20127-63-3 9H-beta-carboline-1-carbaldehyde 9H-pyrido[3,4-b]indole-1-carboxaldehyde InChI=1/C12H8N2O/c15-7-11-12-9(5-6-13-11)8-3-1-2-4-10(8)14-12/h1-7,14