Simultaneous determination of deuterium-labeled ergosterol and brassicasterol in stroke-prone spontaneously hypertensive rats by ultra-high performance liquid chromatography-electrospray ionization-tandem mass spectrometry

A previous study has shown that brassicasterol-d(1) was detected in the serum of stroke-prone spontaneously hypertensive rats after oral administration of ergosterol-d(1). To quantitatively evaluate the serum concentration of brassicasterol-d(1), an ultra-high performance liquid chromatography-electrospray ionization-tandem mass spectrometry method was developed for the simultaneous determination of picolinyl ester-derivatized ergosterol-d(1) and brassicasterol-d(1). The separation was performed on an ODS column (Waters Acquity UPLC BEH C18) with a mobile phase consisting of methanol and water containing 0.1% acetic acid (95/5, v/v). Linear calibration curves in the presence of the serum were obtained in a concentration range of 0.04-8 mu g mL(-1). Recovery rates of 95.6-119% were obtained with an RSD (n = 6) of less than 7.5%. The method was applied to the determination of time-concentration curves of ergosterol-d(1) and brassicasterol-d(1) in stroke-prone spontaneously hypertensive rats, showing a pharmacokinetic profile of ergosterol-d(1) where the peak serum concentration of brassicasterol-d(1) was 3-fold higher than that of ergosterol-d(1).

Automated summary

It was found that brassicasterol-d(1) exists in the serum of stroke-prone spontaneously hypertensive rats. Therefore, an analytical method was developed to simultaneously determine the serum concentration of ergosterol-d(1) and brassicasterol-d(1). The experimental results showed that the peak serum concentration of brassicasterol-d(1) was 3 times higher than that of ergosterol-d(1).