Influence of the uronic acid composition on the gastroprotective activity of alginates from three different genus of Tunisian brown algae

Hiba Hadj Ammar (1) , Sirine Lajili (2) , Nawfel Sakly (1) , Dora Cherif (2) , Christophe Rihouey (3) , Didier Le Cerf (3) , Abderrahman Bouraoui (2) , Hatem Majdoub (1)

1 LIMA - Laboratoire des Interfaces et Matériaux Avancés [Monastir]
2 UM - Université de Monastir - University of Monastir
3 PBS - Polymères Biopolymères Surfaces

Alginates from three genus of Tunisian brown algae were isolated and characterized by size exclusion chromatography and Solid-state NMR spectroscopy. Alginate from Padina pavonica (APP) had the highest molecular weight (Mw) with 147,000 g/mol while it was 85,000 g/mol for alginate from Cystoseira compressa (ACC) and 58,000 g/mol for alginate from Dictyopteris membranaceae (ADM). The mannuronate (M) to guluronate (G) ratios were estimated from spectral deconvolution of the 13C CP/MAS spectra and the results has shown that all the extracts are mannuronic acid-rich alginates with M/G ratio increased in the order ADM – ACC – APP. An interesting gastroprotective effect was observed for the extracts; ADM and ACC exhibited the highest inhibition of gastric lesions, at 50 mg/kg, with 83.41% and 75.39% respectively. Otherwise, it has been shown that the gastroprotective effect of alginates depends mainly on their uronic acid composition.

Mots clés: Sodium alginate; Brown algae; CP-MAS NMR; Deconvolution; Gastroprotective activity; SEC/MALS/VD/DRI

Domaines: Polymères; Matériaux

Hiba Hadj Ammar, Sirine Lajili, Nawfel Sakly, Dora Cherif, Christophe Rihouey, et al.. Influence of the uronic acid composition on the gastroprotective activity of alginates from three different genus of Tunisian brown algae. Food Chemistry, 2018, 239, pp.165 - 171. ⟨10.1016/j.foodchem.2017.06.108⟩. ⟨hal-01869025⟩