Synthesis, modification and biological activity of 2,3-indoles of Glycyrrhetinic acid.

The synthesis of 2,3-indoles of Glycyrrhetinic acid (GLA) and its methyl ester was carried out by the Fischer reaction. Reductive transformations of GLA methyl ester 2,3-indole 3a were carried out to obtain 11-deoxo- and 9,12-diene analogs. N-methylation of 2,3-indole 3a gave N-methyl-indole-11-oxo-18β-olean-12-en-30-oic acid. The antiulcer and anti-inflammatory activity of 2,3-indole 3a was studied in rats and mice. It was found, compound 3a exhibied a pronounced antiulcer activity in the indomethacin model of ulcers in rats and anti-inflammatory activity in the carrageenan model of acute edoema in mice, at a dose of 50 mg/kg. This is the first report of anti-ulcer and anti-inflammatory activities of 2,3-indolo-GLA derivatives.