Method development and validation for ultra-high-pressure LC/MS/MS determination of hop prenylflavonoids in human serum.

Hops (Humulus lupulus L.) are used in the brewing of beer, and hop extracts containing prenylated compounds, such as xanthohumol (XN) and 8-prenylnaringenin (8-PN), are under investigation as dietary supplements for cancer chemoprevention and the management of hot flashes in menopausal women. To facilitate clinical studies of hop safety and efficacy, a selective, sensitive, and fast ultra-high-pressure LC (UHPLC) tandem MS method was developed and validated for the simultaneous determination of the hop prenylflavonoids XN, isoxanthohumol (IX), 6-prenylnaringenin (6-PN), and 8-PN in human serum.

Rapid quantitative analysis of 8-iso-prostaglandin-F(2alpha) using liquid chromatography-tandem mass spectrometry and comparison with an enzyme immunoassay method.

A rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was developed for the measurement of urinary 8-iso-prostaglandin F(2alpha) (8-iso-PGF(2alpha)), a biomarker of lipid peroxidation. Because urine contains numerous F(2) prostaglandin isomers, each with identical mass and similar mass spectrometric fragmentation patterns, chromatographic separation of 8-iso-PGF(2alpha) from its isomers is necessary for its quantitative analysis using MS/MS. We were able to achieve this separation using an isocratic LC method with a run time of less than 9min, which is at least threefold faster than previous methods, while maintaining sensitivity, accuracy, precision, and reliability.