A new 5,7-dihydroxy-3'-methoxy-4'-acetoxyflavone-8-C-β-d-arabinopyranoside-2″-O-(4‴-acetoxy)-glucoside (6) and three known flavone C-glycosides-5,7,3',4'-tetrahydroxyflavone-6-C-xyloside-8-C-β-d-glucoside (lucenin-1) (7), 5,7,3'-trihydroxyflavone-6-C-glucoside-8-C-β-d-glucoside (vicenin-2) (8), and 5,7,4'-trihydroxy-3'-methoxyflavone-6-C-β-d-glucopyranoside-8-C-α-arabinopyranoside (chrysoeriol-6-C-β-d-glucopyranoside-8-C-α-arabinopyranoside) (9)-were isolated from aerial parts of Scleranthus perennis L. (Caryophyllaceae). Their structures were determined through the use of comprehensive spectroscopic and spectrometric methods, and a method for the quantification of the major constituents of S. perennis and S. annuus L. was developed. Furthermore, the anti-collagenase and antioxidant activities of all isolated compounds obtained from extracts and fractions from both Scleranthus species were evaluated. The highest percentage of collagenase inhibition (at 400 µg/mL) was distinguished for methanolic extracts (22.06%, 32.04%) and ethyl acetate fractions (16.59%, 14.40%) from S. annuus and S. perennis. Compounds 6-9 displayed moderate inhibitory activity, with IC50 values ranging from 39.59-73.86 µM.
Keywords: Scleranthus annuus; Scleranthus perennis; antioxidant; c-flavones; collagenase; enzyme inhibition.