A8 avance 3 hd 800 mhz nmr spectrometer

HPLC separations were carried out on an Agilent 1260 Infinity Series analytical or preparative HPLC system equipped with a photodiode array detector and an automated fraction collector. Low resolution HPLC-MS analysis was performed on an Agilent instrument consisting of an automated liquid autosampler, a 1260 Infinity Series HPLC system coupled to a photodiode array detector and a 6120 Series ESI mass spectrometer. A Phenomenex Luna C18 column (5 μm, 4.6 × 100 mm) was used with a flow of 0.6 mL/min and a gradient of 20% MeCN in H₂O to 100% MeCN (+0.1% (v/v) formic acid). High-resolution (HR) HPLC-MS and HR-tandem HPLC-MS were carried out on an Agilent UHD Accurate Mass Qtof LC-MS system, equipped with a 1260 Infinity Series HPLC, an automated liquid sampler, a photodiode array detector, a JetStream ESI source, and the 6540 Series Qtof. For routine analysis, samples were separated on an Agilent Poroshell 120 EC-C18 column (2.7 μm, 3 × 50 mm) operating at 0.4 mL/min with a gradient of 20% MeCN in H₂O to 100% MeCN (+0.1% (v/v) formic acid) over 13 min. NMR spectra were acquired at the Princeton University Department of Chemistry NMR Facilities. Spectra were collected in MeOD-d4 in the triple resonance cryoprobe of a Bruker A8 Avance III HD 800 MHz NMR spectrometer.

HR-MS data for all compounds and their inferred molecular formula are listed in Supplementary Table 1. For structural elucidation, 1D/2D NMR spectra were acquired at the Princeton University Department of Chemistry NMR Facilities on an A8 Avance III HD 800 MHz NMR spectrometer (Bruker) with a triple resonance cryoprobe. The NMR samples of keratinimicin A-D and keratinicyclin A-C were prepared in DMSO-d6, and those of canucin A and B were prepared in CD₃OH. 1D/2D NMR spectra of canucin A, keratinimicin A, and keratinicyclin A are shown (Supplementary Figs. 3, 5, 6). NMR tables listing chemical shift assignments for all compounds can be found in Supplementary Tables 2, 4, 6, and 8–13.