industrially important rifamycin SV and B remain largely unknown. Here, we characterize a network of reactions underlying the biosynthesis of rifamycin SV, S, L, O, and B. The two-subunit transketolase Rif15 and the cytochrome P450 enzyme Rif16 are found to mediate, respectively, a unique C-O bond formation in rifamycin L and an atypical P450 ester-to-ether transformation from rifamycin L to B. Both reactions
Mass spectrometric studies of the path of carbon in photosynthesis: positional isotopic analysis of13C-labelled C4 to C7 sugar phosphates
作者:John K. MacLeod、Ian L. Flanigan、John F. Williams、J. Grant Collins
DOI:10.1002/jms.147
日期:2001.5
The (EIMS) electron ionization massspectrometric fragmentation patterns of the methoxime- and ethoxime-trimethylsilyl (TMS) derivatives of C(4) to C(7) sugars involved as phosphates in the Calvin pathway of photosynthesis in plants were analysed by gas chromatography/EIMS using specifically labelled (13)C analogs. In general, most but not all of the major ions in the mass spectra arise from single carbon-carbon