Halogenated natural products(HNPs)are considered to be emerging contaminants whose environmental distribution and fate are only incompletely known.Therefore,several persistent and bioaccumulative HNP groups,together w...Halogenated natural products(HNPs)are considered to be emerging contaminants whose environmental distribution and fate are only incompletely known.Therefore,several persistent and bioaccumulative HNP groups,together with manmade polychlorinated biphenyls(PCBs)and polybrominated diphenyl ethers(PBDEs),were quantified in the blubber of nine sperm whales(Physeter macrocephalus)stranded on the coast of the Mediterranean Sea in Italy.The naturally occurring polybrominated hexahydroxanthene derivatives(PBHDs;sum of TetraBHD and TriBHD)were the most prominent substance class with up to 77,000 ng/g blubber.The mean PBHD content(35,800 ng/g blubber)even exceeded the one of PCBs(28,400 ng/g blubber),although the region is known to be highly contaminated with manmade contaminants.Based on mean values,Q1∼PBDEs>MeO-BDEs∼2,2′-diMeO-BB 80 and several other HNPs followed with decreasing amounts.All blubber samples contained an abundant compound whose molecular formula(C_(16)H_(19)Br_(3)O_(2))was verified using high-resolution mass spectrometry.The only plausible matching isomer was(2S,4′S,9R,9′S)-2,7-dibromo-4′-bromomethyl-1,1-dimethyl-2,3,4,4′,9,9′-9,9′-hexahydro-1H-xanthen-9-ol(OH-TriBHD),a hydroxylated secondary metabolite previously detected together with TriBHD and TetraBHD in a sponge known to be a natural producer of PBHDs.The estimated mean amount of the presumed OH-TriBHD was 3000 ng/g blubber,which is unexpectedly high for hydroxylated compounds in the lipids of marine mammals.展开更多
The kinetic behaviours of the substitution reaction of rare earth-PHA with CyDTA were studied systemati- cally.The relationship between the rate constant and atomic number was discussed.The rate differentiation val- u...The kinetic behaviours of the substitution reaction of rare earth-PHA with CyDTA were studied systemati- cally.The relationship between the rate constant and atomic number was discussed.The rate differentiation val- ue R_d(R_d=lgk_(z+n)-lgk_z)was proposed to evaluate the possibility of differential kinetic analysis.The R_d value between the neighbouring lanthanide ions first increases and then decreases along with increasing atomic number, so that the middle and heavy rare earth mixture(such as Sm-Gd and Gd-Y)are ideal systems for the differential rate kinetic analysis.展开更多
Polyhalogenated carbazoles(PHCZs)have been widely accepted as emerging pollutants,whereas their ecological and health risks remain uncertain.Herein,female and male Sprague-Dawley(SD)mice were treated with four typical...Polyhalogenated carbazoles(PHCZs)have been widely accepted as emerging pollutants,whereas their ecological and health risks remain uncertain.Herein,female and male Sprague-Dawley(SD)mice were treated with four typical PHCZs to investigate their negative consequences,along with alternations in gutmicrobiota to indicate underlyingmechanisms.In female mice,the relative liver weight ratio increased after four PHCZs exposure;2-bromocarbazole(2-BCZ)increased urine glucose level;3-bromocarbazole(3-BCZ)decreased the glucose and total cholesterol levels;3,6-dichlorocarbazole(3,6-DCCZ)decreased glucose level.The only disturbed biochemical index in male mice was the promoted alkaline phosphatase(ALP)level by 3,6-DCCZ.We also found that the differential blood biochemical indices were correlated with gut microbiota.3-BCZ and 3,6-DCCZ altered Bacteroidetes and Proteobacteria phyla in female and male mice,which were correlated with metabolic disorders.Our findings demonstrated the correlation between PHCZs induced potential hepatotoxicity andmetabolic disordersmay be due to their dioxin-like potentials and endocrine disrupting activities,and the gender differences might result from their estrogenic activities.Overall,data presented here can help to evaluate the ecological and health risks of PHCZs and reveal the underlying mechanisms.展开更多
Comprehensive Summary This paper presents the first general examples of palladium-catalyzed desulfinative cross-coupling reaction of polyhalogenated aryl triflates with aryl sulfinate salts showing an inversion of the...Comprehensive Summary This paper presents the first general examples of palladium-catalyzed desulfinative cross-coupling reaction of polyhalogenated aryl triflates with aryl sulfinate salts showing an inversion of the conventional reactivity order of C-Br>C-Cl>C-OTf.The catalyst system,comprising of Pd(OAc)_(2)and tBuPhSelectPhos,exhibited excellent catalytic reactivity and chemoselectivity toward this reaction.This reaction had a wide range of substrate scopes and provided a simple and efficient method for the construction of functionalized biaryl motifs.Notably,the C-H···Pd interaction from the methine hydrogen of the C2-cyclohexyl group of the indolyl phosphine ligand with the Pd center may contribute a key factor in reactivity and chemoselectivity.Assisting with density functional theory(DFT)calculations,the results revealed that the oxidative addition step in this reaction was a controlling-chemoselectivity step.展开更多
Polyhalogenated carbazoles(PHCZs)are recently raising much attention due to their toxicity and ubiquitous environmental distribution.However,little knowledge is known about their ambient occurrences and the potential ...Polyhalogenated carbazoles(PHCZs)are recently raising much attention due to their toxicity and ubiquitous environmental distribution.However,little knowledge is known about their ambient occurrences and the potential source.In this study,we developed an analytical method based on GC-MS/MS to simultaneously determine 11 PHCZs in PM_(2.5) from urban Beijing,China.The optimized method provided low method limit of quantifications(MLOQs,1.45–7.39 fg/m^(3))and satisfied recoveries(73.4%–109.5%).This method was applied to analyze the PHCZs in the outdoor PM_(2.5)(n=46)and fly ash(n=6)collected from 3 kinds of surrounding incinerator plants(steel plant,medical waste incinerator and domestic waste incinerator).The levels of Σ_(11)PHCZs in PM_(2.5) ranged from 0.117 to 5.54 pg/m^(3)(median 1.18 pg/m^(3)).3-chloro-9H-carbazole(3-CCZ),3-bromo-9H-carbazole(3-BCZ),and 3,6-dichloro-9Hcarbazole(36-CCZ)were the dominant compounds,accounting for 93%.3-CCZ and 3-BCZ were significantly higher in winter due to the high PM_(2.5) concentration,while 36-CCZ was higher in spring,which may be related to the resuspending of surface soil.Furthermore,the levels of11PHCZs in fly ash ranged from 338 to 6101 pg/g.3-CCZ,3-BCZ and 36-CCZ accounted for 86.0%.The congener profiles of PHCZs between fly ash and PM_(2.5) were highly similar,indicating that combustion process could be an important source of ambient PHCZs.To the best of our knowledge,this is the first research providing the occurrences of PHCZs in outdoor PM_(2.5).展开更多
目的建立加速溶剂萃取-凝胶渗透色谱-气相色谱-串联质谱法同时测定鱼类中7种新型有机污染物(咔唑和卤代咔唑类化合物)的分析方法。方法样品与硅藻土研磨混匀后经加速溶剂萃取仪提取,使用凝胶渗透色谱法净化并氮吹至近干,用1mL丙酮复溶...目的建立加速溶剂萃取-凝胶渗透色谱-气相色谱-串联质谱法同时测定鱼类中7种新型有机污染物(咔唑和卤代咔唑类化合物)的分析方法。方法样品与硅藻土研磨混匀后经加速溶剂萃取仪提取,使用凝胶渗透色谱法净化并氮吹至近干,用1mL丙酮复溶。目标化合物采用多反应监测(multiplereactionmonitoring,MRM)模式分析,外标法进行定量。结果咔唑、3-氯咔唑、3-溴咔唑和3,6-二氯咔唑在0.5~50.0μg/kg范围内线性关系良好,相关系数r>0.997;3,6-二溴咔唑、2,7-二溴咔唑和1,3,6,8-四溴咔唑在1.0~100.0μg/kg范围内线性关系良好,相关系数r>0.998。定量限(limits of quantification,LOQs)在0.50~1.00μg/kg之间,在各目标物的1LOQs、2LOQs和10LOQs3个加标水平下,7种咔唑和卤代咔唑类化合物的平均回收率为87.22%~107.27%,相对标准偏差(relative standard deviations,RSDs)为2.70%~8.17%(n=6)。结论该方法自动化程度高、灵敏度高、稳定性好,适用于鱼类中7种咔唑和卤代咔唑类化合物的检测。展开更多
文摘Halogenated natural products(HNPs)are considered to be emerging contaminants whose environmental distribution and fate are only incompletely known.Therefore,several persistent and bioaccumulative HNP groups,together with manmade polychlorinated biphenyls(PCBs)and polybrominated diphenyl ethers(PBDEs),were quantified in the blubber of nine sperm whales(Physeter macrocephalus)stranded on the coast of the Mediterranean Sea in Italy.The naturally occurring polybrominated hexahydroxanthene derivatives(PBHDs;sum of TetraBHD and TriBHD)were the most prominent substance class with up to 77,000 ng/g blubber.The mean PBHD content(35,800 ng/g blubber)even exceeded the one of PCBs(28,400 ng/g blubber),although the region is known to be highly contaminated with manmade contaminants.Based on mean values,Q1∼PBDEs>MeO-BDEs∼2,2′-diMeO-BB 80 and several other HNPs followed with decreasing amounts.All blubber samples contained an abundant compound whose molecular formula(C_(16)H_(19)Br_(3)O_(2))was verified using high-resolution mass spectrometry.The only plausible matching isomer was(2S,4′S,9R,9′S)-2,7-dibromo-4′-bromomethyl-1,1-dimethyl-2,3,4,4′,9,9′-9,9′-hexahydro-1H-xanthen-9-ol(OH-TriBHD),a hydroxylated secondary metabolite previously detected together with TriBHD and TetraBHD in a sponge known to be a natural producer of PBHDs.The estimated mean amount of the presumed OH-TriBHD was 3000 ng/g blubber,which is unexpectedly high for hydroxylated compounds in the lipids of marine mammals.
文摘The kinetic behaviours of the substitution reaction of rare earth-PHA with CyDTA were studied systemati- cally.The relationship between the rate constant and atomic number was discussed.The rate differentiation val- ue R_d(R_d=lgk_(z+n)-lgk_z)was proposed to evaluate the possibility of differential kinetic analysis.The R_d value between the neighbouring lanthanide ions first increases and then decreases along with increasing atomic number, so that the middle and heavy rare earth mixture(such as Sm-Gd and Gd-Y)are ideal systems for the differential rate kinetic analysis.
基金supported by Joint Innovation Fund for Regional Development of National Natural Science Foundation of China(No.U20A20134)Leading Talent of Technological Innovation of Ten-Thousands Talents Program of Zhejiang Province(No.2020R52012).
文摘Polyhalogenated carbazoles(PHCZs)have been widely accepted as emerging pollutants,whereas their ecological and health risks remain uncertain.Herein,female and male Sprague-Dawley(SD)mice were treated with four typical PHCZs to investigate their negative consequences,along with alternations in gutmicrobiota to indicate underlyingmechanisms.In female mice,the relative liver weight ratio increased after four PHCZs exposure;2-bromocarbazole(2-BCZ)increased urine glucose level;3-bromocarbazole(3-BCZ)decreased the glucose and total cholesterol levels;3,6-dichlorocarbazole(3,6-DCCZ)decreased glucose level.The only disturbed biochemical index in male mice was the promoted alkaline phosphatase(ALP)level by 3,6-DCCZ.We also found that the differential blood biochemical indices were correlated with gut microbiota.3-BCZ and 3,6-DCCZ altered Bacteroidetes and Proteobacteria phyla in female and male mice,which were correlated with metabolic disorders.Our findings demonstrated the correlation between PHCZs induced potential hepatotoxicity andmetabolic disordersmay be due to their dioxin-like potentials and endocrine disrupting activities,and the gender differences might result from their estrogenic activities.Overall,data presented here can help to evaluate the ecological and health risks of PHCZs and reveal the underlying mechanisms.
基金the Research Grants Council of the Hong Kong Special Administrative Region,China(PolyU 15302821,15300220,and 25301819)the National Natural Science Foundation of China(21972122)for their financial support.
文摘Comprehensive Summary This paper presents the first general examples of palladium-catalyzed desulfinative cross-coupling reaction of polyhalogenated aryl triflates with aryl sulfinate salts showing an inversion of the conventional reactivity order of C-Br>C-Cl>C-OTf.The catalyst system,comprising of Pd(OAc)_(2)and tBuPhSelectPhos,exhibited excellent catalytic reactivity and chemoselectivity toward this reaction.This reaction had a wide range of substrate scopes and provided a simple and efficient method for the construction of functionalized biaryl motifs.Notably,the C-H···Pd interaction from the methine hydrogen of the C2-cyclohexyl group of the indolyl phosphine ligand with the Pd center may contribute a key factor in reactivity and chemoselectivity.Assisting with density functional theory(DFT)calculations,the results revealed that the oxidative addition step in this reaction was a controlling-chemoselectivity step.
基金supported by the National Key Research and Development Program of China(Nos.2018YFA0901104 and 2019YFE0111100)the National Natural Science Foundation of China(No.91743206)the Special Project of Eco-Environmental Technology for Peak Carbon Dioxide Emissions and Carbon Neutrality(No.RCEES-TDZ-2021-23).
文摘Polyhalogenated carbazoles(PHCZs)are recently raising much attention due to their toxicity and ubiquitous environmental distribution.However,little knowledge is known about their ambient occurrences and the potential source.In this study,we developed an analytical method based on GC-MS/MS to simultaneously determine 11 PHCZs in PM_(2.5) from urban Beijing,China.The optimized method provided low method limit of quantifications(MLOQs,1.45–7.39 fg/m^(3))and satisfied recoveries(73.4%–109.5%).This method was applied to analyze the PHCZs in the outdoor PM_(2.5)(n=46)and fly ash(n=6)collected from 3 kinds of surrounding incinerator plants(steel plant,medical waste incinerator and domestic waste incinerator).The levels of Σ_(11)PHCZs in PM_(2.5) ranged from 0.117 to 5.54 pg/m^(3)(median 1.18 pg/m^(3)).3-chloro-9H-carbazole(3-CCZ),3-bromo-9H-carbazole(3-BCZ),and 3,6-dichloro-9Hcarbazole(36-CCZ)were the dominant compounds,accounting for 93%.3-CCZ and 3-BCZ were significantly higher in winter due to the high PM_(2.5) concentration,while 36-CCZ was higher in spring,which may be related to the resuspending of surface soil.Furthermore,the levels of11PHCZs in fly ash ranged from 338 to 6101 pg/g.3-CCZ,3-BCZ and 36-CCZ accounted for 86.0%.The congener profiles of PHCZs between fly ash and PM_(2.5) were highly similar,indicating that combustion process could be an important source of ambient PHCZs.To the best of our knowledge,this is the first research providing the occurrences of PHCZs in outdoor PM_(2.5).
文摘目的建立加速溶剂萃取-凝胶渗透色谱-气相色谱-串联质谱法同时测定鱼类中7种新型有机污染物(咔唑和卤代咔唑类化合物)的分析方法。方法样品与硅藻土研磨混匀后经加速溶剂萃取仪提取,使用凝胶渗透色谱法净化并氮吹至近干,用1mL丙酮复溶。目标化合物采用多反应监测(multiplereactionmonitoring,MRM)模式分析,外标法进行定量。结果咔唑、3-氯咔唑、3-溴咔唑和3,6-二氯咔唑在0.5~50.0μg/kg范围内线性关系良好,相关系数r>0.997;3,6-二溴咔唑、2,7-二溴咔唑和1,3,6,8-四溴咔唑在1.0~100.0μg/kg范围内线性关系良好,相关系数r>0.998。定量限(limits of quantification,LOQs)在0.50~1.00μg/kg之间,在各目标物的1LOQs、2LOQs和10LOQs3个加标水平下,7种咔唑和卤代咔唑类化合物的平均回收率为87.22%~107.27%,相对标准偏差(relative standard deviations,RSDs)为2.70%~8.17%(n=6)。结论该方法自动化程度高、灵敏度高、稳定性好,适用于鱼类中7种咔唑和卤代咔唑类化合物的检测。
