The Experts below are selected from a list of 94326 Experts worldwide ranked by ideXlab platform
Xinmiao Liang - One of the best experts on this subject based on the ideXlab platform.
-
separation of piper kadsura using preparative supercritical fluid Chromatography combined with preparative reversed phase Liquid Chromatography
Chromatographia, 2018Co-Authors: Huaxia Xin, Yu Jin, Xinmiao Liang, Zhuoshun Dai, Jianfeng Cai, Jiatao FengAbstract:We have developed a separation strategy that employed preparative supercritical fluid Chromatography (prep-SFC) combined with preparative Reversed-Phase Liquid Chromatography (prep-RPLC) to purify compounds from Piper kadsura. The complexity of the sample was effectively reduced by two steps of prep-SFC. The key experimental parameters of prep-SFC were systematically optimized, including an “average-pressure rule” scaling-up method for adjustment of the backpressure of the system. A mixed modifier consisting of ethanol/n-hexane was applied to provide a stable elution. Prep-RPLC was subsequently adopted to purify the SFC fractions due to its good orthogonality with SFC. Furthermore, chiral SFC was used to separate the structural analogues. As a result, 14 compounds with high purity were obtained from one fraction, including three pairs of diastereoisomers. These data indicate that the separation strategy using prep-SFC combined with prep-RPLC is an effective tool to separate complex samples such as natural products.
-
purification of high purity glycyrrhizin from licorice using hydrophilic interaction solid phase extraction coupled with preparative reversed phase Liquid Chromatography
Journal of Chromatography B, 2017Co-Authors: Hongli Jin, Aijin Shen, Yanfang Liu, Xingya Xue, Liang Deng, Jianlian Shi, Yadong Guo, Xinmiao LiangAbstract:Glycyrrhizin (GA), a major bioactive compound in licorice, has been extensively used throughout the world as a medicine to treat chronic viral hepatitis and allergic dermatitis. In this study, a new method based on hydrophilic interaction solid phase extraction (HILIC-SPE) and preparative Reversed-Phase Liquid Chromatography (prep-RPLC) was developed to purify GA with high purity from the complex licorice extract. Via evaluation of retention behavior of GA and flavonoids in different commercially available columns, a hydrophilic column--Click XIon was finally chosen for the purification due to its excellent resolution toward GA and flavonoids under HILIC mode. To optimize the SPE elution conditions, relative factors including water content, pH and ionic strength had been investigated in chromatographic condition. The result indicated that the most appropriate water content was 30% and pH at 4.00, as well as salt concentration should be controlled at 5mM. In addition, the optimization revealed that GA experiences both hydrophilic interaction and ion-exchange interaction on the Click XIon material. According to the chromatographic evaluation, the optimized conditions were applied to HILIC-SPE to enrich GA from licorice, which leads to an increased content of GA from 13.67% to 64.22%. Finally, prep-RPLC was performed to obtain GA with purity higher than 99.00%，which demonstrating great prospect in large-scale preparation of GA.
-
purification of amide alkaloids from piper longum l using preparative two dimensional normal phase Liquid Chromatography reversed phase Liquid Chromatography
Analyst, 2013Co-Authors: Wenya Zhu, Yu Jin, Xinmiao LiangAbstract:A comprehensive off-line two-dimensional Liquid Chromatography (2D-LC) method coupling normal phase Liquid Chromatography (NPLC) and reversed phase Liquid Chromatography (RPLC) was developed for separation and purification of amide alkaloids from Piper longum L. In the first dimension, the crude alkaloid fractions were separated in NPLC mode and 20 fractions were collected. Then fractions 5–20 were selected for further purification in RPLC mode in the second dimension. The purities of RPLC fractions with similar structures were all identified accurately by ultra performance Liquid Chromatography (UPLC). In total, 28 compounds with high purity were obtained and their structures were comprehensively characterized by electrospray ionization-mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) spectroscopy. The results demonstrate that this 2D NPLC × RPLC method with good orthogonality (58.3%) was effective for the preparative separation and purification of amide alkaloids from Piper longum L.
-
purification of saponins from leaves of panax notoginseng using preparative two dimensional reversed phase Liquid Chromatography hydrophilic interaction Chromatography
Analytical and Bioanalytical Chemistry, 2013Co-Authors: Xiujie Guo, Zhimou Guo, Xiuli Zhang, Jiatao Feng, Yuansheng Xiao, Xinmiao LiangAbstract:Saponins are widely distributed in the plant kingdom and have been shown to be active components of many medicinal herbs. In this study, a two-dimensional purification method based on Reversed-Phase Liquid Chromatography coupled with hydrophilic interaction Liquid Chromatography was successfully applied to purify saponins from leaves of Panax notoginseng. Nine saponin reference standards were used to test the separation modes and columns. The standards could not be resolved using C18 columns owing to their limited polar selectivity. However, they were completely separated on a XAmide column in hydrophilic interaction Liquid Chromatography mode, including two pairs of standards that were coeluted on a C18 column. The elution order of the standards on the two columns was sufficiently different, with a correlation coefficient between retention times on the C18 and XAmide columns of 0.0126, indicating good column orthogonality. Therefore, the first-dimension preparation was performed on a C18 column, followed by a XAmide column that was used to separate the fractions in the second dimension. Fifty-four fractions were prepared in the first dimension, with 25 fractions rich in saponins. Eight saponins, including two pairs of isomeric saponins and one new saponin, were isolated and identified from three representative fractions. This procedure was shown to be an effective approach for the preparative isolation and purification of saponins from leaves of P. notoginseng. Moreover, this method could possibly be employed in the purification of low-content and novel active saponins from natural products.
-
comprehensive characterization of stevia rebaudiana using two dimensional reversed phase Liquid Chromatography hydrophilic interaction Liquid Chromatography
Journal of Separation Science, 2012Co-Authors: Zhimou Guo, Yanfang Liu, Xiuli Zhang, Xinmiao LiangAbstract:Abstract Two-dimensional Reversed-Phase Liquid Chromatography/hydrophilic interaction Liquid Chromatography (2D-RPLC/HILIC) system was successfully applied for comprehensive characterization of steviol glycosides from Stevia rebaudiana. The experiments were performed in offline mode using an XCharge C18 column in first dimension and an XAmide column in second dimension. In first dimension, preliminary separation of Stevia aqueous extract was accomplished and 30 fractions were collected. Then fractions 1-20 were selected for further purification and 13 compounds with high purity were obtained in second dimension. Comprehensive characterization of these compounds was completed by determination of their retention time, accurate molecular weight, diagnostic fragmentation ions, and nuclear magnetic resonance spectroscopy. As a result, all nine known steviol glycosides, as well as other four steviol glycosides were fully purified. The result demonstrated that this procedure is an effective approach for the preparative separation and comprehensive characterization of steviol glycosides in Stevia. This 2D-RPLC/HILIC method will be a promising tool for the purification of low-abundance compounds from natural products.
Yanduo Tao - One of the best experts on this subject based on the ideXlab platform.
-
Preparative separation of isoquinoline alkaloids from Corydalis impatiens using middle chromatogram isolated gel column coupled with positively charged reversed‐phase Liquid Chromatography
Journal of Separation Science, 2020Co-Authors: Qi Wang, Wenjie Chen, Qilan Wang, Yanduo Tao, Guoqing Pan, Jun DangAbstract:Positively charged Reversed-Phase Liquid Chromatography was employed for the efficient preparative separation of isoquinoline alkaloids from Corydalis impatiens. Ten commercially available columns were compared for isoquinoline alkaloids analysis. While tailing, overloading, lower resolution, and buffer salts limited the application in purification of isoquinoline compounds of many of these columns, one positively charged Reversed-Phase C18 column (XCharge C18) overcame these drawbacks, allowing for favorable separation resolution, even when loading isoquinoline compounds on a larger, preparative scale. The general separation process is as follows. First, isoquinoline alkaloids are enriched with Corydalis impatiens extract via a middle chromatogram isolated gel column. After column selection, separation is performed on an XCharge C18 analytical column, from which two evident chromatographic peaks are readily obtained. Finally, two isoquinoline alkaloids (protopine and corydamine) are selectively purified on the XCharge C18 preparative column. These results demonstrate that a middle chromatogram isolated gel column coupled with positively charged Reversed-Phase Liquid Chromatography is effective for the preparative separation of isoquinoline alkaloids from Corydalis impatiens.
-
target separation of flavonoids from saxifraga tangutica using two dimensional hydrophilic interaction Chromatography reversed phase Liquid Chromatography
IEEE Journal of Solid-state Circuits, 2018Co-Authors: Jun Dang, Qilan Wang, Huilan Yue, Zenggen Liu, Yun Shao, Qingbo Gao, Li Zhang, Lijuan Mei, Yanduo TaoAbstract:An orthogonally (80.3%) preparative two-dimensional hydrophilic interaction Chromatography/Reversed-Phase Liquid Chromatography method has been established for the isolation and purification of flavonoids from Saxifraga tangutica. Initially, flavonoids were enriched by means of a middle-pressure chromatographic tower (containing middle chromatogram isolated gel). In the first dimension, a XION preparative column was used to separate the flavonoid fractions under the guidance of characteristic ultraviolet absorption spectra of flavonoids and nine flavonoid fractions were obtained. Then, the coeluted flavonoid fractions were selected for further purification via Reversed-Phase Liquid Chromatography with the parent ion peak of quercetin (303), kaempferol (287), or isorhamnetin (317). Several flavonoids could be separated from each hydrophilic interaction Chromatography fraction; furthermore, flavonoids with poor resolution in one-dimensional Liquid Chromatography were isolated in two-dimensional Liquid Chromatography due to the orthogonality. In addition, this technique was valuable for trace flavonoids, which were concentrated in the first stage and separated in the second stage. In total, 18 flavonoids with either quercetin, kaempferol, or isorhamnetin parent nuclei were targetedly obtained, and 15 flavonoids were obtained for the first time from S. tangutica. These results established that the off-line two-dimensional hydrophilic interaction Chromatography/Reversed-Phase Liquid Chromatography technique was efficient for the isolation of flavonoids from Saxifraga tangutica.
-
two dimensional hydrophilic interaction Chromatography reversed phase Liquid Chromatography for the preparative isolation of potential anti hepatitis phenylpropanoids from salvia prattii
IEEE Journal of Solid-state Circuits, 2016Co-Authors: Jun Dang, Qilan Wang, Yanduo Tao, Jianqiang Zhao, Yun Shao, Lijuan Mei, Li ZhangAbstract:Traditional Tibetan medicine is important for discovery of drug precursors. However, knowledge of the chemical composition of traditional Tibetan medicines is very limited due to the lack of appropriate chromatographic purification methods. In the present work, Salvia prattii was taken as an example, and an off-line hydrophilic interaction Liquid Chromatography/Reversed-Phase Liquid Chromatography preparative method was developed for the purification of phenylpropanoids with high purity from a crude sample of Salvia prattii. Based on the separation results of four different chromatographic stationary phases, the first-dimensional preparation was performed on an XAmide preparative column with the crude sample concentration of 62.0 mg/mL, and five main fractions were obtained from the 12.4 g crude sample with a recovery of 54.8%. An XCharge C18 preparative column was applied in the second-dimensional preparation to further isolate the phenylpropanoids from the redissolved first-dimensional fractions with concentration of approximately 50.0 mg/mL. The purities of the phenylpropanoids isolated from the crude sample of Salvia prattii were higher than 98%, indicating that the method was efficient for the purification of phenylpropanoids with high purity from Salvia prattii. Additionally, this method showed great potential in the preparation of phenylpropanoids and can serve as a good example for the purification of phenylpropanoids from other plant materials.
-
separation and characterization of bufadienolides in toad skin using two dimensional normal phase Liquid Chromatography reversed phase Liquid Chromatography coupled with mass spectrometry
Journal of Chromatography B, 2016Co-Authors: Yun Zhang, Yanduo Tao, Hongli Jin, Jianqiang Zhao, Yanfang Liu, Zhimou Guo, Xiuli Zhang, Xiujie Guo, Jixia Wang, Deliang ChenAbstract:Bufadienolides possess various bioactivities especially antitumor. Due to the high structural diversity, the separation of bufadienolides often suffers from coelution problem on conventional RP columns. In this work, an off-line two-dimensional normal-phase Liquid Chromatography×Reversed-Phase Liquid Chromatography (2D-NPLC×RPLC) method was developed to separate and characterize bufadienolides in toad skin. Several RP and NP columns were evaluated with five reference bufadienlides. The XUnion C18 and XAmide columns exhibited superior chromatographic performances for bufadienlide separation, and were selected in RPLC and NPLC, respectively. RPLC was used in the second-dimension for the good compatibility with MS, while NPLC was adopted in the first-dimension. The orthogonality of the 2D-NPLC×RPLC system was investigated by the geometric approach using fifteen bufadienolide mixtures. The result was 49.6%, demonstrating reasonable orthogonality of this 2D-LC system. By combining the 2D-LC system with MS, 64 bufadienlides including 33 minor ones and 11 pairs of isomers in toad skin were identified. This off-line 2D-NPLC×RPLC allowed to solve the coelution problem of bufadienlides in one-dimension RPLC, and thus facilitated the identification significantly.
-
isolation and identification of saponins from the natural pasturage asterothamnus centrali asiaticus employing preparative two dimensional reversed phase Liquid Chromatography hydrophilic interaction Chromatography
Journal of Agricultural and Food Chemistry, 2016Co-Authors: Yanming Wang, Yanduo Tao, Jianqiang Zhao, Lijuan Mei, Junli Yang, Yanping ShiAbstract:Asterothamnus centrali-asiaticus, a kind of characteristic shrub abundant in grassland and desert areas, has been used as forage fodder for camels and goats in Central Asia, and this plant also plays a critical role in the maintenance of desert grassland ecosystems as a result of its tolerance to poor soils and sand burial. However, its chemical composition has been rarely reported. In this study, phytochemical investigation of this pasturage was performed and three new triterpenoid saponins (1–3) were isolated together with nine known triterpenoid saponins (4–12) using preparative two-dimensional Reversed-Phase Liquid Chromatography/hydrophilic interaction Chromatography (2D RPLC/HILIC). Their structures were elucidated via diverse spectroscopic analyses, including infrared (IR) spectrometry, high-resolution electrospray ionization mass spectrometry (HR-ESIMS), and one-dimensional (1D) and 2D nuclear magnetic resonance (NMR). All isolated triterpenoid saponins (1–12) were reported from this genus for the...
Jun Dang - One of the best experts on this subject based on the ideXlab platform.
-
Preparative separation of isoquinoline alkaloids from Corydalis impatiens using middle chromatogram isolated gel column coupled with positively charged reversed‐phase Liquid Chromatography
Journal of Separation Science, 2020Co-Authors: Qi Wang, Wenjie Chen, Qilan Wang, Yanduo Tao, Guoqing Pan, Jun DangAbstract:Positively charged Reversed-Phase Liquid Chromatography was employed for the efficient preparative separation of isoquinoline alkaloids from Corydalis impatiens. Ten commercially available columns were compared for isoquinoline alkaloids analysis. While tailing, overloading, lower resolution, and buffer salts limited the application in purification of isoquinoline compounds of many of these columns, one positively charged Reversed-Phase C18 column (XCharge C18) overcame these drawbacks, allowing for favorable separation resolution, even when loading isoquinoline compounds on a larger, preparative scale. The general separation process is as follows. First, isoquinoline alkaloids are enriched with Corydalis impatiens extract via a middle chromatogram isolated gel column. After column selection, separation is performed on an XCharge C18 analytical column, from which two evident chromatographic peaks are readily obtained. Finally, two isoquinoline alkaloids (protopine and corydamine) are selectively purified on the XCharge C18 preparative column. These results demonstrate that a middle chromatogram isolated gel column coupled with positively charged Reversed-Phase Liquid Chromatography is effective for the preparative separation of isoquinoline alkaloids from Corydalis impatiens.
-
preparative separation of isoquinoline alkaloids from corydalis impatiens using middle chromatogram isolated gel column coupled with positively charged reversed phase Liquid Chromatography
IEEE Journal of Solid-state Circuits, 2020Co-Authors: Qi Wang, Ruitao Yu, Wenjie Chen, Qilan Wang, Jun DangAbstract:: Positively charged Reversed-Phase Liquid Chromatography was employed for the efficient preparative separation of isoquinoline alkaloids from Corydalis impatiens. Ten commercially available columns were compared for isoquinoline alkaloids analysis. While tailing, overloading, lower resolution, and buffer salts limited the application in purification of isoquinoline compounds of many of these columns, one positively charged Reversed-Phase C18 column (XCharge C18) overcame these drawbacks, allowing for favorable separation resolution, even when loading isoquinoline compounds on a larger, preparative scale. The general separation process is as follows. Firstly, isoquinoline alkaloids are enriched with Corydalis impatiens extract via a middle chromatogram isolated gel column. After column selection, separation is performed on an XCharge C18 analytical column, from which two evident chromatographic peaks are readily obtained. Finally, two isoquinoline alkaloids (protopine and corydamine) are selectively purified on the XCharge C18 preparative column. These results demonstrate that a middle chromatogram isolated gel column coupled with positively charged Reversed-Phase Liquid Chromatography is effective for the preparative separation of isoquinoline alkaloids from Corydalis impatiens. This article is protected by copyright. All rights reserved.
-
target separation of flavonoids from saxifraga tangutica using two dimensional hydrophilic interaction Chromatography reversed phase Liquid Chromatography
IEEE Journal of Solid-state Circuits, 2018Co-Authors: Jun Dang, Qilan Wang, Huilan Yue, Zenggen Liu, Yun Shao, Qingbo Gao, Li Zhang, Lijuan Mei, Yanduo TaoAbstract:An orthogonally (80.3%) preparative two-dimensional hydrophilic interaction Chromatography/Reversed-Phase Liquid Chromatography method has been established for the isolation and purification of flavonoids from Saxifraga tangutica. Initially, flavonoids were enriched by means of a middle-pressure chromatographic tower (containing middle chromatogram isolated gel). In the first dimension, a XION preparative column was used to separate the flavonoid fractions under the guidance of characteristic ultraviolet absorption spectra of flavonoids and nine flavonoid fractions were obtained. Then, the coeluted flavonoid fractions were selected for further purification via Reversed-Phase Liquid Chromatography with the parent ion peak of quercetin (303), kaempferol (287), or isorhamnetin (317). Several flavonoids could be separated from each hydrophilic interaction Chromatography fraction; furthermore, flavonoids with poor resolution in one-dimensional Liquid Chromatography were isolated in two-dimensional Liquid Chromatography due to the orthogonality. In addition, this technique was valuable for trace flavonoids, which were concentrated in the first stage and separated in the second stage. In total, 18 flavonoids with either quercetin, kaempferol, or isorhamnetin parent nuclei were targetedly obtained, and 15 flavonoids were obtained for the first time from S. tangutica. These results established that the off-line two-dimensional hydrophilic interaction Chromatography/Reversed-Phase Liquid Chromatography technique was efficient for the isolation of flavonoids from Saxifraga tangutica.
-
two dimensional hydrophilic interaction Chromatography reversed phase Liquid Chromatography for the preparative isolation of potential anti hepatitis phenylpropanoids from salvia prattii
IEEE Journal of Solid-state Circuits, 2016Co-Authors: Jun Dang, Qilan Wang, Yanduo Tao, Jianqiang Zhao, Yun Shao, Lijuan Mei, Li ZhangAbstract:Traditional Tibetan medicine is important for discovery of drug precursors. However, knowledge of the chemical composition of traditional Tibetan medicines is very limited due to the lack of appropriate chromatographic purification methods. In the present work, Salvia prattii was taken as an example, and an off-line hydrophilic interaction Liquid Chromatography/Reversed-Phase Liquid Chromatography preparative method was developed for the purification of phenylpropanoids with high purity from a crude sample of Salvia prattii. Based on the separation results of four different chromatographic stationary phases, the first-dimensional preparation was performed on an XAmide preparative column with the crude sample concentration of 62.0 mg/mL, and five main fractions were obtained from the 12.4 g crude sample with a recovery of 54.8%. An XCharge C18 preparative column was applied in the second-dimensional preparation to further isolate the phenylpropanoids from the redissolved first-dimensional fractions with concentration of approximately 50.0 mg/mL. The purities of the phenylpropanoids isolated from the crude sample of Salvia prattii were higher than 98%, indicating that the method was efficient for the purification of phenylpropanoids with high purity from Salvia prattii. Additionally, this method showed great potential in the preparation of phenylpropanoids and can serve as a good example for the purification of phenylpropanoids from other plant materials.
Qilan Wang - One of the best experts on this subject based on the ideXlab platform.
-
Preparative separation of isoquinoline alkaloids from Corydalis impatiens using middle chromatogram isolated gel column coupled with positively charged reversed‐phase Liquid Chromatography
Journal of Separation Science, 2020Co-Authors: Qi Wang, Wenjie Chen, Qilan Wang, Yanduo Tao, Guoqing Pan, Jun DangAbstract:Positively charged Reversed-Phase Liquid Chromatography was employed for the efficient preparative separation of isoquinoline alkaloids from Corydalis impatiens. Ten commercially available columns were compared for isoquinoline alkaloids analysis. While tailing, overloading, lower resolution, and buffer salts limited the application in purification of isoquinoline compounds of many of these columns, one positively charged Reversed-Phase C18 column (XCharge C18) overcame these drawbacks, allowing for favorable separation resolution, even when loading isoquinoline compounds on a larger, preparative scale. The general separation process is as follows. First, isoquinoline alkaloids are enriched with Corydalis impatiens extract via a middle chromatogram isolated gel column. After column selection, separation is performed on an XCharge C18 analytical column, from which two evident chromatographic peaks are readily obtained. Finally, two isoquinoline alkaloids (protopine and corydamine) are selectively purified on the XCharge C18 preparative column. These results demonstrate that a middle chromatogram isolated gel column coupled with positively charged Reversed-Phase Liquid Chromatography is effective for the preparative separation of isoquinoline alkaloids from Corydalis impatiens.
-
preparative separation of isoquinoline alkaloids from corydalis impatiens using middle chromatogram isolated gel column coupled with positively charged reversed phase Liquid Chromatography
IEEE Journal of Solid-state Circuits, 2020Co-Authors: Qi Wang, Ruitao Yu, Wenjie Chen, Qilan Wang, Jun DangAbstract:: Positively charged Reversed-Phase Liquid Chromatography was employed for the efficient preparative separation of isoquinoline alkaloids from Corydalis impatiens. Ten commercially available columns were compared for isoquinoline alkaloids analysis. While tailing, overloading, lower resolution, and buffer salts limited the application in purification of isoquinoline compounds of many of these columns, one positively charged Reversed-Phase C18 column (XCharge C18) overcame these drawbacks, allowing for favorable separation resolution, even when loading isoquinoline compounds on a larger, preparative scale. The general separation process is as follows. Firstly, isoquinoline alkaloids are enriched with Corydalis impatiens extract via a middle chromatogram isolated gel column. After column selection, separation is performed on an XCharge C18 analytical column, from which two evident chromatographic peaks are readily obtained. Finally, two isoquinoline alkaloids (protopine and corydamine) are selectively purified on the XCharge C18 preparative column. These results demonstrate that a middle chromatogram isolated gel column coupled with positively charged Reversed-Phase Liquid Chromatography is effective for the preparative separation of isoquinoline alkaloids from Corydalis impatiens. This article is protected by copyright. All rights reserved.
-
target separation of flavonoids from saxifraga tangutica using two dimensional hydrophilic interaction Chromatography reversed phase Liquid Chromatography
IEEE Journal of Solid-state Circuits, 2018Co-Authors: Jun Dang, Qilan Wang, Huilan Yue, Zenggen Liu, Yun Shao, Qingbo Gao, Li Zhang, Lijuan Mei, Yanduo TaoAbstract:An orthogonally (80.3%) preparative two-dimensional hydrophilic interaction Chromatography/Reversed-Phase Liquid Chromatography method has been established for the isolation and purification of flavonoids from Saxifraga tangutica. Initially, flavonoids were enriched by means of a middle-pressure chromatographic tower (containing middle chromatogram isolated gel). In the first dimension, a XION preparative column was used to separate the flavonoid fractions under the guidance of characteristic ultraviolet absorption spectra of flavonoids and nine flavonoid fractions were obtained. Then, the coeluted flavonoid fractions were selected for further purification via Reversed-Phase Liquid Chromatography with the parent ion peak of quercetin (303), kaempferol (287), or isorhamnetin (317). Several flavonoids could be separated from each hydrophilic interaction Chromatography fraction; furthermore, flavonoids with poor resolution in one-dimensional Liquid Chromatography were isolated in two-dimensional Liquid Chromatography due to the orthogonality. In addition, this technique was valuable for trace flavonoids, which were concentrated in the first stage and separated in the second stage. In total, 18 flavonoids with either quercetin, kaempferol, or isorhamnetin parent nuclei were targetedly obtained, and 15 flavonoids were obtained for the first time from S. tangutica. These results established that the off-line two-dimensional hydrophilic interaction Chromatography/Reversed-Phase Liquid Chromatography technique was efficient for the isolation of flavonoids from Saxifraga tangutica.
-
two dimensional hydrophilic interaction Chromatography reversed phase Liquid Chromatography for the preparative isolation of potential anti hepatitis phenylpropanoids from salvia prattii
IEEE Journal of Solid-state Circuits, 2016Co-Authors: Jun Dang, Qilan Wang, Yanduo Tao, Jianqiang Zhao, Yun Shao, Lijuan Mei, Li ZhangAbstract:Traditional Tibetan medicine is important for discovery of drug precursors. However, knowledge of the chemical composition of traditional Tibetan medicines is very limited due to the lack of appropriate chromatographic purification methods. In the present work, Salvia prattii was taken as an example, and an off-line hydrophilic interaction Liquid Chromatography/Reversed-Phase Liquid Chromatography preparative method was developed for the purification of phenylpropanoids with high purity from a crude sample of Salvia prattii. Based on the separation results of four different chromatographic stationary phases, the first-dimensional preparation was performed on an XAmide preparative column with the crude sample concentration of 62.0 mg/mL, and five main fractions were obtained from the 12.4 g crude sample with a recovery of 54.8%. An XCharge C18 preparative column was applied in the second-dimensional preparation to further isolate the phenylpropanoids from the redissolved first-dimensional fractions with concentration of approximately 50.0 mg/mL. The purities of the phenylpropanoids isolated from the crude sample of Salvia prattii were higher than 98%, indicating that the method was efficient for the purification of phenylpropanoids with high purity from Salvia prattii. Additionally, this method showed great potential in the preparation of phenylpropanoids and can serve as a good example for the purification of phenylpropanoids from other plant materials.
Zhimou Guo - One of the best experts on this subject based on the ideXlab platform.
-
separation and characterization of bufadienolides in toad skin using two dimensional normal phase Liquid Chromatography reversed phase Liquid Chromatography coupled with mass spectrometry
Journal of Chromatography B, 2016Co-Authors: Yun Zhang, Yanduo Tao, Hongli Jin, Jianqiang Zhao, Yanfang Liu, Zhimou Guo, Xiuli Zhang, Xiujie Guo, Jixia Wang, Deliang ChenAbstract:Bufadienolides possess various bioactivities especially antitumor. Due to the high structural diversity, the separation of bufadienolides often suffers from coelution problem on conventional RP columns. In this work, an off-line two-dimensional normal-phase Liquid Chromatography×Reversed-Phase Liquid Chromatography (2D-NPLC×RPLC) method was developed to separate and characterize bufadienolides in toad skin. Several RP and NP columns were evaluated with five reference bufadienlides. The XUnion C18 and XAmide columns exhibited superior chromatographic performances for bufadienlide separation, and were selected in RPLC and NPLC, respectively. RPLC was used in the second-dimension for the good compatibility with MS, while NPLC was adopted in the first-dimension. The orthogonality of the 2D-NPLC×RPLC system was investigated by the geometric approach using fifteen bufadienolide mixtures. The result was 49.6%, demonstrating reasonable orthogonality of this 2D-LC system. By combining the 2D-LC system with MS, 64 bufadienlides including 33 minor ones and 11 pairs of isomers in toad skin were identified. This off-line 2D-NPLC×RPLC allowed to solve the coelution problem of bufadienlides in one-dimension RPLC, and thus facilitated the identification significantly.
-
preparative separation of a challenging anthocyanin from lycium ruthenicum murr by two dimensional reversed phase Liquid Chromatography hydrophilic interaction Chromatography
RSC Advances, 2015Co-Authors: Hongli Jin, Jianqiang Zhao, Weijia Zhou, Aijin Shen, Fan Yang, Yanfang Liu, Zhimou Guo, Xiuli Zhang, Yanduo TaoAbstract:The preparative separation of anthocyanins by HPLC often suffers from insufficient separation selectivity. In this work, a two-dimensional Liquid (LC-LC) method was established to efficiently purify a challenging anthocyanin in Lycium ruthenicum Murray. Reversed phase Liquid Chromatography (RPLC) was used in the first-dimension preparation to fractionate the sample for its high separation efficiency. After the optimization of second-dimension methods, hydrophilic interaction Chromatography (HILIC) was applied to further isolate the anthocyanin for the good orthogonality to RPLC. To improve HILIC separation for anthocyanins, stationary phases and mobile phases were investigated systematically. A satisfactory result was obtained on a zwitterionic Click XIon column with 1% phosphoric acid as an acidic additive. Using the above method, the anthocyanin and three new alkaloids were isolated from L. ruthenicum for the first time. This RPLC/HILIC method solved the coelution problem of anthocyanin and basic non-anthocyanins in one-dimensional HPLC, benefiting from the significantly improved separation resolution.
-
purification of saponins from leaves of panax notoginseng using preparative two dimensional reversed phase Liquid Chromatography hydrophilic interaction Chromatography
Analytical and Bioanalytical Chemistry, 2013Co-Authors: Xiujie Guo, Zhimou Guo, Xiuli Zhang, Jiatao Feng, Yuansheng Xiao, Xinmiao LiangAbstract:Saponins are widely distributed in the plant kingdom and have been shown to be active components of many medicinal herbs. In this study, a two-dimensional purification method based on Reversed-Phase Liquid Chromatography coupled with hydrophilic interaction Liquid Chromatography was successfully applied to purify saponins from leaves of Panax notoginseng. Nine saponin reference standards were used to test the separation modes and columns. The standards could not be resolved using C18 columns owing to their limited polar selectivity. However, they were completely separated on a XAmide column in hydrophilic interaction Liquid Chromatography mode, including two pairs of standards that were coeluted on a C18 column. The elution order of the standards on the two columns was sufficiently different, with a correlation coefficient between retention times on the C18 and XAmide columns of 0.0126, indicating good column orthogonality. Therefore, the first-dimension preparation was performed on a C18 column, followed by a XAmide column that was used to separate the fractions in the second dimension. Fifty-four fractions were prepared in the first dimension, with 25 fractions rich in saponins. Eight saponins, including two pairs of isomeric saponins and one new saponin, were isolated and identified from three representative fractions. This procedure was shown to be an effective approach for the preparative isolation and purification of saponins from leaves of P. notoginseng. Moreover, this method could possibly be employed in the purification of low-content and novel active saponins from natural products.
-
comprehensive characterization of stevia rebaudiana using two dimensional reversed phase Liquid Chromatography hydrophilic interaction Liquid Chromatography
Journal of Separation Science, 2012Co-Authors: Zhimou Guo, Yanfang Liu, Xiuli Zhang, Xinmiao LiangAbstract:Abstract Two-dimensional Reversed-Phase Liquid Chromatography/hydrophilic interaction Liquid Chromatography (2D-RPLC/HILIC) system was successfully applied for comprehensive characterization of steviol glycosides from Stevia rebaudiana. The experiments were performed in offline mode using an XCharge C18 column in first dimension and an XAmide column in second dimension. In first dimension, preliminary separation of Stevia aqueous extract was accomplished and 30 fractions were collected. Then fractions 1-20 were selected for further purification and 13 compounds with high purity were obtained in second dimension. Comprehensive characterization of these compounds was completed by determination of their retention time, accurate molecular weight, diagnostic fragmentation ions, and nuclear magnetic resonance spectroscopy. As a result, all nine known steviol glycosides, as well as other four steviol glycosides were fully purified. The result demonstrated that this procedure is an effective approach for the preparative separation and comprehensive characterization of steviol glycosides in Stevia. This 2D-RPLC/HILIC method will be a promising tool for the purification of low-abundance compounds from natural products.
-
purification of active bufadienolides from toad skin by preparative reversed phase Liquid Chromatography coupled with hydrophilic interaction Chromatography
IEEE Journal of Solid-state Circuits, 2010Co-Authors: Yanfang Liu, Zhimou Guo, Xiuli Zhang, Jiatao Feng, Yuansheng Xiao, Jing Zhang, Xingya Xue, Jin Ding, Xinmiao LiangAbstract:An isolation method by Reversed-Phase Liquid Chromatography coupled with hydrophilic interaction Chromatography was successfully used to isolate and purify active bufadienolides from Bufo bufo gargarizans Cantor toad skin. In the first step, crude samples were run on an XTerra Prep C18 column. After screening for activity, two fractions were chosen for further purification. A Click beta-Cyclodextrin (Click-CD) column made in our laboratory was used for the second step. Seven compounds, including four stereoisomers, were obtained at high purity. The orthogonal isolation method described here was a powerful tool for isolating bufadienolides, including stereoisomers, from a natural product. This integrated method may be useful for the discovery of novel active compounds from natural products.
