Premium
Examination of structurally selective derivatization of vitamin D 3 analogues by electrospray mass spectrometry
Author(s) -
Weiskopf Andrew S.,
Vouros Paul,
Cunniff Jack,
Binderup Ernst,
Björkling Fredrik,
Binderup Lise,
White MariaChristina,
Posner Gary H.
Publication year - 2001
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.105
Subject(s) - chemistry , derivatization , mass spectrometry , metabolite , chromatography , ion trap , hydroxylation , electrospray ionization , tandem mass spectrometry , electrospray , stereochemistry , organic chemistry , biochemistry , enzyme
The structural specificity of vitamin D derivatization by PTAD (4‐phenyl‐1,2,4‐triazoline‐3,5‐dione) was probed using synthetic analogues and ion trap mass spectrometry. EB 1089, a vitamin D 3 analogue which contains a second site for Diels–Alder cycloaddition on its side‐chain, allowed the examination of derivatization modes and comparisons of ion fragment structures. The origins of a PTAD‐vitamin D 3 ion fragment, commonly used in metabolite characterization and quantitation of vitamin D 3 analogues ( m / z 314), were established; ion trap mass spectrometry revealed that the PTAD comprises a portion of this diagnostic fragment, and is not lost by a retro‐Diels–Alder step. Furthermore, the unique structure of the EB 1089 side‐chain also permits facile determination of its side‐chain metabolism. Use of PTAD derivatization and detection of metabolite‐specific ion fragments identify hydroxylation at the end of the EB 1089 sidechain. It is believed that the results from these studies provide a clearer understanding of the mass spectrometry of triazolinedione derivatives, not only in the specific case of EB 1089, but also in their application to other vitamin D compounds. Copyright © 2001 John Wiley & Sons, Ltd.