Three exopolysaccharides of the beta-(1-->6)-D-glucan type and a beta-(1-->3;1-->6)-D-glucan produced by strains of Botryosphaeria rhodina isolated from rotting tropical fruit.
Four exopolysaccharides (EPS) obtained from Botryosphaeria rhodina strains isolated from rotting tropical fruit (graviola, mango, pinha, and orange) grown on sucrose were purified on Sepharose CL-4B. Total acid hydrolysis of each EPS yielded only glucose. Data from methylation analysis and (13)C NMR spectroscopy indicated that the EPS from the graviola isolate consisted of a main chain of glucopyranosyl (1-->3) linkages substituted at O-6 as shown in the putative structure below: [carbohydrate structure: see text]. The EPS of the other fungal isolates consisted of a linear chain of (1-->6)-linked glucopyranosyl residues of the following structure: [carbohydrate structure: see text]. FTIR spectra showed one band at 891 cm(-1), and (13)C NMR spectroscopy showed that all glucosidic linkages were of the beta-configuration. Dye-inclusion studies with Congo Red indicated that each EPS existed in a triple-helix conformational state. beta-(1-->6)-d-Glucans produced as exocellular polysaccharides by fungi are uncommon.
Vasconcelos
Ana Flora D
AF
Departamento de Física, Química e Biologia, Faculdade de Ciências e Tecnologia, Universidade Estadual Paulista, CP 467, CEP 19060-900, Presidente Prudente, São Paulo, Brazil.
Monteiro
Nilson K
NK
Dekker
Robert F H
RF
Barbosa
Aneli M
AM
Carbonero
Elaine R
ER
Silveira
Joana L M
JL
Sassaki
Guilherme L
GL
da Silva
Roberto
R
de Lourdes Corradi da Silva
Maria
M
D001203:Ascomycota / Q000737:chemistry* / Q000302:isolation & purification; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005638:Fruit / Q000382:microbiology*; D008401:Gas Chromatography-Mass Spectrometry; D005936:Glucans / Q000737:chemistry* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011134:Polysaccharides / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014329:Tropical Climate; D047071:beta-Glucans / Q000737:chemistry* / Q000378:metabolism
D005936:Glucans; D011134:Polysaccharides; D047071:beta-Glucans; C033671:epiglucan; C064197:beta-1,6-glucan