Two new steroidal saponins and two known flavonoid glycosides were isolated from the fruits of Tribulus terrestris. Their structures were assigned by spectroscopic analysis and chemical reaction as 26-O-beta-D-glucopyranosyl-(25R)-5 alpha-furostan-12-one-3beta,22 alpha,26-triol-3-O-beta-D-glucopyranosyl (1 --> 2)-beta-D-glucopyranosyl(1 --> 4)-beta-D-galactopyranoside (1), 26-O-beta-D-glucopyra...

The isolation of four novel acylated flavonoid glycosides from the roots of Saussurea lappa and their identification using a combination of 1D and 2D NMR and mass spectrometry is described. The in vitro antifungal and antibacterial activities of the isolated compounds and their mixture were tested on nine fungal and four bacterial strains, using the microdilution method. The compounds and mixtu...

Four antibacterial compounds were isolated from leaves of guava (Psidium guajava L.), and the structures of these compounds were established on the basis of chemical and spectroscopic evidence. Two new flavonoid glycosides, morin-3-O-alpha-L-lyxopyranoside and morin-3-O-alpha-L-arabopyranoside, and two known flavonoids, guaijavarin and quercetin, were identified. The minimum inhibition concentr...

Methanolic leaf extracts of Erythroxylum australe F. Muell. produced eight O-conjugated flavonoids. Six of the flavonoid aglycones were dihydroisoflavones (all dihydro-orobol derivatives), one a flavanone, eriodictyol, and one a flavonol, quercetin. The major glycosides of the flavonoids included mono-glucosyl-rhamnosyls and dirhamnosyl-glucosides with either 3, 5, 7 or 3', 4' linkage or a comb...

Anthocyanins are an important group of highly hydrosoluble pigments in most species of plants. They are produced by secondary metabolism of plants (pentosophosphate, shikimate and flavonoid pathways) and are accumulated in cell vacuoles. In fruits and vegetables anthocyanins are present in the form of glycosides. The qualitative and quantitative determination of anthocyanins can be performed by...