<prompt> 1st product of tryptophan CatabolismKynurenineXantheurenic acidBradykininMelatonin  <response>: Kynurenine is formed from tryptophan in presence of enzyme tryptophan pyrrolaseRef: DM Vasudevan - Textbook of Biochemistry, 7th edition, page no: 239, fig 18.8 