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Lignans are widespread polyphenolic secondary plant metabolites possessing high biological activity. One of the most promising industrial-scale sources of such compounds is coniferous knotwood, containing a large number of polyphenolic compounds. Their use in pharmaceutical and other industries is limited by the difficulty in obtaining high-purity preparations from plant material and the requirement of advanced separation techniques. In this study, supercritical fluid chromatography on polar stationary phases was proposed for the efficient separation and identification of spruce, pine, fir, and larch knotwood extractives. Among the six tested sorbents, the best results were shown by silica with grafted diol and 2-ethylpyridine groups under conditions of gradient elution with a carbon dioxide–methanol mobile phase, which ensured the efficient retention and separation of analytes due to donor–acceptor interactions. Scaling up the method on a DIOL stationary phase provided a semi-preparative separation of extractives within 30 min to obtain 14 individual compounds with a purity of 90–99% and yields from 0.3 to 51% of the dry extract. These included eight lignans (nortrachelogenin, matairesinol, oxomatairesinol, α-conidendrin, 5-hydroxymatairesinol and its isomer, lariciresinol, and secoisolariciresinol), two oligolignans, three stilbenes (pinosylvin and its methyl ester, pterostilbene), and flavonoid taxifolin. The developed approach is distinguished with low operational costs, low consumption of organic solvents, environmental safety, and it is fully consistent with the principles of green chemistry. [ABSTRACT FROM AUTHOR]

A loading and productivity study was done using three racemates on vancomycin and teicoplanin‐bonded chiral stationary phases of different particle formats. Two columns were packed with 2.7 μm superficially porous particles and two columns were packed with identically bonded 5 μm fully porous particles. The last two columns were packed with specially synthesized 4.5 μm vancomycin and teicoplanin superficially porous particles. The loading of different chiral compounds showed that the columns filled with 2.7‐μm chiral stationary phases were inappropriate for preparative separations due to their very low permeability which precluded high flow rates. However, columns containing 4.5 μm superficially porous (core‐shell) particles were as effective for small‐scale preparative chiral separations as columns filled with classical 5 μm fully porous particles. Comparing the 4.5 μm superficially porous particles and 5 μm fully porous particles teicoplanin columns, the observed respective productivities of 270 and 265 mg/g chiral phase/h for 5‐methyl‐5‐phenyl hydantoin enantiomers were obtained. Particular attention was given to the peculiar case of the mianserin enantiomeric separation on vancomycin columns that gave observed productivities of 200 and 205 mg/g chiral phase/h on the 4.5 μm superficially porous particles and 5 μm fully porous particles, respectively. [ABSTRACT FROM AUTHOR]

In the present study, a green and efficient ultrasonic-assisted extraction method of polyphenols from Hibiscus manihot L. flowers (HMLF) was performed, and the corresponding experimental parameters were optimized by Taguchi OA Design. Meanwhile, a two-step high-speed counter-current chromatography coupled with macroporous resin was successfully established with the optimal two-phase solvent systems comprising EtOAc-MeOH-H2O (100:3:100, v/v/v) and Hex-EtOAc-MeOH-H2O (1:5:1:5, v/v/v/v) to isolate and prepare eight polyphenols with purities exceeding 95%, including two phenolic acids and six flavonoids, respectively. The yield of the isolated polyphenols was determined to be 50.4 mg from the enriched extract in a single run. Moreover, the interactions of the eight isolated compounds with AChE and BuChE were explicitly evaluated and described by molecular docking. This study confirms that the proposed method is a cost-effective and powerful strategy for the scaled-up extraction and preparative separation of the high-purity polyphenols from HMLF, and provides an opportunity for automation and systematic preparation of natural products used in the food and pharmaceutical industries.

The development of Dai medicine is relatively slow, and Zanthoxylum has great economic and medicinal value. It is still difficult to obtain medicinal components from the low-polarity parts of Zanthoxylum belonging to Dai medicine. In this study, we introduced one simple and quick strategy of separating target compounds from the barks of Z. acanthopodium var. timbor by high-performance countercurrent chromatography (HPCCC) with an off-line anti-inflammatory activity screening mode. The development of this strategy was based on the TLC-based generally useful estimation of solvent systems (GUESS) method and HPCCC in combination. This paper presented a rapid method for obtaining target anti-inflammatory compounds. Three lignins were enriched by HPCCC with an off-line inhibition mode of nitric oxide production in lipopolysaccharide-stimulated RAW264.7 macrophage cells, using petroleum ether–ethyl acetate–methanol–water (3:2:3:2) as the solvent system. The results showed that this method was simple and practical and could be applied to trace the anti-inflammatory components of the low-polarity part in Dai medicine. [ABSTRACT FROM AUTHOR]

Dracocephalum heterophyllum Benth is well-known for its ability to alleviate liver heat. In this study, Dracocephalum heterophyllum Benth ethyl acetate extracts were evaluated on mouse models of nonalcoholic steatohepatitis and liver fibrosis. After 6 and 8 weeks of treatment, serum parameters and gene expressions in tissue samples, as well as stained tissue sections, demonstrated that the ethyl acetate extracts were effective in treating these liver diseases. The principal bioactive constituent (rosmarinic acid) was identified and screened by high pressure liquid chromatography-1,1-diphenyl-2-picrylhydrazyl and affinity ultrafiltration-HPLC. The rosmarinic acid was separated from extracts with high purity by medium- and high-pressure liquid chromatography. Finally, the interactions between rosmarinic acid and the key targets of lipid metabolism, oxidative stress and inflammation were verified by molecular docking. Thereby, an indirect regulation of lipid and cholesterol metabolism and inhibition of liver inflammation and liver fibrosis by the studied extract has been observed. This study demonstrated that Dracocephalum heterophyllum Benth ethyl acetate extracts have the potential to treat nonalcoholic steatohepatitis and liver fibrosis, revealing their multi-target and multi-pathway therapeutic characteristics. [ABSTRACT FROM AUTHOR]

Lignans are widespread polyphenolic secondary plant metabolites possessing high biological activity. One of the most promising industrial-scale sources of such compounds is coniferous knotwood, containing a large number of polyphenolic compounds. Their use in pharmaceutical and other industries is limited by the difficulty in obtaining high-purity preparations from plant material and the requirement of advanced separation techniques. In this study, supercritical fluid chromatography on polar stationary phases was proposed for the efficient separation and identification of spruce, pine, fir, and larch knotwood extractives. Among the six tested sorbents, the best results were shown by silica with grafted diol and 2-ethylpyridine groups under conditions of gradient elution with a carbon dioxide–methanol mobile phase, which ensured the efficient retention and separation of analytes due to donor–acceptor interactions. Scaling up the method on a DIOL stationary phase provided a semi-preparative separation of extractives within 30 min to obtain 14 individual compounds with a purity of 90–99% and yields from 0.3 to 51% of the dry extract. These included eight lignans (nortrachelogenin, matairesinol, oxomatairesinol, α-conidendrin, 5-hydroxymatairesinol and its isomer, lariciresinol, and secoisolariciresinol), two oligolignans, three stilbenes (pinosylvin and its methyl ester, pterostilbene), and flavonoid taxifolin. The developed approach is distinguished with low operational costs, low consumption of organic solvents, environmental safety, and it is fully consistent with the principles of green chemistry.

Saxifraga atrata is an important traditional Tibetan medicine used to treat cough and pneumonia, and has tremendous medicinal potential. In this study, we devised a technique to separate 1,1‐diphenyl‐2‐picrylhydrazyl inhibitors from a methanol extract of S. atrata. The material was first processed using MCI GEL CHP20P medium‐pressure liquid chromatography, yielding 1.1 g of the target fraction Fr2. Subsequently, online hydrophilic interaction liquid chromatography‐1,1‐diphenyl‐2‐picrylhydrazyl assay was used to identify prospective 1,1‐diphenyl‐2‐picrylhydrazyl inhibitors, and two 1,1‐diphenyl‐2‐picrylhydrazyl inhibitor fractions (Fr24 and Fr25) were identified from Fr2. Then, medium‐pressure preparation was continued using an XIon column to separate two 1,1‐diphenyl‐2‐picrylhydrazyl inhibitor fractions (Fr24 and Fr25). The target compound was concentrated in fractions Fr24 and Fr25 using reverse‐phase liquid chromatography during further separation procedures. Finally, the purity, structure, and 1,1‐diphenyl‐2‐picrylhydrazyl inhibitory activity of the isolated 1,1‐diphenyl‐2‐picrylhydrazyl inhibitors were determined. Two 1,1‐diphenyl‐2‐picrylhydrazyl inhibitors (adenosine with the half maximal inhibitory concentration of 66.87 ± 14.33 μM and (‐)‐4‐O‐(E)‐caffeoyl‐l‐threonic acid with the half maximal inhibitory concentration of 59.06 ± 5.02 μM) were isolated with purities exceeding 95%. The results showed that this technology is effective in the targeted separation of antioxidants from natural products. [ABSTRACT FROM AUTHOR]

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The development of Dai medicine is relatively slow, and Zanthoxylum has great economic and medicinal value. It is still difficult to obtain medicinal components from the low-polarity parts of Zanthoxylum belonging to Dai medicine. In this study, we introduced one simple and quick strategy of separating target compounds from the barks of Z. acanthopodium var. timbor by high-performance countercurrent chromatography (HPCCC) with an off-line anti-inflammatory activity screening mode. The development of this strategy was based on the TLC-based generally useful estimation of solvent systems (GUESS) method and HPCCC in combination. This paper presented a rapid method for obtaining target anti-inflammatory compounds. Three lignins were enriched by HPCCC with an off-line inhibition mode of nitric oxide production in lipopolysaccharide-stimulated RAW264.7 macrophage cells, using petroleum ether–ethyl acetate–methanol–water (3:2:3:2) as the solvent system. The results showed that this method was simple and practical and could be applied to trace the anti-inflammatory components of the low-polarity part in Dai medicine.

Dracocephalum heterophyllum Benth is well-known for its ability to alleviate liver heat. In this study, Dracocephalum heterophyllum Benth ethyl acetate extracts were evaluated on mouse models of nonalcoholic steatohepatitis and liver fibrosis. After 6 and 8 weeks of treatment, serum parameters and gene expressions in tissue samples, as well as stained tissue sections, demonstrated that the ethyl acetate extracts were effective in treating these liver diseases. The principal bioactive constituent (rosmarinic acid) was identified and screened by high pressure liquid chromatography-1,1-diphenyl-2-picrylhydrazyl and affinity ultrafiltration-HPLC. The rosmarinic acid was separated from extracts with high purity by medium- and high-pressure liquid chromatography. Finally, the interactions between rosmarinic acid and the key targets of lipid metabolism, oxidative stress and inflammation were verified by molecular docking. Thereby, an indirect regulation of lipid and cholesterol metabolism and inhibition of liver inflammation and liver fibrosis by the studied extract has been observed. This study demonstrated that Dracocephalum heterophyllum Benth ethyl acetate extracts have the potential to treat nonalcoholic steatohepatitis and liver fibrosis, revealing their multi-target and multi-pathway therapeutic characteristics.

Pterocephalus hookeri, as a kind of popular traditional Tibetan medicine, is reputed to treat inflammatory related diseases. In the present work, a cyclooxygenase-2 functionalized affinity solid-phase extraction HPLC system was developed and combined with preparative-HPLC for rapidly screening and separating cyclooxygenase-2 ligand from P. hookeri extracts. Firstly, ligands of cyclooxygenase-2 were screened from extracts by affinity solid-phase extraction HPLC system. Then directed by the screening results, the recognized potential active compounds were targeted separated. As a result, the major cyclooxygenase-2 inhibitor of P. hookeri was obtained with a purity of >95%, which was identified as sylvestroside I. To test the accuracy of this method, the anti-inflammatory activity of sylvestroside I was inspected in lipopolysaccharide-induced RAW 264.7 cells. The results show that sylvestroside I significantly suppressed the release of prostaglandin E2 with dose-dependent, which was in good agreement with the screening result of the affinity solid-phase method. This method of integration of screening and targeted separation proved to be very efficient for the recognition and isolation of cyclooxygenase-2 inhibitors from natural products.

In the present study, a green and efficient ultrasonic-assisted extraction method of polyphenols from Hibiscus manihot L. flowers (HMLF) was performed, and the corresponding experimental parameters were optimized by Taguchi OA Design. Meanwhile, a two-step high-speed counter-current chromatography coupled with macroporous resin was successfully established with the optimal two-phase solvent systems comprising EtOAc-MeOH-H 2 O (100:3:100, v/v/v) and Hex-EtOAc-MeOH-H 2 O (1:5:1:5, v/v/v/v) to isolate and prepare eight polyphenols with purities exceeding 95%, including two phenolic acids and six flavonoids, respectively. The yield of the isolated polyphenols was determined to be 50.4 mg from the enriched extract in a single run. Moreover, the interactions of the eight isolated compounds with AChE and BuChE were explicitly evaluated and described by molecular docking. This study confirms that the proposed method is a cost-effective and powerful strategy for the scaled-up extraction and preparative separation of the high-purity polyphenols from HMLF, and provides an opportunity for automation and systematic preparation of natural products used in the food and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

As known to all, bamboo and its juice are important resources for industrial crops as well as functional aliments. In this study, an ionic liquid-involved "sandwich" membranes system was developed for one-step separation of polysaccharides, phenols and amino acids in bamboo juice, which was prepared with solvent-free microwave-ultrasound hyphenated way. After that, the feed liquid enriched the bamboo polysaccharides with high molecular weight, the receptor liquid (stripping phase) contained amino acids and the phenolic compounds were recovered from the ionic liquid phase. Related separation conditions and kinetics were both investigated, and the products together with their yield and bioactivity were all compared between the new systematic separation system and conventional single fraction-targeted ways. According to the whole results, it can be proved that the system and device have the advantages of mild conditions, simple operation, highly hyphenated degree, environmental friendliness, and easy continuous enrichment and recycling to obtain bioactive large and small molecules simultaneously. • Special hyphenated solvent-free extraction was developed for bamboo juice. • Ionic liquid-involved "sandwich" membranes were developed for the first time. • Three types of active components can be prepared simultaneously in one step. • Both yield and products bioactivity were more ideal than those from current ways. • Investigation was comprehensive and waste bamboo materials can be reused. [ABSTRACT FROM AUTHOR]

Pterocephalus hookeri, as a kind of popular traditional Tibetan medicine, is reputed to treat inflammatory related diseases. In the present work, a cyclooxygenase-2 functionalized affinity solid-phase extraction HPLC system was developed and combined with preparative-HPLC for rapidly screening and separating cyclooxygenase-2 ligand from P. hookeri extracts. Firstly, ligands of cyclooxygenase-2 were screened from extracts by affinity solid-phase extraction HPLC system. Then directed by the screening results, the recognized potential active compounds were targeted separated. As a result, the major cyclooxygenase-2 inhibitor of P. hookeri was obtained with a purity of >95%, which was identified as sylvestroside I. To test the accuracy of this method, the anti-inflammatory activity of sylvestroside I was inspected in lipopolysaccharide-induced RAW 264.7 cells. The results show that sylvestroside I significantly suppressed the release of prostaglandin E2 with dose-dependent, which was in good agreement with the screening result of the affinity solid-phase method. This method of integration of screening and targeted separation proved to be very efficient for the recognition and isolation of cyclooxygenase-2 inhibitors from natural products. [ABSTRACT FROM AUTHOR]