melanin metabolic process melanin biosynthetic process Reactome:R-HSA-5662702 melanin synthesis The chemical reactions and pathways resulting in the formation of melanins, pigments largely of animal origin. High molecular weight polymers of indole quinone, they are irregular polymeric structures and are divided into three groups: allomelanins in the plant kingdom and eumelanins and phaeomelanins in the animal kingdom. melanin biosynthesis melanin formation GO:0042438 melanin anabolism biological_process secondary metabolite biosynthetic process pigment biosynthetic process phenol-containing compound biosynthetic process