The fine structure of Chaetangium fastigiatum xylan: studies of the sequence and configuration of the (1→3)-linkages

The polysaccharides of green, red and brown seaweeds: Their basic structure, biosynthesis and function

“…Other 1,3-and mixed 1,3-; 1,4-1inked xylans have been separated from Porphyra umbilicalis, Laurencia pinnatafida (Turvey & Williams, 1970) and Chaetangiumfastigiatum (Cerezo, 1972) all of which also synthesize a galactan. Frei & Preston (1964) mechanically separated the cell wall of P. umbilicalis and Bangiafuscopurpurea and showed that they consisted of 1,3-1inked xylans in a random network of microfibrils.…”

Algal Walls — Composition and Biosynthesis

“…Since these extracts also contain glucose units, it is tentatively suggested by the authors that the polysaccharide from this weed may be a heteropolymer in which the xylose occurs as short branched chains on a glucan backbone. Other (I -+ 3)-and (1 -+ 4)-xylans have been separated from Porphyra umbilicalis, Laurencia pinnatifida (TURVEY and WILLIAMS 1970) and from Chaetangium Jastigiatum CEREZO et al 1971, CEREZO 1972. In contrast to Rhodymenia further extraction with alkali of Porphyra umbilicalis gave a pure (1 -+ 3)-xylan (TURVEY and WIL-LIAMS 1970).…”

Sulfated galactans from the red seaweed Nothogenia fastigiata (Nemaliales, Rhodophyta)

“…Previous work carried out on Chaetangium fastigiatum (former name of Nothogenia fastigiata) showed the presence, among the water-extractable products, of fl-D-(1-3)-, /3-D-(1-> 4)-homoxylan with molecular-weight and structural heterodispersion (Cerezo et al ., 1971 ;Cerezo, 1972) and a family of a-D-(1-* 3)-linked mannans 2-and 6-sulfated with single stubs of /3-(1-> 2)-linked D-xylose (Matulewicz & Cerezo, 1987) . A similar system of polysaccharides has been found in Nemalion vermiculare (Usov et al, 1974(Usov et al, , 1975a 1975b ; Usov & Yarotskii, 1975) and in Liagora sp.…”

“…Nevertheless, a less studied group of red seaweeds synthesizes a system of polysaccharides whose better known components are xylans (Cerezo et al, 1971 ;Cerezo, 1972 ;Nunn et al, 1973a ;Usov et al, 1974 ;Usov & Dobkina, 1988) . These algae also produce a mixture of sulfated polysaccharides from which sulfated a-D-(1-> 3)-linked mannans having single stubs of fl-(1 -2)-xylose were identified (Usov et al, 1974(Usov et al, , 1975a(Usov et al, , 1975bUsov & Yarotskii, 1975 ;Matulewicz & Cerezo, 1987 ;Usov & Dobkina, 1988) .…”