LC/MS Guided Isolation of Alkaloids from Lotus Leaves by pH-Zone-Refining Counter-Current Chromatography

Autor: Rui-Lin Hu, Zhang-Fa Yang, Yuan-Jiang Pan, Xiao-Jing Dai, Cui-Rong Sun, Xia Xu
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Zdroj: Molecules, Vol 16, Iss 3, Pp 2551-2560 (2011)
Druh dokumentu: article
ISSN: 16032551
1420-3049
DOI: 10.3390/molecules16032551
Popis: The traditional methods used in natural product separation primarily target the major components and the minor components may thus be lost during the separation procedure. Consequently, it’s necessary to develop efficient methods for the preparative separation and purification of relatively minor bioactive components. In this paper, a LC/MS method was applied to guide the separation of crude extract of lotus (Nelumbo nucifera Gaertn.) leaves whereby a minor component was identified in the LC/MS analysis. Afterwards, an optimized pH-zone-refining CCC method was performed to isolate this product, identified as N-demethylarmepavine. The separation procedure was carried out with a biphasic solvent system composed of hexane-ethyl acetate-methyl alcohol-water (1:6:1:6, v/v) with triethylamine (10 mM) added to the upper organic phase as a retainer and hydrochloric acid (5 mM) to the aqueous mobile phase eluent. Two structurally similar compounds – nuciferine and roemerine – were also obtained from the crude lotus leaves extract. In total 500 mg of crude extract furnished 7.4 mg of N-demethylarmepavine, 45.3 mg of nuciferine and 26.6 mg of roemerine with purities of 90%, 92% and 96%, respectively. Their structures were further identified by HPLC/ESI-MSn, FTICR/MS and the comparison with reference compounds.
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