Composition and preliminary fractionation of the seed mucilage of Ocimum canum

Abstract

The capsular mucilage of the seeds has been extracted in 7% yield. It is partly O-acetylated (OAc, 4.0%) and contains lipids (?free? 24% and ?bound? 5%). The mucilage is composed of D-glucose, D-galactose, D- mannose, L-arabinose, D-xylose, and L-rhamnose in the approximate ratio 8 : 5 : 2 : 1 : 1 : 2 and uronic acids (8.15%). The uronic acids were identified as D-galacturonic and D-mannuronic acids. The mucilage was fractionated into an acid-soluble fraction, which was significantly acetylated (OAc, 6.6%) and rich in uronic acids (34.4%) and pentosans, and an acid- insoluble fraction rich in hexosans. The latter on further fractionation with alkali gave a glucomannan with glucose and mannose in the ratio 10 : 3, end a galacto-glucomannan with galactose, glucose, and mannose in the ratio 2 : 4 : 1. Thus the mucilage is heterogeneous, containing at least three different polysaccharides, and is comparable to cellulose-containing seed mucilages and acidic bacterial polysaccharides.