Comprehensive Summary Phthalides serve as core structures pervasive in a wide array of natural products and drug molecules,which display a diverse array of biological activities.We report herein a highly efficient dyn...Comprehensive Summary Phthalides serve as core structures pervasive in a wide array of natural products and drug molecules,which display a diverse array of biological activities.We report herein a highly efficient dynamic kinetic resolution of 3-hydroxyphthalides by chiral isothioureas(ITUs)catalyzed asymmetric acylation,facilitating the effective synthesis of a variety of chiral phthalidyl esters with good yields and enantioselectivities.Notably,this reaction features mild reaction conditions,expansive substrate scope as well as good functional group compatibility.In addition,the practicality of this method is underscored by the large-scale synthesis,reduced catalyst loading experiment and the synthesis of the chiral phthalidyl ester prodrug.展开更多
Bacterial cells rely on signaling molecules to communicate with others from the same species and induce certain genes in a process known as quorum sensing (QS). A common molecule is N-acyl homoserine lactone (AHL) whi...Bacterial cells rely on signaling molecules to communicate with others from the same species and induce certain genes in a process known as quorum sensing (QS). A common molecule is N-acyl homoserine lactone (AHL) which is responsible for the expression of virulence and other factors that allow the organisms to compete in a given environment. On the other hand, other bacteria produce certain enzymes such as AHL-lactonase that break down AHL molecules and prevent gene expression of these factors. The aim of this work was to examine the level of degradation of AHL molecules by AHL-lactonase in 62 Bacillus thuringiensis (Bt) strains isolated from Middle Tennessee, Mississippi, and Alabama. N-hexanoyl-homoserine lactone (C<sub>6</sub>-HSL) and N-3-oxo-hexanoyl homoserine lactone (3-oxo-C<sub>6</sub>-HSL), which cause Chromobacterium violaceum (CV026) to produce a purple pigment were tested at different concentrations to view the Bt lactonase activity. In addition, PCR was used to test for the presence of the lactonase gene. The results showed that among the 62 Bt strains, there were 58 that possessed the AHL-lactonase (aiiA) gene and 48 strains were able to degrade C<sub>6</sub>-HSL. At high concentrations of AHL, only 13 strains were able to completely degrade C6-HSL. In addition, degradation of 3-oxo-C<sub>6</sub>-HSL was weak compared to C<sub>6</sub>-HSL. The results also revealed that AHL lactonase was thermostable, and it was concluded that the level of degradation varies in Bt strains. Only 13 of the strains studied have potent inhibitory activity against C<sub>6</sub>-HSL, which may be good to be used in field applications to control agricultural pest.展开更多
Several phenylselenyl esters were selected as precursors of acyl radicals and synthesised by our established method. Treatment of these phenylselenyl esters with tributyltinhydride and AIBN ge...Several phenylselenyl esters were selected as precursors of acyl radicals and synthesised by our established method. Treatment of these phenylselenyl esters with tributyltinhydride and AIBN generated the corresponding acyl radicals, which were found to proceed in 5 exo trig or 6 endo trig cyclisations to afford high yields of cyclopentanones and cyclohexanones, The substitution groups on the substrates have played an important role on the regioselectivity of cyclisations.展开更多
目的评价长链脂酰辅酶A合成酶4(acyl-CoA synthetase long-chain family member 4,ACSL4)对肝癌患者预后的影响。方法系统检索PubMed、Embase、Cochrane Library、Web of science、中国知网、万方医学与维普数据库,检索时间均从建库至2...目的评价长链脂酰辅酶A合成酶4(acyl-CoA synthetase long-chain family member 4,ACSL4)对肝癌患者预后的影响。方法系统检索PubMed、Embase、Cochrane Library、Web of science、中国知网、万方医学与维普数据库,检索时间均从建库至2023年2月,收集ACSL4表达对肝癌患者预后影响的队列研究。文献的筛选过程由2名评估员自主完成。将纳入的研究依据纽卡斯尔-渥太华质量评价量表(Newcastle Ottawa Scale,NOS)进行质量评估,提取文献中肝癌患者的临床病理特征、研究的结局指标及HR(95%CI)等相关数据。运用Stata17.0MP软件对文献数据进行统计分析,采用漏斗图与Egger’s检验探讨偏倚风险。结果共纳入6项队列试验(890例肝癌患者)。Meta分析表明,与ACSL4低表达组患者相比,ACSL4高表达组肝癌患者总生存期(overall survival,OS)较短(HR=1.274,95%CI:1.141~1.422,P<0.001);肝癌患者中,男性ACSL4高表达(OR=1.12,95%CI:1.008~1.224,P<0.05)。Egger’s检验表明研究间存在发表偏倚的可能性较小(P=0.055)。ACSL4表达水平与年龄、肿瘤分期、肿瘤大小和肿瘤包膜是否完整以及是否合并肝硬化的相关性无统计学意义(P均>0.05)。结论ACSL4高表达与肝癌患者较短OS的相关性具有统计学意义,但仍需要更多的高质量临床研究进行验证。展开更多
基金support from the National Natural Science Foundation of China(Grant Nos.22371219,22193011,21971120,21933008 and 22101191)National Science&Technology Fundamental Resource Investigation Program of China(No.2018FY201200)the Fundamental Research Funds for the Central Universities.W.Z.is grateful for the financial support from the program of China Scholarship Council(No.202206240054).
文摘Comprehensive Summary Phthalides serve as core structures pervasive in a wide array of natural products and drug molecules,which display a diverse array of biological activities.We report herein a highly efficient dynamic kinetic resolution of 3-hydroxyphthalides by chiral isothioureas(ITUs)catalyzed asymmetric acylation,facilitating the effective synthesis of a variety of chiral phthalidyl esters with good yields and enantioselectivities.Notably,this reaction features mild reaction conditions,expansive substrate scope as well as good functional group compatibility.In addition,the practicality of this method is underscored by the large-scale synthesis,reduced catalyst loading experiment and the synthesis of the chiral phthalidyl ester prodrug.
文摘Bacterial cells rely on signaling molecules to communicate with others from the same species and induce certain genes in a process known as quorum sensing (QS). A common molecule is N-acyl homoserine lactone (AHL) which is responsible for the expression of virulence and other factors that allow the organisms to compete in a given environment. On the other hand, other bacteria produce certain enzymes such as AHL-lactonase that break down AHL molecules and prevent gene expression of these factors. The aim of this work was to examine the level of degradation of AHL molecules by AHL-lactonase in 62 Bacillus thuringiensis (Bt) strains isolated from Middle Tennessee, Mississippi, and Alabama. N-hexanoyl-homoserine lactone (C<sub>6</sub>-HSL) and N-3-oxo-hexanoyl homoserine lactone (3-oxo-C<sub>6</sub>-HSL), which cause Chromobacterium violaceum (CV026) to produce a purple pigment were tested at different concentrations to view the Bt lactonase activity. In addition, PCR was used to test for the presence of the lactonase gene. The results showed that among the 62 Bt strains, there were 58 that possessed the AHL-lactonase (aiiA) gene and 48 strains were able to degrade C<sub>6</sub>-HSL. At high concentrations of AHL, only 13 strains were able to completely degrade C6-HSL. In addition, degradation of 3-oxo-C<sub>6</sub>-HSL was weak compared to C<sub>6</sub>-HSL. The results also revealed that AHL lactonase was thermostable, and it was concluded that the level of degradation varies in Bt strains. Only 13 of the strains studied have potent inhibitory activity against C<sub>6</sub>-HSL, which may be good to be used in field applications to control agricultural pest.
文摘Several phenylselenyl esters were selected as precursors of acyl radicals and synthesised by our established method. Treatment of these phenylselenyl esters with tributyltinhydride and AIBN generated the corresponding acyl radicals, which were found to proceed in 5 exo trig or 6 endo trig cyclisations to afford high yields of cyclopentanones and cyclohexanones, The substitution groups on the substrates have played an important role on the regioselectivity of cyclisations.
文摘目的评价长链脂酰辅酶A合成酶4(acyl-CoA synthetase long-chain family member 4,ACSL4)对肝癌患者预后的影响。方法系统检索PubMed、Embase、Cochrane Library、Web of science、中国知网、万方医学与维普数据库,检索时间均从建库至2023年2月,收集ACSL4表达对肝癌患者预后影响的队列研究。文献的筛选过程由2名评估员自主完成。将纳入的研究依据纽卡斯尔-渥太华质量评价量表(Newcastle Ottawa Scale,NOS)进行质量评估,提取文献中肝癌患者的临床病理特征、研究的结局指标及HR(95%CI)等相关数据。运用Stata17.0MP软件对文献数据进行统计分析,采用漏斗图与Egger’s检验探讨偏倚风险。结果共纳入6项队列试验(890例肝癌患者)。Meta分析表明,与ACSL4低表达组患者相比,ACSL4高表达组肝癌患者总生存期(overall survival,OS)较短(HR=1.274,95%CI:1.141~1.422,P<0.001);肝癌患者中,男性ACSL4高表达(OR=1.12,95%CI:1.008~1.224,P<0.05)。Egger’s检验表明研究间存在发表偏倚的可能性较小(P=0.055)。ACSL4表达水平与年龄、肿瘤分期、肿瘤大小和肿瘤包膜是否完整以及是否合并肝硬化的相关性无统计学意义(P均>0.05)。结论ACSL4高表达与肝癌患者较短OS的相关性具有统计学意义,但仍需要更多的高质量临床研究进行验证。