Lignans and Other Constituents from Helianthemum sessiliflorum Pers.

One new lignan named 1-O-acetyl prinsepiol (1),in addition to nineteen known compounds including two lignans; 1α-hydroxypinoresinol (2) and (+)˗cycloolivil (3), one fatty acid; ( ̶ )˗pinellic acid (4), f ive phenolic acids; benzoic acid (5), p-hydroxybenzoic acid (6), protocatechuic acid (7), vanillic acid (8) and gallic acid (9), nine flavonoids; ( ̶ )˗epicatechin (10), ( ̶ )˗catechin (11), ( ̶ )˗epigallocatechin (12), ( ̶ )˗gallocatechin (13), astragalin (14), tiliroside (15), quercetrin (16), isoquercetrin (17) and myricitrin (18), and two phytosterols; β-sitosterol (19) and daucosterol (20) were isolated from the aerial parts of AcOEt extract of medicinal plant Helianthemum sessiliflorum Pers . of the family Cistaceae. The structures of all the isolated compounds 1-20 were determined by spectral methods including 1D ( 1H and 13C NMR) and 2D NMR (COSY, HSQC, HMBC and NOESY), HR-ESI-MS, values of optical rotation and chemical correlations with known compounds that have been described in the literature.