400mr ft nmr

Measurements of optical rotations and IR spectra were carried out on a JASCO P-1020 polarimeter and FT/IR-4100 infrared spectrophotometer (JASCO Corporation, Tokyo, Japan), respectively. ESIMS and HRESIMS were performed on a Bruker APEX II (Bruker, Bremen, Germany) mass spectrometer. The NMR spectra were recorded on a Varian 400MR FT-NMR at 400 and 100 MHz for ¹H and ¹³C, respectively or a Varian Unity INOVA500 FT-NMR at 500 and 125 MHz for ¹H and ¹³C, respectively (Varian Inc., Palo Alto, CA, USA). Silica gel or reversed-phase (RP-18, 230–400 mesh) silica gel was used for column chromatography and analytical thin-layer chromatography (TLC) analysis (Kieselgel 60 F-254, 0.2 mm, Merck, Darmstadt, Germany), respectively. Isolation and purification of compounds by high-performance liquid chromatography (HPLC) were achieved using an Hitachi L-2455 HPLC apparatus (Hitachi, Tokyo, Japan) equipped with a Supelco C18 column (250 × 21.2 mm, 5 μm, Supelco, Bellefonte, PA, USA).

Measurements of circular dichroisms, optical rotations, and IR spectra were carried out on a Jasco J-715 CD spectrometer, JASCO P-1020 polarimeter, and FT/IR-4100 infrared spectrophotometer (JASCO Corporation, Tokyo, Japan), respectively. ESIMS was performed on a Bruker APEX II (Bruker, Bremen, Germany) mass spectrometer, and HRESIMS was performed on a Bruker APEX II and Impact HD Q-TOF mass spectrometers (Bruker, Bremen, Germany). The NMR spectra were recorded on a Varian 400MR FT-NMR at 400 and 100 MHz for ¹H and ¹³C, respectively; a Varian Unity INOVA500 FT-NMR (both Varian Inc., Palo Alto, CA, USA) at 500 and 125 MHz for ¹H and ¹³C, respectively; or a JEOL ECZ600R FT-NMR (Japan) at 600 and 150 MHz for ¹H and ¹³C, respectively. Silica gel and reversed-phase (RP-18, 230–400 mesh) silica gel were used for column chromatography and analytical thin-layer chromatography (TLC) analysis (Kieselgel 60 F-254, 0.2 mm, Merck, Darmstadt, Germany), respectively. The isolation and purification of compounds by high-performance liquid chromatography (HPLC) were achieved using a Hitachi L-2455 HPLC apparatus (Hitachi, Tokyo, Japan) equipped with a Supelco C18 column (250 × 21.2 mm, 5 μm, Supelco, Bellefonte, PA, USA).

Values of the specific optical rotation of the isolates were measured with a JASCO P-1020 polarimeter (JASCO Corporation, Tokyo, Japan). Infrared spectra were recorded using a JASCO FT/IR-4100 infrared spectrophotometer (JASCO Corporation, Tokyo, Japan). The CD spectrum was recorded on a Jasco J-815 circular dichroism (CD) spectropolarimeter (JASCO, Tokyo, Japan) in MeOH. ¹H- and ¹³C-NMR spectra were acquired on a Varian 400MR FT-NMR (or Varian Unity INOVA500 FT-NMR) instrument (Varian Inc., Palo Alto, CA, USA) at 400 MHz (or 500 MHz) and 100 MHz (or 125 MHz), respectively, in CDCl₃ or C₆D₆. LR-ESI-MS and HR-ESI-MS experiments were carried out using a Bruker APEX II (Bruker, Bremen, Germany) mass spectrometer. Silica gel (230–400 mesh) was used as the adsorbent for normal-phase column chromatography. Thin-layer chromatography (TLC) analyses were performed with precoated silica gel plates (Kieselgel 60 F-254, 0.2 mm, Merck, Darmstadt, Germany). Further purification of impure fractions or compounds was further achieved by high-performance liquid chromatography on a Hitachi L-7100 HPLC instrument (Hitachi Ltd., Tokyo, Japan) with a Merck Hibar Si-60 column (250 mm × 21 mm, 7 μm; Merck, Darmstadt, Germany) and on a Hitachi L-2455 HPLC apparatus (Hitachi, Tokyo, Japan) with a Supelco C18 column (250 mm × 21.2 mm, 5 μm; Supelco, Bellefonte, PA, USA).