Isolation of a New Ferulate Derivative from Niihime Fruit, a Sour Citrus Fruit, and Its Antioxidative Activity

Abstract

Niihime is a sour Citrus fruit produced along the coast of the Sea of Kumano in the Mie prefecture of Japan. A novel ferulate derivative was isolated from niihime fruit. The structure of the compound was elucidated by spectroscopic analyses and identified as saccharic acid 1,4-lactone 3,5-di-O-ferulate by ¹H-NMR, ¹³C-NMR, and MS analyses. The new compound exhibited significantly higher antioxidative activity than ferulic acid, a parent molecule of the compound, and trolox, a standard antioxidant, as measured by an ORAC assay (P < 0.05). Further, it was abundantly contained in the flavedo, albedo, and segment epidermis of the niihime peel. It was also found in the juice vesicles but not in the seeds.