The metabolism of some 1-hydroxylated indoles in the rat

Abstract

1. A number of N-hydroxylated indole derivatives have been fed to rats and the urinary metabolites compared with those obtained on feeding the corresponding N-H indoles.

2. 1-Methoxy- and 1-acetoxy-indole were metabolized to compounds normally observed on feeding indole.

3. 1-Hydroxy- and l-methoxy-indofe-3-carboxylic acids were both partially excreted unchanged and reduced to indole-3-carboxylic acid which was excreted along with its glucuronide.

4. Indole-3-glyoxylic acid and its 1-methoxy derivative were excreted almost entirely unchanged. l-Hydroxyindole-3-glyoxylic acid was mostly excreted unchanged, but some reduction to indole-3-glyoxylic acid took place. The stability of these acids is associated with their low pK_a values.

5. The significance of the removal in vivo of groups attached through oxygen to the 1 position of indoles in relation to the synthesis of new potential medicinal agents is noted.