Involved in the biosynthesis of epothilones, macrolactones which have a narrow anti-fungal spectrum and microtubule-stabilizing activity. Catalyzes the epoxidation of epothilones C and D to epothilones A and B, respectively. epothilone C + 2 H(+) + O2 + 2 reduced [2Fe-2S]-[ferredoxin] = epothilone A + H2O + 2 oxidized [2Fe-2S]-[ferredoxin] epothilone D + 2 H(+) + O2 + 2 reduced [2Fe-2S]-[ferredoxin] = epothilone B + H2O + 2 oxidized [2Fe-2S]-[ferredoxin] Secondary metabolite biosynthesis; epothilone biosynthesis. Belongs to the cytochrome P450 family.