Unity inova 500 spectrometer

¹H-NMR analysis was carried out using a Varian UNITY INOVA 500 spectrometer operating at 499.839 MHz for proton and equipped with a 5 mm double resonance probe (Agilent Technologies, Santa Clara, CA, USA). One-dimensional proton NMR spectra were obtained by using a 1D Nuclear Overhauser Enhancement Spectroscopy (NOESY) standard pulse sequence to suppress water signals with a relaxation delay of 3 s. For each sample, 256 free induction decays (FIDs) were collected into 64K data points with a spectral width of 6000 Hz spectral with a 90° pulse, an acquisition time of 2 s, and a mixing time of 100 ms. The FIDs were weighted by an exponential function with a 0.5 Hz line-broadening factor prior to Fourier transformation.

Optical rotations were measured with a 343 Plus polarimeter (Perkin Elmer, Waltham, MA, USA). UV spectra were recorded on a JASCO V-530 spectrophotometer, and IR spectra were obtained on a JASCO FT/IR-300E spectrometer (Jasco, Tokyo, Japan). NMR experiments were recorded using a Varian Unity Inova 500 spectrometer (Varian, Palo Alto, CA, USA) and a Bruker Avance III HD 400 spectrometer (Bruker, Billerica, MA, USA) with TMS as an internal standard. HRESIMS analysis was performed on a Waters Synapt G2 mass spectrometer (Waters, Milford, MA, USA). TLC was carried out on precoated silica gel 60 F₂₅₄ glass plates (Merck, Darmstadt, Germany). Visualization of the silica gel TLC was performed using an anisaldehyde-H₂SO₄ spray reagent. The adsorbent used for column chromatography was silica gel 70–230 mesh. HPLC was performed on a Waters 600E Multisolvent Delivery System (Waters, Milford, MA, USA) connected to a Waters 996 Photodiode Array Detector using Zorbax SB-CN (10 μm, 9.4 × 250 mm) and Chiralpak AD-H (5 μm, 250 × 4.6 mm) columns.

The UK was dried in vacuo and dissolved in CD₃OD. ¹H NMR spectra were measured at 500 MHz on a Varian Unity INOVA 500 spectrometer. The solvent peak in CD₃OD (δ = 3.31 ppm) was used as the standard signal. Chemical shifts are expressed in parts per million with reference to the standard signal. NMR signals for the UK were as follows: ¹H NMR (500 MHz, CD₃OD) δ 5.43–5.27 (m, 8H), 4.23 (d, J = 7.6 Hz, 1H, H-1’), 4.16 (m, 2H, H-1), 4.03–3.97 (m, 1H, H-2), 3.92 (dd, J = 10.4 Hz, J = 5.1 Hz, 1H, H-3), 3.82 (d, J = 3.3 Hz, 1H, H-4’), 3.79–3.70 (m, 2H, H-6’), 3.65 (dd, J = 10.5 Hz, J = 4.6 Hz, 1H, H-3), 3.53 (m, 2H, H-2’, H-5’), 3.47 (dd, J = 9.7 Hz, J = 3.4 Hz, 1H, H-3’), 2.91–2.77 (m, 6H), 2.41 (m, 4H), 2.13–2.05 (m, 2H), 0.98 (t, J = 7.5 Hz, 3H). The signals were identical to those reported previously (Rho et al., 1997 ), although we note that all chemical shift values are shifted ca. –0.03 ppm as compared with those reported previously.

UV spectra were taken with a Jasco V-530 spectrophotometer (Jasco, Tokyo, Japan), and IR spectra were obtained on a PerkinElmer Spectrum 400 FT-IR/NIR spectrometer (Waltham, MA, USA). Optical rotations were measured on a PerkinElmer 343 Plus polarimeter (Waltham, MA, USA). HRFDMS were measured on a JMS-T200GC AccuTOF™ GCx-plus High Performance Gas Chromatograph-Time-of-Flight Mass Spectrometer (Jeol Ltd., Tokyo, Japan). NMR experiments were performed on a Varian Unity Inova 500 spectrometer (Varian Inc., Palo Alto, CA, USA) or a Bruker Avance III HD 400 spectrometer (Bruker, Billerica, MA, USA) using DMSO-d₆ and CD₃OD as solvents and TMS as internal standard. Chemical shift values (δ) were reported in parts per million (ppm), and the coupling constants (J) were reported in hertz (Hz). Thin-layer chromatography (TLC) was carried out on precoated silica gel 60 F₂₅₄ plates (Merck, Darmstadt, Germany). Reversed-phase HPLC was performed on a Waters 1525 Binary HPLC pump equipped with a 996 photodiode array (PDA) detector using a Phenomenex Luna C18 (250 × 10 mm, 5 μm) column or a Zorbax Rx C8 (150 × 4.6 mm, 5 μm) with MeOH-H₂O at a flow rate of 2.0 mL/min or 1.0 mL/min, respectively. Separation of diastereomers was carried out on a YMC Amylose-SA chiral column (250 × 4.6 mm, 5 μm) with hexane-ethanol at a flow rate of 1.0 mL/min.

NMR analysis was carried out using a Varian UNITY INOVA 500 spectrometer operating at 499.839 MHz for protons and equipped with a 5 mm double resonance probe (Agilent Technologies, CA, USA). The acquisition parameters of the ¹H-NMR spectra are reported in our previous article [52 (link)]. The FIDs were weighted by an exponential function with a 0.5-Hz line-broadening factor prior to Fourier transformation.