:3.2 and 1:2.4,respectively (guar gum 1:1.6). Molecular weights (M_V) are found to vary from 206000 (smalleaf honeylocust) to 343900 (tara). Melting points are situated between 263-272℃(M_v of guar gum is 430600).

Key words: fenugreek, China honeylocust, smalleaf honeylocust, tara, seed polysaccharide