In enzymology, a biphenyl synthase (EC 2.3.1.177) is an enzyme that catalyzes the chemical reaction:

3 malonyl-CoA + benzoyl-CoA 4 CoA + 3,5-dihydroxybiphenyl + 4 CO₂

Thus, the two substrates of this enzyme are malonyl-CoA and benzoyl-CoA, whereas its three products are CoA, 3,5-dihydroxybiphenyl, and CO₂.

This enzyme belongs to the family of transferases, specifically those acyltransferases transferring groups other than aminoacyl groups. The systematic name of this enzyme class is malonyl-CoA:benzoyl-CoA malonyltransferase. This enzyme is also called BIS.

• Liu B, Beuerle T, Klundt T, Beerhues L (2004). "Biphenyl synthase from yeast-extract-treated cell cultures of Sorbus aucuparia". Planta. 218 (3): 492–6. doi:10.1007/s00425-003-1144-y. PMID 14595561.