2.5.1.139 dimethylallyl diphosphate + umbelliferone - 439502 2.5.1.139 dimethylallyl diphosphate + umbelliferone - 439503 2.5.1.139 additional information enzyme has strict substrate specificity towards umbelliferone and dimethylallyl diphosphate, and a strong preference for the C6 position of the prenylated product (demethylsuberosin), leading to linear furanocoumarins. The C8-prenylated derivative (osthenol) is also formed, but to a much lesser extent 89