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Gynostemma pentaphyllum (Thunb.) Makino represents the popular health food and supplemental product with broad pharmacological activities. The highly polar glycosides, including flavonoids and saponins, are major effective active components that contain diverse sugar positions and quantities, which result in diverse chemical polarities, making it challenging to separate and isolate these components. The present work described the rapid and efficient linear gradient counter‐current chromatography to preparatively separate glycosides from aboveground parts of G. pentaphyllum. Besides, the ethyl acetate and n‐butanol binary mobile phases were achieved through adjusting associated proportions. Six glycosides, including quercetin‐3‐O‐neohesperidoside (1), kaempferol‐3‐O‐robinobioside (2), kaempferol‐3‐O‐neohesperidoside (3), gypenoside LVI (4), ginsenoside Rb3 (5), and gypenoside XLVI (6), were isolated at the purities greater than 98%. Moreover, electrospray ionization mass spectrometry and nuclear magnetic resonance tandem mass spectrometry were conducted for structural identification. According to our findings, the established linear gradient counter‐current chromatography was an efficient approach to separate the highly polar glycosides from aboveground parts of G. pentaphyllum. Our proposed strategy can be used to separate active compounds from other complex natural products. [ABSTRACT FROM AUTHOR]

As a famous health food, roots of Panax quinquefolium L. possessed immune regulation and enhancement of the central nervous system, in which ginsenosides are the main active component with different numbers and positions of sugars, causing different chemical polarities with a challenge for the separation and isolation. In this study, a fast and effective bilinear gradient counter‐current chromatography was proposed for preparative isolation ginsenosides with a broad partition coefficient range from roots of Panax quinquefolium L. In terms of the established method, the mobile phases comprising n‐butanol and ethyl acetate were achieved by adjusting the proportion. Coupled with the preparative HPLC, eleven main ginsenosides were successfully separated, including ginsenoside Rg1 (1), Re (2), acetyl ginsenoside Rg1 (3), Rb1 (4), Rc (5), Rg2 (6), Rb3 (7), quinquefolium R1 (8), Rd (9), gypenoside X VII (10) and notoginsenoside Fd (11), with purities exceeding 95% according to the HPLC results. Tandem mass spectrometry and electrospray ionization mass spectrometry were adopted for recognizing the isolated compound architectures. Our study suggests that linear gradient counter‐current chromatography effectively separates the broad partition coefficient range of ginsenosides compounds from the roots of Panax quinquefolium L. In addition, it can apply to active compound isolation from other complicated natural products. [ABSTRACT FROM AUTHOR]

Diaphragma juglandis fructus contains various bioactive constituents. Fourteen compounds were isolated from Diaphragma juglandis fructus by preparative high performance liquid chromatography (pre-HPLC) and high-speed counter-current chromatography (HSCCC). Their structures were identified by nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESI-MS). Compounds (+)-dehydrovomifoliol (12), (6R,9R)-9-hydroxymegastigman-4-en-3-one (13) and (6R,9S)-9-hydroxymegastigman-4-en-3-one (14) are found from Juglans regia L. for the first time. Compounds dihydrophaseic acid (2), blumenol B (3) and (4S)-4-hydroxy-1-tetralone (11) are isolated from Diaphragma juglandis fructus for the first time. The anti-inflammatory effects of isolated compounds were evaluated by an in vitro model of lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Compounds gallic acid (1), ethyl gallate (9) and (+)-dehydrovomifoliol (12) exhibited inhibitory activity on the nitric oxide production of RAW 264.7 at a concentration of 25 µM. The result indicated that the combination HSCCC with pre-HPLC is an effective way for compound separation and purification. And Diaphragma juglandis fructus constituents have the potential for the treatment of inflammatory-related diseases. [ABSTRACT FROM AUTHOR]

We describe a solid-phase extraction adsorbent based on molecularly imprinted polymers (MIPs), prepared with use of a mimic template. The MIPs were used for the selective extraction and determination of three chlorogenic acids as combined quality markers for Lonicera japonica and Lianhua qingwen granules. The morphologies and surface groups of the MIPs were assessed by scanning electron microscopy, Brunauer-Emmett-Teller surface area analysis, and Fourier transform infrared spectroscopy. The adsorption isotherms, kinetics, and selectivity of the MIPs were systematically compared with those of non-molecularly imprinted polymers. The MIPs showed high selectivity toward three structurally similar chlorogenic acids (chlorogenic acid, cryptochlorogenic acid, and neochlorogenic acid). A procedure using molecularly imprinted solid-phase extraction coupled with high-performance liquid chromatography was established for the determination of three chlorogenic acids from Lonicera japonica and Lianhua qingwen granules. The recoveries of the chlorogenic acids ranged from 93.1% to 101.4%. The limits of detection and limits of quantification for the three chlorogenic acids were 0.003 mg g and 0.01 mg g, respectively. The newly developed method is thus a promising technique for the enrichment and determination of chlorogenic acids from herbal medicines. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Ginkgolic acids (GAs) are abundant in the sarcotesta of ginkgo semen. • PZRCCC was used for the gram-scale preliminary separation of GAs. • Inner-recycling HSCCC mode was used to separate GAs with similar K D -values. • Five main ginkgolic acids were successfully separated with purities over 98%. Abstract An efficient method for the preparative separation and isolation of ginkgolic acids (GAs) from the sarcotesta of Ginkgo biloba L was developed by combining pH-zone-refining counter-current chromatography (PZRCCC) with inner-recycling mode. Two grams of GAs extract were separated by PZRCCC using a two-phase solvent system of n -heptane–ethyl acetate–methanol–water (2:1:3:1, v/v) with 10 mM HCl added to the upper phase as the retention acid and 10 mM triethylamine (TEA) in the lower phase as the elution base. In a one-step PZRCCC separation, two GA compounds, C15:1 and C17:2, were obtained with purities over 98% along with two mixtures. The mixtures were further separated by inner-recycling CCC mode with n -heptane–ethyl acetate–methanol–acetic acid (5:4:1:1, v/v) as the solvent system. Five main GAs were successfully separated with purities over 98%. The structures of the separated GAs were determined based on standard samples coupled with Electrospray Ionization Mass Spectrometry (ESI-MS) results. This separation method of coupling PZRCCC with inner-recycling CCC is effective for the preparation of GAs from the sarcotesta of G. biloba and could be further applied to separate organic acids of low polarity in other natural products. [ABSTRACT FROM AUTHOR]