1.2.1.85 2-hydroxymuconate-6-semialdehyde dehydrogenase 4-amino-3-hydroxybenzoate degradation 4.1.1.77 2-oxo-3-hexenedioate decarboxylase 4-amino-3-hydroxybenzoate degradation 5.3.2.6 2-hydroxymuconate tautomerase 4-amino-3-hydroxybenzoate degradation