CAS 13220-57-0 appears in our catalog under these names: Tryptanthrin, >95% (HPLC), Tryptanthrin, Tryptanthrin/ 99.94% (existing batch purity), Tryptanthrin - Bio-X â„¢, Tryptanthrin, >98.0%(GC). Offered by: TRC, GLPBio, TargetMol, Biosynth, TCI. Available pack sizes: 10mg, 25mg, 5mg, 50mg, 100mg, 250mg, 1g, 500mg.