Analysis of bioactive constituents of Hardy Kiwi ( Actinidia arguta )

Hardy kiwi (Actinidia arguta (Siebold & Zucc.) Planch. ex Miq.) is an indigenous fruit tree in Korea. Compared to other kiwifruits, Hardy kiwifruit is smaller, however, sweeter and is able to be eaten without peeling. Hardy kiwifruits have high contents of vitamin C, lutein, phenolic compounds and several minerals. In order to use other parts of Hardy kiwi, for example, roots or leaves as well as fruits, antioxidant effects and pancreatic lipase inhibitory effects in each part were measured. Moreover, bioactive constituents that are highly related to both effects were investigated. Antioxidant effects and pancreatic lipase inhibitory effects were higher in roots and leaves than in fruits. In those parts, contents of phenolic compound, flavonoid and triterpenoid were five to ten times higher than in fruits. As bioactive constituents, quinic acid derivatives conjugated with phenolic acids were isolated from Hardy kiwifruits. In addition, triterpene derivatives and catechin derivatives were isolated from leaves and roots, respectively. Among these components of Hardy kiwi, quinic acid derivatives and triterpene derivatives effectively suppressed NF-kB activation stimulated by lipopolysaccharide in RAW 264.7 macrophage cells. Conclusively, large amount of sugars and organic acids were contained in Hardy kiwifruits in order to reserve nutrients. On the other hand, a variety of bioactive constituents for growth and defense to disease and stress were included in roots and leaves.