Morphine 6-glucuronide and morphine 3-glucuronide as molecular chameleons with unexpected lipophilicity.
J Med Chem
; 34(4): 1272-5, 1991 Apr.
Article
em En
| MEDLINE
| ID: mdl-2016703
ABSTRACT
Morphine 6-glucuronide, but not morphine 3-glucuronide, is a highly potent opiate receptor agonist. In fact, there is converging evidence that much of the analgesic effect occurring after morphine treatment in humans is due to this metabolite rather than to the parent drug. Yet glucuronides as a rule are considered as highly polar metabolites unable to cross the blood-brain barrier and rapidly excreted by the urinary and/or biliary routes. Here, we report that morphine 6-glucuronide, and to a lesser extent morphine 3-glucuronide, are far more lipophilic than predicted, and in fact not much less lipophilic than morphine itself. Force-field and quantum mechanical calculations indicate that the two glucuronides can exist in conformational equilibrium between extended and folded forms. The extended conformers, because they efficiently expose their polar groups, must be highly hydrophilic forms predominating in polar media such as water; in contrast, the folded conformers mask part of their polar groups, thus being more lipophilic and likely to predominate in media of low polarity such as biological membranes.
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01-internacional
Base de dados:
MEDLINE
Assunto principal:
Derivados da Morfina
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Med Chem
Assunto da revista:
QUIMICA
Ano de publicação:
1991
Tipo de documento:
Article
País de afiliação:
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