Paclitaxel impurity 12/Paclitaxel EP Impurity I/Paclitaxel 10,13-Bis Side Chain/(2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-12b-Acetoxy-12-(benzoyloxy)-4,11-dihydroxy-4a,8,13,13-tetramethyl-5-oxo-2a,3,4,4a,5,6,9,10,11,12,12a,12b-dodecahydro-1H-7,11-methanocyclod
