Structural investigation of phytochemical compounds from Algerian plant Convolvulus tricolor (Convolvulaceae)

The convolvulaceae family composed of about 50 genera and 1500 species is distributed across the world's tropical and subtropical regions [1], although some species also reach temperate zones. Convolvulus tricolor a member of the convolvulaceae family, commonly called dwarf morning glory (local name „Souçane berri“), occurs in the region of Tell in Algeria [2]. Up to now, a few studies have been reported on C. tricolor. Analyses of the genus have demonstrated the presence of polyhydroxy alkaloids [3] and polysaccharides (galactomannans) [4]. The purpose of this present work is to phytochemically investigate some constituents of its leaves, flowers, stems, seeds, roots. The preliminary study of methanolic extracts of seed coats from C. tricolor, exhibited in vitro a very good antileishmanial activity (99.51% inhibition against L. amazonensis) with percentage of cytotoxicity equal to zero. In addition, a strong antioxidant activity has been shown in a DPPH TLC assay for the methanol extract of flowers. The latter was chromatographed on silica gel 70–230 mesh using as gradient eluant containing increasing ratio of MeOH in CHCl3. The isolation and purification were performed by preparative TLC on silica gel and Sephadex LH-20 column, leading six compounds which major compound was identified as the flavonol quercetin-3-O-rhamnoglucoside by using spectral analysis (UV, 1H NMR, 13C NMR, 2D NMR, and MS).