1. Separation and structure determination of nicardipine photoproducts by LC-ESI-MS.
- Author
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Chen SM, Hsieh MC, Chao SH, Chang EE, Wang PY, and Wu AB
- Subjects
- Nicardipine analogs & derivatives, Photochemistry, Calcium Channel Blockers chemistry, Calcium Channel Blockers isolation & purification, Chromatography, High Pressure Liquid methods, Nicardipine chemistry, Nicardipine isolation & purification, Spectrometry, Mass, Electrospray Ionization methods
- Abstract
A sample of 0.104 M nicardipine in methanol was photoirradiated with a Philips 400 W UV lamp for 3 h in a photochemical chamber. A total of four major photoproducts were found from the HPLC chromatogram. The same sample was used for taking LC-MS, while eight major photoproducts were observed and the structures elucidated by analyzing the CID patterns of their respective mass spectra. A reaction scheme of nicardipine is proposed that the photochemical reactions occur mainly via oxidation of 1,4-dihydropyridine moiety, following the stepwise photo-reduction of the m-nitro group and demethylation of the ester group at 5-position of the pyridine ring.
- Published
- 2008
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