Indole-3-carboxaldehyde - 13 C 8 (3-Formylindole- 13 C 8 ) is the 13 C-labeled Indole-3-carboxaldehyde. Indole-3-carboxaldehyde , a banlangen extract, is the product of the oxidative degradation of indole-3-acetic acid (IAA) by crude enzyme preparations from etiolated pea seedlings. Indole-3-carboxaldehyde is a biochemical used to prepare analogs of the indole phytoalexin cyclobrassinin. Indole-3-carboxaldehyde also enhances the epithelial barrier and anti-inflammatory activity in the intestinal tract.