Heterogeneity and structural investigation of galactomannans isolated from the seeds of cassia sericea

✍ Scribed by Gudipati Muralikrishna; Rudrapatnam N. Tharanathan; U. Ramadas Bhat

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 460 KB
• Volume: 182
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(88)84096-5

✦ Synopsis

Two homogeneous galactomannans were isolated from the seeds of Cassiu sericea and investigated by methylation analysis, periodate and CrO, oxidation, 'H-and 13C-n.m.r. spectroscopy, and reaction with a-D-galactosidase. The polysaccharides had backbones of (l-+3)-and occasional (l-4)-linked p-r>-mannopyranosyl residues and side chains, at positions 6, of single a-D-galactopyranosyl groups. One of the polysaccharides also had a few non-reducing terminal mannosyl groups.

The endosperm of many plant seeds (mainly belonging to the family Leguminoseae) contains galactomannans which have attracted much attention, and the ratio of mannose and galactose, the nature and distribution of the galactose side-chains along the mannose backbone, and the d.p. affect the solubility, gelling, and functional characteristics lA3. Seeds of several Cussiu species have been in-vestigated4-l2 and we now report on the polysaccharides isolated from the seeds of Cussia sericea. This plant is reported to arrest the growth and spread of the noxious weed Purfheniu~, the pollen of which causes allergy in human@.

RESULTS AND DISCUSSION

Aqueous extraction of the 60-mesh powder of the seeds furnished cold-watersoluble (CWS) and hot-water-soluble (HWS) polysaccharides in yields of 65 and 24%, respectively. The crude polysaccharides were composed mainly of mannose and galactose (Table I). Only 83% of CWS redissolved in water and the insoluble