Jms 700 high resolution mass spectrophotometer

The UV and IR spectra were recorded on Hitachi-UV-3200 and JASCO 320-A spectrometers. The ¹H-, ¹³C NMR and 2D-NMR spectra were recorded on a Bruker AMX-500 spectrometer with tetramethylsilane (TMS) as internal standard. Chemical shifts (δ) are given in ppm relative to tetramethylsilane internal standard. Jeol JMS-700 High Resolution Mass Spectrophotometer was utilized for the mass determination. Electron impact mode of ionization was used, keeping ionization energy of 70ev. Resolution was set up to 10 k direct probe was used with temperature ramp setting, initial temperature 50 °C rise with rate of 32 °C per minute and final temperature set up to 350 °C. Thin layer chromatography (TLC) was carried out on precoated silica gel F254 plates (E. Merck, Darmstadt, Germany); detection was performed at 254 nm and by spraying with p-anisaldehyde/H₂SO₄ reagent. All chemicals were purchased from Sigma Chemical Company (St. Louis, MO, USA).

¹H and ¹³C NMR spectra were recorded at NMR Unit at the College of Pharmacy, Sattam Bin Abdulaziz University on a UltraShield Plus 500 MHz (Bruker) spectrometer operating at 500 MHz for proton and 125 MHz for carbon, respectively. The chemical shift values are reported in δ (ppm) relative to the internal standard TMS or residual solvent peak, and the coupling constants (J) are reported in Hertz (Hz). 2D-NMR experiments (COSY, HSQC, HMBC and NOESY) were obtained using standard Bruker program. Jeol JMS-700 High Resolution Mass Spectrophotometer was used for accurate mass determination. Electron Impact mode with ionization energy of 70 eV was accustomed. Direct probe, temperature ramp setting was used with initial temperature 50 °C; increasing 32 °C per minute and final temperature 350 °C set up, and resolution was adjusted to 10k. Thin layer chromatography (TLC) was performed on pre-coated silica gel F₂₅₄ plates (E. Merck, Darmstadt, Germany); detection was done at 254 nm and by spraying with p-anisaldehyde/H₂SO₄ reagent followed by heating at 110 °C for 1–2 min. Centrifugal preparative thin layer chromatography (CPTLC) was performed on chromatotron (Harrison Research, Palo Alto, California, CA, USA). Plates coated with 2 mm of silica gel 60, 0.04–0.06 mm were used. All solvents used were of analytical grade. Silymarin was purchased from Sigma Aldrich (St. Louis, USA).