Inova 400 mhz system

The dried herb, Sparganium stoloniferum (Rhizoma Sparganii, RS) was purchased from Yi-Kang Chain Medicine Co. (Xi'an, China). Standardization of this drug was consistent with the regulations of the State Food and Drug Administration. The pure compound Grailsine-Al-glycoside (Figure 1) was purified from aqueous extract of RS (RS-W) through the silica gel (SiO₂; 230-400 mesh, Merck, Shanghai, China) and Sephadex G-25 (Sigma, St. Louis, MO) column chromatography [10 ]. ³H and ¹³C spectra were recorded on a Varian INOVA-400 MHz system (Varian, Palo Alto, CA). TOF-MS spectra were obtained on an AXIMA-CFR™ plus MALDI-TOF Mass Spectrometer (SHIMADZU, Beijing, China). Elements were analyzed on a Vario EL III (Elementar Analysensysteme GmbH, Hanau, Germany), and monosaccharide composition was analyzed using the general method.

The reactions were monitored for their completion by thin layer chromatography (TLC) using aluminium-backed Macherey-Nagel ALUGRAM Sil G/UV254 plates pre-coated with 0.25 mm silica gel 60Å. Column chromatography was carried out on silica gel 60 (particle size 200–300 mesh) with a silica to compound ratio of 30:1 by mass or neutral alumina as the adsorbent for conventional preparative chromatography.
NMR spectra were recorded on a Varian INOVA 400 MHz system or a Varian PremiumShield VNMRS 600 MHz system operating at 399.94 or 599.74 MHz, respectively. Chemical shifts (δ) are reported in parts per million (ppm) relative to tetramethylsilane (TMS) or against the residual protonated solvent signal as reference. Coupling constants (J) are reported in Hz.
Melting points were obtained on a Reichert Hot Stage or a Mettler FP62 melting point apparatus. High-resolution mass spectra were recorded on a Waters Acquity UPLC coupled in tandem to a Waters photodiode array (PDA) detector and a SYNAPT G1 HDMS mass spectrometer.