The title compound, 2-（3-silatranylpropylamino）-4-dichlorophenyl-5,5-dimethyl- 1,3,2-dioxaphosphorinane-2-oxide （2（C20H33N2O6Psi）？C2H6O？CH4O, Mr = 991.20）, has been synthe- sized by the nucleophilic substituti...The title compound, 2-（3-silatranylpropylamino）-4-dichlorophenyl-5,5-dimethyl- 1,3,2-dioxaphosphorinane-2-oxide （2（C20H33N2O6Psi）？C2H6O？CH4O, Mr = 991.20）, has been synthe- sized by the nucleophilic substitution reaction of 2-chloro-4-phenyl-5,5-dimethyl-1,3,2-dioxa- phosphorinane-2-oxide with γ-aminopropylsilatrane, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P with a = 10.3783（15）, b = 11.2402（17）, c = 12.1675（18） ？, ？ = 70.653（4）, ？ = 82.908（4）, ？ = 85.690（4）？, V = 1328.1（3） ？3, Z = 1, Dc = 1.239 g/cm3, μ = 0.19 mm？1, F（000） = 532, the final R = 0.0640 and wR = 0.2090 for 3615 observed reflections with I 〉 2？（I）. The cyclic dioxaphosphorinane ring in the molecule adopts a thermodynamically stable cis conformation, while the silatrane fragment forms a cage-like structure in which there exists an intramolecular Si？N donor-acceptor bond. In the crystal structure, centrosymmetrically related molecules are linked by pairs of N–H？？？O hydrogen bonds into dimers, generating rings with graph-set motif R22（8）. Furthermore, a couple of O（7）–H（10）？？？O（3） hydrogen bonds were formed by O atom of P=O and H atom from hydroxyl in the solvent ethanol. Thermal property of the compound was also studied by means of thermogravimetry （TGA）. The thermal analysis and preliminary fireproofing test show that the title compound has good flame retardance.展开更多
The title compound 2-ethoxy-spiro[2H-1,4,2-benzoxazaphosphorine-3（4H）,1＇-cycloheptane] 2-oxide （C15H22NO3P） was synthesized by the Mannich-type reaction of ο-amino-phenol with ethyl dichlorophosphinite and cyclo...The title compound 2-ethoxy-spiro[2H-1,4,2-benzoxazaphosphorine-3（4H）,1＇-cycloheptane] 2-oxide （C15H22NO3P） was synthesized by the Mannich-type reaction of ο-amino-phenol with ethyl dichlorophosphinite and cycloheptanone, and structurally characterized by single-crystal X-ray diffraction analysis. It crystallizes in orthorhombic, space group P212121 with a = 8.9840（12）, b = 9.2978（12）, c = 37.205（5） A, V= 3107.8（7） ,A^3, Z= 8, Mr = 295.31, Dc = 1.262 g/cm^3, F（000） = 1264, μ = 0.184 mm^-1, S = 1.026, the final R = 0.0502 and wR = 0.1017 for 3849 observed reflections with Ⅰ 〉 2σ（Ⅰ） and 378 variable parameters. The structure exhibits that the six-membered phosphorus heterocycle is in the envelope conformation.展开更多
Phenylurea reacted with dichlorophenylphosphine and aldehydes or ketones by Mannich-type reaction in anhydrous benzene to give five-mem- bered phosphorous heterocyclic compounds.However.derivatives of α-ureidoalkylph...Phenylurea reacted with dichlorophenylphosphine and aldehydes or ketones by Mannich-type reaction in anhydrous benzene to give five-mem- bered phosphorous heterocyclic compounds.However.derivatives of α-ureidoalkylphosphonic acids were obtained as the reaction performed in glacial acetic acid.展开更多
Six coordination compounds of Pt(Ⅱ)L_2 and Ir(Ⅲ)L_3 type(where L is PT^-, 3Me-PT^-or 4Me-PT^-)are reported here.Four coordination compounds of the latter two ligands have never been reported before,while PT^-'s ...Six coordination compounds of Pt(Ⅱ)L_2 and Ir(Ⅲ)L_3 type(where L is PT^-, 3Me-PT^-or 4Me-PT^-)are reported here.Four coordination compounds of the latter two ligands have never been reported before,while PT^-'s were synthesized with H_2PtCl_6 and(NH_4)_3IrCl_6 respectively,which were different from the methods of Davidson et al.~1 and Sterinbrech^2.They were characterized by elemental analysis, UV,IR,~1HNMR and molar conductance.Their structural formulas have been determined,and the mechanism of synthetic reaction has been discussed.展开更多
The metaphosphate anion, PO_3, was detected in the negative-ion chemicalionization mass spectra of 2,6,7-trioxa-1-phospbabicyclo[2.2. 2] octane-1-oxides.
The stability of the coordination compounds of the first transition series metal ions(Mn(Ⅱ),Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ)and Zn(Ⅱ))with 2-mercaptopyridine-1- oxide is reported.A coordination compound CoL_2 is synthesized and...The stability of the coordination compounds of the first transition series metal ions(Mn(Ⅱ),Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ)and Zn(Ⅱ))with 2-mercaptopyridine-1- oxide is reported.A coordination compound CoL_2 is synthesized and characterized for the first time.展开更多
The interaction between 4-（4-hydroxybut-2-ynyloxy）-3-（phenylsulfonyl）-1,2,5-oxadiazole-2-oxide （FB） and bovine serum albumin （BSA） was studied by spectroscopic methods including fluorescence and UV-Vis absorpt...The interaction between 4-（4-hydroxybut-2-ynyloxy）-3-（phenylsulfonyl）-1,2,5-oxadiazole-2-oxide （FB） and bovine serum albumin （BSA） was studied by spectroscopic methods including fluorescence and UV-Vis absorption spectroscopy. The quenching mechanism of fluorescence of BSA by FB was considered to be a dynamic quenching procedure. The number of binding sites n and apparent binding constant K were measured by fluorescence quenching method. The results indicate that there is FB molecular binding with BSA, and forming 1 ： 1 complex. The thermodynamic parameters such as △H, △G and △S, etc., were calculated, The results indicate that the binding reaction is mainly entropy-driven and hydrophobic forces play major role in the binding reaction, The distance r between donor （BSA） and acceptor （FB） was obtained according to Forster theory of non-radioactive energy transfer.展开更多
<正> The syntheses of a series of 2-[bis-(2-chloroethyl)amino]-6-alkoxylmethyl-tetrahydro-2H-1, 3, 2-oxazaphosphonne-2-oxide are described The structures of all target compounds have been determined by 1H NMR, M...<正> The syntheses of a series of 2-[bis-(2-chloroethyl)amino]-6-alkoxylmethyl-tetrahydro-2H-1, 3, 2-oxazaphosphonne-2-oxide are described The structures of all target compounds have been determined by 1H NMR, MS and elementary analysis, and their configurations and conformations have been studied by 31P NMR and X-ray diffraction analysis. The properties of NMR and MS of these compounds are discussed展开更多
Three new metal-organic complexes, namely [Zn(POA)2(H2O)2](1), [Zn(POA)2(H2O)2]·2H2O(2) and [Zn(POA)2]n(3), have been synthesized by organic ligand 2-carboxylic acid-4-nitropyridine-1-oxide(POA) and zinc(Ⅱ) ions...Three new metal-organic complexes, namely [Zn(POA)2(H2O)2](1), [Zn(POA)2(H2O)2]·2H2O(2) and [Zn(POA)2]n(3), have been synthesized by organic ligand 2-carboxylic acid-4-nitropyridine-1-oxide(POA) and zinc(Ⅱ) ions. The structures of complexes 1~3 are characterized by single-crystal X-ray analysis, XRD powder diffraction analysis, infrared spectroscopy and thermal stability analysis method. Complex 1 belongs to monoclinic system, space group C2/c with a = 22.8215(15), b = 7.5613(16), c = 10.048(3) ?, β = 109.47°, V = 1634.7(6) ?~3, Z = 4, F(000) = 944, Dc = 1.900 g/cm^3, C(12)H(10)N4O(12)Zn, Mr = 467.61 and μ = 1.584 mm^(-1). The whole molecule presents "V" shape. Complex 2 is a centrosymmetric structure in triclinic system with space group P1: a = 7.4728(5), b = 7.6825(6), c = 8.5184(6) ?, α = 65.975(2), β = 79.87(2), γ = 89.855(2)°, V = 4384.1(5) ?~3, Z = 1, F(000) = 256, Dc = 1.908 g/cm^3, C(12)H(14)N4O(14)Zn, Mr = 503.64 and μ = 1.492 mm^(-1). Complex 3 is a one-dimensional chain structure belonging to monoclinic system and space group P21/c with a = 4.9456(6), b = 12.5322(14), c = 11.2514(13) ?, β = 97.313(11)°, V = 6916.8(14) ?~3, Z = 2, F(000) = 432, Dc = 2.072 g/cm^3, C(12)H6N4O(10)Zn, Mr = 431.58, and μ = 1.852 mm^(-1). In three complexes, six oxygen atoms from the surrounding coordination atoms form a ZnO6 distorted octahedral coordination geometry around the zinc ions. Meanwhile, fluorescent properties of the three complexes were investigated at room temperature. The fluorescence spectroscopic analysis demonstrated that the ligand POA shows red-shift after coordinating with the zinc(Ⅱ) ions.展开更多
This study preliminarily investigates the structure-activity relationships of novel [5,6]-fused ring energetic materials derived from the 6-nitro-7-azido-pyrazol [3,4-d][1,2,3]triazine 2-oxide(ICM-103) skeleton, empha...This study preliminarily investigates the structure-activity relationships of novel [5,6]-fused ring energetic materials derived from the 6-nitro-7-azido-pyrazol [3,4-d][1,2,3]triazine 2-oxide(ICM-103) skeleton, emphasizing the role of functional group substitution in tailoring key properties such as detonation performance and mechanical sensitivity. Strategic incorporation of nitrogen-rich substituents(e.g., hydrazine, guanidine) into the 1,2,3-triazine 2-oxide framework yielded compounds with diverse performance characteristics. Notably, compound 2 demonstrates energy performance(D = 8916 m·s^(-1) and P = 36.80 GPa) comparable to RDX, yet with lower mechanical sensitivity(IS = 37 J). Theoretical calculations show that the properties of the substituents themselves and their coupling with the molecular skeleton jointly determine the key properties of the target molecules. This study provides a framework for the customized design of energetic materials by linking the chemical properties of substituents with the performance parameters of target molecules. These findings highlight the potential of local molecular structural modification driven by structure-activity relationship analysis in promoting the development of next-generation energetic materials and lay a solid foundation for future research in this field.展开更多
AIM: To investigate in vitro the therapeutic effect and mechanisms of silybin in a cellular model of hepatic steatosis.METHODS: Rat hepatoma FaO cells were loaded with lipids by exposure to 0.75 mmol/L oleate/palmitat...AIM: To investigate in vitro the therapeutic effect and mechanisms of silybin in a cellular model of hepatic steatosis.METHODS: Rat hepatoma FaO cells were loaded with lipids by exposure to 0.75 mmol/L oleate/palmitate for 3 h to mimic liver steatosis. Then, the steatotic cells were incubated for 24 h with different concentrations (25 to 100 μmol/L) of silybin as phytosome complex with vitamin E. The effects of silybin on lipid accumulation and metabolism, and on indices of oxidative stress were evaluated by absorption and fluorescence microscopy, quantitative real-time PCR, Western blot, spectrophotometric and fluorimetric assays.RESULTS: Lipid-loading resulted in intracellular triglyceride (TG) accumulation inside lipid droplets, whose number and size increased. TG accumulation was mediated by increased levels of peroxisome proliferator-activated receptors (PPARs) and sterol regulatory element-binding protein-1c (SREBP-1c). The lipid imbalance was associated with higher production of reactive oxygen species (ROS) resulting in increased lipid peroxidation, stimulation of catalase activity and activation of nuclear factor kappa-B (NF-κB). Incubation of steatotic cells with silybin 50 μmol/L significantly reduced TG accumulation likely by promoting lipid catabolism and by inhibiting lipogenic pathways, as suggested by the changes in carnitine palmitoyltransferase 1 (CPT-1), PPAR and SREBP-1c levels. The reduction in fat accumulation exerted by silybin in the steatotic cells was associated with the improvement of the oxidative imbalance caused by lipid excess as demonstrated by the reduction in ROS content, lipid peroxidation, catalase activity and NF-κB activation.CONCLUSION: We demonstrated the direct anti-steatotic and anti-oxidant effects of silybin in steatotic cells, thus elucidating at a cellular level the encouraging results demonstrated in clinical and animal studies.展开更多
The activity of proteinase is reported to correlate with the development and progression of nonalcoholic fatty liver disease(NAFLD).Puromycin-sensitive aminopeptidase(PSA/NPEPPS)is an integral nontransmembrane enzyme ...The activity of proteinase is reported to correlate with the development and progression of nonalcoholic fatty liver disease(NAFLD).Puromycin-sensitive aminopeptidase(PSA/NPEPPS)is an integral nontransmembrane enzyme that functions to catalyze the cleavage of amino acids near the N-terminus of polypeptides.A previous study suggested that this enzyme acts as a regulator of neuropeptide activity;however,the metabolic function of this enzyme in the liver has not been explored.Here,we identified the novel role of PSA in hepatic lipid metabolism.Specifically,PSA expression was lower in fatty livers from NAFLD patients and mice(HFD,ob/ob,and db/db).PSA knockdown in cultured hepatocytes exacerbated diet-induced triglyceride accumulation through enhanced lipogenesis and attenuated fatty acid β-oxidation.Moreover,PSA mediated activation of the master regulator of antioxidant response,nuclear factor erythroid 2-related factor 2(NRF2),by stabilizing NRF2 protein expression,which further induced downstream antioxidant enzymes to protect the liver from oxidative stress and lipid overload.Accordingly,liver-specific PSA overexpression attenuated hepatic lipid accumulation and steatosis in ob/ob mice.Furthermore,in human liver tissue samples,decreased PSA expression correlated with the progression of NAFLD.Overall,our findings suggest that PSA is a pivotal regulator of hepatic lipid metabolism and its antioxidant function occurs by suppressing NRF2 ubiquitination.Moreover,PSA may be a potential biomarker and therapeutic target for treating NAFLD.展开更多
Keeping in view the biological activities of 1,3,2-dioxaphosphorinane-2-one and oxime esters. some compounds possessing these two moieties have been synthesized. The configurational assignment and the ratio of cis/tra...Keeping in view the biological activities of 1,3,2-dioxaphosphorinane-2-one and oxime esters. some compounds possessing these two moieties have been synthesized. The configurational assignment and the ratio of cis/trans diastereomers of target products were performed on basis of H-1 NMR. P-31 NMR and confirmed by X-ray diffraction analysis.展开更多
Iron oxidation is a prevalent and important biogeochemical process in paddy soil,but little is known about whether and how microbially mediated iron oxidation is coupled with carbon assimilation,particularly under mic...Iron oxidation is a prevalent and important biogeochemical process in paddy soil,but little is known about whether and how microbially mediated iron oxidation is coupled with carbon assimilation,particularly under microaerobic conditions.Here,we investigated kinetics of CO_2 assimilation and Fe(Ⅱ)oxidation in an incubation experiment with paddy soil under suboxic conditions,and profiled the associated microbial community using DNA-stable isotope probing and 16S r RNA gene-based sequencing.The results showed that CO_2 assimilation and Fe(II)oxidation in the gradient tubes were predominantly mediated by the microbes enriched in the paddy soil,primarily Azospirillum and Magnetospirillum,as their relative abundances were higher in the^( 13)C heavy fractions compared to^( 12)C heavy fractions.This study provided direct evidence of chemoautotrophic microaerophiles linking iron oxidation and carbon assimilation at the oxic–anoxic interface in the paddy soil ecosystem.展开更多
As a potential substitute for fatty acids,common low-cost oils could be used to produce acetyl-CoA derivatives,which meet the needs of low-cost industrial production.However,oils are hydrophobic macromolecules and can...As a potential substitute for fatty acids,common low-cost oils could be used to produce acetyl-CoA derivatives,which meet the needs of low-cost industrial production.However,oils are hydrophobic macromolecules and cannot be directly transported into cells.In this study,caveolin was expressed in Saccharomyces cerevisiae to absorb exogenous oils.The expression of caveolin fused with green fluorescent protein showed that caveolin mediated the formation of microvesicles in S.cerevisiae and the addition of 5,6-carboxyfluorescein showed that caveolae had the ability to transport exogenous substances into cells.The intracellular and extracellular triacylglycerol levels were then detected after the addition of soybean oil pre-stained with Nile Red,which proved that caveolae had the ability to absorb the exogenous oils.Lastly,caveolin for oils absorption and lipase from Bacillus pumilus for oil hydrolysis were co-expressed in the naringenin-producing Saccharomyces cerevisiae strain,resulting in naringenin production increasing from 222 mg/g DCW(dry cell weight)(231 mg/L)to 269 mg/g DCW(241 mg/L).These results suggested that the caveolin-mediated transporter independent oil transport system would provide a promising strategy for the transport of hydrophobic substrates.展开更多
基金Supported by the Youth Foundation of Hubei Educational Committee(No.Q20151902)the State Undergraduate Innovative Training Program(No.201410517002)the Start-up Foundation for Doctor of Hubei University for Nationalities(No.MY2013B027)
文摘The title compound, 2-（3-silatranylpropylamino）-4-dichlorophenyl-5,5-dimethyl- 1,3,2-dioxaphosphorinane-2-oxide （2（C20H33N2O6Psi）？C2H6O？CH4O, Mr = 991.20）, has been synthe- sized by the nucleophilic substitution reaction of 2-chloro-4-phenyl-5,5-dimethyl-1,3,2-dioxa- phosphorinane-2-oxide with γ-aminopropylsilatrane, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P with a = 10.3783（15）, b = 11.2402（17）, c = 12.1675（18） ？, ？ = 70.653（4）, ？ = 82.908（4）, ？ = 85.690（4）？, V = 1328.1（3） ？3, Z = 1, Dc = 1.239 g/cm3, μ = 0.19 mm？1, F（000） = 532, the final R = 0.0640 and wR = 0.2090 for 3615 observed reflections with I 〉 2？（I）. The cyclic dioxaphosphorinane ring in the molecule adopts a thermodynamically stable cis conformation, while the silatrane fragment forms a cage-like structure in which there exists an intramolecular Si？N donor-acceptor bond. In the crystal structure, centrosymmetrically related molecules are linked by pairs of N–H？？？O hydrogen bonds into dimers, generating rings with graph-set motif R22（8）. Furthermore, a couple of O（7）–H（10）？？？O（3） hydrogen bonds were formed by O atom of P=O and H atom from hydroxyl in the solvent ethanol. Thermal property of the compound was also studied by means of thermogravimetry （TGA）. The thermal analysis and preliminary fireproofing test show that the title compound has good flame retardance.
文摘The title compound 2-ethoxy-spiro[2H-1,4,2-benzoxazaphosphorine-3（4H）,1＇-cycloheptane] 2-oxide （C15H22NO3P） was synthesized by the Mannich-type reaction of ο-amino-phenol with ethyl dichlorophosphinite and cycloheptanone, and structurally characterized by single-crystal X-ray diffraction analysis. It crystallizes in orthorhombic, space group P212121 with a = 8.9840（12）, b = 9.2978（12）, c = 37.205（5） A, V= 3107.8（7） ,A^3, Z= 8, Mr = 295.31, Dc = 1.262 g/cm^3, F（000） = 1264, μ = 0.184 mm^-1, S = 1.026, the final R = 0.0502 and wR = 0.1017 for 3849 observed reflections with Ⅰ 〉 2σ（Ⅰ） and 378 variable parameters. The structure exhibits that the six-membered phosphorus heterocycle is in the envelope conformation.
基金the National Natural Science Foundation of People's Republic of China:
文摘Phenylurea reacted with dichlorophenylphosphine and aldehydes or ketones by Mannich-type reaction in anhydrous benzene to give five-mem- bered phosphorous heterocyclic compounds.However.derivatives of α-ureidoalkylphosphonic acids were obtained as the reaction performed in glacial acetic acid.
文摘Six coordination compounds of Pt(Ⅱ)L_2 and Ir(Ⅲ)L_3 type(where L is PT^-, 3Me-PT^-or 4Me-PT^-)are reported here.Four coordination compounds of the latter two ligands have never been reported before,while PT^-'s were synthesized with H_2PtCl_6 and(NH_4)_3IrCl_6 respectively,which were different from the methods of Davidson et al.~1 and Sterinbrech^2.They were characterized by elemental analysis, UV,IR,~1HNMR and molar conductance.Their structural formulas have been determined,and the mechanism of synthetic reaction has been discussed.
文摘The metaphosphate anion, PO_3, was detected in the negative-ion chemicalionization mass spectra of 2,6,7-trioxa-1-phospbabicyclo[2.2. 2] octane-1-oxides.
文摘The stability of the coordination compounds of the first transition series metal ions(Mn(Ⅱ),Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ)and Zn(Ⅱ))with 2-mercaptopyridine-1- oxide is reported.A coordination compound CoL_2 is synthesized and characterized for the first time.
基金Project supported by the National Natural Science Foundation of China （Nos. 30570015, 20373051 ）, the Natural Science Foundation of Hubei Province （Nos. 2006ABA333, 2005ABC002）, and the Science Foundation of Hubei Provincial Educational Department （No. D200528003）, and the Science Research Foundation of Chinese Ministry of Education （No. [2006]8IRT0543）.
文摘The interaction between 4-（4-hydroxybut-2-ynyloxy）-3-（phenylsulfonyl）-1,2,5-oxadiazole-2-oxide （FB） and bovine serum albumin （BSA） was studied by spectroscopic methods including fluorescence and UV-Vis absorption spectroscopy. The quenching mechanism of fluorescence of BSA by FB was considered to be a dynamic quenching procedure. The number of binding sites n and apparent binding constant K were measured by fluorescence quenching method. The results indicate that there is FB molecular binding with BSA, and forming 1 ： 1 complex. The thermodynamic parameters such as △H, △G and △S, etc., were calculated, The results indicate that the binding reaction is mainly entropy-driven and hydrophobic forces play major role in the binding reaction, The distance r between donor （BSA） and acceptor （FB） was obtained according to Forster theory of non-radioactive energy transfer.
基金Project supported by the National Natural Science Foundation of China and the Postdoctor Science Foundation
文摘<正> The syntheses of a series of 2-[bis-(2-chloroethyl)amino]-6-alkoxylmethyl-tetrahydro-2H-1, 3, 2-oxazaphosphonne-2-oxide are described The structures of all target compounds have been determined by 1H NMR, MS and elementary analysis, and their configurations and conformations have been studied by 31P NMR and X-ray diffraction analysis. The properties of NMR and MS of these compounds are discussed
基金supported by Industrial pilot(key)project in Fujian Province(No.2017H0018)Subsidized Project for Postgraduates’Innovative Fund in Scientific Research of Huaqiao University。
文摘Three new metal-organic complexes, namely [Zn(POA)2(H2O)2](1), [Zn(POA)2(H2O)2]·2H2O(2) and [Zn(POA)2]n(3), have been synthesized by organic ligand 2-carboxylic acid-4-nitropyridine-1-oxide(POA) and zinc(Ⅱ) ions. The structures of complexes 1~3 are characterized by single-crystal X-ray analysis, XRD powder diffraction analysis, infrared spectroscopy and thermal stability analysis method. Complex 1 belongs to monoclinic system, space group C2/c with a = 22.8215(15), b = 7.5613(16), c = 10.048(3) ?, β = 109.47°, V = 1634.7(6) ?~3, Z = 4, F(000) = 944, Dc = 1.900 g/cm^3, C(12)H(10)N4O(12)Zn, Mr = 467.61 and μ = 1.584 mm^(-1). The whole molecule presents "V" shape. Complex 2 is a centrosymmetric structure in triclinic system with space group P1: a = 7.4728(5), b = 7.6825(6), c = 8.5184(6) ?, α = 65.975(2), β = 79.87(2), γ = 89.855(2)°, V = 4384.1(5) ?~3, Z = 1, F(000) = 256, Dc = 1.908 g/cm^3, C(12)H(14)N4O(14)Zn, Mr = 503.64 and μ = 1.492 mm^(-1). Complex 3 is a one-dimensional chain structure belonging to monoclinic system and space group P21/c with a = 4.9456(6), b = 12.5322(14), c = 11.2514(13) ?, β = 97.313(11)°, V = 6916.8(14) ?~3, Z = 2, F(000) = 432, Dc = 2.072 g/cm^3, C(12)H6N4O(10)Zn, Mr = 431.58, and μ = 1.852 mm^(-1). In three complexes, six oxygen atoms from the surrounding coordination atoms form a ZnO6 distorted octahedral coordination geometry around the zinc ions. Meanwhile, fluorescent properties of the three complexes were investigated at room temperature. The fluorescence spectroscopic analysis demonstrated that the ligand POA shows red-shift after coordinating with the zinc(Ⅱ) ions.
基金financial support from the National Natural Science Foundation of China (Grant No.22375190)。
文摘This study preliminarily investigates the structure-activity relationships of novel [5,6]-fused ring energetic materials derived from the 6-nitro-7-azido-pyrazol [3,4-d][1,2,3]triazine 2-oxide(ICM-103) skeleton, emphasizing the role of functional group substitution in tailoring key properties such as detonation performance and mechanical sensitivity. Strategic incorporation of nitrogen-rich substituents(e.g., hydrazine, guanidine) into the 1,2,3-triazine 2-oxide framework yielded compounds with diverse performance characteristics. Notably, compound 2 demonstrates energy performance(D = 8916 m·s^(-1) and P = 36.80 GPa) comparable to RDX, yet with lower mechanical sensitivity(IS = 37 J). Theoretical calculations show that the properties of the substituents themselves and their coupling with the molecular skeleton jointly determine the key properties of the target molecules. This study provides a framework for the customized design of energetic materials by linking the chemical properties of substituents with the performance parameters of target molecules. These findings highlight the potential of local molecular structural modification driven by structure-activity relationship analysis in promoting the development of next-generation energetic materials and lay a solid foundation for future research in this field.
基金Supported by MIUR-COFIN(Prot.20089SRS2X_002)Compagnia San Paolo Torino+1 种基金University of Genovaand Fondazione CARIGE
文摘AIM: To investigate in vitro the therapeutic effect and mechanisms of silybin in a cellular model of hepatic steatosis.METHODS: Rat hepatoma FaO cells were loaded with lipids by exposure to 0.75 mmol/L oleate/palmitate for 3 h to mimic liver steatosis. Then, the steatotic cells were incubated for 24 h with different concentrations (25 to 100 μmol/L) of silybin as phytosome complex with vitamin E. The effects of silybin on lipid accumulation and metabolism, and on indices of oxidative stress were evaluated by absorption and fluorescence microscopy, quantitative real-time PCR, Western blot, spectrophotometric and fluorimetric assays.RESULTS: Lipid-loading resulted in intracellular triglyceride (TG) accumulation inside lipid droplets, whose number and size increased. TG accumulation was mediated by increased levels of peroxisome proliferator-activated receptors (PPARs) and sterol regulatory element-binding protein-1c (SREBP-1c). The lipid imbalance was associated with higher production of reactive oxygen species (ROS) resulting in increased lipid peroxidation, stimulation of catalase activity and activation of nuclear factor kappa-B (NF-κB). Incubation of steatotic cells with silybin 50 μmol/L significantly reduced TG accumulation likely by promoting lipid catabolism and by inhibiting lipogenic pathways, as suggested by the changes in carnitine palmitoyltransferase 1 (CPT-1), PPAR and SREBP-1c levels. The reduction in fat accumulation exerted by silybin in the steatotic cells was associated with the improvement of the oxidative imbalance caused by lipid excess as demonstrated by the reduction in ROS content, lipid peroxidation, catalase activity and NF-κB activation.CONCLUSION: We demonstrated the direct anti-steatotic and anti-oxidant effects of silybin in steatotic cells, thus elucidating at a cellular level the encouraging results demonstrated in clinical and animal studies.
基金supported by the National Natural Science Foundation of China(82070881,82070836,and 81970752)the National Science Fund for Distinguished Young Scholars(81925007)the‘Talent Project’of Army Medical University(2017R013,2019R047,and 2019XQYYYJ003-2).
文摘The activity of proteinase is reported to correlate with the development and progression of nonalcoholic fatty liver disease(NAFLD).Puromycin-sensitive aminopeptidase(PSA/NPEPPS)is an integral nontransmembrane enzyme that functions to catalyze the cleavage of amino acids near the N-terminus of polypeptides.A previous study suggested that this enzyme acts as a regulator of neuropeptide activity;however,the metabolic function of this enzyme in the liver has not been explored.Here,we identified the novel role of PSA in hepatic lipid metabolism.Specifically,PSA expression was lower in fatty livers from NAFLD patients and mice(HFD,ob/ob,and db/db).PSA knockdown in cultured hepatocytes exacerbated diet-induced triglyceride accumulation through enhanced lipogenesis and attenuated fatty acid β-oxidation.Moreover,PSA mediated activation of the master regulator of antioxidant response,nuclear factor erythroid 2-related factor 2(NRF2),by stabilizing NRF2 protein expression,which further induced downstream antioxidant enzymes to protect the liver from oxidative stress and lipid overload.Accordingly,liver-specific PSA overexpression attenuated hepatic lipid accumulation and steatosis in ob/ob mice.Furthermore,in human liver tissue samples,decreased PSA expression correlated with the progression of NAFLD.Overall,our findings suggest that PSA is a pivotal regulator of hepatic lipid metabolism and its antioxidant function occurs by suppressing NRF2 ubiquitination.Moreover,PSA may be a potential biomarker and therapeutic target for treating NAFLD.
文摘Keeping in view the biological activities of 1,3,2-dioxaphosphorinane-2-one and oxime esters. some compounds possessing these two moieties have been synthesized. The configurational assignment and the ratio of cis/trans diastereomers of target products were performed on basis of H-1 NMR. P-31 NMR and confirmed by X-ray diffraction analysis.
基金funded by the National Natural Science Foundations of China(41420104007,41330857,and 41701295)Guangdong Natural Science Funds for Distinguished Young Scholar(2014A030306041)and Special Support Program(2016)
文摘Iron oxidation is a prevalent and important biogeochemical process in paddy soil,but little is known about whether and how microbially mediated iron oxidation is coupled with carbon assimilation,particularly under microaerobic conditions.Here,we investigated kinetics of CO_2 assimilation and Fe(Ⅱ)oxidation in an incubation experiment with paddy soil under suboxic conditions,and profiled the associated microbial community using DNA-stable isotope probing and 16S r RNA gene-based sequencing.The results showed that CO_2 assimilation and Fe(II)oxidation in the gradient tubes were predominantly mediated by the microbes enriched in the paddy soil,primarily Azospirillum and Magnetospirillum,as their relative abundances were higher in the^( 13)C heavy fractions compared to^( 12)C heavy fractions.This study provided direct evidence of chemoautotrophic microaerophiles linking iron oxidation and carbon assimilation at the oxic–anoxic interface in the paddy soil ecosystem.
基金This work was supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(32021005)the National Natural Science Foundation of China(21908078).
文摘As a potential substitute for fatty acids,common low-cost oils could be used to produce acetyl-CoA derivatives,which meet the needs of low-cost industrial production.However,oils are hydrophobic macromolecules and cannot be directly transported into cells.In this study,caveolin was expressed in Saccharomyces cerevisiae to absorb exogenous oils.The expression of caveolin fused with green fluorescent protein showed that caveolin mediated the formation of microvesicles in S.cerevisiae and the addition of 5,6-carboxyfluorescein showed that caveolae had the ability to transport exogenous substances into cells.The intracellular and extracellular triacylglycerol levels were then detected after the addition of soybean oil pre-stained with Nile Red,which proved that caveolae had the ability to absorb the exogenous oils.Lastly,caveolin for oils absorption and lipase from Bacillus pumilus for oil hydrolysis were co-expressed in the naringenin-producing Saccharomyces cerevisiae strain,resulting in naringenin production increasing from 222 mg/g DCW(dry cell weight)(231 mg/L)to 269 mg/g DCW(241 mg/L).These results suggested that the caveolin-mediated transporter independent oil transport system would provide a promising strategy for the transport of hydrophobic substrates.
