Ltq ft instrument

Melting points were uncorrected and were measured on a Mettler Toledo instrument. IR spectra were recorded on an Alpha II FT-IR spectrometer from Bruker in the region of 4000–600 cm^–1, using KBr pellet technique with 1.0 cm^–1 resolution at room temperature. 1D and 2D NMR spectra were obtained on a Bruker DRX 500 (500 MHz for ¹H and 125 MHz for ¹³C spectra) spectrometer (Bruker, Rheinstetten, Germany) with chemical shifts reported as δ (ppm), using TMS as an internal standard. The ESI-MS were obtained on LTQ-FT instrument (Thermo Scientific). LC–MS were measured with Shimadzu LC–MS system using a L-column 2 ODS (I.D. 2.1 × 100 mm, Chemical Evaluation and Research Institute, Japan), at a flow rate of 0.2 mL min⁻¹ with a detection wavelength of 300 nm and FMW (HCOOH/MeCN/H₂O = 1:12:87) as eluent, ESI+ 4.5 kV, ESI− 3.5 kV, 250 °C. Optical rotations were measured on a Perkin-Elmer 341 polarimeter. Silica gel 60 (230–400 mesh E. Merck, Darmstadt, Germany) and Sephadex^® LH-20 were employed for CC, the solvent mixing systems for elution were mainly CH₂Cl₂/MeOH for the phytochemical study with increasing polarity and pure MeOH, while precoated aluminum sheets Silica gel 60 F254 were used for TLC [53 (link)].