Apollo c18 column

Analytic HPLC was performed with one of three systems: a Waters Alliance 2695 separation module (Milford, MA) equipped with a Waters 2998 diode array detector and an analytical Apollo C-18 column (250 mm × 4.6 mm, 5 μm) or a Dionex Ultimate 3000 Focused separation module (Bannockburn, IL) equipped with a DAD-3000(RS) and MWD-3000(RS) diode array detector and an Acclaim 120 C-18 column (4.6 mm × 100 mm, 3 μm) or an Agilent 1200 Series Quaternary LC system and an Eclipse XDB-C18 column (150mm × 4.6 mm, 5 μm, 80Å) equipped with an Agilent 6120 Quadrupole MSD mass spectrometer (Agilent Technologies, Santa Clara, CA). Semi-preparative HPLC was performed with a Waters 600 controller and pump (Milford, MA) equipped with a 996 diode array detector, 717plus autosampler, and an Apollo C-18 column (250 mm × 10 mm, 5 μm) purchased from Grace (Deerfield, IL). LC-electrospray ionization (ESI)-mass spectroscopy (MS) was performed using an Agilent 6120 Quadrupole MSD mass spectrometer (Agilent Technologies, Santa Clara, CA) equipped with an Agilent 1200 Series Quaternary LC system and an Eclipse XDB-C18 column (150mm × 4.6 mm, 5 μm, 80Å). High resolution (HR)-MS was performed using a Bruker BioTOF II, and NMR data were collected using a Varian Unity Inova 400 MHz spectrometer (Varian, Inc., Palo Alto, CA).

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).