Title: Spectral characteristics of grapefruit oil peel furanocoumarins and coumarins Authors
Submitted to: Proceedings of Florida State Horticultural Society
Publication Type: Proceedings
Publication Acceptance Date: October 12, 2007
Publication Date: March 20, 2008
Citation: Cesar, T.B., Manthey, J.A. 2007. Spectral characteristics of grapefruit peel oil furanocoumarins and coumarins. Proceedings of Florida State Horticultural Society. 120:295-298. Interpretive Summary: Consumption of grapefruit juice will cause an interference in the proper metabolism of certain prescription drugs. This interference is called "grapefruit/drug interaction". The compounds responsible for this interaction are furanocoumarins. In the present study, 10 new furanocoumarins were isolated and their chemical structures were preliminarily characterized by several analytical methods, including UV, infrared, and mass spectral analysis. The results suggest that these compounds represent a new class of furanocoumarins in grapefruit juice.
Technical Abstract: Grapefruit peel oil (GPO) contains numerous coumarins and furanocoumarins, many of which are uncharacterized. In this study, ten of these compounds were isolated and studied by UV, FTIR, and mass spectroscopy (MS). These isolations were achieved by silica gel chromatography, preparative TLC, and reversed-phase HPLC. Mass spectral analysis of the furanocoumarins showed that these compounds were complex derivatives of bergaptol (5-hydroxypsoralen), the majority of which contained variously substituted geranyl side chains. The three coumarins isolated in this study also contained substituted geranyl side chains. Analysis by FTIR provided additional information about the functional groups and the possible structures of these compounds. These compounds will be used in bioassays to augment our understanding of the structure/activity relationships of these compounds in human cell biology, particularly pertaining to "grapefruit/drug" interactions.