Completed preparative separation of alkaloids from Cephaltaxus fortunine by step-pH-gradient high-speed counter-current chromatography

Z, Liu; Du, Qizhen; Wang, Kuiwu; Xiu, Lili; Song, Guihong

doi:10.1016/j.chroma.2009.03.083

Cited by 38 publications

(14 citation statements)

References 19 publications

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“…pH stepwise elution or pH step gradient has the same utility but is based on compound acid/basic characteristics while increasing/decreasing the mobile phaseʼs pH. In the first, an equal small amount of acid and base (less than 20 mM) is used as a retainer and eluter, while the second works with the excessive addition of acid or base in the mobile phase [45], achieving higher/lower pHs. One-step pH gradient CPC was applied for the isolation of bitter acids from hops.…”

Section: Stepwise Elution (Flow Rate Step Gradient) !mentioning

confidence: 99%

Gradient Elution in Countercurrent Chromatography

Leitão

Costa

2015

Planta Med

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Countercurrent chromatography is a form of liquid-liquid partition chromatography in which the stationary liquid phase is retained in the apparatus without the use of a solid support. Gradient elution in countercurrent chromatography can be used in many different ways, such as linear gradients, stepwise elution gradients, pH gradients, etc. The main goal of using the gradient approach is to shorten the duration of the separation and improve resolution, especially when the retention range of the sample to be purified is broadening and, thus, the compounds cannot be purified by only one solvent system. The principle is based on modifying the mobile phase to increase the elution strength with no or minimum changes in the stationary phase, which can be a difficult task since both phases are in intimate contact all the time. The most common ways to perform gradients in countercurrent chromatography are changing the mobile's phase polarity, flow rate, and pH, what is called linear or step gradient, flow rate gradient, pH gradient, respectively.

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Section: Stepwise Elution (Flow Rate Step Gradient) !mentioning

confidence: 99%

Gradient Elution in Countercurrent Chromatography

Leitão

Costa

2015

Planta Med

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“…Comparing with extraction, latter processes are more complex and important. Thus, much work has attempted to improve the analysis and separation of alkaloids from extracts, with chromatography being considered effective and adopted as the prevalent method [2][3][4][5]. Stationary phases or adsorbents are important in chromatography and related techniques (e.g.…”

Section: Introductionmentioning

confidence: 99%

Selective extraction and separation of oxymatrine from Sophora flavescens Ait. extract by silica-confined ionic liquid

Tian

Row

2012

Journal of Chromatography B

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“…So it is suitable for separation and purification of active components from natural products. Many successful applications have been reported on the purification of different kinds of active compounds from natural products, such as alkaloids [9][10][11][12], flavonoids [13][14][15][16][17], coumarins [18][19][20][21], anthraquinones [22][23][24], polyphenols [25], diterpenoids [26][27][28][29], saponins [30][31][32], and so on. Separation and purification of tanshinones from Salvia miltiorrhiza Bunge by HSCCC has been reported previously [27][28][29].…”

Section: Introductionmentioning

confidence: 99%