Caudiquinol: A Meroterpenoid with an Intact C20 Geranylgeranyl Chain Isolated from Garcinia caudiculata

Abstract

The tropical Garcinia genus of flowering plants is a prolific producer of aromatic natural products including polyphenols, flavonoids, and xanthones. In this study, we report the first phytochemical investigation of Garcinia caudiculata Ridl. from the island of Borneo. Fractionation, purification, and structure elucidation by MS and NMR resulted in the discovery of two meroterpenoids. One was a benzofuranone lactone previously isolated from Iryanthera grandis and Rhus chinensis, and the second was a new hydroquinone methyl ester that we named caudiquinol. Both natural products are rare examples of plant meroterpenoids with an intact geranylgeranyl chain.