Alveld-producing saponins. I. Chemical studies
Ceh, L.; Hauge, J.G.
Acta Veterinaria Scandinavica 22(3-4): 391-402
1981
ISSN/ISBN: 0044-605X PMID: 7344529 Document Number: 181832
The saponin fraction of Narthecium ossifragum has been previously described as a sarsasapogenin glycoside with the structure arabinose-galactose-xylose-glucose-sarsasapogenin. In a renewed study of the phototoxic lamb disease, alveld, in which this saponin has been implicated, the saponin fraction was further investigated. There are 2 saponins, 9 major and a minor fraction. Both have a branched trisaccharide on C-3 of the sapogenin. Galactose is directly attached to C-3 in both saponins. The major saponin has glucose and arabinose attached to galactose; the minor saponin has glucose and xylose. The names narthecin and xylosin are suggested for the spirostanol form of these 2 saponins. In fresh juice from leaves a slight amount of narthecin is found. Most of the saponin is present in the furostanol form, with glucose on C-26. Enzymatic hydrolysis showed that this glucose is bound as a .beta.-glucoside. From specific rotations in partial hydrolysates, the saccharide on C-3 is a slight amount of a .beta.-D-glucoside, .alpha.-L-araboside and .beta.-D-galactoside.