JOURNAL OF MOLECULAR LIQUIDS
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2024
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IF 5.3
Chuxin Qi,Lifang Chen,Zhiwen Qi
The heterogeneous liquid–liquid O-glycosidation is a crucial step in pharmaceutical synthesis. Herein, a theoretical methodology based on COSMO-RS, quantum chemical calculations combined with Transformer-CNN model was used to screen ionic liquids (ILs) as phase transfer catalysts (PTCs) to intensify O-glycosidation between 4-nitrophenol and 2,3,4,6-tetra-O-acetyl-α-D-galactopyranosyl bromide. The anions of ILs were screened by the evaluation of ILs hydrophilicity via infinite dilution selectivity of ILs and the molecular descriptor HB_acc3 of the anion using COSMO-RS, a predictive model for thermodynamic properties. Additionally, the binding energy between the phenoxide anion and IL cation was used to assess reaction extent in the aqueous phase through quantum chemical calculation. The cations of ILs were evaluated by the infinite dilution selectivity of the combination between phenoxide anion and IL cations, and physical properties including viscosity and melting point were also predicted using an advanced Transformer-CNN model. The screened IL 1-octyl-3-methylimidazolium acetate and 1-hexyl-3-methylimidazolium acetate were demonstrated its superior catalytic activity for the aromatic O-glycosidation of not only 4-nitrophenol, but also various phenols and thiophenols. Moreover, the presence of PTCs enhances the likelihood of the reactant migrating into another phase. This behavior is validated by COSMO-RS calculated liquid–liquid equilibrium (LLE) and interaction energy analysis. The method provides great potential for screening and designing ILs as phase transfer catalysts for heterogeneous liquid–liquid reactions.
研究领域:
有机化学
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药物合成
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计算化学
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产品关联
DOI
高影响因子
Foods
·
2022
·Vol. 11
·期 6
·882
·
IF 5.561
Liangqin Xie,Zeyuan Deng,Jie Zhang,Huanhuan Dong,Wei Wang,Banghuai Xing,Xiaoru Liu
Flavonoids are well known for their extensive health benefits. However, few studies compared the differences between flavonoid O-glycoside and C-glycoside. In this work, flavonoid O-glycoside (isoquercitrin), C-glycoside (orientin), and their aglycones (quercetin and luteolin) were chosen to compare their differences on antioxidant activities and metabolism during in vitro digestion and in vivo. In vitro digestion, the initial antioxidant activity of the two aglycones was very high; however, they both decreased more sharply than their glycosides in the intestinal phase. The glycosidic bond of flavonoid O-glycoside was broken in the gastric and intestinal stage, while the C-glycoside remained unchanged. In vivo, flavonoid O-glycoside in plasma was more elevated than C-glycoside on the antioxidant activity; however, flavonoid C-glycoside in urine was higher than O-glycoside. These results indicate that differences of flavonoid glycosides and their aglycones on antioxidant activity are closely related to their structural characteristics and metabolism in different samples. Aglycones possessed higher activity but unstable structures. On the contrary, the sugar substituents reduced the activity of flavonoids while improving their stability and helping to maintain antioxidant activities after digestion. Especially the C-glycoside was more stable because the stability of the C–C bond is higher than that of the C–O bond, which contributes to the difference between flavonoid O-glycoside and C-glycoside on the absorption and metabolism in vivo. This study provided a new perspective for comparing flavonoid O-glycoside, flavonoid C-glycoside, and their aglycones on their structure–activity relationship and metabolism.Keywords:flavonoid;O-glycoside;C-glycoside;aglycones;in vitro digestion;antioxidant activity
研究领域:
营养学
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药理学
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生物化学
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产品关联
DOI
PubMed
高影响因子
Journal of Food Measurement and Characterization
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2021
·Vol. 15
·期 5
·3873-3883
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IF 2.431
Qian Zheng-ming,Huang Qi,Feng Xiao-long,Li De-qiang
Given the safety of synthetic antioxidants, people are increasingly inclined to develop and use natural antioxidants. However, rapid screening and identification of active ingredients from the complex systems of natural products is one of the major challenges for the modernization of traditional Chinese medicine. In this study, online extraction-high performance liquid chromatography-diode array detection-quadrupole time-of-flight mass spectrometry coupled with ABTS antioxidant assay (OLE-HPLC-DAD-QTOF-MS/MS-ABTS), in which sample preparation, separation, detection and antioxidant assay were integrated in a single step, was used to rapidly identify antioxidant components from the different parts of Citrus reticulata , including its peels, leaves, vascular bundies and seeds. After method validation (system adaptability, extraction yield and repeatability), the four samples of different botanical parts were analyzed. As a result, among 49 found chromatographic peaks, 33 peaks displayed varying degrees of antioxidant activity and 39 peaks were tentatively or unambiguously identified based on their retention time, UV spectrum and mass spectrometry information and the comparison with reference substance and data in literature, including 10 phenolic acids, 9 polymethoxy flavonoids, 7 flavonoid- O -glycosides and 13 other ingredients. It is concluded that the established method is simple, fast, and reliable, which not only saves the materials and solvents as well as time, but also reduces the risk of degradation of chemical components during the extraction process, suitable for rapid screening and identification of antioxidant components of complex mixture.
研究领域:
生药学
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分析化学
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天然产物
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中药学
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产品关联
DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
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2019
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IF 3.579
Xinfeng Zhang,Sijie Zhang,Beibei Gao,Zheng Qian,Jingjing Liu,Shihua Wu,Jinping Si
Recently, the flowers of Dendrobium catenatum ( D. officinale ) have been approved as new food ingredient. This study aimed to investigate the herb-markers and their antioxidant activities in methanolic extracts of D. catenatum flowers, and to establish the quality evaluation methods for raw materials and their products of flower by HPLC. The methanolic extract of 11 strains of D. catenatum flowers were found to contain a high content of total phenol and flavonoids, and they possessed potential antioxidant capacities based on DPPH radical scavenging assay. A total of 21 phenolic herb-markers were selected according to the similarity and principal component analysis of the chromatographic fingerprinting profiles. Their structures were further elucidated by UV, HPLC-DAD-ESI-QTOF-MS/MS and NMR analyses. The identified compounds included 2 phenylpropanoids, 11 C -glycosylflavones and 6 O -glycosylflavones, which could be employed as the indicators for quantitative evaluation of the quality and authenticity of the flowers. Based on the pre-column DPPH/ABTS + -HPLC analysis, the major compounds contributed to the antioxidative activity were identified as 1- O -caffeoyl- β -D-glucoside, rutin and isoquercitrin, all of which, were also the most abundant constituents in the methanolic extract. The results suggest the potential of D. catenatum flowers as a new antioxidant resources for medicinal and food products.
研究领域:
生药学
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分析化学
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食品科学
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药学
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植物学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2023
·
IF 6.1
Yujia Ou,Lijingting Xu,Mingrong Chen,Xiaodan Lu,Zebin Guo,Baodong Zheng
A novel antidiabetic glycoprotein (PG) was isolated and purified from Porphyra haitanensis, and its structure and inhibiting activity on α-amylase and α-glucosidase were analyzed. The purity of the PG was 95.29 ± 0.21%, and its molecular weight was 163.024 ± 5.55 kDa. The PG had a tetramer structure with α- and β-subunits, and it contained 54.12 ± 0.86% protein (with highly hydrophobic amino acids) and 41.19% ± 0.64% carbohydrate (composed of galactose). The PG was linked via an O-glycosidic bond, exhibiting an α-helical structure and high stability. In addition, the PG inhibited the activities of α-amylase and α-glucosidase, by changing the enzyme’s structure toward the PG’s structure in a noncompetitive inhibition mode. Molecular docking results showed that the PG inhibited α-amylase activity by hydrophobic interaction, whereas it inhibited α-glucosidase activity by hydrogen bonds and hydrophobic interaction. Overall, the PG was linked to polysaccharides via O-glycosidic bonds, showing an α-helical configuration and a hydrophobic effect, which altered the configuration of α-amylase and α-glucosidase and exerted hypoglycemic activity. This study provides insights into analyzing the structure and antidiabetic activity of glycoproteins.
研究领域:
生物化学
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药理学
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分子生物学
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海洋生物学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）