There is a close relationship between the biological functions of lipids and their structures, and various isomers greatly increases the complexity of lipid structures. The C=C bond location and sn-position are two of...There is a close relationship between the biological functions of lipids and their structures, and various isomers greatly increases the complexity of lipid structures. The C=C bond location and sn-position are two of the essential attributes that determine the structures of unsaturated lipids. However, simultaneous identification of both attributes remains challenging. Here, we develop a visible-light-activated aziridination reaction system, which enables the dual-resolving of the C=C bond location and sn-position isomerism of in lipids when combines with liquid chromatography-mass spectrometry(LC-MS). Based on the derivatization of C=C bonds with Ph I=NTs, their location in lipids could be easily identified by tandem MS. Especially, the sn-position isomers of unsaturated phosphatidylcholine(PC) can be separated and quantified by LC-MS after the derivatization. By using the proposed method, the significant changes of the sn-position isomers ratios of PC in mouse brain ischemia were revealed. This study offers a powerful tool for deep lipid structural biology.展开更多
Hydrogen-bonded organic frameworks(HOFs)are a promising candidate for optical sensing,but the lack of effective design strategies poses significant challenges to the construction of HOFs for organic acid sensing.In th...Hydrogen-bonded organic frameworks(HOFs)are a promising candidate for optical sensing,but the lack of effective design strategies poses significant challenges to the construction of HOFs for organic acid sensing.In this work,the first HOF for organic acid sensing is reported by constructing a multiplepyridine carbazole-based dense HOF,namely HOF-FJU-206,from a tripyridine-carbazole molecular 3,6-bis(pyridin-4-yl)-9-(4-(pyridin-4-yl)phenyl)-9H-carbazole(CPPY)with carbazole center for luminescence,pyridyl sites for its responsive of hydrogen proton,and narrow channels in the dense framework for the diffusion of hydrogen protons.HOF-FJU-206 exhibits differential responsively fluorescence sensing and recovery properties to formic,acetic,and propionic acids with different molecular sizes and p Kavalue(acid dissociation constant).The dissociation degree of various acids can be determined by analyzing the slope of changes in both peak wavelength and intensity of in-situ fluorescence,which easily enables the dual-corrective recognition of different acids.The varying degree of protonation at pyridine sites is proved to be the reason for differential sensing of various acids,as demonstrated by1H NMR spectra,X-ray photoelectron spectroscopy(XPS)characterization,and modeling studies.展开更多
应用正、反相硅胶和葡聚糖凝胶柱色谱等技术对藜(Chenopodium album L.)的黄酮类化学成分进行了分离和纯化.从藜中分离得到2种黄酮类化合物,分别为异鼠李素3-O-芸香糖苷(1)、槲皮素3-O-β-D-呋喃芹糖(1→2)-O-[α-L-鼠李糖(1→6)]-β-D...应用正、反相硅胶和葡聚糖凝胶柱色谱等技术对藜(Chenopodium album L.)的黄酮类化学成分进行了分离和纯化.从藜中分离得到2种黄酮类化合物,分别为异鼠李素3-O-芸香糖苷(1)、槲皮素3-O-β-D-呋喃芹糖(1→2)-O-[α-L-鼠李糖(1→6)]-β-D-葡萄糖苷(2).采用纸片扩散法进行了抑菌试验.结果表明,黎的95%(体积分数)乙醇提取液对大肠埃希菌有明显的抑菌效果,最低抑菌浓度(MIC)为32mg/L.展开更多
On the basis of density functional theory and electronegativity equalization princi-ple, a new scheme has been developed for determination of atomic charges and bond charges in large molecules. In the new scheme, the ...On the basis of density functional theory and electronegativity equalization princi-ple, a new scheme has been developed for determination of atomic charges and bond charges in large molecules. In the new scheme, the molecular electron density ρmol(r) is partitioned as where ρα(r) and ρα-β(r) are the electron densities located on the atom α and bond α-β, respectively. The parameters A, B, C and D are the valence-state electronegativity and valence-state hardness. They are obtained by calibrating through model molecule calculations and are transferable and consistently usable for calculating the charge distributions in large molecules. The new scheme is tested through determination of atomic charges and bond charges in several large molecules. It has been shown that the re-sults of atomic charges and bond charges obtained by the new scheme dovetail those obtained by ab initio method very well. In addition, the new scheme presented here has the advantage of simplicity, rapidness and easy perform as well, so that it provides an efficient and practi-cal method for calculation of the charge distribution for a macromolecular system.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos.22074111, 22004093 and 22004092)the National Key Research and Development Program of China (No.2021YFC2700700)the support of the start-up funds of Wuhan University and the National Youth Talents Plan of China。
文摘There is a close relationship between the biological functions of lipids and their structures, and various isomers greatly increases the complexity of lipid structures. The C=C bond location and sn-position are two of the essential attributes that determine the structures of unsaturated lipids. However, simultaneous identification of both attributes remains challenging. Here, we develop a visible-light-activated aziridination reaction system, which enables the dual-resolving of the C=C bond location and sn-position isomerism of in lipids when combines with liquid chromatography-mass spectrometry(LC-MS). Based on the derivatization of C=C bonds with Ph I=NTs, their location in lipids could be easily identified by tandem MS. Especially, the sn-position isomers of unsaturated phosphatidylcholine(PC) can be separated and quantified by LC-MS after the derivatization. By using the proposed method, the significant changes of the sn-position isomers ratios of PC in mouse brain ischemia were revealed. This study offers a powerful tool for deep lipid structural biology.
基金supported by the National Natural Science Foundation of China(Nos.22271046,21971038,21975044)the Fujian Provincial Department of Science and Technology(No.2019L3004)the Foundation of National Key Laboratory of Human Factors Engineering(No.HFNKL2023W04)。
文摘Hydrogen-bonded organic frameworks(HOFs)are a promising candidate for optical sensing,but the lack of effective design strategies poses significant challenges to the construction of HOFs for organic acid sensing.In this work,the first HOF for organic acid sensing is reported by constructing a multiplepyridine carbazole-based dense HOF,namely HOF-FJU-206,from a tripyridine-carbazole molecular 3,6-bis(pyridin-4-yl)-9-(4-(pyridin-4-yl)phenyl)-9H-carbazole(CPPY)with carbazole center for luminescence,pyridyl sites for its responsive of hydrogen proton,and narrow channels in the dense framework for the diffusion of hydrogen protons.HOF-FJU-206 exhibits differential responsively fluorescence sensing and recovery properties to formic,acetic,and propionic acids with different molecular sizes and p Kavalue(acid dissociation constant).The dissociation degree of various acids can be determined by analyzing the slope of changes in both peak wavelength and intensity of in-situ fluorescence,which easily enables the dual-corrective recognition of different acids.The varying degree of protonation at pyridine sites is proved to be the reason for differential sensing of various acids,as demonstrated by1H NMR spectra,X-ray photoelectron spectroscopy(XPS)characterization,and modeling studies.
文摘应用正、反相硅胶和葡聚糖凝胶柱色谱等技术对藜(Chenopodium album L.)的黄酮类化学成分进行了分离和纯化.从藜中分离得到2种黄酮类化合物,分别为异鼠李素3-O-芸香糖苷(1)、槲皮素3-O-β-D-呋喃芹糖(1→2)-O-[α-L-鼠李糖(1→6)]-β-D-葡萄糖苷(2).采用纸片扩散法进行了抑菌试验.结果表明,黎的95%(体积分数)乙醇提取液对大肠埃希菌有明显的抑菌效果,最低抑菌浓度(MIC)为32mg/L.
文摘On the basis of density functional theory and electronegativity equalization princi-ple, a new scheme has been developed for determination of atomic charges and bond charges in large molecules. In the new scheme, the molecular electron density ρmol(r) is partitioned as where ρα(r) and ρα-β(r) are the electron densities located on the atom α and bond α-β, respectively. The parameters A, B, C and D are the valence-state electronegativity and valence-state hardness. They are obtained by calibrating through model molecule calculations and are transferable and consistently usable for calculating the charge distributions in large molecules. The new scheme is tested through determination of atomic charges and bond charges in several large molecules. It has been shown that the re-sults of atomic charges and bond charges obtained by the new scheme dovetail those obtained by ab initio method very well. In addition, the new scheme presented here has the advantage of simplicity, rapidness and easy perform as well, so that it provides an efficient and practi-cal method for calculation of the charge distribution for a macromolecular system.
