Glucosides of Limonoids

Limonoids are one of the two bitter principles in Citrus . Recently, limonoids have been shown to be present as glucoside derivatives in the Rutaceae. The 17-β-D-glucopyranosides of 17 citrus limonoids have been isolated from Citrus and its hybrids. Four such compounds have been also isolated from noncitrus members of the Rutaceae. They are all nonbitter. The glucosidation of limonoids is an enzymic conversion of bitter to nonbitter compounds and is a natural limonoid debittering process taking place in Citrus . This chapter describes the discovery, occurrence, biosynthesis and possible biological significance of limonoid glucosides in Citrus .