Structure of two glucans and a galactofuranomannan from the lichen Umbilicaria mammulata

Bioactive lichen metabolites: alpine habitats as an untapped source

“…Among the dozens of lichens studied for their polysaccharide content, some species are frequently found in cool montane to alpine zones. These are Cladonia species (Iacomini et al 1985), Cetraria islandica (Ingolfsdottir et al 1994b), Thamnolia vermicularis (Olafsdottir et al 1999(Olafsdottir et al , 2007, Peltigera species (Fukuoka et al 1968;Omarsdottir et al 2006b) and Umbilicaria species (Nishikawa et al 1969;Carbonero et al 2006). They produce a variety of polysaccharides, including a-and b-glucans, galactomannanns and some heteroglycans, the b-glucans being often found in high amounts (Olafsdottir and Ingolfdottir 2001).…”

Lichen Polysaccharides

“…Also, alkali solutions have been used to extract these compounds. The polysaccharides present in the thalli of Umbilicaria mammulata were isolated by an exhaustive method starting with successive extraction with hot water at 100 o C followed by extraction of the residue with hot 2% KOH at 100 o C. The alkaline extract was further treated with Fehlings solution to yield the 1,3--glucan from the supernantant and a 1,6--glucan was obtained from the precipitated Fehlings complex (Carbonero et al, 2006). In our laboratory, we have used a similar alkaline extraction procedure to isolate a polysaccharide from Usnea cf.…”

“…Nonreducing end units were composed of Xylose (Cordeiro et al, 2007). In 2006, (1→3)-and (1→6)-linked -glucans, namely laminaran and pustulan and galactofuranomannan which have a main chain of (1→6)-linked -mannopyranosyl residues, partially substituted at O-2, O-4 were isolated from another lichen Umbilicaria mammulata (Carbonero et al, 2006) Coccomyxa mucigena of the lichen Peltigera aphthosa was thought to be the origin of this heteropolysaccharide since the lichen thallus yielded a polysaccharide of different structure. A colleman like heteropolysaccharide was isolated from the cyano lichen Collema flaccidum.…”

“…Lichen polysaccharides, can also be used as a taxonomic tool to differentiate some lichen species, since some of the heteropolysaccharides and their chemical characters are unique to certain groups of lichens (Carbonero et al, 2006 andCordeiro et al, 2007). Further, the polysaccharides content of the lichen photobiont may be used as a marker in algal symbiont taxonomy (Cordeiro et al, 2007).…”

Structural Elucidation and Antioxidant Activity of a Polysaccharide from Mycelia Fermentation of Hirsutella sinensis Isolated from Ophiocordyceps sinensis

“…In recent years, many polysaccharides and polysaccharide-protein complexes isolated from fungi have been used as a source of therapeutic agents [1,2]. Many studies showed that fungi polysaccharide have series of pharmacological action, including anti-oxidation, hypoglycemic, boost immunity, anti-fatigue and anti-cancer [3][4][5][6][7].…”