 Tryptophan is converted to indole-3-acetaldoxime (IAOx) by cytochrome p450 enzymes (the redundant CYP92B3 and CYP79B3 in "Arabidopsis thaliana") using NADPH and molecular Oxygen.A separate p450 enzyme (CYP83B1 in "Arabidopsis") catalyzes a second subsequent monooxygenase reaction to create a proposed the intermediate 1-"aci"-nitro-2-indolyl-ethane.A cysteine is utilized by glutathione S-transferase (GST) in a conjugation process to produce a S-alkylthiohydroximate derivative, which is then cleaved off by a C-S lyase (like the SUR1 enzyme found in "Arabidopsis") to create a free thiol.