Efficient synthesis of phosphonodepsipeptides derived from norleucine

Evaluation of silica from different vendors as the solid support of anion‐exchange chiral stationary phases by means of preferential sorption and liquid chromatography

“…The structure of the selector (Figure ) was confirmed by NMR spectroscopy performed on an Agilent 400‐MR DDR2 spectrometer operating at 400.13 MHz for 1 H and 100.62 MHz for 13 C. The selector coverage was determined (based on nitrogen content) from elemental analysis performed on a Perkin‐Elmer 2400 instrument. Racemic analytes used for the evaluation of the CSPs (Figure ) were synthesized according to published procedures , for details see Supporting Information. Structures of the selector and analytes were drawn in ISIS draw (MDL Information Systems, Hayward, CA, USA).…”

“…Modification of silica materials and immobilization of the selector is described in Supporting Information (SI). The structure of the selector (Figure 1) was confirmed by NMR spectroscopy performed on an Agilent 400-MR DDR2 spectrometer operating at 400.13 MHz for 1 H and 100.62 MHz for 13 C. The (Figure 2) were synthesized according to published procedures [37], for details see Supporting Information. Structures of the selector and analytes were drawn in ISIS draw (MDL Information Systems, Hayward, CA, USA).…”

Unusual activity pattern of leucine aminopeptidase inhibitors based on phosphorus containing derivatives of methionine and norleucine

“…High resolution mass spectra (HRMS) were obtained on a Fourier transform mass spectrometer (FTMS) LTQ-orbitrap XL (Thermo Fisher, Bremen, Germany) in the electrospray ionisation mode. Reverse phase HPLC (RP-HPLC) purification of the target compounds was performed as described previously by Pícha et al [38]. All chemicals were of analytical grade, obtained from commercial suppliers (Sigma-Aldrich and Fluka, Prague, Czech Republic and Poznań, Poland, Merck, Darmstadt, Germany, POCh, Gliwice, Poland) and were used without further purification.…”

“…The phosphonic analogue of norleucine (3, Nle-P) was obtained from the respective aldehyde as described by Pícha et al [38,40]. The syntheses of the phosphinic compounds Met-PH (2), Nle-PH (4) and Met-ψ[P(O)(OH)CH 2 ]-Ala (5) were recently published elsewhere and we have only provided the detailed physico-chemical characteristics that weren′t reported in our previous communication here [41].…”

“…The syntheses of the phosphinic compounds Met-PH (2), Nle-PH (4) and Met-ψ[P(O)(OH)CH 2 ]-Ala (5) were recently published elsewhere and we have only provided the detailed physico-chemical characteristics that weren′t reported in our previous communication here [41]. The preparation of the phosphonate esters 6-8 was achieved by the coupling of monobenzyl 1-(Nbenzyloxycarbonylamino)pentyl phosphonate with the respective derivatives of L-lactic acid and is described in detail elsewhere [38,40]. (5) …”