DETECTION OF SCOPOLIN IN THE GRAPEFRUIT (CITRUS-PARADISI MACF.)

Ripe fruits of Citrus paradisi MACF. and their juices contain high con centrations of scopolin (beta-glucopyranoside of 7-hydroxy-6-methoxyco umarin). The identity of the aglycon being scopoletin was pr-oven anal ysing extracts of beta-glucosidase-treated fruit preparations with TLC , HPLC and GC-MS techniques. The naturally occurring glycoside was ide ntified as the glucoside of scopeletin comparing it with authentic sco polin. The intake of scopolin of either grapefruits or juices thereof leads to a renal excretion of its aglycon as a glucuronide. The excret ion is complete within 24 h. An enzymatic hydrolysis of the glucuronid e produces scopoletin (i.e. aglycon) which can be quantified by HPLC. Mass spectra revealed that scopoletin releases one methyl-and two carb onyl-groups. The molecule finally breaks into fragments of 51 and 69 a tomic mass units.