A method for the synthesis of 9,11-secosteroids starting from the natural corticosteroid cortisol is described. There are two key steps in this approach, combining chemistry and synthetic biology. Stereo- and regioselective hydroxylation at C9 (steroid numbering) is carried out using whole-cell biocatalysis, followed by the chemical cleavage of the C–C bond of the vicinal diol. The two-step method features mild reaction conditions and completely excludes the use of toxic oxidants.
Methylphosphonic acid (MPA) is introduced as an internal standard for the determination of the phosphorus content of carbonated beverages (cola drinks) by quantitative 31 P-NMR analysis.Phosphorus in cola beverages was analyzed as phosphate in ten commercially available drinks.Phosphate concentration in the studied samples was in the range of 3.5 to 6.1 mM. The preparation of the samples included: degassing of commercially available beverages, addition of MPA as an internal standard, D 2 O for signal locking and a solution of NaOH to ensure a basic environment in the sample. The calibration graphs of the MPA standard and analyte showed a linear response in the concentration range of interest. The measured values of the phosphoric acid standard solutions lay within the confidence limits of the MPA, showing that these compounds give a similar response in NMR analysis. The measured concentrations of phosphorus were in good agreement with the values detected by the traditional spectrophotometric method. The presented 31 P-NMR method using MPA as an internal standard is reliable and simple for the determination of the phosphorus content of cola type beverages.
Asymmetric Synthesis of the 2,2,3-Trisubstituted Cyclopentanone, D-Ring Fragment of 9,11-Secosterols. -(KOLLO, M.; AAV, R.; TAMP, S.; JARVET, J.; LOPP*, M.; Tetrahedron 70 (2014) 38, 6723-6727, http://dx.
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