Urodiolenone from grapefruit juice, a urinary metabolite found in hypertensive subjects

Article abstract of DOI:10.1016/0031-9422(88)83100-5

Urodiolenone, a compound isolated from the urine of hypertensive subjects, is a 1:1 epimeric mixture of two dihydroxy derivatives of nookatone, a constituent of grapefruit. The structure of urodiolenone was suggested by NMR spectroscopy and confirmed by partial synthesis from nootkatone, a sesquiterpenoid ketone with a valencene skeleton. In addition, we show that urodiolenone itself is also present in the grapefruit in free form and possibly also as a glucuronide. The question whether urodiolenone is produced exogenously or endogenously is discussed.