ABSTRACT
Objective: A novel method for the separation of alkaloids from Nelumbinis Folium by pH-zone-refining counter-current chromatography (pH-ZRCCC). Methods: The two-phase solvent system composed of MtBE-methanol-water (4:1:5), 10 mmol/L triethylamine (TEA) in organic stationary phase and 5 mmol/L HCl in aqueous mobile phase. The upper phase was used as the stationary phase, while the lower phase was used as the mobile phase. In one-step elution under the conditions of a flow rate of 1.5 mL/min, 800 r/min and the effluent was detected at 254 nm. Results: From 2.18 g of the crude extract, 110 mg N-nornuciferin, 420 mg O-nornuciferin, 310 mg nuciferine, and 190 mg roemerine were obtained and each with a purity of over 98% as determined by HPLC. The structures of the isolated compounds were identified by HPLC, MS, and 1H-NMR. Conclusion: The present pH-ZRCCC method may be applied to the purification of other various alkaloids from natural products.
ABSTRACT
Objective: A novel method for the analysis of alkaloids in Nelumbo nucifera leaves was established by SPE-RRLC-Q-TOF mass spectrometry. Methods: The crude sample was extracted by 1% HCl with ultrasound-assisted extraction, then purified by SPE column, and eluted with ammonia-methanol (5:95). After concentration, the residue was dissolved by methanol solution. The real sample was analyzed by RRLC-Q-TOF. A Welch Materials C18 column was applied in the RRLC separation using acetonitrile and water as mobile phase. The elutes were detected by Q-TOF to obtain the MS spectra with extract molecular weights under positive ion mode. Results: Nine alkaloids were identified. Conclusion: This method can be used to rapidly determine the alkaloids of N. nucifera leaves.