Antiinflammatory and antioxidant flavonoids from Helichrysum kraussii and H. odoratissimum flowers

Abstract

Organic extracts of the flowers of Helichrysum kraussii and H. odoratissimum contain several bioactive flavonoids, characterized by 1H NMR, 13C NMR and mass spectrometry. Four flavonoids, 5,6-dihydroxy-3,7,8-trimethoxyflavone, 5,7-dihydroxy-3-methoxyflavone, 3′,4′,5,7-tetrahydroxy-3-methoxyflavone and 3′,4′,3,5- tetrahydroxy-7-methoxyflavone, have antioxidant activity by the DPPH free radical assay, while 5,6-dihydroxy-3,7,8-trimethoxyflavone and 3′,4′,3,5-tetrahydroxy-7-methoxyflavone have promising anti-inflammatory activity.