Methylenedioxy bridge-forming cytochrome P450 involved in the biosynthesis of isoquinoline alkaloids. Converts (S)-cheilanthifoline to (S)-stylopine, (S)-scoulerine to (S)-nandinine and (S)-tetrahydrocolumbamine to (S)-canadine. Can be involved in both sanguinarine and berberine biosynthesis. Catalyzes an oxidative reaction that does not incorporate oxygen into the product. (S)-cheilanthifoline + O2 + reduced [NADPH--hemoprotein reductase] = (S)-stylopine + H(+) + 2 H2O + oxidized [NADPH--hemoprotein reductase] (S)-tetrahydrocolumbamine + O2 + reduced [NADPH--hemoprotein reductase] = (S)-canadine + H(+) + 2 H2O + oxidized [NADPH--hemoprotein reductase] (S)-scoulerine + O2 + reduced [NADPH--hemoprotein reductase] = (S)-nandinine + H(+) + 2 H2O + oxidized [NADPH--hemoprotein reductase] kcat is 13.8 min(-1) for (S)-cheilanthifoline. Optimum pH is 8.0. Optimum temperature is between 30-35 degrees Celsius. Expressed in roots and at lower levels in stems, leaves and plantlets. Belongs to the cytochrome P450 family.