Attenuation of metabolic dysfunctions in the skeletal muscles of type 1 diabetic rats by Stevia rebaudiana extracts, via AMPK upregulation and antioxidant activities.

Background: Stevia rebaudiana Bertoni leaves are well-known for their sweetness and have been used as a non-caloric sweetener in several countries. It has numerous therapeutic properties which have been proven safe and effective over hundreds of years. In the present study, we aimed to evaluate the possible antioxidant effects of stevia extracts and their role in regulating AMPK in type-1 diabetic rats.

Polyoxygenated flavonoids from Eugenia edulis.

Leaves of Eugenia edulis contain the new polyoxygenated flavonoid derivatives, gossypetin-3,8-dimethyl ether-5-O-beta-glucoside; gossypetin-3,5-dimethyl ether, and myricetin-3,5,3'-trimethyl ether. In addition, ten known polyphenolics were also isolated and identified. All structures were established on the basis of chemical and spectral evidence, including ESI-MS and 13C NMR.

Caffeoyl sugar esters and an ellagitannin from Rubus sanctus.

The new natural caffeoyl esters, 3,6-di-O-caffeoyl-(alpha/beta)-glucose and 1-O-caffeoyl-beta-xylose, together with the hitherto unknown natural tannin, 2,3-O-hexahydroxydiphenoyl-4,6-O-sanguisorboyl-(alpha/beta)-glucose, have been isolated from the aqueous alcohol aerial part extract of Rubus sanctus. Establishment of all structures was based on the chemical and spectral evidence, including ESI-MS and 2D NMR.

Acylated flavonol diglucosides from Lotus polyphyllos.

Three acylated flavonol diglucosides, kaempferol 3-O-beta-(6"-O-E-p-coumaroylglucoside)-7-O-beta-glucoside; quercetin 3-O-beta-(6"-O-E-p-coumaroylglucoside)-7-O-beta-glucoside; isorhamnetin 3-O-beta-(6"-O-E-p-coumaroylglucoside)-7-O-beta-glucoside were isolated from the whole plant aqueous alcohol extract of Lotus polyphyllos. The known 3,7-di-O-glucosides of the aglycones kaempferol, quercetin and isorhamnetin were also characterized. All structures were established on the basis of chemical and spectral evidence.