Using complementary mass spectrometric approaches for the determination of methylprednisolone metabolites in human urine.
Rapid Commun Mass Spectrom
; 26(5): 541-53, 2012 Mar 15.
Article
em En
| MEDLINE
| ID: mdl-22302494
ABSTRACT
RATIONALE The metabolism of methylprednisolone is revisited in order to find new metabolites that could be important for distinguishing between different routes of administration. Recently developed liquid chromatography/tandem mass spectrometry (LC/MS/MS) strategies for the detection of corticosteroid metabolites have been applied to the study of methylprednisolone metabolism. METHODS:
The structures of these metabolites were studied using two complementary mass spectrometric techniques LC/MS/MS in product ion scan mode with electrospray ionization and gas chromatography/mass spectrometry (GC/MS) in full scan mode with electron ionization. Metabolites were also isolated by semipreparative liquid chromatography fractionation. Each fraction was divided into two aliquots; one was studied by LC/MS/MS and the other by GC/MS after methoxyamine-trimethylsilyl derivatization.RESULTS:
The combination of all the structural information allowed us to propose a comprehensive picture of methylprednisolone metabolism in humans. Overall, 15 metabolites including five previously unreported compounds have been detected. Specifically, 16ß,17α,21-trihydroxy-6α-methylpregna-1,4-diene-3,11,20-trione, 17α,20ß,21-trihydroxy-6α-methylpregna-1,4-diene-3, 11-dione, 11ß,17α,21-trihydroxy-6α-hydroxymethylpregna-1,4-diene-3,20-dione, 11ß,17α,20ξ,21-tetrahydroxy-6α-hydroxymethylpregna-1,4-diene-3-one, and 17α,21-dihydroxy-6α-hydroxymethylpregna-1,4-diene-3,11,20-trione are proposed as feasible structures for the novel metabolites. In addition to the expected biotransformations reduction of the C20 carbonyl, oxidation of the C11 hydroxy group, and further 6ß-hydroxylation, we propose that hydroxylation of the 6α-methyl group can also take place.CONCLUSIONS:
New metabolites have been identified in urine samples collected after oral administration of 40 mg of methylprednisolone. All identified metabolites were found in all samples collected up to 36 h after oral administration. However, after topical administration of 5 g of methylprednisolone aceponate, neither the parent compound nor any of the metabolites were detected.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Metilprednisolona
/
Espectrometria de Massas em Tandem
/
Glucocorticoides
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Cromatografia Gasosa-Espectrometria de Massas
Limite:
Humans
/
Male
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article