Antioxidant and antiproliferative activities of phytochemicals from Quince (Cydonia vulgaris) peels

Fifty-nine secondary metabolites have been isolated from Cydonia vulgaris peels and characterised on the basis of their spectroscopic features. Among them, five metabolites, 3b-(18-hydroxylinoleoyl)-28- hydroxyurs-12-ene (12), 3b-linoleoylurs-12-en-28-oic acid (15), 3b-oleoyl-24-hydroxy-24-ethylcholesta- 5,28(29)-diene (24), tiglic acid 1-O-b-D-glucopyranoside (35), and 6,9-dihydroxymegastigmasta-5, 7-dien-3-one 9-O-b-D-gentiobioside (46), have been isolated and elucidated for the first time. All of the compounds were tested for their radical-scavenging and antioxidant activities by measuring their capacity to scavenge the 2,20-diphenyl-1-picrylhydrazyl (DPPH) radical, and anion superoxide radical and to induce the reduction of Mo(VI) to Mo(V). The antiproliferative activity of all the most abundant compounds by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) bioassay on murine B16-F1 melanoma cells has been also assessed.