Antitumor and antioxidant activities of polysaccharides from the seaweed Durvillaea antarctica.

The present study was carried out to determine the antitumor and antioxidant activities of the seaweed Durvillaea antarctica. Extraction and purification of polysaccharides from D. antarctica were performed.

Effect of light intensity on steviol glycosides production in leaves of Stevia rebaudiana plants.

Stevia rebaudiana leaf extracts contain stevioside and rebaudioside A, two steviol glycosides (SGs) used as natural sweeteners because of their non-toxic, thermally stable and non-caloric properties. Indeed, leaf extracts can be up to 300 times sweeter than sucrose. Stevioside and rebaudioside A have organoleptic differences, the first one having an undesirable bitterness and the second one a higher sweetener capacity.

The inhibitory effects of squalene-derived triterpenes on protein phosphatase PP2A.

This paper reports testing 15 polyether triterpenes with a squalene carbon skeleton for inhibitory effects on type 2A protein phosphatase. Two compounds, 16-hydroxydehydrothyrsiferol 10 and thyrsenol B 14, exhibited significant inhibitory action at a concentration of 10 microM. Comparison with thyrsiferyl-23-acetate 1 showed that a similar spatial disposition for the hydroxy group around C-15 or C-16 was the structural feature shared by these metabolites.