1,7,8,9-Tetrahydropyrano(2,3-g)indole-2-carboxylic acid 81257-90-1 Acide 7,8,9-trihydro-pyranno(2,3-g)indole-2-carboxylique [French] Pyrano(2,3-g)indole-2-carboxylic acid, 1,7,8,9-tetrahydro-