Fig. 3: The formation of Taxol tetracyclic core skeleton with an oxetane ester.
From: Biosynthesis of the highly oxygenated tetracyclic core skeleton of Taxol
a HPLC analysis of in vivo reaction for S. cerevisiae strain YCYP725A55 expressing CYP725A55 and TCPR using 2α-benzoyloxy-7β-acetoxytaxusin (15) as the substrate. Substrate was marked with compound number and products were marked with A and B. S. cerevisiae strain YTCPR expressing TCPR was used as the control. b Mass spectra (ESI) of new peak (A). c Mass spectra (ESI) of new peak (B). d HPLC analysis of in vivo reaction for S. cerevisiae strain YCYP725A55 expressing CYP725A55 and TCPR using 2-deacetyl-2α-benzoylbaccatin I (17) as the substrate. Substrate was marked with compound number. S. cerevisiae strain YTCPR expressing TCPR was used as the control. These experiments were performed three times with similar results each time. e Oxidation reaction of hexa-oxygenated taxoid derivatives catalyzed by CYP725A55. Labeled or regular methyl was marked with red. Arrow with a cross indicated this reaction was failed. f Proposed process of the formation of oxetane ester. 18O was marked with red. Source data are provided as a Source Data file.
