Chemical composition of hydroethanolic extracts from Siparuna guianensis, medicinal plant used as anxiolytics in Amazon region

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-3,7-di-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 were also found in low content in S. guianensis and were tentatively characterized as quercetin-3-O-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.