BIOLOGICALLY-ACTIVE COMPOUNDS IN CITRUS-FRUIT PEELS

Since 1980's we have been investigating biologically active compounds in citrus fruit peels. We have successfully isolated eighty-five compounds including hitherto unreported thirty-eight new compounds. They were flavonoid glycosides, phenyl propanoid glycosides, terpenoids, terpenoid glycosides, limonoid glycosides, alkyl glycosides, compounds containing nitrogen, and cyclic peptides. In this manuscript, our studies are briefly reviewed focussing on the isolation and relationship between the structures of the compounds and their biological activity.