Linear mannan in the endosperm of Schizolobium amazonicum

The seed endosperm from the Leguminosae Schizolobium amazonicum was shown to consist of three different parts: (i) the embryo side or interior section; (ii) the seed coat side or exterior section; and (iii) an intermediate zone rich in galactomannan with a 3:1 Man/Gal ratio located between the two sides of the seeds. The exterior section was submitted to a series of hot water and alkaline extractions and the remaining product investigated by monosaccharide analysis, 13C NMR, X-ray and electron diffraction, together with electron microscopy. After an extraction with 16% NaOH, a linear beta (1->4) microfibrillar mannan could be isolated in this portion of the seeds. This is the first time that a pure mannan fraction has been found in the seed of a Leguminosae.