Phytochemical Study of Fagraea spp. Uncovers a New Terpene Alkaloid with Anti-Inflammatory Properties

Abstract

Phytochemical investigation of the stem bark of F. racemosa JACK ex WALL (Loganiaceae) from East Java, Indonesia, has resulted in the isolation of a new alkaloid fagraeoside along with the iridoid glycoside secologanoside. Fagraeoside may be derived from the condensation of secologanin with L-asparagine, and represents a rare example of a terpene alkaloid in which the amino acid component is non-aromatic. Investigation of three additional species of Fagraea provided known lignans, iridoid or secoiridoid glycosides, and flavanol-6-C-glucosides, thus it is likely that iridoid and secoiridoid glucosides are chemotaxonomic markers for the Fagraea genus. Fagraeoside inhibited the production of prostaglandin E2 in 3T3 murine fibroblasts (IC50 ~5.1 µM), and was not cytotoxic to this cell line or to a P388 murine leukaemia cell line. Selected isolated compounds, including fagraeoside, showed low to moderate activity in anti-acetylcholinesterase screening.