Perkin elmer 343 polarimeter

Merck silica gel (100–200 mesh) column chromatography Sigma Aldrich, St. Louis, MO, USA and preparative thin-layer chromatography Sigma Aldrich, St. Louis, MO, USA were used to purify synthesized compounds. Compounds were identified and characterized using ¹H NMR and ¹³C NMR (Bruker DPX-300, Bruker, Manning Park Billerica, MA, USA), IR (Perkin-Elmer 1640 FT-IR, PerkinElmer, Waltham, MA, USA) and Mass (WATERS Micro-mass ZQ 4000; ESI Probe, Waters, Milford, MA, USA) spectrometers. A Perkin-Elmer 343 Polari meter (PerkinElmer, Waltham, MA, USA) was used to measure optical rotations. A Buchi B-540 melting point apparatus (Sigma Aldrich, St. Louis, MO, USA) was used to record melting points. Reactions were conducted under dry nitrogen atmospheric conditions. Solvents were distilled prior to their use.

Melting points were determined with a Reichert Thermovar apparatus and are uncorrected (Reichert Technologies, Buffalo, NY, USA). Optical rotations were measured at room temperature on a Perkin Elmer 343 polarimeter (Perkin Elmer, Waltham, MA, USA). IR spectra were recorded with a Perkin-Elmer 1600 FT spectrometer (Perkin Elmer, Waltham, MA, USA). ¹H and ¹³C NMR spectra were run in CDCl₃ solution at 500.1 and 125.8 MHz, respectively, in a Bruker AMX-500 spectrometer (Bruker Corporation, Billerica, MA, USA) with pulsed field gradient, using this solvent signal (CDCl3, at δH7.26 and δC77.0) as internal standard. Chemical shifts are given in ppm (δ). EI and HREIMS were taken in a Micromass Autospect instrument (Manchester, UK) at 70 eV (probe). HRESIMS data were recorded on a Waters Micromass LCT Premier XE (Manchester, UK). Column chromatographies were made on silica gel (40∓63 μm, Merck, Darmstadt, Germany), and Sephadex LH-20 (Amersham Pharmacia Biotech AB, Uppsala, Sweden). Preparative and semipreparative HPLC was performed on a Beckman System Gold 125P (Beckman Coulter Life Sciences, Brea, CA, USA) equipped with a diode-array detector Beckman Coulter 168 and preparative Interstil Prep-sil (Gasukuro Kogio) (20 mm × 250 mm, 10 µm) and semipreparative Beckman Ultrasphere silica (10 mm × 250 mm, 5 µm) columns.

Optical rotations were measured on a Perkin-Elmer 343 polarimeter (Perkin Elmer, Waltham, MA, USA). UV spectra were recorded on a Specord UV−vis spectrometer (Carl Zeiss, Jena, Germany) in CHCl₃. NMR spectra were recorded in DMSO-d₆ on a Bruker DPX-500 (Bruker BioSpin GmbH, Rheinstetten, Germany) and a Bruker DRX-700 (Bruker BioSpin GmbH, Rheinstetten, Germany) spectrometer, using TMS as an internal standard. HRESIMS spectra were measured on an Agilent 6510 Q-TOF LC mass spectrometer (Agilent Technologies, Santa Clara, CA, USA) and a Maxis impact mass spectrometer (Bruker Daltonics GmbH, Rheinstetten, Germany).
Low-pressure liquid column chromatography was performed using silica gel (50/100 μm, Imid, Russia). Plates (4.5 cm × 6.0 cm) precoated with silica gel (5–17 μm, Imid) were used for thin-layer chromatography. Preparative HPLC was carried out on a Shimadzu LC-20 chromatograph (Shimadzu USA Manufacturing, Canby, OR, USA) using a YMC ODS-AM (YMC Co., Ishikawa, Japan) (5 µm, 10 mm × 250 mm) and YMC SIL (YMC Co., Ishikawa, Japan) (5 µm, 10 mm × 250 mm) columns with a Shimadzu RID-20A refractometer (Shimadzu Corporation, Kyoto, Japan).