Estudo químico de carboidratos isolados do micélio do cogumelo medicinal Grifola frondosa (“Maitake”)
Carregando...
Data
2014-06-26
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
The mushrooms have been used as food and medicine for thousands of years. Among
them, Grifola frondosa (“Maitake”) may be on the most versatile and promising
medicinal mushrooms for use as a dietary supplement. Besides the high nutritional
value, they are a good source of compounds such as carbohydrates that can act as
biological response modifiers. In this work, β-D-glucans (PSF2-GfM and MRSF2K-GfM
fractions) and heteropolysaccharides unusual in the literature (MEPF3CW-GfM and
PF2K-GfM fractions) were isolated from the mycelium, grown in solid culture, of the G.
frondosa, by successive aqueous and alkaline extractions, followed by fractionation
through freeze-thawing, precipitation of soluble material with a Fehling solution, and
dialysis using a membrane with an exclusion limit of 1000 kDa. The chemical structures
were established based on monossacharide composition, periodate oxidation,
methylation analysis, HPSEC-MALLS and NMR studies. The branched β-D-glucans
(GLC-GfM) found were similar to those previously described for the fungus, which
contains a (13)- linked β-Glcp main-chain, substituted at O-6 by single-unit -Glcp
side-chains, on the average of one to every third residues of the backbone, but with
different molar masses and water solubility. In adittion, novel heteropolymers were
obtained. One was a fucomannogalactan (FMG-GfM), with a molar mass of 175 x 103
g mol-1, was shown to have a main chain of (1→6)-linked α-D-Galp and 3-O-Me-α-DGalp,
both of which are partially substituted at O-2, principally, by 3-O-α-D-Manp-α-LFucp
groups. The other was a fucoxylomannan (FXM-GfM) (Mw 202 x 103 g.mol-1),
which consisted of backbone of (13)-linked α-D-Manp units, totally substituted at O-4
mainly by 4-O-α-L-Fucp-β-D-Xylp disaccharide. Thus, the polymers obtained from
Grifola frondosa may could be good candidates for evaluation of its biological effect,
considering the results obtained for others similar mushrooms polysaccharides.
Descrição
Palavras-chave
Cogumelos medicinais, Grifola frondosa, Maitake, Heteropolissacarídeos, β-glucanas, Estrutura química, Medicinal mushroom, Grifola frondosa, Maitake, Heteropolysaccharides, β- glucans, Chemical structure
Citação
SILVA, E. V. Estudo químico de carboidratos isolados do micélio do cogumelo medicinal Grifola frondosa (“Maitake”). 2014. 123 f. Dissertação (Mestrado em Química) - Universidade Federal de Goiás, Catalão, 2014.