ABSTRACT
Siparuna guianensis Aubl., Siparunaceae, is used as anxiolytic plants in folk medicine by South-American indians, "caboclos" and river-dwellers. This work focused the evaluation of phenolic composition of hydroethanolic extract of S. guianensis through HPLC-DAD-ESI/MS/MS. The constituents exhibited protonated, deprotonated and sodiated molecules and the MS/MS fragmentation of protonated, deprotonated and sodiated molecules provided product ions with rich structural information. Vicenin-2 (apigenin-6,8-di-C-glucoside) was the main constituent found in S. guianensis together quercetin-3,7-di-O-rhamnoside and kaempferol-3,7di-O-rhamnoside. A commercial extract of Passiflora incarnata (Phytomedicine) was used as surrogate standard and also was analyzed through HPLC-DAD-ESI/ MS/MS, showing flavones C-glycosides as constituents, among them, vicenin-2 and vitexin. The main constituent was vitexin. Flavonols triglycosides was also found in low content in S. guianensis and were tentatively characterized as quercetin-3O-rutinoside-7-O-rhamnoside, quercetin-3-O-pentosyl-pentoside-7-O-rhamnoside and kaempferol-3-O-pentosyl-pentoside-7-O-rhamnoside. Apigenin and kaempferol derivatives had been reported as anxiolytic agents. Flavonoids present in this extract were correlated with flavonoids reported as anxiolytics.
ABSTRACT
Chemical study of three medicinal plants: from leaves of Piper renitens (Miq.) Yunck, Piperaceae, and Siparuna guianensis Aubl., Siparunaceae, and from flowers of Alternanthera brasiliana (L.) Kuntze, Amaranthaceae, resulted in isolation of nine compounds: three steroids, β-sitosterol, stigmasterol from P. renitens and sitosterol-3-O-β-D-glucopyranoside from A. brasiliana, the diterpene kaurane ent-kauran-16α,17-diol from P. renitens, two derivatives kaempferol-methylether, kumatakenine (kaempferol-3,7-dimethylether) and kaempferol-3,7,3'-trimethylether from S. guianensis and three flavones, crysoeriol (5,7,4'-trihydroxy-3'-methoxyflavone), tricin (5,7,4'-trihydroxy-3',5'-dimethoxyflavone) and 7-O-β-D-glucopyranoside-5,4'-dihydroxy-3'-methoxyflavone from A. brasiliana. Compounds structures were determinate using 1D and 2D ¹H NMR and 13C spectral data, mass and IR spectra, comparing with literature data.