Occurrence of a novel galactopinitol and its changes with other non-reducing sugars during development of Leucaena laucocephala seeds.

A new cyclitol which is abundant in the late developmental stages of leucaena (Leucaena leucocephala (Lam.) de Wit) seeds was identified by HPLC, NMR, and GC-MS as O-alpha-D-galactopyranosyl-(1-->1)-3-O-methyl-D-chiroinositol, a new galactopinitol. This galactopinitol was initially detected midway through seed development and increased to 10.2 mg (gDW)-1, but decreased in mature seeds to its about a half. Stachyose content increased greatly and remained the most abundant of the soluble sugars in mature seeds (25.6 mg (g DW)-1). Artificial drying at 73% relative humidity of 70 DPA immature seeds induced the accumulation of raffinose, stachyose, galactopinitol and galactinol, but the total amounts of these sugars were only about half of those found in mature seeds. Seed germination decreased following an initial increase after 8 d artificial drying to a moisture content of 24%, and this dehydration damage probably is because of underdevelopment of seed tissue. Galactopinitol changes in a similar fashion to the oligosaccharides during the late developmental stage and dehydration experiment, implying that galactopinitol may play a role in desiccation tolerance of leucaena seeds.