Analytical Characterization of Muraymycin Analogues

UV spectra were recorded on an Ultraspec 8000 spectrometer (GE, Pittsburgh, PA, USA). NMR data were recorded at 400 MHz for ¹H and 100 MHz for ¹³C with Varian Inova NMR spectrometers (Agilent, Santa Clara, CA). HRMS spectra were recorded on an AB SCIEX Q-TOF 5600 System (AB Sciex, Framingham, MA, USA). Analytic HPLC was performed with Dionex Ultimate 3000 or Agilent 1200. Semipreparative HPLC was performed with a Waters 600 controller and pump (Milford, MA) equipped with a 996 diode array detector, 717 plus autosampler, and an Apollo C₁₈ column (250 × 10 mm, 5 µm) purchased from Grace (Deerfield, IL). All solvents used were of HPLC grade and purchased from Fisher Scientific. Muraymycins D1-D4 were isolated from Streptomyces sp. NRRL 30475 as described.^{29 (link)} The synthesis and analytical characterization of 11a,^{16 (link)}12,^{17 (link),24 ,26 (link)}13a,^{18 (link)} and 13b,^{18 (link)} have been previously reported (Figure S24-S27).