The system of sulfated α-(1 → 3)-linked d-mannans from the red seaweed Nothogenia fastigiata: Structures, antiherpetic and anticoagulant properties

Structural analysis of two xylomannans extracted from Nothogenia fastigiata was carried out. The results are consistent with the general pattern previously reported for other xylo-mannans of the same system, α-(1 → 3)-linked d-mannans 2- and 6-sulfated and having single stubs of β-(1 → 2)-linked d-xylose, but one of the new samples contains a significant amount of 2,6-disulfated units. Both xylomannans studied are obtained as complexes with a β-d-(1 → 3)-, α-l-(1 → 4)-galactan and a β-d-(1 → 3)-, β-d-(1 → 4)-‘mixed linkage’ xylan co-existing in the seaweed, a fact that limits the accuracy of the data determined. The structures of the galactan and the xylan are similar to those previously informed for this seaweed. The antiviral activity against four different herpes simplex viral strains and the anticoagulant properties of all the xylo-mannans of the system are reported.Two xylomannans from Nothogenia fastigiata follow the structural pattern of other xylo-mannans of this seaweed, i.e. α-(1 → 3)-linked d-mannans 2- and 6-sulfated and having single stubs of β-(1 → 2)-linked d-xylose. Both are obtained as complexes with a galactan and a xylan also present in this seaweed. The antiherpetic and the anticoagulant properties of all the xylo-mannans of the system are reported.