A new tropane alkaloid from the leaves of Erythroxylum subsessile isolated by pH‐zone‐refining counter‐current chromatography

Abstract

Tropane alkaloids are bioactive metabolites with great importance in the pharmaceutical industry and the most important class of natural products found in the Erythroxylum genus. However, these compounds are usually separated by traditional chromatographic techniques, in which the sample is progressively purified in multiple chromatographic steps, resulting in a time- and solvent-consuming procedure. In this work we present the isolation of a novel alkaloid, 6β,7β-dibenzoyloxytropan-3α-ol, together with the two known 3α-benzoyloxynortropan-6β-ol and 3α,6β-dibenzoyloxytropane alkaloids, directly from the crude alkaloid fraction from the leaves of Erythroxylum subsessile, by using a single run pH-zone-refining counter-current chromatography method. The ethyl acetate/water (1:1, v/v) biphasic solvent system with triethylamine and HCl as retention and eluter agents, respectively, was used to isolate tropane alkaloids for the first time. The structures of the isolated alkaloids were elucidated by spectroscopic methods.

Simultaneous analysis of tropane alkaloids in teas and herbal teas by liquid chromatography coupled to high‐resolution mass spectrometry (Orbitrap)

“…GC, LC, and CE are the techniques most commonly used in the analysis or isolation of TAs . When GC is used, capillary columns of fused silica such as DB1 or DB5 provide a good separation of many alkaloids with a high sensitivity and selectivity, although their GC analysis should include a derivatization step .…”

Preparative separation of bioactive polyphenol resveratrol from Polygonum cuspidatum Sieb. et Zucc. by pH‐zone‐refining countercurrent chromatography

“…Generally more than ten fold sample loading capacity can be achieved for pH-zone-refining countercurrent chromatography compared with conventional countercurrent chromatography, which constitutes the main advantage for preparative separation by pH-zone-refining mode. At present, many papers are available for separation of acidic and basic components from complicated matrix of natural products [23][24][25][26][27][28][29][30][31] or synthetic mixtures [32][33][34][35], in which all the analytes to be separated are typical organic acids or bases in light of their carboxyl group or amino group. It is assumed that pH-zone-refining mode can only be applied in separation of ionic components and it has been well explored in preparative separation of typical organic acids or bases.…”

Application of pH‐zone‐refining countercurrent chromatography in the chiral separation of two β‐adrenergic blocking agents

“…In recent years, Abbreviation: TEBA, triethylbenzylammonium chloride Conflict of interest: The authors declared no conflict of interest. pH-zone-refining countercurrent chromatography has been effectively and successfully applied in the separation of acidic and basic components from complicated matrix of natural products [9][10][11][12][13][14][15] or synthetic mixtures [16][17][18].…”

“…Ionic components form a highly concentrated rectangular peak associated with its specific pH value by adding a retainer in the stationary phase and a eluter in the mobile phase and thus they could be purified easily from nonionic impurities . In recent years, pH‐zone‐refining countercurrent chromatography has been effectively and successfully applied in the separation of acidic and basic components from complicated matrix of natural products or synthetic mixtures .…”