Combined reverse-phase HPLC-atmospheric pressure chemical ionization MS
analysis of the biosynthetic product (retention time = 8.6 ±
0.1 min) generated by the recombinant acetyl transferase with 10-DAB
and acetyl CoA as cosubstrates (Upper spectrum) and of
authentic baccatin III (retention time = 8.6 ± 0.1 min;
Lower spectrum). The diagnostic mass spectral fragment
ions are at m/z 605 (P +
NH4+), 587 (PH+), 572
(PH+ − CH3), 527 (PH+ −
CH3COOH), and 509 (PH+ − (CH3COOH
− H2O). For column, solvent, flow rates, and instrument
details, see Materials and Methods.