Accelerated solvent extraction and pH‐zone‐refining counter‐current chromatographic purification of yunaconitine and 8‐deacetylyunaconitine from Aconitum vilmorinianumKom

Abstract

This study aimed to seek an efficient method to extract and purify yunaconitine and 8-deacetylyunaconitine from Aconitum vilmorinianum Kom. by accelerated solvent extraction combined with pH-zone-refining counter-current chromatography. The major extraction parameters for accelerated solvent extraction were optimized by an orthogonal test design L9 (3)(4). Then a separation and purification method was established using pH-zone-refining counter-current chromatography with a two-phase solvent system composed of petroleum ether/ethyl acetate/methanol/water (5:5:2:8, v/v) with 10 mM triethylamine in the upper phase and 10 mM HCl in the lower phase. From 2 g crude extract, 224 mg of 8-deacetylyunaconitine (I) and 841 mg of yunaconitine (II) were obtained with a purity of over 98.0%. The chemical structures were identified by ESI-MS and (1)H and (13)C NMR spectroscopy.

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

“…The reverse displacement pH-zone-refining counter-current chromatography technique was chosen due to its ability to rapidly and easily separate weak bases, like alkaloids, with low solvent consumption. Despite the small number of studies on the isolation of tropane alkaloids by CCC [19], many other types of alkaloids have been separated by conventional HSCCC, with or without the use of pH gradients and pH-zone-refining CCC techniques [15][16][17][18][22][23][24][25]. However, the great chemical diversity of alkaloids requires the development of enhanced solvent systems for each sample.…”

“…It is based on the use of a retainer agent (acid or base) in the stationary phase to retain the analytes in the column and a displacer (or eluter) agent (acid or base) in the mobile phase to elute the analytes according to their p K a /p K b values and their hydrophobicity, thus generating highly concentrated rectangular peaks with minimum overlapping . Since its development by Ito in the 1990s, many types of alkaloids have been separated and purified by pH‐zone‐refining CCC, including indole, isoquinoline, morphinane, and aporfine alkaloids . However, there is only one report regarding the use of this technique to isolate tropane alkaloids .…”