Involved in the biosynthesis of prenylated phenolics natural products which contribute to the bitter taste of beer and display broad biological activities (Probable). Catalyzes the first prenylation step in the beta-bitter acid pathway. Abble to transfer dimethylallyl diphosphate (DMAPP) or geranyl diphosphate (GPP) to phlorisovalerophenone (PIVP), phlorisobutrylphenone (PIMP) and naringenin chalcone. Can also use phlorisobutyrophenone (PIBP) and phlormethylbutanophenone (PMBP) as substrates, but not 6'-O-methylated chalcone or naringenin