Constituents of Cydonia vulgaris:  Isolation and Structure Elucidation of Four New Flavonol Glycosides and Nine New α-Ionol-Derived Glycosides

In a previous paper, we described the isolation of four new sesterterpenes from Cydonia vulgaris Pers. Here we report the isolation of four new flavonol glycosides (1−4) and nine new α-ionol-derived glycosides (5−13) together with the known 3-oxo-α-ionol 9-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside (14), vomifoliol 9-O-β-d-glucopyranoside (roseoside) (15), and vomifoliol 9-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside (16) from the MeOH extract of the aerial parts of C. vulgaris Pers. (Rosaceae). All structures were elucidated by spectroscopic methods, including the concerted application of one-dimensional NMR and two-dimensional NMR techniques (COSY-90 and HETCOR). Keywords: Cydonia vulgaris; Rosaceae; flavonol glycosides; α-ionol glycosides; 1H and 13C NMR (one- and two-dimensional)