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Título:
Analysis of the polysaccharides from Cladophora falklandica: some aspects of their action on the hemostatic system
Autor/es:
PAULA X. ARATA; MARÍA PAULA RAFFO; IRENE QUINTANA; MARINA CIANCIA
Lugar:
Nusa Dua, Bali
Reunión:
Simposio; 21th International Seaweed Symposium; 2013
Resumen:
Analysis
of the polysaccharides from Cladophora
falklandica. Some aspects of their action on the haemostatic system
Arata PX1, Raffo,
MP2, Quintana I3, Ciancia M*,1,4
1Cátedra de Química de Biomoléculas, Departamento de
Biología Aplicada y Alimentos, Facultad de Agronomía, Universidad de Buenos
Aires, Argentina ciancia@agro.uba.ar
2CENPAT-CONICET, Puerto Madryn, Chubut, Argentina
3Laboratorio de Hemostasia y Trombosis, Departamento de
Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de
Buenos Aires, Argentina
4CIHIDECAR-CONICET, Departamento de Química Orgánica,
Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires,
Argentina
Seaweeds from the Cladophorales
synthesize sulfated xyloarabinogalactans. Those from C. rupestris have 3-linked b-D-galactose units sulfated on
C-6, while the arabinopyranose units are 4-linked and sulfated on C-3. Besides,
ramifications of single stubs of galactose and b-D-xylopyranose, as well as 4-linked
xylose disaccharide ramifications were also present [1]. C. falklandica was collected in the high intertidal zone of
protected wave-cut platforms composed by siltstone at Punta Este (42º 46'
48'' S, 64º 57' W; Patagonia,
Argentina) in
September 2010. This species is extensively distributed along the Patagonian
coast from 42° to 54°S. The room-temperature (CX1-CX3, 19.2 % of the milled
seaweed), and 90º (CC1-CC3, 10.0 %) water extracts have galactose and arabinose
as major sugars and similar quantities of xylose (11.5-7.7 %). However, while
in CX1, CC2 and CC3, galactose is the major monosaccharide constituent, in the
other samples, arabinose predominates. Percentage of sulfate decreases during
the extraction sequence (27.3-15.4 %, expressed as SO3Na). No uronic
acids were present, and only minor amounts of pyruvic acid were found. Anticoagulant
properties of the extracts were evaluated using PT, APTT and TT. APTT and TT
were prolonged by all the extracts, in a dose dependent manner. The most
powerful effect was observed in the APTT test by CX2 suggesting that it may
affect the intrinsic and/or common pathway of coagulation. However, its
behavior in tests involving direct studies on the fibrin network formation gave
opposite results. The lagtime of the fibrinformation was inversely proportional to the concentration, and
the maximum velocity strongly increased with concentration of CX2. These latest
results indicate a procoagulant activity. We are currently trying to interpret
this, since both methods reflect the conversion of fibrinogen to fibrin but
they are also sensitive to the presence of inhibitors that may be present in
plasma.
[1] Painter, TJ in ?The
Polysaccharides? (ed. G.O.Aspinall), Academic Press, London, Vol.2, pp 196-285 (1983).
Category of presentation: Poster