In order to reveal the effect of 2-hydroxy-3-naphthyl hydroxamic acid(H205)on the flotation behavior and action mechanism of bastnaesite,single-mineral flotation experiments of bastnaesite were conducted.The flotation...In order to reveal the effect of 2-hydroxy-3-naphthyl hydroxamic acid(H205)on the flotation behavior and action mechanism of bastnaesite,single-mineral flotation experiments of bastnaesite were conducted.The flotation recovery of bastnaesites can be achieved more than 90%when the aeration rate is 40 mL/min,the rotational speed is 200 r/min,the H205 dosage is 120 mg/L,and the pulp pH ranges from 7 to 9.The action mechanism of H205 on the surface of bastnaesite was studied by simultaneous thermogravimetry and differential scanning calorimetry(TG-DSC),Zeta potential measurements,Fourier transform-infrared spectra(FT-IR)and X-ray photoelectron spectroscopy(XPS).These analysis results show that under suitable flotation conditions,H205 has an obvious adsorption phenomenon on the surface of bastnaesite.The adsorption involves electrostatic interactions and chemical interactions,namely H205 has a strong collecting ability of bastnaesite due to the synergism of electrostatic adsorption and chemical adsorption.This study systematically reveals the flotation behavior and adsorption mechanism of H205 on the surface of bastnaesite,and provides useful theoretical guidance for efficient flotation separation of bastnaesite.展开更多
A series of potential HDACIs containing diverse Zn^(2+)-chelating hydroxamate moieties were synthesized and evaluated for their anticancer activity in vitro on HeLa,A549,and HepG2 cell lines.The A549 cell line was the...A series of potential HDACIs containing diverse Zn^(2+)-chelating hydroxamate moieties were synthesized and evaluated for their anticancer activity in vitro on HeLa,A549,and HepG2 cell lines.The A549 cell line was the most sensitive,and the most active compound,e8,exhibited an IC_(50) value of 1.68μmol/L,surpassing the positive control,SAHA(IC_(50)=4.85μmol/L).Additionally,compound e8 demonstrated lower toxicity to normal WI-38 cells compared to SAHA(IC_(50)=415.93μmol/L vs.9.09μmol/L).Furthermore,e8 efficiently induced G0/G1 phase cell cycle arrest and apoptosis in A549 cells.Molecular docking studies showed that compound e8 coordinated the Zn^(2+) cation at the enzyme’s active site and formed hydrophobic and hydrogen bonds within the hydrophobic pocket of the enzyme,resulting in stable docking with the HDAC enzyme.These studies suggested that compound e8 has the potential to be developed as a promising lead for further optimization and development of HDACIs.展开更多
In order to improve the recovery of tungsten ores containing tin minerals,anisic hydroxamic acid(p-methoxy benzohydroxanic acid,PMOB)was synthesized and introduced as novel collector in the flotation of scheelite,wolf...In order to improve the recovery of tungsten ores containing tin minerals,anisic hydroxamic acid(p-methoxy benzohydroxanic acid,PMOB)was synthesized and introduced as novel collector in the flotation of scheelite,wolframite and cassiterite.The flotation performance and adsorption mechanism were investigated by micro/batch flotation,zeta potential measurements and density functional theory(DFT).The micro flotation results showed that the recoveries of scheelite,wolframite and cassiterite using PMOB as collector are 97.45%,95.77% and 90.08%,respectively,and the corresponding recoveries are 91.00%,84.30% and 84.67% for benzohydroxamic acid(BHA).The batch flotation results revealed that the collector dosage could be reduced by about 45% for PMOB compared with BHA,in the case of similar flotation indicators.Zeta potential measurements indicated that PMOB could be adsorbed on the mineral surfaces by chemisorption.Moreover,density functional theory(DFT)calculation results showed that the substituent group—OCH_(3)endues PMOB stronger electron donation ability and hydrophobicity compared with benzohydroxamic acid(BHA),pmethyl benzohydroxamic acid(PMB)and p-hydroxyl benzohydroxamic acid(PHB).展开更多
In this paper,using methyl cinnamate as raw material,the new cinnamic hydroxamic acid collector(CIHA)was synthesized by the hydroxylamine method.The collector performance of hydroxamic acid was investigated for scheel...In this paper,using methyl cinnamate as raw material,the new cinnamic hydroxamic acid collector(CIHA)was synthesized by the hydroxylamine method.The collector performance of hydroxamic acid was investigated for scheelite and gangue calcite,and the flotation separation test of scheelite and calcite was carried out with CIHA as the collector.The interaction mechanism between hydroxamic acid and scheelite minerals has also been investigated through zeta potential,Fourier transform infrared spectroscopy(FTIR)experiments,X-ray photoelectron spectroscopy(XPS)experiments,and density functional theory(DFT)calculation.The single mineral flotation test and artificially mixed ore showed that CIHA had an excellent collection effect and selectivity.Zeta potential,FTIR,and XPS showed that CIHA was adsorbed on the scheelite surface by strong chemical adsorption.The active group of CIHA was analyzed through quantum chemical calculation.It was speculated that C=O and N-O bonds could synthesize a five-membered chelated hydroxamic acid group with Ca element chelate on scheelite surface,changing hydrophobicity and making it more likely to emerge from the pulp.展开更多
Flotation separation of smithsonite from calcite is difficult due to their similar surface properties.In the present study,a reagent scheme of depressant calcium lignosulphonate(CLS) and collector benzyl hydroxamic ac...Flotation separation of smithsonite from calcite is difficult due to their similar surface properties.In the present study,a reagent scheme of depressant calcium lignosulphonate(CLS) and collector benzyl hydroxamic acid(BHA) was introduced in the flotation of smithsonite from calcite.Microflotation tests revealed that the efficient flotation of smithsonite from calcite could only be obtained with the addition order of BHA before CLS,which was opposite to the widely-used order that adding depressant prior to the collector.The zeta potential measurements indicated that BHA selectively adsorbed onto smithsonite surface,then not allowed the CLS adsorption onto the smithsonite surface rather than calcite surface because of the steric hindrance,thereby the smithsonite surface remained hydrophobic while calcite surface became more hydrophilic after the addition of CLS.As a result,the calcite flotation was completely depressed while the smithsonite flotation recovery was still in high value,leading to the optimal flotation separation performance.展开更多
The effect of hydroxamic acid starch (HAS) and hydroxamic acid polyacrylamide (HPAM) on the flotation of diaspore and kaolinite was investigated by flotation test. It is found that HAS depresses diaspore but activates...The effect of hydroxamic acid starch (HAS) and hydroxamic acid polyacrylamide (HPAM) on the flotation of diaspore and kaolinite was investigated by flotation test. It is found that HAS depresses diaspore but activates kaolinite in acidic pulp,while HPAM activates both diaspore and kaolinite in the pH range of 2.010.5. The measurement of zeta potential shows that both HAS and HPAM can increase zeta potential of negatively charged diaspore, which indicates the existence of chemical bonding or hydrogen bonding between the reagents and diaspore. By covering the collector dodecyl amine(DDA) on diaspore surface,HAS increases the hydrophilicity of minerals and depresses the flotation of diaspore,however HPAM activates the flotation of diaspore by increasing the adsorption of DDA on diaspore surface.展开更多
Background: Histone deacetylases(HDACs) inhibitors are new anti-fibrotic drugs that inhibit the activity of hepatic stellate cells. The present study focused on the anti-fibrotic function of HDAC inhibitor suberoylani...Background: Histone deacetylases(HDACs) inhibitors are new anti-fibrotic drugs that inhibit the activity of hepatic stellate cells. The present study focused on the anti-fibrotic function of HDAC inhibitor suberoylanilide hydroxamic acid(SAHA) by suppressing transforming growth factor-β1(TGF-β1) signaling. Methods: Male Sprague-Dawley rats were used to induce liver fibrosis with carbon tetrachloride(CCl 4) and LX2 cell(human hepatic stellate cell line) was stimulated by TGF-β1. Both animals and cells were treated with SAHA. The Smad7 and connective tissue growth factor(CTGF) mRNA levels were detected by real-time polymerase chain reaction(PCR). Western blotting was used to examine the protein levels of CTGF, Histone H3(H3), Smad7, Smad2/3, Acetyl-Histone H3(AH3), HDAC2, α-smooth muscle actin( α-SMA), HDAC6, p-Smad2/3 and HDAC8. In addition, the TGF-β1 and liver enzyme levels from rat serum were detected. Histopathological changes were examined by hematoxylin and eosin(HE), Sirius red and Masson trichrome staining. The α-SMA expression was detected by immumohistochemical staining. Results: Compared with control group, the TGF-β1 and liver enzyme levels from rat serum, together with the mRNA levels of CTGF and protein levels of CTGF, HDAC2, α-SMA, HDAC6, p-Smad2/3 and HDAC8 were elevated in fibrotic rats( P < 0.01). But the Smad7 mRNA and AH3 protein levels were notably suppressed in the fibrotic rats( P < 0.01). Pathological examination showed the typical changes of liver fibrosis in the fibrotic rats. After the treatment with SAHA, the levels of liver enzymes, TGF-β1, CTGF, HDAC2, α-SMA, HDAC6, p-Smad2/3 and HDAC8 were reduced( P < 0.01) and Smad7 and AH3 protein contents were elevated in liver fibrotic rats( P < 0.01). Moreover, immumohistochemistry showed that SAHA significantly suppressed the α-SMA protein content in fibrotic liver( P < 0.01). Conclusion: The HDAC inhibitor SAHA alleviated liver fibrosis by suppressing the TGF-β1 signaling.展开更多
The performance of hydroxamic polyacrylamide(HPAM) in mineral flotation was tested on the samples of calcite, diaspore and pyrite. It is found that HPAM expresses intensive depression on pyrite and can be used as effe...The performance of hydroxamic polyacrylamide(HPAM) in mineral flotation was tested on the samples of calcite, diaspore and pyrite. It is found that HPAM expresses intensive depression on pyrite and can be used as effective depressants for pyrite. The depression mechanism of HPAM to pyrite was investigated by the determination of contact angle, zeta potential, adsorptive capacity for collectors and infrared spectrum. A lower contact angle, more negative zeta potential, less xanthate adsorptive capacity, and the formation of chemical bonding were determined, which reveals that the strong chemical interactions exist between HPAM and pyrite surface. The group electronegativity of HPAM was calculated to explain the differences of interaction between reagent and minerals.展开更多
The extraction separation of germanium from indium raffinate in hydrometallurgical zinc process was discussed. The conditions and mechanism of the extraction with hydroxamic acid HGS98 have been investigated in detail...The extraction separation of germanium from indium raffinate in hydrometallurgical zinc process was discussed. The conditions and mechanism of the extraction with hydroxamic acid HGS98 have been investigated in detail. The results show that u sing 2% (mass fraction) hydroxamic acid HGS98 and 5% D 2EHPA as synergist, germanium is extracted (1 stage) over 99% in 5 min at phase ratio ( V o∶ V a) of 1∶5 from indium raffinate with original acidity. Then, using 2 mol·L -1 NH 4F as strip liquor, the stripping recovery is over 98% in 15 min at phase ratio of 1∶1. This process has the following advantages:easy to operate, high recovery and selectivity, and lower investment cost. It provides a new way to recover rare metal-germanium from metallurgical spent residues.展开更多
The flotation and surface interaction of rutile with nonyl hydroxamic acid were investigated in this work. The results show that the adsorption density and flotation recovery of rutile have similar tendency, especiall...The flotation and surface interaction of rutile with nonyl hydroxamic acid were investigated in this work. The results show that the adsorption density and flotation recovery of rutile have similar tendency, especially the maximum recovery and adsorption occur at pH about 7.5. In terms of Fourier transform infrared（FTIR） spectroscopic analysis, chemical adsorption is identified on the surface of rutile, where a chelate of O,O-five-membered rings with Ti^4＋ on the surface of rutile may form. Adsorption measurements, Zeta potential test, IR spectrum analyses, and solution chemistry calculations illustrate that the adsorption on the rutile surface involves both physical and chemical adsorption, while chemical adsorption is dominant.展开更多
The complexes RE_2(DHYA)_3 centre dot nH_2O in the title bar were synthesizedthrough some reactions of trivalent rare-earth ions. In the process of synthesis, dihydroxamicacids were taken as ligands while the alcohol ...The complexes RE_2(DHYA)_3 centre dot nH_2O in the title bar were synthesizedthrough some reactions of trivalent rare-earth ions. In the process of synthesis, dihydroxamicacids were taken as ligands while the alcohol was taken as a solvent. The ligands includedadipylhydroxamic acid (ADHA), p-phthalichydroxamic acid (PPHA), oxalohydroxamic acid (OXHA),butadihydroxamic acid (BDHA), o-phthalichydroxamic acid (OPHA), benzoylhydroxamic acid (BHA), etc.Measured at 25 deg C, the molar conductances in various modes are 13.00-21.05 S centre dot cm^2centre dot mol^(-1), which shows that rare-earth complexes are nonelectrolytes and the hydroxaminogroups of the complexes have taken part in bonding. Infrared spectra, ultraviolet spectra, nuclearmagnetic resonance (~1HNMR) spectra, and fluorescence spectra were used to investigate thecomplexes. Experiments have proved that the complexes of En^(3+)and Tb^(3+) with aromatic hydroxamicacids have good fluorescent characteristics.展开更多
Periodontitis is a type of chronic inflammation in the gingival tissue caused by infectious bacteria colonizing the surface of the teeth,leading to the destruction of tooth-supporting tissues and loss of alveolar bone...Periodontitis is a type of chronic inflammation in the gingival tissue caused by infectious bacteria colonizing the surface of the teeth,leading to the destruction of tooth-supporting tissues and loss of alveolar bone.Suberoylanilide hydroxamic acid(SAHA),a class of histone deacetylase(HDAC)inhibitor,has the potential to stimulate osteoblast differentiation by acetylating histone proteins,and thus suppressing the expression of adipogenic and chondrogenic genes.However,the effect of SAHA on the differentiation of human periodontal ligament stem cells(hPDLSCs)is yet to be elucidated.Herein,we investigated the effects of SAHA on in vitro proliferation and differentiation of hPDLSCs by MTT assay,Alizarin Red-S,and alkaline phosphatase staining,and real-time PCR.Notably,300 ng/mL SAHA treatment enhanced the proliferation and mineralization of hPDLSCs,indicating their osteogenic potential.Moreover,a significant enhancement of osteogenesis gene markers and proteins was observed.We also demonstrated that ERK is a positive regulator of Runx2 transcription factors during osteoblast differentiation.These results indicate that SAHA may be a useful osteogenic induction agent for periodontal bone regeneration.展开更多
An N-hydroxyl peptide unit of H-L-Pro-L-Ala-L-Ala-β-（BnO）Ala-OMe was synthesized by stepwise chain building method in solution. Then, based on nitrilotriacetic acid backbone and this N-hydroxyl peptide unit, a nove...An N-hydroxyl peptide unit of H-L-Pro-L-Ala-L-Ala-β-（BnO）Ala-OMe was synthesized by stepwise chain building method in solution. Then, based on nitrilotriacetic acid backbone and this N-hydroxyl peptide unit, a novel chiral tripodal ligand P as an analogue of desferrichrome, has been synthesized. In neutral pH, ligand P formed stable tri（hydroxamato）- iron（Ⅲ） complexes which showed a maximum absorptiota （∑max=2750 M^-lcm^-1） at 422 nm in UV-Vis spectra. The characteristic absorption spectra are similar to those of natural trihydroxamate-type siderophores.展开更多
Ynamides are electron-rich alkynes with unique reactivities and act as flexible building blocks in organic synthesis.Therefore,the investigation for transformation of ynamides with exceptional selectivity and efficien...Ynamides are electron-rich alkynes with unique reactivities and act as flexible building blocks in organic synthesis.Therefore,the investigation for transformation of ynamides with exceptional selectivity and efficiency is attractive and interesting.Herein,we report an oxoarylation of ynamides with N-aryl hydroxamic acids.In the presence of catalytic Cu(OTf)_(2),both the terminal and internal ynamides could undergo an addition/[3,3] sigmatropic rearrangement cascade with N-aryl hydroxamic acids to achieve oxoarylation,along with providing selective entry to(ortho-amino)arylacetamides and oxindoles.Moreover,deuterium-labelling reaction and gram-scale reaction were conducted to probe the mechanism and showcase the scalability.展开更多
Novel Co（Ⅱ） complexes with dihydroxamic acids functionalized N-pivot lariat ether CoL^1-CoL^4 were synthesized and characterized.Their oxygenation constants（ln K_（O2）） and thermodynamic parameters（△H°,△...Novel Co（Ⅱ） complexes with dihydroxamic acids functionalized N-pivot lariat ether CoL^1-CoL^4 were synthesized and characterized.Their oxygenation constants（ln K_（O2）） and thermodynamic parameters（△H°,△S°） were measured.And their catalytic performance in oxidation of p-xylene to p-toluic acid（PTA） was investigated.The enhancement of O_2-binding and catalytic oxidation activity by the oxa aza crown ether ring of the cobalt complexes were discussed.展开更多
BACKGROUND Hepatocellular carcinoma(HCC)is a common clinical condition with a poor prognosis and few effective treatment options.Potent anticancer agents for treating HCC must be identified.Epigenetics plays an essent...BACKGROUND Hepatocellular carcinoma(HCC)is a common clinical condition with a poor prognosis and few effective treatment options.Potent anticancer agents for treating HCC must be identified.Epigenetics plays an essential role in HCC tumorigenesis.Suberoylanilide hydroxamic acid(SAHA),the most common histone deacetylase inhibitor agent,triggers many forms of cell death in HCC.However,the underlying mechanism of action remains unclear.Family with sequence similarity 134 member B(FAM134B)-induced reticulophagy,a selective autophagic pathway,participates in the decision of cell fate and exhibits anticancer activity.This study focused on the relationship between FAM134B-induced reticulophagy and SAHA-mediated cell death.AIM To elucidate potential roles and underlying molecular mechanisms of reticulophagy in SAHA-induced HCC cell death.METHODS The viability,apoptosis,cell cycle,migration,and invasion of SAHA-treated Huh7 and MHCC97L cells were measured.Proteins related to the reticulophagy pathway,mitochondria-endoplasmic reticulum(ER)contact sites,intrinsic mitochondrial apoptosis,and histone acetylation were quantified using western blotting.ER and lysosome colocalization,and mitochondrial Ca^(2+)levels were characterized via confocal microscopy.The level of cell death was evaluated through Hoechst 33342 staining and propidium iodide colocalization.Chromatin immunoprecipitation was used to verify histone H4 lysine-16 acetylation in the FAM134B promoter region.RESULTS After SAHA treatment,the proliferation of Huh7 and MHCC97L cells was significantly inhibited,and the migration and invasion abilities were greatly blocked in vitro.This promoted apoptosis and caused G1 phase cells to increase in a concentration-dependent manner.Following treatment with SAHA,ER-phagy was activated,thereby triggering autophagy-mediated cell death of HCC cells in vitro.Western blotting and chromatin immunoprecipitation assays confirmed that SAHA regulated FAM134B expression by enhancing the histone H4 lysine-16 acetylation in the FAM134B promoter region.Further,SAHA disturbed the Ca^(2+)homeostasis and upregulated the level of autocrine motility factor receptor and proteins related to mitochondria-endoplasmic reticulum contact sites in HCC cells.Additionally,SAHA decreased the mitochondrial membrane potential levels,thereby accelerating the activation of the reticulophagy-mediated mitochondrial apoptosis pathway and promoting HCC cell death in vitro.CONCLUSION SAHA stimulates FAM134B-mediated ER-phagy to synergistically enhance the mitochondrial apoptotic pathway,thereby enhancing HCC cell death.展开更多
The first synthesis and structural characterization by X-ray crystallography of racemic 2,2＇-dihydroxy-[1,1＇]binaphthalenyl-3,3＇-bis-hydroxamic acids were reported.The com-pound（C28H30N4O8,Mr = 550.56） crystalliz...The first synthesis and structural characterization by X-ray crystallography of racemic 2,2＇-dihydroxy-[1,1＇]binaphthalenyl-3,3＇-bis-hydroxamic acids were reported.The com-pound（C28H30N4O8,Mr = 550.56） crystallizes in orthorhombic system,Fdd2 space group with a = 13.055（3）,b = 34.871（7）,c = 12.570（3） ,V = 5722（2） 3,Z = 8,Dc = 1.278 g/cm3,λ = 0.71073 ,μ（MoKα） = 0.095 mm-1,F（000） = 2320,S = 1.021,R = 0.0349 and wR = 0.0802 for 1757 observed reflections with I 〉 2σ（I）.The N-H and O atom are involved in two-dimensional intermolecular hydrogen bond nets,which further stabilize the structure.展开更多
TWO complexes of compositions [Zn（H2shi）（CHsCOO）]. （1） and [Cd（H2shih（H20）]. （2） （H3shi = salicylhydroxamic acid） have been prepared under solvothermal conditions. They are characterized by X-ray single-c...TWO complexes of compositions [Zn（H2shi）（CHsCOO）]. （1） and [Cd（H2shih（H20）]. （2） （H3shi = salicylhydroxamic acid） have been prepared under solvothermal conditions. They are characterized by X-ray single-crystal diffraction, IR and elemental analysis. The crystal of 1 belongs to the tetragonal system, space group I41/a with a = 18.972（3）, b = 18.972（3）, c = 10.938（2） A, V= 3937.1（I） A3, C9H9NOsZn, Mr - 276.54, Z = 16, Dc = 1.866 g/cm3,μ = 2.500 mm-1, F（000） = 2240, the final R = 0.0425 and wR = 0.123. The crystal of 2 belongs to the monoclinic system, space group P2/c with a = 16.647（3）, b = 6.4577（I）, c = 6.5623（I） A, V = 702.4（2） A3, C14H4Cd2N2OT, Mr = 434.68, Z = 2, Dc = 2.055 g/cm3,μ = 1.599 mm-1, F（000） = 432, the final R = 0.0211 and wR = 0.0761. They both possess I-D polymeric chain structures. The luminescent properties of complexes I and 2 have been investigated.展开更多
In this work, we conducted a QSAR study on 18 molecules using descriptors from the Density Functional Theory (DFT) in order to predict the inhibitory activity of hydroxamic acids on histone deacetylase 7. This study i...In this work, we conducted a QSAR study on 18 molecules using descriptors from the Density Functional Theory (DFT) in order to predict the inhibitory activity of hydroxamic acids on histone deacetylase 7. This study is performed using the principal component analysis (PCA) method, the Ascendant Hierarchical Classification (AHC), the linear multiple regression method (LMR) and the nonlinear multiple regression (NLMR). DFT calculations were performed to obtain information on the structure and information on the properties on a series of hydroxamic acids compounds studied. Multivariate statistical analysis yielded two quantitative models (model MLR and model MNLR) with the quantum descriptors: electronic affinity (AE), vibration frequency of the OH bond (ν(OH)) and that of the NH bond (ν(NH)). The LMR model gives statistically significant results and shows a good predictability R2 = 0.9659, S = 0.488, F = 85 and p-value . Electronic affinity is the priority descriptor in predicting the activity of HDAC7 inhibitors in this study. The results obtained suggest that the descriptors derived from the DFT could be useful to predict the activity of histone deacetylase 7 inhibitors. These models were evaluated according to the criteria of Tropsha et al.展开更多
The conventional collector for diaspore mineral is oleic acid,which is highly insoluble and must be used in high dosage in bauxite flotation,that is the great drawback of oleic acid in use.Octylic hydroxamic acid was ...The conventional collector for diaspore mineral is oleic acid,which is highly insoluble and must be used in high dosage in bauxite flotation,that is the great drawback of oleic acid in use.Octylic hydroxamic acid was synthesized,and its collecting ability to certain minerals in bauxite:diaspore and kaolinite were studied.The collecting power of various reagents to diaspore in an incremental sequence was shown as follows:oleic acid<octylic hydroxamic acid,while the incremental sequence of the collecting power to kaolinite was like this:octylic hydroxamic acid < oleic acid.It could be seen that octylic hydroxamic acid had the capability of high collectivity and good selectivity,and octylic hydroxamic acid was chosen to use in the following experiments.Reduced zeta potential showed the adsorption of the anionic collector on the mineral.By the adsorptive capability and IR(infrared ray)tests,the adsorption of octylic hydroxamic acid on diaspore was determined to be chemical absorption,which was greater than that of oleic acid,as it was absorption by hydrogen bond.展开更多
基金Project supported by the Natural Science Foundation Innovation Group Project of Hubei Province(2023AFA044)the National Natural Science Foundation of China(52222405)+1 种基金the Science and Technology Research Project of Education Department of Hubei Province(Q20221505)the China Postdoctoral Science(2023M731041)。
文摘In order to reveal the effect of 2-hydroxy-3-naphthyl hydroxamic acid(H205)on the flotation behavior and action mechanism of bastnaesite,single-mineral flotation experiments of bastnaesite were conducted.The flotation recovery of bastnaesites can be achieved more than 90%when the aeration rate is 40 mL/min,the rotational speed is 200 r/min,the H205 dosage is 120 mg/L,and the pulp pH ranges from 7 to 9.The action mechanism of H205 on the surface of bastnaesite was studied by simultaneous thermogravimetry and differential scanning calorimetry(TG-DSC),Zeta potential measurements,Fourier transform-infrared spectra(FT-IR)and X-ray photoelectron spectroscopy(XPS).These analysis results show that under suitable flotation conditions,H205 has an obvious adsorption phenomenon on the surface of bastnaesite.The adsorption involves electrostatic interactions and chemical interactions,namely H205 has a strong collecting ability of bastnaesite due to the synergism of electrostatic adsorption and chemical adsorption.This study systematically reveals the flotation behavior and adsorption mechanism of H205 on the surface of bastnaesite,and provides useful theoretical guidance for efficient flotation separation of bastnaesite.
文摘A series of potential HDACIs containing diverse Zn^(2+)-chelating hydroxamate moieties were synthesized and evaluated for their anticancer activity in vitro on HeLa,A549,and HepG2 cell lines.The A549 cell line was the most sensitive,and the most active compound,e8,exhibited an IC_(50) value of 1.68μmol/L,surpassing the positive control,SAHA(IC_(50)=4.85μmol/L).Additionally,compound e8 demonstrated lower toxicity to normal WI-38 cells compared to SAHA(IC_(50)=415.93μmol/L vs.9.09μmol/L).Furthermore,e8 efficiently induced G0/G1 phase cell cycle arrest and apoptosis in A549 cells.Molecular docking studies showed that compound e8 coordinated the Zn^(2+) cation at the enzyme’s active site and formed hydrophobic and hydrogen bonds within the hydrophobic pocket of the enzyme,resulting in stable docking with the HDAC enzyme.These studies suggested that compound e8 has the potential to be developed as a promising lead for further optimization and development of HDACIs.
基金Projects(2020GDASYL-20200302009,2020GDASYL-20200302004,2019GDASYL-0501007)supported by Guandong Academy of Sciences,ChinaProject(2020YFC1909202)supported by Ministry of Science and Technology of China。
文摘In order to improve the recovery of tungsten ores containing tin minerals,anisic hydroxamic acid(p-methoxy benzohydroxanic acid,PMOB)was synthesized and introduced as novel collector in the flotation of scheelite,wolframite and cassiterite.The flotation performance and adsorption mechanism were investigated by micro/batch flotation,zeta potential measurements and density functional theory(DFT).The micro flotation results showed that the recoveries of scheelite,wolframite and cassiterite using PMOB as collector are 97.45%,95.77% and 90.08%,respectively,and the corresponding recoveries are 91.00%,84.30% and 84.67% for benzohydroxamic acid(BHA).The batch flotation results revealed that the collector dosage could be reduced by about 45% for PMOB compared with BHA,in the case of similar flotation indicators.Zeta potential measurements indicated that PMOB could be adsorbed on the mineral surfaces by chemisorption.Moreover,density functional theory(DFT)calculation results showed that the substituent group—OCH_(3)endues PMOB stronger electron donation ability and hydrophobicity compared with benzohydroxamic acid(BHA),pmethyl benzohydroxamic acid(PMB)and p-hydroxyl benzohydroxamic acid(PHB).
基金the National Nature Science Foundation of China(No.51774152)Jiangxi Provincial Education Department(GJJ200816)+1 种基金“Double height project”in Jiangxi province(No.[2022]223)the National Nature Science Foundation of China(No.52264023).
文摘In this paper,using methyl cinnamate as raw material,the new cinnamic hydroxamic acid collector(CIHA)was synthesized by the hydroxylamine method.The collector performance of hydroxamic acid was investigated for scheelite and gangue calcite,and the flotation separation test of scheelite and calcite was carried out with CIHA as the collector.The interaction mechanism between hydroxamic acid and scheelite minerals has also been investigated through zeta potential,Fourier transform infrared spectroscopy(FTIR)experiments,X-ray photoelectron spectroscopy(XPS)experiments,and density functional theory(DFT)calculation.The single mineral flotation test and artificially mixed ore showed that CIHA had an excellent collection effect and selectivity.Zeta potential,FTIR,and XPS showed that CIHA was adsorbed on the scheelite surface by strong chemical adsorption.The active group of CIHA was analyzed through quantum chemical calculation.It was speculated that C=O and N-O bonds could synthesize a five-membered chelated hydroxamic acid group with Ca element chelate on scheelite surface,changing hydrophobicity and making it more likely to emerge from the pulp.
基金the support of Natural Science Foundation of China (51804238, 51904214)the Open Foundation of State Key Laboratory of Mineral Processing, BGRIMM Technology (No. BGRIMM-KJSKL-2021-22)the Fundamental Research Funds for the Central Universities (2021IVA110, 2021IVA039)。
文摘Flotation separation of smithsonite from calcite is difficult due to their similar surface properties.In the present study,a reagent scheme of depressant calcium lignosulphonate(CLS) and collector benzyl hydroxamic acid(BHA) was introduced in the flotation of smithsonite from calcite.Microflotation tests revealed that the efficient flotation of smithsonite from calcite could only be obtained with the addition order of BHA before CLS,which was opposite to the widely-used order that adding depressant prior to the collector.The zeta potential measurements indicated that BHA selectively adsorbed onto smithsonite surface,then not allowed the CLS adsorption onto the smithsonite surface rather than calcite surface because of the steric hindrance,thereby the smithsonite surface remained hydrophobic while calcite surface became more hydrophilic after the addition of CLS.As a result,the calcite flotation was completely depressed while the smithsonite flotation recovery was still in high value,leading to the optimal flotation separation performance.
文摘The effect of hydroxamic acid starch (HAS) and hydroxamic acid polyacrylamide (HPAM) on the flotation of diaspore and kaolinite was investigated by flotation test. It is found that HAS depresses diaspore but activates kaolinite in acidic pulp,while HPAM activates both diaspore and kaolinite in the pH range of 2.010.5. The measurement of zeta potential shows that both HAS and HPAM can increase zeta potential of negatively charged diaspore, which indicates the existence of chemical bonding or hydrogen bonding between the reagents and diaspore. By covering the collector dodecyl amine(DDA) on diaspore surface,HAS increases the hydrophilicity of minerals and depresses the flotation of diaspore,however HPAM activates the flotation of diaspore by increasing the adsorption of DDA on diaspore surface.
基金supported by a grant from the National Natural Science Foundation of China(81870413)
文摘Background: Histone deacetylases(HDACs) inhibitors are new anti-fibrotic drugs that inhibit the activity of hepatic stellate cells. The present study focused on the anti-fibrotic function of HDAC inhibitor suberoylanilide hydroxamic acid(SAHA) by suppressing transforming growth factor-β1(TGF-β1) signaling. Methods: Male Sprague-Dawley rats were used to induce liver fibrosis with carbon tetrachloride(CCl 4) and LX2 cell(human hepatic stellate cell line) was stimulated by TGF-β1. Both animals and cells were treated with SAHA. The Smad7 and connective tissue growth factor(CTGF) mRNA levels were detected by real-time polymerase chain reaction(PCR). Western blotting was used to examine the protein levels of CTGF, Histone H3(H3), Smad7, Smad2/3, Acetyl-Histone H3(AH3), HDAC2, α-smooth muscle actin( α-SMA), HDAC6, p-Smad2/3 and HDAC8. In addition, the TGF-β1 and liver enzyme levels from rat serum were detected. Histopathological changes were examined by hematoxylin and eosin(HE), Sirius red and Masson trichrome staining. The α-SMA expression was detected by immumohistochemical staining. Results: Compared with control group, the TGF-β1 and liver enzyme levels from rat serum, together with the mRNA levels of CTGF and protein levels of CTGF, HDAC2, α-SMA, HDAC6, p-Smad2/3 and HDAC8 were elevated in fibrotic rats( P < 0.01). But the Smad7 mRNA and AH3 protein levels were notably suppressed in the fibrotic rats( P < 0.01). Pathological examination showed the typical changes of liver fibrosis in the fibrotic rats. After the treatment with SAHA, the levels of liver enzymes, TGF-β1, CTGF, HDAC2, α-SMA, HDAC6, p-Smad2/3 and HDAC8 were reduced( P < 0.01) and Smad7 and AH3 protein contents were elevated in liver fibrotic rats( P < 0.01). Moreover, immumohistochemistry showed that SAHA significantly suppressed the α-SMA protein content in fibrotic liver( P < 0.01). Conclusion: The HDAC inhibitor SAHA alleviated liver fibrosis by suppressing the TGF-β1 signaling.
文摘The performance of hydroxamic polyacrylamide(HPAM) in mineral flotation was tested on the samples of calcite, diaspore and pyrite. It is found that HPAM expresses intensive depression on pyrite and can be used as effective depressants for pyrite. The depression mechanism of HPAM to pyrite was investigated by the determination of contact angle, zeta potential, adsorptive capacity for collectors and infrared spectrum. A lower contact angle, more negative zeta potential, less xanthate adsorptive capacity, and the formation of chemical bonding were determined, which reveals that the strong chemical interactions exist between HPAM and pyrite surface. The group electronegativity of HPAM was calculated to explain the differences of interaction between reagent and minerals.
文摘The extraction separation of germanium from indium raffinate in hydrometallurgical zinc process was discussed. The conditions and mechanism of the extraction with hydroxamic acid HGS98 have been investigated in detail. The results show that u sing 2% (mass fraction) hydroxamic acid HGS98 and 5% D 2EHPA as synergist, germanium is extracted (1 stage) over 99% in 5 min at phase ratio ( V o∶ V a) of 1∶5 from indium raffinate with original acidity. Then, using 2 mol·L -1 NH 4F as strip liquor, the stripping recovery is over 98% in 15 min at phase ratio of 1∶1. This process has the following advantages:easy to operate, high recovery and selectivity, and lower investment cost. It provides a new way to recover rare metal-germanium from metallurgical spent residues.
基金financially supported by the National Natural Science Foundation of China (No. 51474254)the Ph.D. Programs Foundation of Ministry of Education of China (No. 20120162110008)+2 种基金China Postdoctoral Science Foundation (No. 2013M531813)the Planned Science and Technology Project of Hunan Province, China (No. 2012SK3233)the Independent Exploration and Innovation Projects of Master of Central South University (No. 2014zzts275)
文摘The flotation and surface interaction of rutile with nonyl hydroxamic acid were investigated in this work. The results show that the adsorption density and flotation recovery of rutile have similar tendency, especially the maximum recovery and adsorption occur at pH about 7.5. In terms of Fourier transform infrared（FTIR） spectroscopic analysis, chemical adsorption is identified on the surface of rutile, where a chelate of O,O-five-membered rings with Ti^4＋ on the surface of rutile may form. Adsorption measurements, Zeta potential test, IR spectrum analyses, and solution chemistry calculations illustrate that the adsorption on the rutile surface involves both physical and chemical adsorption, while chemical adsorption is dominant.
基金This Work was Financially Supported by the National Natural Science Foundation ofjiangxi Province (-1181).
文摘The complexes RE_2(DHYA)_3 centre dot nH_2O in the title bar were synthesizedthrough some reactions of trivalent rare-earth ions. In the process of synthesis, dihydroxamicacids were taken as ligands while the alcohol was taken as a solvent. The ligands includedadipylhydroxamic acid (ADHA), p-phthalichydroxamic acid (PPHA), oxalohydroxamic acid (OXHA),butadihydroxamic acid (BDHA), o-phthalichydroxamic acid (OPHA), benzoylhydroxamic acid (BHA), etc.Measured at 25 deg C, the molar conductances in various modes are 13.00-21.05 S centre dot cm^2centre dot mol^(-1), which shows that rare-earth complexes are nonelectrolytes and the hydroxaminogroups of the complexes have taken part in bonding. Infrared spectra, ultraviolet spectra, nuclearmagnetic resonance (~1HNMR) spectra, and fluorescence spectra were used to investigate thecomplexes. Experiments have proved that the complexes of En^(3+)and Tb^(3+) with aromatic hydroxamicacids have good fluorescent characteristics.
基金the National Research Foundation of Korea(NRF)and funded by the Ministry of Education(No.2018R1A6A1A03025582)the National Research Foundation of Korea(NRF-2019R1D1A3A03103828).
文摘Periodontitis is a type of chronic inflammation in the gingival tissue caused by infectious bacteria colonizing the surface of the teeth,leading to the destruction of tooth-supporting tissues and loss of alveolar bone.Suberoylanilide hydroxamic acid(SAHA),a class of histone deacetylase(HDAC)inhibitor,has the potential to stimulate osteoblast differentiation by acetylating histone proteins,and thus suppressing the expression of adipogenic and chondrogenic genes.However,the effect of SAHA on the differentiation of human periodontal ligament stem cells(hPDLSCs)is yet to be elucidated.Herein,we investigated the effects of SAHA on in vitro proliferation and differentiation of hPDLSCs by MTT assay,Alizarin Red-S,and alkaline phosphatase staining,and real-time PCR.Notably,300 ng/mL SAHA treatment enhanced the proliferation and mineralization of hPDLSCs,indicating their osteogenic potential.Moreover,a significant enhancement of osteogenesis gene markers and proteins was observed.We also demonstrated that ERK is a positive regulator of Runx2 transcription factors during osteoblast differentiation.These results indicate that SAHA may be a useful osteogenic induction agent for periodontal bone regeneration.
文摘An N-hydroxyl peptide unit of H-L-Pro-L-Ala-L-Ala-β-（BnO）Ala-OMe was synthesized by stepwise chain building method in solution. Then, based on nitrilotriacetic acid backbone and this N-hydroxyl peptide unit, a novel chiral tripodal ligand P as an analogue of desferrichrome, has been synthesized. In neutral pH, ligand P formed stable tri（hydroxamato）- iron（Ⅲ） complexes which showed a maximum absorptiota （∑max=2750 M^-lcm^-1） at 422 nm in UV-Vis spectra. The characteristic absorption spectra are similar to those of natural trihydroxamate-type siderophores.
基金financial support by the National Natural Science Foundation of China (Nos.21878264,21971222)。
文摘Ynamides are electron-rich alkynes with unique reactivities and act as flexible building blocks in organic synthesis.Therefore,the investigation for transformation of ynamides with exceptional selectivity and efficiency is attractive and interesting.Herein,we report an oxoarylation of ynamides with N-aryl hydroxamic acids.In the presence of catalytic Cu(OTf)_(2),both the terminal and internal ynamides could undergo an addition/[3,3] sigmatropic rearrangement cascade with N-aryl hydroxamic acids to achieve oxoarylation,along with providing selective entry to(ortho-amino)arylacetamides and oxindoles.Moreover,deuterium-labelling reaction and gram-scale reaction were conducted to probe the mechanism and showcase the scalability.
基金supported by Chongqing Education Commission(No.KJ1400632)
文摘Novel Co（Ⅱ） complexes with dihydroxamic acids functionalized N-pivot lariat ether CoL^1-CoL^4 were synthesized and characterized.Their oxygenation constants（ln K_（O2）） and thermodynamic parameters（△H°,△S°） were measured.And their catalytic performance in oxidation of p-xylene to p-toluic acid（PTA） was investigated.The enhancement of O_2-binding and catalytic oxidation activity by the oxa aza crown ether ring of the cobalt complexes were discussed.
基金the National Natural Science Foundation of China,No.82260127Guizhou Provincial Science and Technology Projects,No.Qiankehe Jichu-ZK[2021]365 and Qiankehe Jichu-ZK[2021]364+2 种基金National Natural Science Foundation Cultivation Project of Guizhou Medical University,No.20NSP016Guizhou Provincial Natural Science Foundation,No.[2021]4029 and[2022]4017Science and Technology Foundation of Guizhou Provincial Health Commission,No.gzwjkj2019-1-102.
文摘BACKGROUND Hepatocellular carcinoma(HCC)is a common clinical condition with a poor prognosis and few effective treatment options.Potent anticancer agents for treating HCC must be identified.Epigenetics plays an essential role in HCC tumorigenesis.Suberoylanilide hydroxamic acid(SAHA),the most common histone deacetylase inhibitor agent,triggers many forms of cell death in HCC.However,the underlying mechanism of action remains unclear.Family with sequence similarity 134 member B(FAM134B)-induced reticulophagy,a selective autophagic pathway,participates in the decision of cell fate and exhibits anticancer activity.This study focused on the relationship between FAM134B-induced reticulophagy and SAHA-mediated cell death.AIM To elucidate potential roles and underlying molecular mechanisms of reticulophagy in SAHA-induced HCC cell death.METHODS The viability,apoptosis,cell cycle,migration,and invasion of SAHA-treated Huh7 and MHCC97L cells were measured.Proteins related to the reticulophagy pathway,mitochondria-endoplasmic reticulum(ER)contact sites,intrinsic mitochondrial apoptosis,and histone acetylation were quantified using western blotting.ER and lysosome colocalization,and mitochondrial Ca^(2+)levels were characterized via confocal microscopy.The level of cell death was evaluated through Hoechst 33342 staining and propidium iodide colocalization.Chromatin immunoprecipitation was used to verify histone H4 lysine-16 acetylation in the FAM134B promoter region.RESULTS After SAHA treatment,the proliferation of Huh7 and MHCC97L cells was significantly inhibited,and the migration and invasion abilities were greatly blocked in vitro.This promoted apoptosis and caused G1 phase cells to increase in a concentration-dependent manner.Following treatment with SAHA,ER-phagy was activated,thereby triggering autophagy-mediated cell death of HCC cells in vitro.Western blotting and chromatin immunoprecipitation assays confirmed that SAHA regulated FAM134B expression by enhancing the histone H4 lysine-16 acetylation in the FAM134B promoter region.Further,SAHA disturbed the Ca^(2+)homeostasis and upregulated the level of autocrine motility factor receptor and proteins related to mitochondria-endoplasmic reticulum contact sites in HCC cells.Additionally,SAHA decreased the mitochondrial membrane potential levels,thereby accelerating the activation of the reticulophagy-mediated mitochondrial apoptosis pathway and promoting HCC cell death in vitro.CONCLUSION SAHA stimulates FAM134B-mediated ER-phagy to synergistically enhance the mitochondrial apoptotic pathway,thereby enhancing HCC cell death.
基金Supported by the National Natural Science Foundation of China (No. 20971029)Natural Science Foundation of Guangxi Province (No. 2010GXNSFD013018 and 2010GXNSFF013001)
文摘The first synthesis and structural characterization by X-ray crystallography of racemic 2,2＇-dihydroxy-[1,1＇]binaphthalenyl-3,3＇-bis-hydroxamic acids were reported.The com-pound（C28H30N4O8,Mr = 550.56） crystallizes in orthorhombic system,Fdd2 space group with a = 13.055（3）,b = 34.871（7）,c = 12.570（3） ,V = 5722（2） 3,Z = 8,Dc = 1.278 g/cm3,λ = 0.71073 ,μ（MoKα） = 0.095 mm-1,F（000） = 2320,S = 1.021,R = 0.0349 and wR = 0.0802 for 1757 observed reflections with I 〉 2σ（I）.The N-H and O atom are involved in two-dimensional intermolecular hydrogen bond nets,which further stabilize the structure.
基金Supported by the National Natural Science Foundation of China(21272167,51404234 and U140710123)a project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institution and KLSLRC(KLSLRC-KF-13-HX-1)
文摘TWO complexes of compositions [Zn（H2shi）（CHsCOO）]. （1） and [Cd（H2shih（H20）]. （2） （H3shi = salicylhydroxamic acid） have been prepared under solvothermal conditions. They are characterized by X-ray single-crystal diffraction, IR and elemental analysis. The crystal of 1 belongs to the tetragonal system, space group I41/a with a = 18.972（3）, b = 18.972（3）, c = 10.938（2） A, V= 3937.1（I） A3, C9H9NOsZn, Mr - 276.54, Z = 16, Dc = 1.866 g/cm3,μ = 2.500 mm-1, F（000） = 2240, the final R = 0.0425 and wR = 0.123. The crystal of 2 belongs to the monoclinic system, space group P2/c with a = 16.647（3）, b = 6.4577（I）, c = 6.5623（I） A, V = 702.4（2） A3, C14H4Cd2N2OT, Mr = 434.68, Z = 2, Dc = 2.055 g/cm3,μ = 1.599 mm-1, F（000） = 432, the final R = 0.0211 and wR = 0.0761. They both possess I-D polymeric chain structures. The luminescent properties of complexes I and 2 have been investigated.
文摘In this work, we conducted a QSAR study on 18 molecules using descriptors from the Density Functional Theory (DFT) in order to predict the inhibitory activity of hydroxamic acids on histone deacetylase 7. This study is performed using the principal component analysis (PCA) method, the Ascendant Hierarchical Classification (AHC), the linear multiple regression method (LMR) and the nonlinear multiple regression (NLMR). DFT calculations were performed to obtain information on the structure and information on the properties on a series of hydroxamic acids compounds studied. Multivariate statistical analysis yielded two quantitative models (model MLR and model MNLR) with the quantum descriptors: electronic affinity (AE), vibration frequency of the OH bond (ν(OH)) and that of the NH bond (ν(NH)). The LMR model gives statistically significant results and shows a good predictability R2 = 0.9659, S = 0.488, F = 85 and p-value . Electronic affinity is the priority descriptor in predicting the activity of HDAC7 inhibitors in this study. The results obtained suggest that the descriptors derived from the DFT could be useful to predict the activity of histone deacetylase 7 inhibitors. These models were evaluated according to the criteria of Tropsha et al.
基金National Key Fundamental Research and Development Program (No.2005cb623701)
文摘The conventional collector for diaspore mineral is oleic acid,which is highly insoluble and must be used in high dosage in bauxite flotation,that is the great drawback of oleic acid in use.Octylic hydroxamic acid was synthesized,and its collecting ability to certain minerals in bauxite:diaspore and kaolinite were studied.The collecting power of various reagents to diaspore in an incremental sequence was shown as follows:oleic acid<octylic hydroxamic acid,while the incremental sequence of the collecting power to kaolinite was like this:octylic hydroxamic acid < oleic acid.It could be seen that octylic hydroxamic acid had the capability of high collectivity and good selectivity,and octylic hydroxamic acid was chosen to use in the following experiments.Reduced zeta potential showed the adsorption of the anionic collector on the mineral.By the adsorptive capability and IR(infrared ray)tests,the adsorption of octylic hydroxamic acid on diaspore was determined to be chemical absorption,which was greater than that of oleic acid,as it was absorption by hydrogen bond.
