Quercetin 3-O-beta-D-glucopyranoside is a quercetin O-glucoside that is quercetin with a beta-D-glucosyl residue attached at position 3. Isolated from Lepisorus contortus, it exhibits antineoplastic activityand has been found to decrease the rate of polymerization and sickling of red blood cells It has a role as an antineoplastic agent, a plant metabolite, a bone density conservation agent, an osteogenesis regulator, an antioxidant, a histamine antagonist, an antipruritic drug and a geroprotector. It is a quercetin O-glucoside, a tetrahydroxyflavone, a beta-D-glucoside and a monosaccharide derivative. It is functionally related to a beta-D-glucose. It is a conjugate acid of a quercetin 3-O-beta-D-glucopyranoside(1-).