Study on Characterization of the Degradation Products and Dynamics of Valtrate in the Artificial Gastrointestinal Fluid by HPLC- ESI MS/MSn

Abstract

The present study developed a systematic method for the degradation products and dynamics of valtrate in artificial intestinal fluid and gastric fluid. HPLC-electrospray tandem mass spectrometry (HPLC-ESI-MSn) was applied to separate the degradation products of valtrate and identify structures of the main degradation products. Samples were separated on an Agilent Extend-Cl8 by gradient elution using acetonitrile and water–acetic acid (0.25%, v/v). Analysis was performed in positive ion mode with 3000 V of capillary voltage, 40 psi of atomization pressure, 10 L min−1 dry nitrogen gas velocity, and m/z 100–1000 of scan range. Six degradation products were all identified to own the stem-nucleus structures of baldrinals. Two of them were identified through the reference substances. An HPLC method with isocratic elution using acetonitrile and water (68:32, v/v) at 254 nm was established to determine content change of valtrate in artificial intestinal fluid and gastric fluid at different time points. The method was validated with good linearity in wide linear ranges (r2 = 0.9999), and good intra-day precision (RSD = 1.0%). The degradations of valtrate in artificial intestinal fluid and gastric fluid follow pseudo-first-order kinetic process, the half-life period in artificial gastric fluid is 1.73 hr, and in artificial intestinal fluid it is 1.61 hr. This study enriched the knowledge on degradation products of valtrate and may reveal the mechanism of the degradation of valtrate.