ANALYTICAL AND BIOANALYTICAL CHEMISTRY
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2012
·Vol. 404
·期 5
·1477-1484
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IF 3.778
Zhang Lei,Dai Xiaojun,Xu Fei,Wang Fuqiang,Gong Bolin,Wei Yinmao
A novel imidazole-functionalized stationary phase for hydrophilic interaction chromatography (HILIC) was prepared via surface-initiated atom transfer radical polymerization (SI-ATRP). 1-Vinylimidazole as a monomer was polymerized on the surface of initiator-immobilized silica by SI-ATRP using CuCl and 2,2′-bipyridyl as a catalyst. The graft chain length and polymer grafting density were controlled by varying the ratio of monomer to initiator. The resulting materials were characterized by elemental analysis and thermogravimetric analysis. Then, high-performance liquid chromatography separation of eight nucleobases/nucleosides was performed on the imidazole-functionalized chromatographic column in HILIC mode. The effects of mobile phase composition, buffer pH, and column temperature on the separation of nucleobases/nucleosides were investigated, and the retention mechanisms were studied. Chromatographic parameters were calculated, and the results showed that surface adsorption through hydrogen bonding and electrostatic interaction dominated the retention behavior of the solutes in HILIC mode. Lastly, the stationary phase was successfully used to determine the nucleobases and nucleosides from Cordyceps militaris .
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JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
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2011
·
IF 2.733
Shu Liu,Jun Yan,Junpeng Xing,Fengrui Song,Zhiqiang Liu,Shuying Liu
The liquid chromatography–tandem mass spectrometry (LC–MS/MS) methods were used to identify the pharmacologically active n-butanol extract from Compound Indigowoad Root Granule . As a result, eighteen compounds belonging to various structural classes such as nucleosides, purines, flavonoids and amino acid were unambiguously identified. Then an in vitro neuraminidase (NA) inhibition assay was carried out to examine the inhibitory activity of the standard samples and extracts on NA. After which, ultrafiltration liquid chromatography with photodiode array detection coupled to electrospray ionization tandem mass spectrometry (ultrafiltration LC–MS/MS) was used to study NA inhibitory activity of standard flavones and n-butanol extract of Compound Indigowoad Root Granule. This method is highly selective and sensitive, and it could be used for characterization of bioactive compounds and botanical extracts. The result provides some enlightenment for the explanation of the antiviral activity of Compound Indigowoad Root Granule and some guidance for natural anti-influenza medicine development.
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CHROMATOGRAPHIA
·
2011
·Vol. 73
·期 9
·865-870
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IF 1.075
Dai Xiaojun,Qian Xiaolei,Gong Bolin,Wei Yinmao
In this work, tetrazole-functionalized stationary phase was prepared with nitrile-modified silica by an ammonium-catalyzed (3 + 2) azide-nitrile cycloaddition reaction. The prepared stationary phase was used for separation of nucleobases and nucleosides by hydrophilic interaction chromatography (HILIC) mode. A typical HILIC mechanism was observed at higher content of acetonitrile (>85%, v / v ) in the mobile phase. The retention mechanism of the column was investigated by the models used for describing partitioning and surface adsorption through adjustment ratio of water in the mobile phase, and by the influence of salt concentration, buffer pH, and temperature on the retention of solutes. The results illustrated that the surface adsorption through hydrogen bonding dominated the retention behavior of nucleobases/nucleosides under HILIC mode. From the separation ability, the tetrazole-functionalized stationary phase could become a valuable alternative for the separation of the compounds concerned.
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JOURNAL OF SEPARATION SCIENCE
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2011
·Vol. 34
·期 22
·3115-3122
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IF 2.631
Xiaojun Dai,Yuan He,Yinmao Wei,Bolin Gong
A one-step procedure based on surface-initiated atom transfer radical polymerization (SI-ATRP) to hydrophilize monodisperse poly(chloromethylstyrene-co-divinylbenzene) beads has been presented in this work, using 2-hydroxyl-3-[4-(hydroxymethyl)-1 H -1,2,3-triazol-1-yl]propyl 2-methylacrylate (HTMA) as a monomer. The chain length of the grafted poly(HTMA) was controlled via varying the ratio of HTMA to initiator on the surface of the beads. When using the grafted beads as a stationary phase in hydrophilic interaction chromatography (HILIC), good resolution for nucleobases/nucleosides was obtained with acetonitrile aqueous solution as an eluent; while for phenolic acids and glycosides, they could be eluted and separated in the presence of TFA. The retention time of the solutes increased with the amount of the grafted HTMA. The retention mechanisms of solutes were investigated by the effects of mobile phase composition and buffer pH on the retention of solutes. The results illustrated that the retention behaviors of the tested solutes were dominated by hydrogen bonding interaction and electrostatic interaction. From the chemical structure of the ligands, the modified beads could not only be used as a stationary phase in HILIC, but also act as a useful building block to develop new stationary phases for other chromatographic modes such as affinity media.
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JOURNAL OF CHROMATOGRAPHY A
·
2024
·
IF 3.8
Yali Yang,Jia Chen,Xiaojing Liang,Bei Liu,Kaijun Quan,Xiuhui Liu,Hongdeng Qiu
In this paper, three imidazole- and C18- bifunctional silica stationary phases (Sil-Im-C18) were prepared by adjusting introduction interval of octadecyltrichlorosilane (ODS) and 3-imidazol-1-ylpropyl(trimethoxy)silane (TMPImS), which can be used for reversed-phase liquid chromatography (RPLC) and ion exchange chromatography (IEC) with adjustable performance. The successful preparation of Sil-Im-C18 were confirmed by the characterizations of elemental analysis, infrared spectroscopy (FTIR) and contact angle (CA). Chromatographic performance of Sil-Im-C18 were evaluated by the separation of Tanaka test mixture, alkylbenzenes, linear PAHs and a set of analytes with different properties (uracil, phenol, 1,2-dinitrobenzene and naphthalene), and compared with commonly used C18 column. It was found that the chromatographic performance of Sil-Im-C18 changed significantly with the difference in bonding amount of imidazole and C18. Sil-Im-C18 demonstrated the excellent separation performance towards polycyclic aromatic hydrocarbons (PAHs), phenylesters, phenylamines , phenols and inorganic anions, and notably, nucleobases and nucleosides can be separated using pure water as mobile phases . The van Deemter plot showed that the column efficiency of Sil-Im-C18-3 was 64,933 plate· m − 1 for naphthalene, indicated that Sil-Im-C18 was reasonably chromatographic columns. The RSD values of retention time were 0.22 %-0.61 % for 10 needles alkylbenzenes injected continuously at 50 °C to investigate thermal stability and repeatability, all the fluctuations of k of naphthalene were less than 2.3 % for Sil-Im-C18-1 during flushing 24 h with the mobile phase at different pH values (pH = 3 and 8), the retention time of alkylbenzenes were almost same for Sil-Im-C18-1 at different time, the RSD values of retention time of alkylbenzenes were 0.45 %-2.28 % for two batches Sil-Im-C18-1, revealing the excellent repeatability, thermal stability, durability and reproducibility of Sil-Im-C18, and implying a commercial prospect.
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JOURNAL OF CHROMATOGRAPHY A
·
2011
·
IF 4.194
Hongyue Guo,Renhua Liu,Jinjin Yang,Bingcheng Yang,Xinmiao Liang,Changhu Chu
A novel type of zwitterionic HILIC stationary phase was prepared by covalently bonding the l -azido lysine on silica gel via click chemistry. The key intermediate azido lysine was synthesized by transformation the amino group in l -Boc-lysine to corresponding azido group and subsequent removal of the N-protected group (Boc). Finally, the azido lysine was covalently bonded to silica beads by click chemistry to get click lysine. Its structure was confirmed by FT-IR and elemental analysis. The new stationary phase showed good HILIC characteristics, when it was applied to separate polar and hydrophilic compounds, such as organic acids, cephalosporins and carbapenems. Compared with the commercial stationary phases, such as Atlantics HILIC and ZIC-HILIC, click lysine displayed better or similar chromatographic behaviors.
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SENSORS AND ACTUATORS B-CHEMICAL
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2017
·
IF 5.401
Haiyan Liu,Yunfeng Bai,Jun Qin,Haiyan Wang,Yuzhen Wang,Zezhong Chen,Feng Feng
A novel sensitive fluorescence method was developed for adenosine detection by using adenosine aptamer, Exo I and a 2-aminopurine-modified DNA (2-AP probe). 2-AP probe was completely complementary to adenosine aptamer. This strategy took advantage of the high binding affinity of adenosine aptamer and the susceptibility of 2-aminopurine (2-AP) to the local base stacking environment. In the absence of the adenosine, the formation of double-stranded DNA (dsDNA) through the hybridization of the aptamer with the 2-AP probe prevented the digestion of 2-AP probe by Exo I. The fluorescence of 2-AP was significantly quenched due to the base-stacking interaction. In the presence of adenosine, the binding of adenosine with the aptamer prevented the hybridization between aptamer and 2-AP probe, leading to the digestion of 2-AP probe by Exo I and the release of 2-AP. The fluorescence was recovered. A limit of detection of 0.30 μM and a linear range from 10 μM to 600 μM ( R 2 = 0.9933) were achieved by this assay. Moreover, adenosine analogs did not produce any significant change in the fluorescence intensity response, indicating good selectivity of this sensor for adenosine detection. Finally, it was used for the diluted serum sample.
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TALANTA
·
2017
·
IF 4.162
Pingxiu Tang,Zilin Chen
Hypercrosslinked polymers (HCPs) are currently receiving great attention due to their unique characteristics and potential uses in diverse areas. However, the field of HCPs for open-tubular capillary electrochromatography (OT-CEC) separations has not been explored. Here, a knitted aromatic polymer (KAP) was in-situ grown on the inner wall of the capillary column for OT-CEC for the first time. The silylating reagent containing phenyl was served as monomer , immobilized on the inner wall of the capillary column, and then KAPs-modified capillary column was prepared through in-situ hypercrosslinking reaction. The surface structure and morphology of KAPs-modified capillary column was characterized by Fourier transform infrared spectra (FT-IR) and scanning electron microscopy (SEM). The prepared capillary columns showed good separation performance for neutral compounds, small biomolecules, such as nucleosides , amino acids , small peptides, and non-steroidal anti-inflammatory drugs, sulfa drugs. In addition, the KAPs-modified capillaries showed good reproducibility, with relative standard deviations for intra-day, inter-day and column-to-column runs less than 1.59%, 2.55%, and 5.19% respectively. The strategy of in-situ immobilization of KAPs provides a new approach for the application of the material in the analytical fields.
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Science China-Chemistry
·
2025
·
IF 9.7
Chen Qianqian,Xu Haoxing,Zhao Bingyue,Patehebieke Yeersen,Zhao Zerun,Wang Xiao
The selective nucleoside synthesis through direct condensation between nucleobase and unactivated sugar in aqueous media has long been a formidable obstacle for the early chemical transformations hypothesized to construct the RNA World, due to product complexity and the low selectivity of the desired isomer. The preference of β-furanoside, the extant RNA component, has never been documented. Here we report an aqueous ribosylation mediated by divalent transition-metal ions, which unprecedentedly enhances the selectivity of furanosyl ribonucleosides as opposed to the traditionally predominating pyranosyl ones, with the furanoside/pyranoside ratio reaching up to 9/1. Furthermore, β-furanoside stands out for the first time as the most prevalent isomer in the presence of zinc and ammonium salts. The mechanism of this selectivity is elucidated with density functional theory calculations. The selectivity for β-furanoside can be further elevated via the adsorption on a zinc mineral. These findings exhibit as the first example that the selection of nucleosides with the desired, canonical configuration might be completed in the early stage of the RNA-forming process as opposed to later evolution, promoted by simple and widespread transition-metal minerals. The study may also find its value in synthetic chemistry as a guideline for developing a sustainable and selective glycosylation process.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2024
·
IF 5.7
Yan He,Zihao Cheng,Jingyu Zhang,Yu Chen,Guode Zhao,Hong Tang,Yufen Liao,Tingmin Ye,Ying Peng,Weiwei Li,Jiang Zheng
Myristicin (MYR) mainly occurs in nutmeg and belongs to alkoxy-substituted allylbenzenes, a class of potentially toxic natural chemicals. RNA interaction with MYR metabolites in vitro and in vivo has been investigated in order to gain a better understanding of MYR toxicities. We detected two guanosine adducts (GA1 and GA2), two adenosine adducts (AA1 and AA2), and two cytosine adducts (CA1 and CA2) by LC-MS/MS analysis of total RNA extracts from cultured primary mouse hepatocytes and liver tissues of mice after exposure to MYR. An order of nucleoside adductions was found to be GAs > AAs > CAs, and the result of density functional theory calculations was in agreement with that detected by the LC-MS/MS-based approach. In vitro and in vivo studies have shown that MYR was oxidized by cytochrome P450 enzymes to 1′-hydroxyl and 3′-hydroxyl metabolites, which were then sulfated by sulfotransferases (SULTs) to form sulfate esters. The resulting sulfates would react with the nucleosides by SN1 and/or SN2 reactions, resulting in RNA adduction. The modification may alter the biochemical properties of RNA and disrupt RNA functions, perhaps partially contributing to the toxicities of MYR.
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TALANTA
·
2024
·
IF 5.6
Xiaoning Liang,Chaoman He,Hong Shen
Neutrophils play a pivotal role in innate immunity by releasing ROS through respiratory bursts to neutralize various pathogenic factors. However, excessive ROS release can cause tissue damage. Adenosine is an endogenous anti-inflammatory molecule inhibiting respiratory burst to protect the host. Adenosine aptamers with antibody-like properties and good stability are expected to act as adenosine antagonists with functional modulation capability. This study compares the effects of adenosine and its aptamer on the respiratory bursts of salivary polymorphonuclear leukocytes and circulating polymorphonuclear leukocytes using a programmable stopped-flow injection approach, ensuring rapid and efficient analysis while maintaining the neutrophils’ viability. The results show that primed salivary polymorphonuclear leukocytes exhibit specificities that differ from circulating polymorphonuclear leukocytes. Adenosine aptamer can function as an inhibitory antagonist that distinguishes between physiologically controlled and excessive priming of neutrophils, showing potential application prospects in immunotherapy.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Song Shu,Yaling Chen,Hongyu Xiang,Yinghao Chu
The electrochemical reduction of nitrate (NO3–, NO3RR) and nitrite (NO2–, NO2RR) enables sustainable, carbon-neutral, and decentralized routes to produce ammonia (NH3). Copper-based materials are promising electrocatalysts for NO3– conversion; however, their performance in selective conversion to NH3 is still poor. Herein, we present a Cu–Co tandem catalyst inspired by the conversion of NO3–-to-NH3 in nature, which can easily remove NO2– via the collaboration of two active centers. A mechanistic study has elucidated the tandem catalytic process, where direct electron transfer coupled with H+ bonding plays a dominant role in the NO3–-to-NO2– conversion at the Cu site, followed by the further reduction of NO2– to NH3 at the Co site. The Cu3Co1-NC electrode delivers a NO3– removal efficiency of 80% at −0.58 V vs reversible hydrogen electrode, with a NH3 yield rate of 490 μg·h–1·cm–2 and an FE of 77%. More importantly, the as-prepared Cu3Co1-NC electrode maintains comparable activity and stability for complex NO3RR systems with coexisting substrates, which is promising for sustainable ammonia synthesis and its application.
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