title: 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.
abstract: 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.
authors.affiliation: Departamento de Física, Química e Biologia, Faculdade de Ciências e Tecnologia, Universidade Estadual Paulista, CP 467, CEP 19060-900, Presidente Prudente, São Paulo, Brazil.
authors.forename: Ana Flora D
authors.initials: AF
authors.lastname: Vasconcelos
authors.forename: Nilson K
authors.initials: NK
authors.lastname: Monteiro
authors.forename: Robert F H
authors.initials: RF
authors.lastname: Dekker
authors.forename: Aneli M
authors.initials: AM
authors.lastname: Barbosa
authors.forename: Elaine R
authors.initials: ER
authors.lastname: Carbonero
authors.forename: Joana L M
authors.initials: JL
authors.lastname: Silveira
authors.forename: Guilherme L
authors.initials: GL
authors.lastname: Sassaki
authors.forename: Roberto
authors.initials: R
authors.lastname: da Silva
authors.forename: Maria
authors.initials: M
authors.lastname: de Lourdes Corradi da Silva
mesh_terms: 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
chemical_list: D005936:Glucans; D011134:Polysaccharides; D047071:beta-Glucans; C033671:epiglucan; C064197:beta-1,6-glucan