Rhizoctonia solani fucomannogalactan: Chemical characterization and antiproliferative activity

Abstract

A fucomannogalactan from Rhizoctonia solani biomass was obtained after hot aqueous extraction and purified by freeze-thaw cycles and gel filtration chromatography on Sepharose CL-6B. The polysaccharide was homogeneous after HPSEC/RID analysis (M/M~1.1), displaying an average molecular weight of 15.4×10Da. Its chemical structure was determined by methylation analysis (GC/MS) and spectroscopy (FTIR, 1D and 2D NMR). The polysaccharide had a branched α-1,6-linked Galp backbone with 66% linear residues, a number of which were at O-3 methylated. Side chains (34%) were always linked at O-2 positions of the main chain and consisted of single, non-reducing ends of α-d-Manp (6%) and α-l-Fucp (28%). Analysis of its biological activity showed that the highly purified fucomannogalactan from R. solani inhibited the proliferation of colon cancer cells in vitro, but that it did not have the same activity against lung cancer cells.

CARACTERIZAÇÃO QUÍMICA E AVALIAÇÃO DA CITOTOXICIDADE DE UM HETEROPOLISSACARÍDEO ISOLADO DA BIOMASSA DO Colletotrichum gloeosporioides

“…O gel selecionado e as condições da análise foram semelhantes ao trabalho efetuado por Alexandre e colaboradores. 18…”

“…Os processos de extração dos polissacarídeos da biomassa seguiram procedimentos já descritos na literatura. 18,20,21 A primeira extração efetuada com álcool etílico, removeu 16% de compostos hidrofóbicos e de pequena massa molecular, como oligossacarídeos livres, gerando um resíduo de 45 gramas, que após maceração foi submetido a extração aquosa a quente (4x), procedimento capaz de isolar polissacarídeos da parede celular como: β-glucanas, galactanas e mananas. 12,18,[22][23][24] Os extratos aquosos foram reunidos e congelados (E H2O-C ).…”