Hydroxylated Tung oil (HTO) based nonionic polyurethane dispersion (HTO-NPUD) were synthesized using dicyclohexyl methane diisocyanate (HMDI) and HTO as main hydrophobic materials whereas polyethylene glycol-800 (PEG-...Hydroxylated Tung oil (HTO) based nonionic polyurethane dispersion (HTO-NPUD) were synthesized using dicyclohexyl methane diisocyanate (HMDI) and HTO as main hydrophobic materials whereas polyethylene glycol-800 (PEG-800) as hydrophilic chain extender. To effectively study the effects of HTO on properties of NPUD, polypropylene glycol-400(PPG-400) based NPUD was prepared by HMDI reacting with PPG-400 and PEG-800. The structures of those novel nonionic polyurethane dispersions were characterized by FTIR and 1H NMR. Moreover, particle size and size distribution, cloud point and surface tension had been investigated. Results showed that, by comparing with PPG based NPUD (PPG-NPUD), the introduction of HTO into NPUD result in larger particle size and more uniformed particle size distribution, higher cloud point and lower surface tension.展开更多
Hydroxylated Polychlorinated Biphenyls （HO-PCBs） are the metabolite of polychlorinated biphenyls and have drawn much attention because they have hazard on human health and ecosystems. Molecular connectivity index ca...Hydroxylated Polychlorinated Biphenyls （HO-PCBs） are the metabolite of polychlorinated biphenyls and have drawn much attention because they have hazard on human health and ecosystems. Molecular connectivity index calculation has been performed for 19 HO-PCB compounds. A number of statistically based parameters have been extracted. Linear relationship between chromatographic retention index （RI） and the molecular connectivity index of 15 compounds in the training set has been established by multiple linear regression method. The other 4 HO-PCBs are used as the external test set. The result shows that the parameters can be well used to express the quantitative structure-retention relationship （QSRR） of HO-PCBs. Good stability and predictive ability have been demonstrated by leave-one-out cross-validation and the external test set.展开更多
向多壁碳纳米管引入羟基基团,改善了其在制冷剂R141b中的分散性和稳定性。同时研究了不同质量分数纳米流体热导率、表面颗粒沉积、接触角变化对核沸腾传热性能的影响。结果表明:羟基化碳纳米流体强化沸腾传热,强化率随质量分数的增加而...向多壁碳纳米管引入羟基基团,改善了其在制冷剂R141b中的分散性和稳定性。同时研究了不同质量分数纳米流体热导率、表面颗粒沉积、接触角变化对核沸腾传热性能的影响。结果表明:羟基化碳纳米流体强化沸腾传热,强化率随质量分数的增加而增加,沸腾后期有所下降。在测试浓度范围内,质量分数为0.05%,热通量为87.4 k W·m-2时,强化率达到最大168%。流体的热导率随着质量分数的增加而增大,质量分数为0.10%时其热导率是纯R141b的1.18倍。分析认为:纳米流体热导率的增加、表面沉积颗粒及纳米颗粒扰动是强化传热的主要影响因素,接触角变化的影响可忽略不计。结论由质量分数为0.03%纳米流体沸腾过程高速成像得到验证。展开更多
Cholest-5-en-24-oxo-3, 19-diacetate was synthesized starting from stigmasterol 3 via seven step reactions in 21.0% overall yield. It can be served as a key intermediate for the synthesis of many biologically active 1...Cholest-5-en-24-oxo-3, 19-diacetate was synthesized starting from stigmasterol 3 via seven step reactions in 21.0% overall yield. It can be served as a key intermediate for the synthesis of many biologically active 19-hydroxylated sterols.展开更多
A new C 60 derivative hydroxylated fullerene epoxide [C 60 (OH) x (O) y ] was prepared by the reaction of C 60 benzene solution with aqueous NaOH and H 2O 2 in the presence of tetrabutylammoni...A new C 60 derivative hydroxylated fullerene epoxide [C 60 (OH) x (O) y ] was prepared by the reaction of C 60 benzene solution with aqueous NaOH and H 2O 2 in the presence of tetrabutylammonium hydroxide(TBAH) as the catalyzer. The structure of hydroxylated fullerene epoxide was characterized by FT IR, NMR and MS , and it was found that it is easy to hydrolyze to fullerol.展开更多
Photocatalytic reduction of U(VI)represents a novel and effective manner for the removal of U(VI)pollutant from radioactive wastewater.Herein,we successfully incorporated hydrogen into VO_(2)nanosheets,which strengthe...Photocatalytic reduction of U(VI)represents a novel and effective manner for the removal of U(VI)pollutant from radioactive wastewater.Herein,we successfully incorporated hydrogen into VO_(2)nanosheets,which strengthened the interaction between VO_(2)and U(VI),thereby achieving a highly active and stable photocatalyst for U(VI)reduction.With the increase of H content in hydric VO_(2)(H_(x)-VO_(2))nanosheets,the bandgap shrank from 2.29 to 1.66 eV,whereas the position of conduction bands remained more negative than the reduction potential of U(VI)/U(IV)(0.41 V vs.NHE).When irradiated by simulated sunlight,the U(VI)removal efficiency over H0.613-VO_(2)nanosheets reached up to 95.4%within 90 min,which largely outperformed 28.3%of pristine VO_(2)nanosheets.The mechanistic study demonstrated that the hydroxylated surface gave rise to the balanced O confinement sites in VO_(2)(011),leading to the stabilized adsorption configuration and increased binding strength of UO_(2)^(2+)on H_(x)-VO_(2)nanosheets.展开更多
An efficient solid-phase synthesis method for novel heterocyclic ketene aminals containing a hydroxyl group has been developed. The loading of the substrate on the resin through the hydroxyl group and the protection o...An efficient solid-phase synthesis method for novel heterocyclic ketene aminals containing a hydroxyl group has been developed. The loading of the substrate on the resin through the hydroxyl group and the protection of the amine by the Schiff base were the key steps in the synthesis.展开更多
The possibility of a graphene bilayer nanosensor for the detection of explosive molecules was modeled using computational chemistry. A pore was designed on a graphene bilayer structure with three strategically placed ...The possibility of a graphene bilayer nanosensor for the detection of explosive molecules was modeled using computational chemistry. A pore was designed on a graphene bilayer structure with three strategically placed perimeter hydroxyl (OH) groups built around the edge of an indented, two-dimensional hexagonal pore. This hydroxylated pore and models of various explosive molecules were optimized using MM2 molecular mechanics parameters. Values were calculated for the molecule-surface interaction energy (binding energy), E, for 22 explosive molecules on a flat graphene bilayer and on the specially designed hydroxylated pore within the bilayer. The molecule-surface binding energy for trinitrotoluene (TNT) increased from 17.9 kcal/mol on the flat graphene bilayer to 42.3 kcal/mol on the hydroxylated pore. Due to the common functionality of nitro groups that exist on many explosive molecules, the other explosive molecules studied gave similar enhancements based on the specific hydrogen bonding interactions formed within the pore. Each of the 22 explosive adsorbate molecules showed increased molecule-surface interaction on the bilayer hydroxylated pore as compared to the flat bilayer. For the 22 molecules, the average E for the flat graphite surface was 15.8 kcal/mol and for the hydroxylated pore E was 33.8 kcal/mol. An enhancement of adsorption should make a detection device more sensitive. Nanosensors based on a modified graphene surface may be useful for detecting extremely low concentrations of explosive molecules or explosive signature molecules.展开更多
We investigated the occurrence and distribution of terrestrial-derived hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers(OH-GDGTs) in the Han River system and their potential impact on the application of t...We investigated the occurrence and distribution of terrestrial-derived hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers(OH-GDGTs) in the Han River system and their potential impact on the application of the ring index of OH-GDGTs(RI-OH) as a sea surface temperature(SST) proxy in the eastern Yellow Sea. Thereby, we analyzed various samples collected along the Han River and from its surrounding areas(South Korea, n = 34). The OHGDGTs were found in all samples investigated. OH-GDGT-0 was the dominant OH-GDGT component in the estuary and marine samples while OH-GDGT-2 was generally dominant in the soils, the lake sediments and the river suspended particulate matter(SPM). Our results thus suggests a possible warm bias of the RI-OH-derived summer SSTs in the coastal zone to which a large amount of terrestrial organic matter is being supplied. Further studies are necessary to better assess the applicability of the RI-OH proxy in the eastern Yellow Sea.展开更多
Macroscale superlubricity is a prospective strategy in modern tribology to dramatically reduce friction and wear of mechanical equipment;however,it is mainly studied for point-to-surface contact or special friction pa...Macroscale superlubricity is a prospective strategy in modern tribology to dramatically reduce friction and wear of mechanical equipment;however,it is mainly studied for point-to-surface contact or special friction pairs in experiments.In this study,a robust macroscale superlubricity for point-to-point contact on a steel interface was achieved for the first time by using hydroxylated modified boron nitride nanosheets with proton-type ionic liquids(ILs)as additives in ethylene glycol aqueous(EG_(aq)).The detailed superlubricity process and mechanism were revealed by theoretical calculations and segmented experiments.The results indicate that hydration originating from hydrated ions can significantly reduce the shear stress of EG_(aq),which plays an essential role in achieving superlubricity.Moreover,the IL induces a tribochemical reaction to form a friction-protective film.Hydroxylated boron nitride nanosheets(HO-BNNs)function as a polishing and self-repairing agent to disperse the contact stress between friction pairs.Superlubricity involves the change in lubrication state from boundary lubrication to mixed lubrication.This finding can remarkably extend the application of superlubricity for point-to-point contact on steel surfaces for engineering applications.展开更多
The new chromium （VI） oxidizing reagent isoquinolinium bromochromate （IQBC） was prepared and characterized. The IQBC has been found to be stable and an efficient solid reagent which can be easily prepared in good ...The new chromium （VI） oxidizing reagent isoquinolinium bromochromate （IQBC） was prepared and characterized. The IQBC has been found to be stable and an efficient solid reagent which can be easily prepared in good yield. It act as an efficient brominating reagent for hydroxylated aromatic compounds as well as good oxidizing reagent for the conversion of alcohols to carbonyl compounds in good to excellent yield. The synthesized isoquinolinium bromochromate is more ideal reagent, with number of specification including： higher yield, mild conditions and easy preparation. The results obtained with isoquinolinium bromochromate are satisfactory and suggest that the reagent has few advantages over the existing chromium （VI） reagents.展开更多
Adsorption of single gold （Au） atom at three kinds of sites （hollow, bridge and top） on the hydroxylated β-cristobalite SiO2 （1 1 1） surface was studied using the first-principles calculations with general grad...Adsorption of single gold （Au） atom at three kinds of sites （hollow, bridge and top） on the hydroxylated β-cristobalite SiO2 （1 1 1） surface was studied using the first-principles calculations with general gradient approximation （GGA）. The results of adsorption energies and density of electronic states （DOS） suggest that the hollow and bridge sites have the basically equal capability of binding Au, while the ability of the Top site is weaker. Two new energy levels emerge after the adsorption at all sites; in DOS of the Hollow configuration, one locates at -0.15 eV, composed of Au 5d and O 2p electronic states, another just crosses through the Fermi level, consisting of Au 6s, H 1s and O 2p. In addition, Mulliken population analyses indicate that electron transfer takes place between the Au atom and the surface H and O atoms in the Hollow and Bridge configurations, which can be used to interpret the adsorption of Au onto the positions. However, neither H nor O chemically bonds with Au atom.展开更多
Polycyclic aromatic hydrocarbons(PAHs)and hydroxylated polycyclic aromatic hydrocarbons(OH-PAHs)were investigated in the soil of the Fildes Peninsula,Antarctica.Various analytes were detected,and the concentration of ...Polycyclic aromatic hydrocarbons(PAHs)and hydroxylated polycyclic aromatic hydrocarbons(OH-PAHs)were investigated in the soil of the Fildes Peninsula,Antarctica.Various analytes were detected,and the concentration of OH-PAHs was 0.3001.847 ng g 1 dry weight,with the dominant components being danthron and 1-hydroxy-phenanthrene.The relationship between soil total organic matter(TOM),OH-PAHs,and the parent PAHs in the soil was studied.No significant correlation was detected between the spatial distribution of OH-PAHs and the occurrence of PAHs,whereas a positive correlation with TOM was found.展开更多
5-Demethylnobile tin(5-DMN),a hydroxylated polymethoxyflavone(OH-PMF)identified in aged citrus peels,has demonstrated health benefiting effects in previous studies.5-DMN undergoes biotransformation in vivo,yielding 5,...5-Demethylnobile tin(5-DMN),a hydroxylated polymethoxyflavone(OH-PMF)identified in aged citrus peels,has demonstrated health benefiting effects in previous studies.5-DMN undergoes biotransformation in vivo,yielding 5,3’-didemethylnobiletin(5,3’-DDMN),5,4’-didemethylnobiletin(5,4’-DDMN)and5,3’,4’-tridemethylnobiletin(5,3’,4’-TDMN).However,the anti-cancer effects of 5-DMN and its in vivo metabolites against HepG2 cells remain unclear.In this study,an efficient chemical synthetic method was developed to obtain 5-DMN and its 3 metabolites,and their molecular structures were confirmed by;H NMR and LC-MS.Cytotoxicity,cell cycle arrestment,apoptosis and caspase-3 expression were investigated to evaluate the anti-liver cancer effects of these OH-PMFs on HepG2 cells.The results showed that all 4 compounds inhibited the proliferation of HepG2 cells in a concentration-dependent manner.Their anti-proliferative activity was exerted through inducing G2/M phase arrestment,cell apoptosis and promoting expression of a key apoptotic protein called cleaved caspase-3.Our results indicated that 5,3’-DDMN and5,3’,4’-TDMN showed a stronger inhibitory activity on cell proliferation than 5-DMN,followed by 5,4’-DDMN.The expression of cleaved caspase-3 was the highest in cells treated with 5,4’-DDMN,implying that the apoptosis induced by other OH-PMFs might be mediated by other apoptotic execution proteins.Our research reveals the application potential and scientific evidence for the production and functionality of OH-PMFs.展开更多
文摘Hydroxylated Tung oil (HTO) based nonionic polyurethane dispersion (HTO-NPUD) were synthesized using dicyclohexyl methane diisocyanate (HMDI) and HTO as main hydrophobic materials whereas polyethylene glycol-800 (PEG-800) as hydrophilic chain extender. To effectively study the effects of HTO on properties of NPUD, polypropylene glycol-400(PPG-400) based NPUD was prepared by HMDI reacting with PPG-400 and PEG-800. The structures of those novel nonionic polyurethane dispersions were characterized by FTIR and 1H NMR. Moreover, particle size and size distribution, cloud point and surface tension had been investigated. Results showed that, by comparing with PPG based NPUD (PPG-NPUD), the introduction of HTO into NPUD result in larger particle size and more uniformed particle size distribution, higher cloud point and lower surface tension.
基金supported by the Natural Science Foundation of Zhejiang Province(No.LY12B07013 LY12C03009+1 种基金 Y5090304)State Key Laboratory of Environmental Chemistry and Ecotoxicology,Chinese Academy of Sciences(KF2011-19)
文摘Hydroxylated Polychlorinated Biphenyls （HO-PCBs） are the metabolite of polychlorinated biphenyls and have drawn much attention because they have hazard on human health and ecosystems. Molecular connectivity index calculation has been performed for 19 HO-PCB compounds. A number of statistically based parameters have been extracted. Linear relationship between chromatographic retention index （RI） and the molecular connectivity index of 15 compounds in the training set has been established by multiple linear regression method. The other 4 HO-PCBs are used as the external test set. The result shows that the parameters can be well used to express the quantitative structure-retention relationship （QSRR） of HO-PCBs. Good stability and predictive ability have been demonstrated by leave-one-out cross-validation and the external test set.
文摘向多壁碳纳米管引入羟基基团,改善了其在制冷剂R141b中的分散性和稳定性。同时研究了不同质量分数纳米流体热导率、表面颗粒沉积、接触角变化对核沸腾传热性能的影响。结果表明:羟基化碳纳米流体强化沸腾传热,强化率随质量分数的增加而增加,沸腾后期有所下降。在测试浓度范围内,质量分数为0.05%,热通量为87.4 k W·m-2时,强化率达到最大168%。流体的热导率随着质量分数的增加而增大,质量分数为0.10%时其热导率是纯R141b的1.18倍。分析认为:纳米流体热导率的增加、表面沉积颗粒及纳米颗粒扰动是强化传热的主要影响因素,接触角变化的影响可忽略不计。结论由质量分数为0.03%纳米流体沸腾过程高速成像得到验证。
基金We are grateful to the National Natural Science Foundation of China (No. 29932030) and Natural Science Foundation (No. 970154) of Guangdong Province for financial support for this work.
文摘Cholest-5-en-24-oxo-3, 19-diacetate was synthesized starting from stigmasterol 3 via seven step reactions in 21.0% overall yield. It can be served as a key intermediate for the synthesis of many biologically active 19-hydroxylated sterols.
文摘A new C 60 derivative hydroxylated fullerene epoxide [C 60 (OH) x (O) y ] was prepared by the reaction of C 60 benzene solution with aqueous NaOH and H 2O 2 in the presence of tetrabutylammonium hydroxide(TBAH) as the catalyzer. The structure of hydroxylated fullerene epoxide was characterized by FT IR, NMR and MS , and it was found that it is easy to hydrolyze to fullerol.
基金This work was supported by the National Natural Science Foundaiton of China(Nos.21902130 and 21976147)Sichuan Science and Technology Program(Nos.2020YFG0160,2020YFG0191,2020YFS0345,2020JDJQ0060,and 2020JDRC0089)+3 种基金the project of State Key Laboratory of Environment-friendly Energy Materials in SWUST(No.18fksy0218)research fund of SWUST for PhD(No.18zx7149)Natural Science Foundation of Anhui province(Nos.2008085QB81 and 2008085QA33)the Education Department of Anhui Province Foundation(No.KJ2019A0503).
文摘Photocatalytic reduction of U(VI)represents a novel and effective manner for the removal of U(VI)pollutant from radioactive wastewater.Herein,we successfully incorporated hydrogen into VO_(2)nanosheets,which strengthened the interaction between VO_(2)and U(VI),thereby achieving a highly active and stable photocatalyst for U(VI)reduction.With the increase of H content in hydric VO_(2)(H_(x)-VO_(2))nanosheets,the bandgap shrank from 2.29 to 1.66 eV,whereas the position of conduction bands remained more negative than the reduction potential of U(VI)/U(IV)(0.41 V vs.NHE).When irradiated by simulated sunlight,the U(VI)removal efficiency over H0.613-VO_(2)nanosheets reached up to 95.4%within 90 min,which largely outperformed 28.3%of pristine VO_(2)nanosheets.The mechanistic study demonstrated that the hydroxylated surface gave rise to the balanced O confinement sites in VO_(2)(011),leading to the stabilized adsorption configuration and increased binding strength of UO_(2)^(2+)on H_(x)-VO_(2)nanosheets.
文摘An efficient solid-phase synthesis method for novel heterocyclic ketene aminals containing a hydroxyl group has been developed. The loading of the substrate on the resin through the hydroxyl group and the protection of the amine by the Schiff base were the key steps in the synthesis.
文摘The possibility of a graphene bilayer nanosensor for the detection of explosive molecules was modeled using computational chemistry. A pore was designed on a graphene bilayer structure with three strategically placed perimeter hydroxyl (OH) groups built around the edge of an indented, two-dimensional hexagonal pore. This hydroxylated pore and models of various explosive molecules were optimized using MM2 molecular mechanics parameters. Values were calculated for the molecule-surface interaction energy (binding energy), E, for 22 explosive molecules on a flat graphene bilayer and on the specially designed hydroxylated pore within the bilayer. The molecule-surface binding energy for trinitrotoluene (TNT) increased from 17.9 kcal/mol on the flat graphene bilayer to 42.3 kcal/mol on the hydroxylated pore. Due to the common functionality of nitro groups that exist on many explosive molecules, the other explosive molecules studied gave similar enhancements based on the specific hydrogen bonding interactions formed within the pore. Each of the 22 explosive adsorbate molecules showed increased molecule-surface interaction on the bilayer hydroxylated pore as compared to the flat bilayer. For the 22 molecules, the average E for the flat graphite surface was 15.8 kcal/mol and for the hydroxylated pore E was 33.8 kcal/mol. An enhancement of adsorption should make a detection device more sensitive. Nanosensors based on a modified graphene surface may be useful for detecting extremely low concentrations of explosive molecules or explosive signature molecules.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP)(No.NRF-2016R1A2B3015388)
文摘We investigated the occurrence and distribution of terrestrial-derived hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers(OH-GDGTs) in the Han River system and their potential impact on the application of the ring index of OH-GDGTs(RI-OH) as a sea surface temperature(SST) proxy in the eastern Yellow Sea. Thereby, we analyzed various samples collected along the Han River and from its surrounding areas(South Korea, n = 34). The OHGDGTs were found in all samples investigated. OH-GDGT-0 was the dominant OH-GDGT component in the estuary and marine samples while OH-GDGT-2 was generally dominant in the soils, the lake sediments and the river suspended particulate matter(SPM). Our results thus suggests a possible warm bias of the RI-OH-derived summer SSTs in the coastal zone to which a large amount of terrestrial organic matter is being supplied. Further studies are necessary to better assess the applicability of the RI-OH proxy in the eastern Yellow Sea.
基金The authors are gratefully for the financial support provided by the Youth Innovation Promotion Association CAS(2021422).
文摘Macroscale superlubricity is a prospective strategy in modern tribology to dramatically reduce friction and wear of mechanical equipment;however,it is mainly studied for point-to-surface contact or special friction pairs in experiments.In this study,a robust macroscale superlubricity for point-to-point contact on a steel interface was achieved for the first time by using hydroxylated modified boron nitride nanosheets with proton-type ionic liquids(ILs)as additives in ethylene glycol aqueous(EG_(aq)).The detailed superlubricity process and mechanism were revealed by theoretical calculations and segmented experiments.The results indicate that hydration originating from hydrated ions can significantly reduce the shear stress of EG_(aq),which plays an essential role in achieving superlubricity.Moreover,the IL induces a tribochemical reaction to form a friction-protective film.Hydroxylated boron nitride nanosheets(HO-BNNs)function as a polishing and self-repairing agent to disperse the contact stress between friction pairs.Superlubricity involves the change in lubrication state from boundary lubrication to mixed lubrication.This finding can remarkably extend the application of superlubricity for point-to-point contact on steel surfaces for engineering applications.
文摘The new chromium （VI） oxidizing reagent isoquinolinium bromochromate （IQBC） was prepared and characterized. The IQBC has been found to be stable and an efficient solid reagent which can be easily prepared in good yield. It act as an efficient brominating reagent for hydroxylated aromatic compounds as well as good oxidizing reagent for the conversion of alcohols to carbonyl compounds in good to excellent yield. The synthesized isoquinolinium bromochromate is more ideal reagent, with number of specification including： higher yield, mild conditions and easy preparation. The results obtained with isoquinolinium bromochromate are satisfactory and suggest that the reagent has few advantages over the existing chromium （VI） reagents.
基金Funded by the Fundamental Research Funds for the Central Universities (No. CUGL100240)
文摘Adsorption of single gold （Au） atom at three kinds of sites （hollow, bridge and top） on the hydroxylated β-cristobalite SiO2 （1 1 1） surface was studied using the first-principles calculations with general gradient approximation （GGA）. The results of adsorption energies and density of electronic states （DOS） suggest that the hollow and bridge sites have the basically equal capability of binding Au, while the ability of the Top site is weaker. Two new energy levels emerge after the adsorption at all sites; in DOS of the Hollow configuration, one locates at -0.15 eV, composed of Au 5d and O 2p electronic states, another just crosses through the Fermi level, consisting of Au 6s, H 1s and O 2p. In addition, Mulliken population analyses indicate that electron transfer takes place between the Au atom and the surface H and O atoms in the Hollow and Bridge configurations, which can be used to interpret the adsorption of Au onto the positions. However, neither H nor O chemically bonds with Au atom.
基金The research was supported by the National Natural Science Foundation of China(Grant nos.41976222,41406088 and 21377032)Open Fund for the Key Laboratory of Ocean-Atmospheric Chemistry and Global Change,State Oceanic Administration,China(Grant no.GCMAC1812)+2 种基金Open Fund for the State Key Laboratory of Environmental Chemistry and Ecotoxicology,China(Grant no.KF2018-05)National Key Research and Development Project of China(Grant no.2019YF0901104)We also thank Chinese Arctic and Antarctic Administration and Polar Research Institute of China for the arrangements during the 30th Chinese National Antarctic Research Expedition in 2014.
文摘Polycyclic aromatic hydrocarbons(PAHs)and hydroxylated polycyclic aromatic hydrocarbons(OH-PAHs)were investigated in the soil of the Fildes Peninsula,Antarctica.Various analytes were detected,and the concentration of OH-PAHs was 0.3001.847 ng g 1 dry weight,with the dominant components being danthron and 1-hydroxy-phenanthrene.The relationship between soil total organic matter(TOM),OH-PAHs,and the parent PAHs in the soil was studied.No significant correlation was detected between the spatial distribution of OH-PAHs and the occurrence of PAHs,whereas a positive correlation with TOM was found.
文摘5-Demethylnobile tin(5-DMN),a hydroxylated polymethoxyflavone(OH-PMF)identified in aged citrus peels,has demonstrated health benefiting effects in previous studies.5-DMN undergoes biotransformation in vivo,yielding 5,3’-didemethylnobiletin(5,3’-DDMN),5,4’-didemethylnobiletin(5,4’-DDMN)and5,3’,4’-tridemethylnobiletin(5,3’,4’-TDMN).However,the anti-cancer effects of 5-DMN and its in vivo metabolites against HepG2 cells remain unclear.In this study,an efficient chemical synthetic method was developed to obtain 5-DMN and its 3 metabolites,and their molecular structures were confirmed by;H NMR and LC-MS.Cytotoxicity,cell cycle arrestment,apoptosis and caspase-3 expression were investigated to evaluate the anti-liver cancer effects of these OH-PMFs on HepG2 cells.The results showed that all 4 compounds inhibited the proliferation of HepG2 cells in a concentration-dependent manner.Their anti-proliferative activity was exerted through inducing G2/M phase arrestment,cell apoptosis and promoting expression of a key apoptotic protein called cleaved caspase-3.Our results indicated that 5,3’-DDMN and5,3’,4’-TDMN showed a stronger inhibitory activity on cell proliferation than 5-DMN,followed by 5,4’-DDMN.The expression of cleaved caspase-3 was the highest in cells treated with 5,4’-DDMN,implying that the apoptosis induced by other OH-PMFs might be mediated by other apoptotic execution proteins.Our research reveals the application potential and scientific evidence for the production and functionality of OH-PMFs.
