Characterization of oxalic acid derivatives as new metabolites of metamizol (dipyrone) in incubated hen's egg and human
摘要:
Metamizol (dipyrone, 1), a widely used drug with effective analgesic and antispasmodic properties, shows severe side effects like agranulocytosis and anaphylactic shock reactions, the reasons of which are not known until today. After oral administration 1 is completely metabolized. All hitherto known metabolites have an intact pyrazolinone ring structure like the parent compound and are completely extractable from urine with polar organic solvents. However, only a fractional amount of the applied dosage can be recovered by this procedure. To clarify the reason of this deficit of unknown metabolites we followed the hypothesis of oxidative rupture of the heterocyclic ring during metabolism of 1. on the basis of former in vitro results we now were able to identify in quality three oxalic acid derivatives and one acetic acid phenylhydrazide as new metabolites of metamizol in the allantoic fluid (AF) of incubated hen's eggs as well as in human urine by means of GC-MS analysis and comparison with unequivocally synthesized authentic reference compounds. Whereas the oxamazide 7, the phenylhydrazide 8 and N-methyloxamic acid 9 are only present in trace concentrations and therefore cannot account for the deficit in the balance of metabolites, the oxalic acid monohydrazide 11 seems to be excreted in higher amount. But quantitative determination of this new metabolite would be required to answer the open questions concerning the biotransformation of metamizol and thereby to detect new facts about mode of action and side effects of this drug. (c) 2005 Elsevier B.V.All rights reserved.
Oxidative Ringöffnung von 3(2H)-Pyrazolonen mit Periodat
作者:Horst Weber、Eva Wollenberg
DOI:10.1002/ardp.19883210912
日期:——
gegen Singulett‐Sauerstoff stabil. Keine Unterschiede zeigen die Titelverbindungen 1, 3 und 5 bei der Reaktion mit Natriummetaperiodat, wobei unter Ringöffnung die Oxidationsprodukte 2, 4 und 6 gebildet werden. Die 1H‐ und 13C‐NMR‐Spektren von 4 zeigen ähnlich wie bei 2 das Vorliegen rotamerer Formen bei Raumtemperatur.
Characterization of oxalic acid derivatives as new metabolites of metamizol (dipyrone) in incubated hen's egg and human
作者:Julia C. Wessel、Magdalena Matyja、Michael Neugebauer、Heiko Kiefer、Thomas Daldrup、Fuad A. Tarbah、Horst Weber
DOI:10.1016/j.ejps.2005.11.010
日期:2006.5
Metamizol (dipyrone, 1), a widely used drug with effective analgesic and antispasmodic properties, shows severe side effects like agranulocytosis and anaphylactic shock reactions, the reasons of which are not known until today. After oral administration 1 is completely metabolized. All hitherto known metabolites have an intact pyrazolinone ring structure like the parent compound and are completely extractable from urine with polar organic solvents. However, only a fractional amount of the applied dosage can be recovered by this procedure. To clarify the reason of this deficit of unknown metabolites we followed the hypothesis of oxidative rupture of the heterocyclic ring during metabolism of 1. on the basis of former in vitro results we now were able to identify in quality three oxalic acid derivatives and one acetic acid phenylhydrazide as new metabolites of metamizol in the allantoic fluid (AF) of incubated hen's eggs as well as in human urine by means of GC-MS analysis and comparison with unequivocally synthesized authentic reference compounds. Whereas the oxamazide 7, the phenylhydrazide 8 and N-methyloxamic acid 9 are only present in trace concentrations and therefore cannot account for the deficit in the balance of metabolites, the oxalic acid monohydrazide 11 seems to be excreted in higher amount. But quantitative determination of this new metabolite would be required to answer the open questions concerning the biotransformation of metamizol and thereby to detect new facts about mode of action and side effects of this drug. (c) 2005 Elsevier B.V.All rights reserved.