CYP72A9 converted GA4, GA9, and GA12 to GA1, GA20, and GA53, as verified by comparison to authentic standards. Chromatogram of selected ions of m/z 546 for GA1, m/z 224 for GA4, m/z 270 for GA9, m/z 358 for GA12, m/z 476 for GA20, and m/z 239 for GA53. It is noteworthy that the y axis scale for each reaction is arbitrary for clarity, and the GA1 region has been amplified 20 times to allow easier visualization (inlet window). Control, yeast strain harboring pESC-Leu empty vector. This experiment was repeated at least three times with similar results.