Antioxidative and Antiinflammatory Compounds from Tropical Gingers: Isolation, Structure Determination, and Activities of Cassumunins A, B, and C, New Complex Curcuminoids from Zingiber cassumunar

Assay-guided isolation gave three new compounds, cassumunins A, B, and C, having both antioxidant and antiinflammatory activities, from the rhizomes of a tropical ginger, Zingiber cassumunar. Antioxidant activity and antiinflammatory activity were measured using a thiocyanate method and a 12-O-tetradecanoylphorbol 13-acetate-induced method on mouse ear, respectively. The antioxidant activity of cassumunins A-C is stronger than that of curcumin, and their antiinflammatory activity is also stronger than that of curcumin. Spectroscopic analysis of cassumunins A-C revealed them to be a new type of complex curcumin. Antioxidant and antiinflammatory activities of cassumunins suggested that the substituted group at the 5'-position of curcumin increased both activities