The effect of the presence of trace SO_(2)in industrial flue gas on the amine-scrubbing-based absorption process for CO_(2)capture has been a matter of concern.This study aimed to investigate the effect of trace SO_(2...The effect of the presence of trace SO_(2)in industrial flue gas on the amine-scrubbing-based absorption process for CO_(2)capture has been a matter of concern.This study aimed to investigate the effect of trace SO_(2)on the CO_(2)capture process using piperazine-based amine absorbents,focusing on SO_(2)-resistance capability,SO_(2)/CO_(2)absorption selectivity,and cyclic stability.The presence of trace SO_(2)not only restrains CO_(2)absorption,but also promotes the formation of carbamate within the piperazine-based amine absorbents.Remarkably,the incorporation of aminoethyl group in piperazine-based amine absorbents can enhance the SO_(2)-resistance capability by promoting the formation of carbamate,while piperazine-based amine absorbents with hydroxyethyl group can promote the formation of bicarbonate to reduce the SO_(2)-resistance capability.The work offers valuable insights into the efficient application of novel amine absorbents for CO_(2)capture from practical industrial flue gas.展开更多
Aim To establish a sensitive HPLC method for determination of piperazine ferulate and to study its pharmacokinetics in healthy volunteers. Methods Piperazine ferulate was separated on a Shimadzu C_ 18 column with acet...Aim To establish a sensitive HPLC method for determination of piperazine ferulate and to study its pharmacokinetics in healthy volunteers. Methods Piperazine ferulate was separated on a Shimadzu C_ 18 column with acetic acid (0.1%)-methanol (60 ∶ 40, V/V) as mobile phase after liquid-liquid extraction, and detection was performed at 310 nm. Piperazine ferulate pharmacokinetic parameters after a single oral dose of 200 mg of piperazine ferulate dispersible tablets in 20 healthy male volunteers were calculate...展开更多
As important constitutes in many drugs, piperazine comprised compounds are of great interest for drug design. In this paper, two piperazine-based compounds were synthesized for the first time, with different strategie...As important constitutes in many drugs, piperazine comprised compounds are of great interest for drug design. In this paper, two piperazine-based compounds were synthesized for the first time, with different strategies exploited. For one compound, a highly reactive intermediate of isothiocyanate was constructed to get the desired piperazinecarbothioamide. The synthesis of the other compound was completed sequentially through Friedel-Crafts acylation, coupling reaction and Michael addition. Both synthetic routes have short steps and acceptable yields, and such strategies can be applied to the synthesis of similar oioerazine-containin~ comoounds.展开更多
A cocrystal of diosgenin with piperazine in 2:1 stoichiometry was successfully synthesized.The solid form was prepared by liquid assisted grinding,slurry and crystallization methods.The cocrystal was characterized by ...A cocrystal of diosgenin with piperazine in 2:1 stoichiometry was successfully synthesized.The solid form was prepared by liquid assisted grinding,slurry and crystallization methods.The cocrystal was characterized by powder X-ray diffraction,differential scanning calorimetry,thermogravimetric analysis,Fourier transform infrared spectroscopy,and structure determined by single crystal X-ray diffraction,the hydrogen bonds formed into fish bone structure along the[010]direction and all the molecules packed into 3D layer structure along a axis.After formation of cocrystal,the solubility of diosgenin was improved,and the solubility value in 0.2%SDS solution was approximately 1.5 times as large as that of the parent material.展开更多
A series of fluorine- and piperazine-containing 1,2,4-triazole thione derivatives were synthesized by the Mannich reaction of triazole intermediates with various substituted piperazines and formaldehyde in high yields...A series of fluorine- and piperazine-containing 1,2,4-triazole thione derivatives were synthesized by the Mannich reaction of triazole intermediates with various substituted piperazines and formaldehyde in high yields. Structures of title compounds were confirmed by melting points, IR,~1H NMR,^（13）C NMR and elemental analysis. The preliminary bioassays for 17 novel title compounds showed that several compounds have significant fungicidal activity against Cercospora arachidicola, Physalospora piricola and Rhizoctonia cerealis at 50 mg/m L.展开更多
Absorption rate of CO2 into aqueous solution of N-methyldiethanolamine (MDEA) blended with diethanolamine (DEA) and piperazine (PZ) was studied and a kinetic model was established. It is shown that homogeneous activat...Absorption rate of CO2 into aqueous solution of N-methyldiethanolamine (MDEA) blended with diethanolamine (DEA) and piperazine (PZ) was studied and a kinetic model was established. It is shown that homogeneous activation mechanism could explain this absorption process. The absorption rate coefficients of carbon dioxide into MDEA aqueous solution blended with DEA, PZ or DEA+PZ were compared with each other. The results demonstrated that the different activation effect of DEA, PZ and DEA+PZ on the carbon dioxide absorption comes from the difference in CO2 combination rate, transport of PZ and DEA to MDEA and the regeneration rate of PZ and DEA.展开更多
A phosphorus-nitrogen containing flame retardant additive of poly（phosphoric acid piperazine）, defined as PPAP, was synthesized by the salt-forming reaction between anhydrous piperazine and phosphoric acid, and the ...A phosphorus-nitrogen containing flame retardant additive of poly（phosphoric acid piperazine）, defined as PPAP, was synthesized by the salt-forming reaction between anhydrous piperazine and phosphoric acid, and the dehydration polymerization under heating in nitrogen atmosphere. Its chemical structure was well characterized by Fourier transform infrared（FTIR） spectroscopy, ^（13）C and ^（31）P solid-state nuclear magnetic resonance measurements. The synthesized PPAP and curing agent m-phenylenediamine were blended into epoxy resin（EP） to prepare flame retardant EP thermosets. The effects of PPAP on the fire retardancy and thermal degradation behavior of cured EP/PPAP composites were investigated by limiting oxygen index（LOI）, vertical burning（UL-94）, thermogravimetric analysis/infrared spectrometry（TG-IR） and cone calorimeter tests. The morphologies and chemical compositions of char residues for cured epoxy resin were investigated by scanning electron microscopy（SEM） and X-ray photoelectron spectroscopy（XPS）, respectively. The results demonstrated that the flame retardant EP thermosets successfully passed UL-94 V-0 flammability rating and the LOI value was as high as 30.8% when incorporating 5 wt% PPAP into the EP thermosets. The TGA results indicated that the synthesized PPAP flame retardant additive possessed high thermal stability and excellent charring capability. Meanwhile, the incorporation of PPAP stimulated the epoxy resin matrix to decompose and charring ahead of time due to its catalytic decomposition effect, which led to a higher char yield at high temperature. The morphological structures and the analysis results of XPS for char residues of EP thermosets revealed that the introduction of PPAP benefited the formation of a sufficient, more compact and homogeneous char layer containing phosphorus-nitrogen flame retardant elements on the material surface during combustion. The formed char layer with high quality effectively prevented the heat transmission and diffusion, limited the production of combustible gases, and inhibited the emission of smoke, leading to the reduction of heat and smoke release.展开更多
A soluble, poly（ethylene glycol）-supported piperazine catalyst was prepared. This soluble catalyst efficiently catalyzes the Knoevenagel condensation of various aromatic aldehydes with diethyl malonate or ethyl acet...A soluble, poly（ethylene glycol）-supported piperazine catalyst was prepared. This soluble catalyst efficiently catalyzes the Knoevenagel condensation of various aromatic aldehydes with diethyl malonate or ethyl acetoacetate in a homogeneous phase to afford the desired alkenes in good purity and yield with a facile work-up process. It was found that the polymer reagent could be repeatedly used at least four times without the too much loss of activity. The catalyst has shown a good activity, stability, and recycling capability.展开更多
A series of piperazine-based Gemini and Bola surfactants were synthesized. Gemini 1 and 5 have well surface activities. Their critical micelle concentrations （cmc） is 6.47×10^-4 mol/L and 1.17×10^-3mol/L, ...A series of piperazine-based Gemini and Bola surfactants were synthesized. Gemini 1 and 5 have well surface activities. Their critical micelle concentrations （cmc） is 6.47×10^-4 mol/L and 1.17×10^-3mol/L, respectively. Bola surfactants 2 and compound 3, possessing better water solubility, have lower surface activities. Calculation, carried out by MM2 energy minimization, showed that compound with more hydrophobic chains in a spacer of limited length is difficult to be synthesized.展开更多
A rapid analysis method of piperazine ferulate tablets by optic-fiber sensing technology with UV-vis absorption spectrum was established. Qualitative and quantitative data were obtained and compared by maximum and min...A rapid analysis method of piperazine ferulate tablets by optic-fiber sensing technology with UV-vis absorption spectrum was established. Qualitative and quantitative data were obtained and compared by maximum and minimum wavelength, absorbance and contrast spectra. Similarity method was used to identify authenticity of drugs. The difference of contents measured by this method and UV determination method in China Pharmacopoeia showed no statistical significance (P40.05), while the similarity can be used as a parameter to identify the authenticity of drugs.展开更多
Two series of 1-（benzoxazole-2-yl）piperazine （Sa-i） and 4-（benzoxazole-2-yl）piperidine compounds （10a-i） were designed, synthesized and evaluated for their α1-AR antagonistic activities. Biological assay in v...Two series of 1-（benzoxazole-2-yl）piperazine （Sa-i） and 4-（benzoxazole-2-yl）piperidine compounds （10a-i） were designed, synthesized and evaluated for their α1-AR antagonistic activities. Biological assay in vitro indicated that 10h showed slightly stronger α1-AR antagonistic activity to that of our lead compound 1.展开更多
Derivatives of piperazine,which is one of the most important heterocycles,are often used as linkers to connect active substructures that show promising bioactivities,especially in the field of agrochemicals.From 2000 ...Derivatives of piperazine,which is one of the most important heterocycles,are often used as linkers to connect active substructures that show promising bioactivities,especially in the field of agrochemicals.From 2000 to 2022,many piperazine-containing compounds were found to exhibit excellent activities against fungi,bacteria,insects,plant viruses,and weeds and have also been used as plant growth regulators.Currently,the development of novel pesticides to prevent the invasion of crop pathogens and ensure the quality and yields of crops is still needed.We herein investigated and summarized the role that piperazine plays in the discovery of pesticides to provide a comprehensive summary of the broad activities of piperazine derivatives in agricultural applications and offer a potential reference for novel pesticide design using piperazine-containing compounds.Moreover,structure–activity relationships(SARs)analyses of bioactive piperazine-containing compounds are also discussed for a deeper understanding.展开更多
6/3-（4-Chlorophenyl）-s-triazolo[3, 4-b][1, 3, 4]thiadiazoles （2,a-e） and （Sa-e） were synthesized respectively by intermolecular cyclization of 5-aryl / 4-chlorophenyl-4-amino-3- mercapto-1, 2, 4-triazoles （la-e...6/3-（4-Chlorophenyl）-s-triazolo[3, 4-b][1, 3, 4]thiadiazoles （2,a-e） and （Sa-e） were synthesized respectively by intermolecular cyclization of 5-aryl / 4-chlorophenyl-4-amino-3- mercapto-1, 2, 4-triazoles （la-e） and （4） with 4-chlorobenzoic acid / aryl acids, which were condensed with piperazine under phase transfer catalyst TBAB to yield the corresponding free bases of monopiperazine derivatives and followed to form water-soluble salts （3a-e） and （6a-e） with hydrochloric acid in good yields. The in vitro biological results showed that piperazine group conjugated with the above fused heterocycles played an important role in antibacterial activity. The structures of novel compounds were confirmed by IR, ＇H NMR, MS and elemental analysis.展开更多
In the search of novel neuroprotective agents with higher potency than our previously identified antiischemic stroke drug candidate 1, a series of novel dicarbonyl piperazine derivatives were synthesized and evaluated...In the search of novel neuroprotective agents with higher potency than our previously identified antiischemic stroke drug candidate 1, a series of novel dicarbonyl piperazine derivatives were synthesized and evaluated on their neuroprotective activity via oxygen–glucose deprivation test in the neuron-like PC12 cells, hypoxia tolerance model in mice and focal cerebral ischemia model in rats. The result obtained indicated that compounds 7f, 7k and 7o, exhibited neuroprotective activity. Particularly,compound 7o containing 2,5-dimethylpiperazin moiety, showed prolonged life time of mice and reduced cerebral infarction of rats, which provided a potential candidate for the development of neuroprotective agents.展开更多
A new positively thermo-sensitive hydrogel was designed and synthesized by a condensation polymerization reaction of ethylenediaminetetraacetic dianhydride（EDTAD） and piperazine（PA） to give poly（ethylenediaminete...A new positively thermo-sensitive hydrogel was designed and synthesized by a condensation polymerization reaction of ethylenediaminetetraacetic dianhydride（EDTAD） and piperazine（PA） to give poly（ethylenediaminetetraacetic dianhydride-copiperazine） （PEP）.The obtained polymers＇ structure was characterized by FTIR and ^（13）C NMR.The backbone of the polymer linked by amide bond and abundant of carboxyl groups as pendant group could form strong intermolecular and intramolecular hydrogen bond at lower temperature and dissociate at higher temperature,resulting in the polymer with thermo-sensitivity.The aqueous solution of PEP at lower temperature（〈20℃） showed micro-gel formation and transformed to transparent solution at higher temperature（〉40℃）.Transition temperature shifted to higher value with the increasing of concentration.The hydrogel exhibited reversible phase transition and the transmittance change was not weakened by multiple temperature changes.展开更多
The surface tension study is very crucial for the design of CO2 gas absorption contacting equipment. The significance of the surface tension has been increasing due to its consideration in various technological fields...The surface tension study is very crucial for the design of CO2 gas absorption contacting equipment. The significance of the surface tension has been increasing due to its consideration in various technological fields. This property influences the mass transfer and hydrodynamics of gas absorption systems, mainly multiphase systems, in which the interface between gas and liquid exists. Therefore, in this study, surface tension of aqueous solutions of sodium L-prolinate(SP) and piperazine(PZ) blends were measured at ten different temperatures from(298.15 to 343.15) K. The SP mass fractions were 0.10, 0.20, and 0.30;while the mass fractions of PZ were 0.02 and 0.05. The experimental results showed that the surface tension increase with increasing the mass fractions of SP and PZ in aqueous blends, and decrease linearly with rising temperature. The experimental data of surface tension were correlated by two empirical correlations as a function of temperature and mass fractions for estimating the predicted data using the optimized correlation coefficients. Moreover, the modeling of surface tension data was carried out using Artificial Neural Network(ANN) approach. The results obtianed from ANN modeling were compared with applied empirical correlation. It was found that the ANN approach outperformed the empirical correlation used in this study. Besides, a quantitative analysis of variation(ANOVA) was performed in order to determine the significance of data. The surface tension of aqueous SP and SP + PZ was also compared with various conventional solvents.展开更多
A novel model for the 1: 2 complex of piperazine with some phenols in solution is established and verified. In CDCl3 solution, one piperazine molecule is tied to two phenol molecules by hydrogen bonds of O-H---N and N...A novel model for the 1: 2 complex of piperazine with some phenols in solution is established and verified. In CDCl3 solution, one piperazine molecule is tied to two phenol molecules by hydrogen bonds of O-H---N and N-H---O. And the protons of >NH and -OH groups exchange quickly and simultaneously between the atoms of phenol oxygen and piperazine nitrogen.展开更多
The present study was designed to investigate the influence of the pretreatment of piperazine ferulate on pharmacokinetic parameters of methotrexate in methotrexate-induced renal injury rats.A simple and efficient hig...The present study was designed to investigate the influence of the pretreatment of piperazine ferulate on pharmacokinetic parameters of methotrexate in methotrexate-induced renal injury rats.A simple and efficient high performance liquid chromatography coupled with mass spectrometry(HPLC-MS)method was developed to determine methotrexate in rat plasma.Methotrexate and syringic acid(internal standard)were extracted from rat plasma samples by protein precipitation with acetonitrile.The analysis was performed on a CAPCELL PAK C18column(150 mm×4.6 mm,5μm)with acetonitrile and 5 mmol/l ammonium acetate aqueous(10:90,v/v).The linear range was 5.0×10-2to 100.0μg/ml for methotrexate.Other parameters were all within the acceptance criteria.The validated method was successfully applied the pharmacokinetic study of methotrexate between two methotrexate treated groups(with and without the pretreatment of piperazine ferulate).Compared with the methotrexate treated alone group,the pharmacokinetic parameters in the methotrexate with the pretreatment of piperazine ferulate group showed significantly lower MRT(0-t),MRT(0-∞) and T1/2.Results suggested that methotrexate can be rapidly eliminated,cleared or metabolized in rat blood,which might be related to the pretreatment of piperazine ferulate.The method provided deeper insights into rational clinical use of methotrexate with the pretreatment of piperazine ferulate on cancer patients with renal dysfunction.展开更多
We have designed and synthesized a series of new phthalimidopiperazines, biological activity test show that the target compounds(Ic, Ie, ii) can inhibit HIV-I RT with IC50 20.0, 43.8, and 63.7 mu M, respectively.
Two new coordination polymers, [Cd（N3）2（Baep）l/2]n （1） and [Cd2（N3）4（CH3OH）（Bapp）I/.2]n （2） （Baep = 1,4-bis（2-aminoethyl）piperazine, Bapp = 1,4-bis（3-aminopropyl）piperazine） were synthesized. The c...Two new coordination polymers, [Cd（N3）2（Baep）l/2]n （1） and [Cd2（N3）4（CH3OH）（Bapp）I/.2]n （2） （Baep = 1,4-bis（2-aminoethyl）piperazine, Bapp = 1,4-bis（3-aminopropyl）piperazine） were synthesized. The crystal of 1 is of monoclinic system, space group P21/c with a = 9.341（7）, b = 11.677（9）, c = 8.195（6） A, fl = 93.925（13）, V= 891.8（11） A3, Z= 4, μ（MoKa） = 2.42 mm-1, Mr = 280.58, Dc = 2.090 g/cm3, the final R = 0.0297 and wR = 0.0720. The crystal of 2 is of triclinic system, space group PI with a = 9.121（5）, b = 9.666（5）, c = 10.250（6） A, a = 72.91（2）, β= 77.10（2）, V = 73.95（2）°, V = 820.0（8）°, Z = 2,μ（MoKa） = 2.62 mm-1, Mr= 522.10, Dc = 2.114 g/cm3, the final R = 0.0251 and wR = 0.0632. Single-crystal X-ray diffraction studies reveal that 1 is a 3D structure based on a dinuclear unit {Cd2（N3）a（Baep）}, in which the Baep ligands formed in situ display two different bridging modes. Compound 2 also has a 3D structure based on a tetranuclear cluster {Cda（N3）8（CH3OH）2（Bapp）}, in which the azido anions exhibit four different bridging modes （μ-1,1, μ-1,3, μ-l,l,1 and μ-1,1,3）. The thermal stability and fluorescent property of 1 and 2 have also been investigated.展开更多
基金supported by the Major Science and Technology Project of Anhui Province(201903a07020004)the National Natural Science Foundation of China(22208078)the Fundamental Research Funds for the Central Universities(JZ2023HGTB0226).
文摘The effect of the presence of trace SO_(2)in industrial flue gas on the amine-scrubbing-based absorption process for CO_(2)capture has been a matter of concern.This study aimed to investigate the effect of trace SO_(2)on the CO_(2)capture process using piperazine-based amine absorbents,focusing on SO_(2)-resistance capability,SO_(2)/CO_(2)absorption selectivity,and cyclic stability.The presence of trace SO_(2)not only restrains CO_(2)absorption,but also promotes the formation of carbamate within the piperazine-based amine absorbents.Remarkably,the incorporation of aminoethyl group in piperazine-based amine absorbents can enhance the SO_(2)-resistance capability by promoting the formation of carbamate,while piperazine-based amine absorbents with hydroxyethyl group can promote the formation of bicarbonate to reduce the SO_(2)-resistance capability.The work offers valuable insights into the efficient application of novel amine absorbents for CO_(2)capture from practical industrial flue gas.
文摘Aim To establish a sensitive HPLC method for determination of piperazine ferulate and to study its pharmacokinetics in healthy volunteers. Methods Piperazine ferulate was separated on a Shimadzu C_ 18 column with acetic acid (0.1%)-methanol (60 ∶ 40, V/V) as mobile phase after liquid-liquid extraction, and detection was performed at 310 nm. Piperazine ferulate pharmacokinetic parameters after a single oral dose of 200 mg of piperazine ferulate dispersible tablets in 20 healthy male volunteers were calculate...
基金National Basic Research Program of China(Grant No.2012CB518000)the National Natural Science Foundation of China(Grant No.21172012)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20120001110010)
文摘As important constitutes in many drugs, piperazine comprised compounds are of great interest for drug design. In this paper, two piperazine-based compounds were synthesized for the first time, with different strategies exploited. For one compound, a highly reactive intermediate of isothiocyanate was constructed to get the desired piperazinecarbothioamide. The synthesis of the other compound was completed sequentially through Friedel-Crafts acylation, coupling reaction and Michael addition. Both synthetic routes have short steps and acceptable yields, and such strategies can be applied to the synthesis of similar oioerazine-containin~ comoounds.
基金support by National Key research and development Program of China(Grant No.2016YFC1000900)CAMS Innovation Found for Medical Sciences(Grant No.2017-I2M-1-010)+1 种基金Construction and application of technology integration system for efficient identification of natural/effective active small molecules(Grant No.2018ZX09711001-001)National Science and Technology Major Project of China(Grant No.2018ZX09711001-010).
文摘A cocrystal of diosgenin with piperazine in 2:1 stoichiometry was successfully synthesized.The solid form was prepared by liquid assisted grinding,slurry and crystallization methods.The cocrystal was characterized by powder X-ray diffraction,differential scanning calorimetry,thermogravimetric analysis,Fourier transform infrared spectroscopy,and structure determined by single crystal X-ray diffraction,the hydrogen bonds formed into fish bone structure along the[010]direction and all the molecules packed into 3D layer structure along a axis.After formation of cocrystal,the solubility of diosgenin was improved,and the solubility value in 0.2%SDS solution was approximately 1.5 times as large as that of the parent material.
基金supported by the National Natural Science Foundation of China (No. 21372133)‘‘111’’ Project of Ministry of Education of China (No. B06005)
文摘A series of fluorine- and piperazine-containing 1,2,4-triazole thione derivatives were synthesized by the Mannich reaction of triazole intermediates with various substituted piperazines and formaldehyde in high yields. Structures of title compounds were confirmed by melting points, IR,~1H NMR,^（13）C NMR and elemental analysis. The preliminary bioassays for 17 novel title compounds showed that several compounds have significant fungicidal activity against Cercospora arachidicola, Physalospora piricola and Rhizoctonia cerealis at 50 mg/m L.
文摘Absorption rate of CO2 into aqueous solution of N-methyldiethanolamine (MDEA) blended with diethanolamine (DEA) and piperazine (PZ) was studied and a kinetic model was established. It is shown that homogeneous activation mechanism could explain this absorption process. The absorption rate coefficients of carbon dioxide into MDEA aqueous solution blended with DEA, PZ or DEA+PZ were compared with each other. The results demonstrated that the different activation effect of DEA, PZ and DEA+PZ on the carbon dioxide absorption comes from the difference in CO2 combination rate, transport of PZ and DEA to MDEA and the regeneration rate of PZ and DEA.
基金financially supported by the Fundamental Research Funds for the Central Universities (No.2572014EB06-02)National Natural Science Foundation of China (No.51673035)Heilongjiang Major Research Projects (No.GA15A101)
文摘A phosphorus-nitrogen containing flame retardant additive of poly（phosphoric acid piperazine）, defined as PPAP, was synthesized by the salt-forming reaction between anhydrous piperazine and phosphoric acid, and the dehydration polymerization under heating in nitrogen atmosphere. Its chemical structure was well characterized by Fourier transform infrared（FTIR） spectroscopy, ^（13）C and ^（31）P solid-state nuclear magnetic resonance measurements. The synthesized PPAP and curing agent m-phenylenediamine were blended into epoxy resin（EP） to prepare flame retardant EP thermosets. The effects of PPAP on the fire retardancy and thermal degradation behavior of cured EP/PPAP composites were investigated by limiting oxygen index（LOI）, vertical burning（UL-94）, thermogravimetric analysis/infrared spectrometry（TG-IR） and cone calorimeter tests. The morphologies and chemical compositions of char residues for cured epoxy resin were investigated by scanning electron microscopy（SEM） and X-ray photoelectron spectroscopy（XPS）, respectively. The results demonstrated that the flame retardant EP thermosets successfully passed UL-94 V-0 flammability rating and the LOI value was as high as 30.8% when incorporating 5 wt% PPAP into the EP thermosets. The TGA results indicated that the synthesized PPAP flame retardant additive possessed high thermal stability and excellent charring capability. Meanwhile, the incorporation of PPAP stimulated the epoxy resin matrix to decompose and charring ahead of time due to its catalytic decomposition effect, which led to a higher char yield at high temperature. The morphological structures and the analysis results of XPS for char residues of EP thermosets revealed that the introduction of PPAP benefited the formation of a sufficient, more compact and homogeneous char layer containing phosphorus-nitrogen flame retardant elements on the material surface during combustion. The formed char layer with high quality effectively prevented the heat transmission and diffusion, limited the production of combustible gases, and inhibited the emission of smoke, leading to the reduction of heat and smoke release.
基金Supported by the National Natural Science Foundation of China(No.20872001)the Natural Science Foundation of Education Administration of Anhui Province,China(No.KJ2008A064)
文摘A soluble, poly（ethylene glycol）-supported piperazine catalyst was prepared. This soluble catalyst efficiently catalyzes the Knoevenagel condensation of various aromatic aldehydes with diethyl malonate or ethyl acetoacetate in a homogeneous phase to afford the desired alkenes in good purity and yield with a facile work-up process. It was found that the polymer reagent could be repeatedly used at least four times without the too much loss of activity. The catalyst has shown a good activity, stability, and recycling capability.
文摘A series of piperazine-based Gemini and Bola surfactants were synthesized. Gemini 1 and 5 have well surface activities. Their critical micelle concentrations （cmc） is 6.47×10^-4 mol/L and 1.17×10^-3mol/L, respectively. Bola surfactants 2 and compound 3, possessing better water solubility, have lower surface activities. Calculation, carried out by MM2 energy minimization, showed that compound with more hydrophobic chains in a spacer of limited length is difficult to be synthesized.
文摘A rapid analysis method of piperazine ferulate tablets by optic-fiber sensing technology with UV-vis absorption spectrum was established. Qualitative and quantitative data were obtained and compared by maximum and minimum wavelength, absorbance and contrast spectra. Similarity method was used to identify authenticity of drugs. The difference of contents measured by this method and UV determination method in China Pharmacopoeia showed no statistical significance (P40.05), while the similarity can be used as a parameter to identify the authenticity of drugs.
基金the National High-Tech Research and Development Plan(No.2002AA2Z3118)
文摘Two series of 1-（benzoxazole-2-yl）piperazine （Sa-i） and 4-（benzoxazole-2-yl）piperidine compounds （10a-i） were designed, synthesized and evaluated for their α1-AR antagonistic activities. Biological assay in vitro indicated that 10h showed slightly stronger α1-AR antagonistic activity to that of our lead compound 1.
基金The financial supports from National Natural Science Foundation of China(NSFC,Nos.32072445,21762012)the Program of Introducing Talents to Chinese Universities(No.D20023)+1 种基金the S&T Planning Project of Guizhou Province(No.[2017]5788)Graduate Research Fund in Guizhou Province(No.YJSKYJJ[2021]038).
文摘Derivatives of piperazine,which is one of the most important heterocycles,are often used as linkers to connect active substructures that show promising bioactivities,especially in the field of agrochemicals.From 2000 to 2022,many piperazine-containing compounds were found to exhibit excellent activities against fungi,bacteria,insects,plant viruses,and weeds and have also been used as plant growth regulators.Currently,the development of novel pesticides to prevent the invasion of crop pathogens and ensure the quality and yields of crops is still needed.We herein investigated and summarized the role that piperazine plays in the discovery of pesticides to provide a comprehensive summary of the broad activities of piperazine derivatives in agricultural applications and offer a potential reference for novel pesticide design using piperazine-containing compounds.Moreover,structure–activity relationships(SARs)analyses of bioactive piperazine-containing compounds are also discussed for a deeper understanding.
基金This project was supported by the State Basic Research and Development Project(No.G1998051112).
文摘6/3-（4-Chlorophenyl）-s-triazolo[3, 4-b][1, 3, 4]thiadiazoles （2,a-e） and （Sa-e） were synthesized respectively by intermolecular cyclization of 5-aryl / 4-chlorophenyl-4-amino-3- mercapto-1, 2, 4-triazoles （la-e） and （4） with 4-chlorobenzoic acid / aryl acids, which were condensed with piperazine under phase transfer catalyst TBAB to yield the corresponding free bases of monopiperazine derivatives and followed to form water-soluble salts （3a-e） and （6a-e） with hydrochloric acid in good yields. The in vitro biological results showed that piperazine group conjugated with the above fused heterocycles played an important role in antibacterial activity. The structures of novel compounds were confirmed by IR, ＇H NMR, MS and elemental analysis.
基金supported by Shanghai Natural Science Foundation(No.12ZR1450100)
文摘In the search of novel neuroprotective agents with higher potency than our previously identified antiischemic stroke drug candidate 1, a series of novel dicarbonyl piperazine derivatives were synthesized and evaluated on their neuroprotective activity via oxygen–glucose deprivation test in the neuron-like PC12 cells, hypoxia tolerance model in mice and focal cerebral ischemia model in rats. The result obtained indicated that compounds 7f, 7k and 7o, exhibited neuroprotective activity. Particularly,compound 7o containing 2,5-dimethylpiperazin moiety, showed prolonged life time of mice and reduced cerebral infarction of rats, which provided a potential candidate for the development of neuroprotective agents.
基金supported by the National Natural Science Foundation of China(No.30870609)
文摘A new positively thermo-sensitive hydrogel was designed and synthesized by a condensation polymerization reaction of ethylenediaminetetraacetic dianhydride（EDTAD） and piperazine（PA） to give poly（ethylenediaminetetraacetic dianhydride-copiperazine） （PEP）.The obtained polymers＇ structure was characterized by FTIR and ^（13）C NMR.The backbone of the polymer linked by amide bond and abundant of carboxyl groups as pendant group could form strong intermolecular and intramolecular hydrogen bond at lower temperature and dissociate at higher temperature,resulting in the polymer with thermo-sensitivity.The aqueous solution of PEP at lower temperature（〈20℃） showed micro-gel formation and transformed to transparent solution at higher temperature（〉40℃）.Transition temperature shifted to higher value with the increasing of concentration.The hydrogel exhibited reversible phase transition and the transmittance change was not weakened by multiple temperature changes.
基金CO2 Research Centre (CO2RES), Universiti Teknologi PETRONAS for financial and technical support to complete the present research work
文摘The surface tension study is very crucial for the design of CO2 gas absorption contacting equipment. The significance of the surface tension has been increasing due to its consideration in various technological fields. This property influences the mass transfer and hydrodynamics of gas absorption systems, mainly multiphase systems, in which the interface between gas and liquid exists. Therefore, in this study, surface tension of aqueous solutions of sodium L-prolinate(SP) and piperazine(PZ) blends were measured at ten different temperatures from(298.15 to 343.15) K. The SP mass fractions were 0.10, 0.20, and 0.30;while the mass fractions of PZ were 0.02 and 0.05. The experimental results showed that the surface tension increase with increasing the mass fractions of SP and PZ in aqueous blends, and decrease linearly with rising temperature. The experimental data of surface tension were correlated by two empirical correlations as a function of temperature and mass fractions for estimating the predicted data using the optimized correlation coefficients. Moreover, the modeling of surface tension data was carried out using Artificial Neural Network(ANN) approach. The results obtianed from ANN modeling were compared with applied empirical correlation. It was found that the ANN approach outperformed the empirical correlation used in this study. Besides, a quantitative analysis of variation(ANOVA) was performed in order to determine the significance of data. The surface tension of aqueous SP and SP + PZ was also compared with various conventional solvents.
文摘A novel model for the 1: 2 complex of piperazine with some phenols in solution is established and verified. In CDCl3 solution, one piperazine molecule is tied to two phenol molecules by hydrogen bonds of O-H---N and N-H---O. And the protons of >NH and -OH groups exchange quickly and simultaneously between the atoms of phenol oxygen and piperazine nitrogen.
文摘The present study was designed to investigate the influence of the pretreatment of piperazine ferulate on pharmacokinetic parameters of methotrexate in methotrexate-induced renal injury rats.A simple and efficient high performance liquid chromatography coupled with mass spectrometry(HPLC-MS)method was developed to determine methotrexate in rat plasma.Methotrexate and syringic acid(internal standard)were extracted from rat plasma samples by protein precipitation with acetonitrile.The analysis was performed on a CAPCELL PAK C18column(150 mm×4.6 mm,5μm)with acetonitrile and 5 mmol/l ammonium acetate aqueous(10:90,v/v).The linear range was 5.0×10-2to 100.0μg/ml for methotrexate.Other parameters were all within the acceptance criteria.The validated method was successfully applied the pharmacokinetic study of methotrexate between two methotrexate treated groups(with and without the pretreatment of piperazine ferulate).Compared with the methotrexate treated alone group,the pharmacokinetic parameters in the methotrexate with the pretreatment of piperazine ferulate group showed significantly lower MRT(0-t),MRT(0-∞) and T1/2.Results suggested that methotrexate can be rapidly eliminated,cleared or metabolized in rat blood,which might be related to the pretreatment of piperazine ferulate.The method provided deeper insights into rational clinical use of methotrexate with the pretreatment of piperazine ferulate on cancer patients with renal dysfunction.
文摘We have designed and synthesized a series of new phthalimidopiperazines, biological activity test show that the target compounds(Ic, Ie, ii) can inhibit HIV-I RT with IC50 20.0, 43.8, and 63.7 mu M, respectively.
基金supported by the National Basic Research Program of China(973Program,2012CB821702)the National Natural Science Foundation of China(21173221and20903096)+1 种基金the State Key Laboratory of Structural ChemistryFujian Institute of Research onthe Structure of Matter,Chinese Academy of Sciences,Fuzhou,Fujian350002,China
文摘Two new coordination polymers, [Cd（N3）2（Baep）l/2]n （1） and [Cd2（N3）4（CH3OH）（Bapp）I/.2]n （2） （Baep = 1,4-bis（2-aminoethyl）piperazine, Bapp = 1,4-bis（3-aminopropyl）piperazine） were synthesized. The crystal of 1 is of monoclinic system, space group P21/c with a = 9.341（7）, b = 11.677（9）, c = 8.195（6） A, fl = 93.925（13）, V= 891.8（11） A3, Z= 4, μ（MoKa） = 2.42 mm-1, Mr = 280.58, Dc = 2.090 g/cm3, the final R = 0.0297 and wR = 0.0720. The crystal of 2 is of triclinic system, space group PI with a = 9.121（5）, b = 9.666（5）, c = 10.250（6） A, a = 72.91（2）, β= 77.10（2）, V = 73.95（2）°, V = 820.0（8）°, Z = 2,μ（MoKa） = 2.62 mm-1, Mr= 522.10, Dc = 2.114 g/cm3, the final R = 0.0251 and wR = 0.0632. Single-crystal X-ray diffraction studies reveal that 1 is a 3D structure based on a dinuclear unit {Cd2（N3）a（Baep）}, in which the Baep ligands formed in situ display two different bridging modes. Compound 2 also has a 3D structure based on a tetranuclear cluster {Cda（N3）8（CH3OH）2（Bapp）}, in which the azido anions exhibit four different bridging modes （μ-1,1, μ-1,3, μ-l,l,1 and μ-1,1,3）. The thermal stability and fluorescent property of 1 and 2 have also been investigated.
