Sulfated and pyruvylated galactans from Caribean Green seaweeds with anticoagulant activity

MARINA CIANCIA; PAULA X. ARATA; IRENE QUINTANA; DILSIA CANELON; ALIRICA SUAREZ; REINALDO COMPAGNONE

Nusa Dua, Bali

Simposio; 21th International Seaweed Symposium; 2013

International Seaweed Association

Sulfated and pyruvylated galactans from Caribbean green seaweeds with anticoagulant activity   Ciancia, M*,1,2, Arata, PX1, Quintana, I3, Canelón, D.4, Suarez, A5, Compagnone R.6   1Cátedra de Química de Biomoléculas, Departamento de Biología Aplicada y Alimentos, Facultad de Agronomía, Universidad de Buenos Aires, Argentina ciancia@agro.uba.ar 2CIHIDECAR-CONICET, Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina. 3Laboratorio de Hemostasia y Trombosis, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina, 4Escuela de Bioanálisis, Facultad de Medicina, Universidad Central de Venezuela. 5Facultad de Farmacia,  Universidad Central de Venezuela. 6Escuela de Química, Facultad de Ciencias, Universidad Central de Venezuela, Venezuela.   The order Bryopsidales has been divided into two suborders. The Halimedineae are generally present in tropical and subtropical habitats. From this suborder, only the structural features of the heteroglycan sulfate from Caulerpa racemosa were previously reported. It was a branched polymer containing, 3-linked galactose, terminal- and 4-linked xylose, and 4- and 3,4-linked arabinose residues. Sulfate groups, when present, were located on C-3 of 4-linked arabinose and C-6 of 3-linked galactose units. No pyruvic acid was informed [1]. We studied the structures of the major sulfated polysaccharides from three different species, Penicillus capitatus, Udotea flabellum, and Halimeda opuntia (Halimedineae). Analysis of the water extracts showed that all of them are mainly sulfated pyruvylated galactans. The room temperature water extract from U. flabellum (UDA) comprises galactose, sulfate and pyruvic acid in a molar ratio 1.0:0.7:0.3. Methylation analysis and NMR spectra showed 3-linked b-D-galactose units (~38 %, 6-sulfated) and 35 % have pyruvic acid ketals giving a 6-membered ring. However, 30 % of the latter units are also sulfated on C-2. The room-temperature water extract from P. capitatus was fractionated by ion exchange chromatography, giving two major fractions (PA1 and PA6, molar ratio Gal:Sulf:Pyr, 1.0:0.8:0.6, and 1.0:0.9:0.3, respectivelly). PA1 comprises 44% of 4,6-O-(1´-(R)-carboxy)ethylidene-b-D-galactopyranose units (~ 70%, sulfated on C-2), and 25 % 3-linked 6-sulfated units as major structures. The NMR spectra of these galactans showed signals similar to those of UDA, but there are some additional signals. The most evident were tentatively assigned to C-1/H-1, C-2/H-2 and C-3/H-3 of 3-linked b-D-galactose units sulfated on C-2 (d 103.1/4.83, 76.6/4.46, and 79.2/4.25, respectively).   Category of presentation: Oral