Antioxidant properties of 6-methoxyflavonol glycosides from the aerial parts of Chenopodium bonus-henricus L

Radical scavenging and antioxidant activities of nine flavonoids previously isolated from the aerial parts of Chenopodium bonus-henricus L. were established using DPPH and ABTS free radicals as well as inhibition of lipid peroxidation in a linoleic acid system by the ferric thiocyanate method. Patuletin glycosides, compounds 1, 2 and 7 showed the highest DPPH (85.78%, 85.59%, 86.07%) and ABTS activity (90.64%, 90.27%, 90.76%) compared to Vitаmin C. Spinacetin and 6-methoxykaempferol glycosides compounds 4, 6 and 3, 5 respectively possessed a significantly low DPPH activity and demonstrated a high ABTS radical-scavenging activity. Spinacetin and 6methoxykaempferol glycosides, compounds 8 and 9, containing esterified ferulic acid in their moiety, demonstrated a moderate DPPH (53.46%, 45.52%) and a high ABTS (83.41%, 74.51%) activity. All flavonoids inhibited significantly the lipid peroxidation of linoleic acid. The results suggest that the aerial parts of C. bonus-henricus L. could be a potential source of flavonoids with radical-scavenging and antioxidant activities..