Application of stepwise gradients in counter-current chromatography: A rapid and economical strategy for the one-step separation of eight coumarins from Seseli resinosum

Pyranocoumarins from Root Extracts of Peucedanum praeruptorum Dunn with Multidrug Resistance Reversal and Anti-Inflammatory Activities

“…The 15 known compounds were identified as (+)-praeruptorin A (2) [20,21], (+)-praeruptorin B (3) [20,21], (+)-praeruptorin E (4) [20][21][22], selinidin (5) [23], cis-3′,4′-diisovalerylkhellactone (6) [19,24], pteryxin (7) [6], suksdorfin (8) [25,26], Pd-Ib (9) [27,28], qianhucoumarin D (10) [20,21], (+)-samidin (11) [25,[29][30][31], laserpitin (12) [32], (9R,10R)-9-acetoxy-8,8-dimethyl-9,10-dihydro-2H,8H-benzo [1,2-b:3,4-b′]dipyran-2-one-10-yl-ester (13) [33], bergapten (14) [34,35], xanthotoxin (15) [36], and falcalindiol (16) [37][38][39][40].…”

Two-dimensional countercurrent chromatography × high performance liquid chromatography with heart-cutting and stop-and-go techniques for preparative isolation of coumarin derivatives from Peucedanum praeruptorum Dunn

“…The results showed that neither the Arizona system nor the expanded Arizona system could achieve satisfactory Kd values for all of the target compounds (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16), while the acetone solvent system works well. For example, in solvent systems S1 and S3, the target compounds exhibited much higher Kd values, which were deemed unsuitable for CCC separation.…”

“…Successful applications of CCC have also been reported to separate and purify plant-derived natural products [9]. Recent reports have also revealed that many natural products could be isolated by flow-rate gradient elution CCC or stepwise solvent gradient CCC [10][11][12]. On the other hand, the recently developed high performance countercurrent chromatography (HPCCC), whose separation times are minutes rather than hours, has shown powerful separation ability [13].…”

Centrifugal partition chromatography elution gradient for isolation of sesquiterpene lactones and flavonoids from Anvillea radiata

“…However this involves a second CPC run and thus long total separation time. To perform the purification of germacranolides and the separation of flavonoids in the same run, it is also possible to attempt an elution gradient will lead to an increase in selectivity as it covers a wide polarity range [21,22]. Linear gradient elution, less involved rather than stepwise gradient, consists in a progressive mobile phase polarity change during the elution step while retaining the same stationary phase.…”

“…However it was not powerful enough to separate simultaneously both germacranolides and flavonoids present in the extract due to the wide range of polarity of these two molecular families. Gradient elution was introduced in CCC for addressing the problems of complex mixture separation, improving the selectivity and the resolution efficiency, reducing the separation time [21]. However, gradient elution in CCC is not as straightforward as it is in highperformance liquid chromatography because any changes to the CCC mobile phase composition lead inevitably, to a modification of the stationary phase [22].…”