Novel anti-hyperglycemic sulfated pyruvylated polysaccharide from marine macroalga Hydropuntia edulis

Dipeptidyl peptidase is a crucial enzyme that regulates glucose metabolism by degrading incretins, such as glucagon-like-pep- tide-1, thereby reducing insulin secretion from the pancreatic b-cells. Consequently, dipeptidyl peptidase-IV inhibitors are an important remedial approach to moderate the hyperglycemic pathophysiology. A pyruvylated polysaccharide characterized as [!3)-4,6-O-(1-carboxyethylidene)-b-D-galp-(2SO3 )-(1!4)-3,6-a-L- AnGalp-(2OMe)-(1!], isolated from the marine macroalga Hydropuntia edulis, showed attenuation potential against dipep- tidyl peptidase-IV (IC50 4.44 lM). The structure was elucidated using mass and one/two-dimensional nuclear magnetic resonance spectroscopic analyses of hydrolyzed polysaccharide besides glycosidic linkages obtained from partially methylated alditol acet- ate derivative. The isolated polysaccharide also revealed potential anti-carbolytic properties against a-amylase/a-glucosidase (IC50 45–47 lM). The results proved the candidacy of pyruvylated poly- saccharide isolated from H. edulis as a potential therapeutic lead against hyperglycemia