H+ + 4-hydroxybenzoate → phenol + CO2
coenzyme A + 4-hydroxybenzoate + ATP → 4-hydroxybenzoyl-CoA + diphosphate + AMP
2 H+ + NAD(P)H + 4-hydroxybenzoate + oxygen → H2O + NAD(P)+ + hydroquinone + CO2
S-adenosyl-L-methionine + 4-hydroxybenzoate → S-adenosyl-L-homocysteine + methylparaben
NAD(P)H + H+ + 4-hydroxybenzoate + oxygen → protocatechuate + H2O + NAD(P)+
4-hydroxybenzoate + geranyl diphosphate → 3-geranyl-4-hydroxybenzoate + diphosphate
all-trans-decaprenyl diphosphate + 4-hydroxybenzoate → 3-decaprenyl-4-hydroxybenzoate + diphosphate
2 NADPH + 2 bromide + 2 oxygen + 5 H+ + 4-hydroxybenzoate → 2 NADP+ + 4 H2O + 2,4-dibromophenol + CO2
5-phospho-α-D-ribose 1-diphosphate + H+ + 4-hydroxybenzoate → 4-(β-D-ribofuranosyl)hydroxybenzene 5'-phosphate + diphosphate + CO2
NADPH + H+ + 4-hydroxybenzoate + oxygen → protocatechuate + H2O + NADP+
4-hydroxybenzoate + UDP-α-D-glucose → 4-(β-D-glucosyloxy)benzoate + H+ + UDP
L-glutamate + 4-hydroxybenzoate + ATP → H+ + diphosphate + AMP + N-(4-hydroxybenzoyl)-L-glutamate
4-hydroxybenzoate + all-trans-nonaprenyl diphosphate → 3-nonaprenyl-4-hydroxybenzoate + diphosphate
all-trans-heptaprenyl diphosphate + 4-hydroxybenzoate → 3-heptaprenyl-4-hydroxybenzoate + diphosphate
H+ + 4-hydroxybenzoate + ATP → diphosphate + 4-hydroxybenzoyl-adenylate
2 H+ + NADPH + 4-hydroxybenzoate + bromide + oxygen → 2 H2O + NADP+ + 3-bromo-4-hydroxybenzoate
all-trans-hexaprenyl diphosphate + 4-hydroxybenzoate → diphosphate + 3-hexaprenyl-4-hydroxybenzoate
all-trans-octaprenyl diphosphate + 4-hydroxybenzoate → 3-octaprenyl-4-hydroxybenzoate + diphosphate
H2O + 4-hydroxybenzaldehyde + NAD+ → 2 H+ + NADH + 4-hydroxybenzoate
H2O + 4,4'-(1E)-prop-1-ene-1,2-diyldiphenol + oxygen → S-1-(4-hydroxyphenyl)-ethanol + H+ + 4-hydroxybenzoate
cyanidin 3-O-glucoside-7-O-(6-O-(p-hydroxybenzoyl)-glucoside) + 1-O-4-hydroxybenzoyl-β-D-glucose → H+ + 4-hydroxybenzoate + cyanidin 3-O-glucoside-7-O-(6-O-(4-O-(glucosyl)-oxybenzoyl)-glucoside)
delphinidin 3-O-rutinoside + 1-O-4-hydroxybenzoyl-β-D-glucose → H+ + 4-hydroxybenzoate + delphinidin 3-O-rutinoside-7-O-glucoside
delphinidin 3-O-rutinoside-7-O-(6-O-(p-hydroxybenzoyl)-glucoside) + 1-O-4-hydroxybenzoyl-β-D-glucose → H+ + 4-hydroxybenzoate + delphinidin 3-O-rutinoside-7-O-(6-O-(4-O-(glucosyl)-oxybenzoyl)-glucoside)
a reduced electron donor + 4-methoxybenzoate + oxygen → an oxidized electron donor + H2O + formaldehyde + 4-hydroxybenzoate
H2O + 4-hydroxybenzaldehyde + NADP+ → 2 H+ + NADPH + 4-hydroxybenzoate
H2O + 4-hydroxybenzaldehyde + NAD(P)+ → 2 H+ + NAD(P)H + 4-hydroxybenzoate
2,4'-dihydroxyacetophenone + oxygen → 2 H+ + formate + 4-hydroxybenzoate
H2O + 4-hydroxybenzoate 1-phenylethylidene → H+ + acetophenone hydrazone + 4-hydroxybenzoate
H2O + 4-chlorobenzoate → H+ + 4-hydroxybenzoate + chloride
H2O + 4-hydroxybenzoyl-CoA → coenzyme A + H+ + 4-hydroxybenzoate
NADPH + H+ + oxygen + benzoate → H2O + NADP+ + 4-hydroxybenzoate
chorismate → pyruvate + 4-hydroxybenzoate
cyanidin-3-O-β-D-glucoside + 1-O-4-hydroxybenzoyl-β-D-glucose → 4-hydroxybenzoate + cyanidin 3,7-di-O-β-D-glucoside