Structural variety of glucans from Ganoderma lucidum fruiting bodies

Ganoderma lucidum, widely used in traditional medicine, has several biological properties. Polysaccharides, mainly glucans, are known as one of its main bioactive compounds. Consequently, the achievement and chemical investigation of such molecules are of pharmaceutical interest. Herein, we obtained water-insoluble and water-soluble polysaccharides from G. lucidum by alkaline extraction. Fractionation process yielded three fractions (GLC-1, GLC-2, and GLC-3). All samples showed to be composed mainly of glucans. GLC-1 is a linear (1 → 3)-linked β-glucan; GLC-2 is a mixture of three different linear polysaccharides: (1 → 3)-β-glucan, (1 → 3)-α-glucan, and (1 → 4)-α-mannan; while GLC-3 is a branched β-glucan with a (1 → 4)-linked main chain, which is branched at O-3 or O-6 by (1 → 3)- or (1 → 6)-linked side chains. This research reports the variability of glucans in Ganoderma lucidum fruiting bodies and applicable methodologies to obtain such molecules. These polysaccharides can be further applied in biological studies aiming to investigate how their chemical differences may affect their biological properties.