... subacid organic compound made in microbial fermentation. 2). Kojic acid, (5-hydroxy-2-hydroxymethyl-1,4-pyrone, CAS: 501-30-4) ... of tyrosinase andprohibitting DOPA oxidation.Application: (1) Cosmetics: Kojic acid, (5-hydroxy-2-hydroxymethyl-1,4-pyrone, CAS: 501-30-4) ... . recommendation usage for cosmetics: 0.2~1.0%.(2) Raw Materials: Kojic acid, (5-hydroxy-2-hydroxymethyl-1,4-pyrone, CAS: 501-30-4) ...