Polysaccharides of the lichens Cetraria islandica and Ramalina usnea

Gorin, Philip A.J.; Iacomini, Marcello

doi:10.1016/0008-6215(84)85090-9

Cited by 128 publications

(51 citation statements)

References 25 publications

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“…These were obtained in low yields from S. ramulosum (family Stereocaulaceae) [6], R. celastri [2] and R. usnea [7] (family Ramalinaceae). Further studies must be reviewed with other Ramalina species to observe if laminaran is also present in all of them.…”

Section: Resultsmentioning

confidence: 99%

“…These structures are distinct from a highly branched L-D-glucan isolated from the basidiomycetous lichen Dictyonema glabratum [4] (formerly Cora pavonia) and di¡erent from those of free ascomycetes, which have K or L structures with less than 10% of branching [5]. Linear (1C3)-linked L-D-glucans have been previously isolated from the lichens Stereocaulon ramulosum [6], Ramalina usnea [7] and Ramalina celastri [2].…”

Section: Introductionmentioning

confidence: 99%

“…In the most species studied, the K-D-glucans have (1C3)-and (1C4)-linkages whose ratio showed considerable variation [5,6,7,8] (1:1 to 4:1), controlling their solubility or insolubility in cold water. The water-insoluble K-D-glucans that contain alternate (1C3)-and (1C4)-linkages resemble nigeran (mycodextran) and have been isolated from nine species of the genus Cladonia [3].…”

Section: Introductionmentioning

confidence: 99%

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Comparative studies of the polysaccharides isolated from lichenized fungi of the genus Cladonia: significance as chemotypes

Carbonero¹

2001

FEMS Microbiology Letters

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L-D-Glucans of the laminaran type were prepared from 15 Cladonia spp., Cladonia bellidiflora, Cladonia boryi, Cladonia clathrata, Cladonia connexa, Cladonia crispatula, Cladonia furcata, Cladonia gracilis, Cladonia ibitipocae, Cladonia imperialis, Cladonia miniata, Cladonia penicillata, Cladonia salmonea, Cladonia signata, Cladonia substellata and Cladonia uncialis. They were extracted with 10% aqueous KOH at 100³C, giving polysaccharides with varying yields and proportions of mannose, galactose and glucose. Their aqueous solutions were freeze^thawed giving precipitates of mixed K-glucan (nigeran) and L-glucans, which were isolated and suspended in aqueous 0.5% KOH at 50³C, which preferentially dissolved the L-glucan. In the case of the C. uncialis product, it was subjected to methylation analysis, which gave rise to 2,4,6-tri-O-methylglucitol acetate only, corresponding to (1C3)-linkages. Its specific rotation (+4³) and one-and twodimensional nuclear magnetic resonance (NMR) spectra were consistent with L-linkages.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Comparative studies of the polysaccharides isolated from lichenized fungi of the genus Cladonia: significance as chemotypes

Carbonero¹

2001

FEMS Microbiology Letters

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“…A fase clorofórmica contendo os acetatos de alditóis foi coletada, e após secura, a amostra foi ressolubilizada em acetona para ser analisada por cromatografia líquido-gasosa (GLC). As análises por GLC foram efetuadas em cromatógrafo gasoso Hewlett Packard modelo 5890 A Série II, com detector de ionização de chama (FID) e injetor à temperatura de 250 °C, coluna capilar DB-210 (30 m × 0,25 mm de diâmetro interno), com espessura de filme de 0,25 µm a 220 °C, e nitrogênio como gás de arraste em fluxo de 2,0 mL/min [12] . O grau de esterificação das pectinas foi determinado por espectroscopia de infravermelho (FT-IR -Fourier transform-infrared), em espectrofotômetro BOMEM MB-100.…”

Section: Métodosunclassified

Polissacarídeos extraídos da gabiroba (Campomanesia xanthocarpa Berg): propriedades químicas e perfil reológico

Santos¹,

Petkowicz²,

Haminiuk³

et al. 2010

Polímeros

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Resumo:A Campomanesia xanthocarpa Berg (Myrtaceae) é uma frutífera nativa brasileira, com ampla distribuição natural na região Sul. Embora apresente frutificação abundante, produza frutos com características sensoriais e nutricionais atrativas, esses não são coletados e se perdem nos campos. Neste trabalho, a polpa do fruto sem semente (1500 g) foi triturada em etanol / água na proporção de 1:4 (v/v), refluxada por 15 minutos em temperatura de ebulição. O resíduo obtido foi submetido a extrações sequenciais. As extrações foram otimizadas utilizando um planejamento fatorial 2 2 , tendo como variáveis a concentração do ácido cítrico (0,5 e 5%) e a temperatura (50 e 100 °C). Os polissacarídeos provenientes de diferentes extrações foram caracterizados quanto à composição química e perfil reológico. Os altos teores de ácidos urônicos, arabinose e galactose detectados em todas as frações, indicam que estas são constituídas por polissacarídeos pécticos. Os polissacarídeos extraídos da polpa da gabiroba apresentaram um comportamento pseudoplástico. Todas as frações apresentaram como característica resistência frente às variações de temperatura. Quando submetidas a ciclos de aquecimento e posterior resfriamento estes géis retornam à sua estrutura original. Palavras-chave: Pectina, reologia, composição química. Polysaccharide Isolated From Gabiroba (Campomanesia xanthocarpa Berg): Chemical Properties and Rheology ProfileAbstract: The Campomanesia xanthocarpa Berg (Myrtaceae) is a Brazilian native fruit, widely abundant in the Southern region. Despite their large fructification, in addition to nutritional and attractive sensory characteristics, these fruits are not collected, being lost in the fields. In this work, the fruit pulp without seed (1500 g) was crushed in ethanol/water at a ratio of 1:4 (v/v), refluxed for 15 minutes at boiling temperature. The residue obtained was subjected to sequential extractions. The extractions were optimized using a factorial design 2 2 , with the concentration of citric acid (0.5 and 5%) and temperature (50 and 100 °C) as variables. The polysaccharides were characterized according to their chemical composition and rheological profile. The high concentrations of uronic acids, arabinose and galactose, detected in all fractions, indicate that they consist of pectin. The results showed that the extraction method was efficient for fractionation of pectin from different areas of the cell wall. The polysaccharides extracted from the fruit pulp of gabiroba showed a pseudoplastic behavior. All the fractions were resistant to temperature variations. When these gels are heated up and cooled down, they adopt their original structure. Keywords: Pectin, rheology, chemical composition. IntroduçãoPectinas são heteropolissacarideos complexos encontrados na parede celular primária e nas camadas intercelulares dos vegetais. Estão associadas aos polissacarídeos estruturais, contribuindo para adesão entre as células e para a resistência mecânica da parede celular [1] . Estruturalmente, as pectinas são consti...

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“…Galactoglucomannans were obtained from above combined supernatants, then treated with Fehling solution (300 ml) and the insoluble Cu complexes were isolated by centrifugation and converted to galactoglucomannans [10]. The supernatants were neutralized with HOAc, dialyzed against tap water and then deionized with mixed ion exchange resins.…”

Section: Preparation Of Galactoglucomannans and Galactomannoglucansmentioning

confidence: 99%

Galactomannoglucans of lichenized fungi of Cladonia spp.: significance as chemotypes

Woranovicz-Barreira¹

1999

FEMS Microbiology Letters

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Polysaccharides of the lichens Cetraria islandica and Ramalina usnea

Cited by 128 publications

References 25 publications

Comparative studies of the polysaccharides isolated from lichenized fungi of the genus Cladonia: significance as chemotypes

Comparative studies of the polysaccharides isolated from lichenized fungi of the genus Cladonia: significance as chemotypes

Polissacarídeos extraídos da gabiroba (Campomanesia xanthocarpa Berg): propriedades químicas e perfil reológico

Galactomannoglucans of lichenized fungi of Cladonia spp.: significance as chemotypes

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