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Exploring Ester Prodrugs: A Comprehensive Review of Approaches, Applications, and Methods
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作者 Guangyang Zhou 《Pharmacology & Pharmacy》 2024年第8期269-284,共16页
The review provides an overview of the approaches, applications, and methods for ester prodrugs. Ester prodrugs are pharmacologically inactive compounds in their original form but become active drugs on biotransformat... The review provides an overview of the approaches, applications, and methods for ester prodrugs. Ester prodrugs are pharmacologically inactive compounds in their original form but become active drugs on biotransformation within the body, which offers advantages concerning the solubility, stability, and targeted delivery of the active drug. Several approaches of ester prodrugs have been reviewed in this review, including simple ester prodrugs, amino acid ester prodrugs, sugar ester prodrugs, lipid ester prodrugs, and polymeric ester prodrugs. This review incorporates in vitro and in vivo methods as well as the characterization of physical and chemical properties for ester prodrugs, cell culture systems, enzymatic assays, and animal models—all of these having a very important bearing on the evaluation of stability, bioavailability, and efficacy for ester prodrugs. While the benefits of using ester prodrugs are significant, there are also disadvantages like instability, poor or variable enzymatic hydrolysis, and toxicity from released promoieties or by-products. This review discusses solutions to the various limitations that include enhancing stability with ionizable promoieties and using physiologically-based pharmacokinetic modeling. The review also highlights the application of ester prodrugs in neurological disorders, such as Parkinson’s disease, and the ongoing efforts to address the critical limitations in treatment efficacy. Future prodrug strategies are poised to advance significantly by harnessing diverse transport mechanisms across the blood-brain barrier and integrating nanotechnology. 展开更多
关键词 ester Prodrugs Solubility BIOAVAILABILITY Stability ester Prodrug Approaches Simple ester Prodrugs Amino Acid ester Prodrugs Sugar ester Prodrugs Lipid ester Prodrugs Polymeric ester Prodrugs esterase-Responsive Nanoparticles Hydrolysis Cancer Treatment Cardiovascular Diseases Neurological Disorders
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Pathogenic contribution of cholesteryl ester accumulation in the brain to neurodegenerative disorders
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作者 Michiko Shirane 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第10期2099-2100,共2页
Cholesteryl esters(CEs) have been increasingly implicated in neurodegenerative disorders such as Alzheimer's disease(AD).Alois Alzheimer noted three prominent neuropathologic features in his original analysis of t... Cholesteryl esters(CEs) have been increasingly implicated in neurodegenerative disorders such as Alzheimer's disease(AD).Alois Alzheimer noted three prominent neuropathologic features in his original analysis of the AD brain:senile plaques,neurofibrillary tangles,and lipid granule accumulation.Senile plaques,which are aggregates of amyloid-beta(Aβ),and neurofibrillary tangles,which are aggregates of phosphorylated tau,have been regarded as more consistent characteristics of the AD brain compared with lipid granule accumulation and thus have been studied more intensively(Foley,2010). 展开更多
关键词 esterS ester cholesteryl
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Structural characteristics of phenylboronic acid-modified astaxanthin ester and its effect on DSS-induced ulcerative colitis by blocking reactive oxygen species and maintaining intestinal homeostasis
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作者 Xing Qiao Hongyan Li +4 位作者 Qun Gao Zhigao Wang Jie Xu Lu Yang Changhu Xue 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第5期2754-2764,共11页
A novel and reactive oxygen species(ROS)responsive astaxanthin phenylboronic acid derivative(AstaDPBA)was constructed by grafting phenylboronic acid(PBA)onto astaxanthin succinate diester(AstaD),and its chemical struc... A novel and reactive oxygen species(ROS)responsive astaxanthin phenylboronic acid derivative(AstaDPBA)was constructed by grafting phenylboronic acid(PBA)onto astaxanthin succinate diester(AstaD),and its chemical structure and physicochemical property were identified.AstaD-PBA could effectively improve the ROS quenching ability in the lipopolysaccharide(LPS)-induced RAW264.7 cell inflammation model.Then,the bioactivity of AstaD-PBA was studied by 4 zebrafish ROS-responsive infl ammatory models induced by LPS,copper(Cu^(2+)),high-fat diet,and dextran sodium sulfate(DSS).The results suggest that AstaD-PBA might have high biosafety and the best effect on ulcerative colitis(UC)induced by DSS.Furtherly,AstaDPBA significantly alleviated and treated weight loss and colonic shrinkage,inhibited infl ammatory cytokines,and maintained microbiota homeostasis to improve UC in C57BL/6J mice.Alistipes and Oscillibacter were expected to be considered UC marker fl ora according to the Metastats analysis and Pearson correlation Mantel test(P<0.01)of 16S rRNA gene sequencing data.In conclusion,AstaD-PBA has been promised to be a functional compound to improve UC and maintain intestinal microbiota homeostasis. 展开更多
关键词 Astaxanthin ester Reactive oxygen species-responsive Ulcerative colitis Intestinal microbiota Inflammatory cytokines
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Non-flammable long chain phosphate ester based electrolyte via competitive solventized structures for high-performance lithium metal batteries
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作者 Li Liao Zhiqiang Han +16 位作者 Xuanjie Feng Pan Luo Jialin Song Yin Shen Xiaoshuang Luo Xinpeng Li Xuanzhong Wen Bo Yu Junchen Chen Bingshu Guo Mingshan Wang Yun Huang Hongmei Zhang Mengmeng Yin Jiangtao Liu Yuanhua Lin Xing Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第10期156-165,I0004,共11页
Safety remains a persistent challenge for high-energy-density lithium metal batteries(LMBs).The development of safe and non-flammable electrolytes is especially important in harsh conditions such as high temperatures.... Safety remains a persistent challenge for high-energy-density lithium metal batteries(LMBs).The development of safe and non-flammable electrolytes is especially important in harsh conditions such as high temperatures.Herein,a flame-retardant,low-cost and thermally stable long chain phosphate ester based(tributyl phosphate,TBP)electrolyte is reported,which can effectively enhance the cycling stability of highly loaded high-nickel LMBs with high safety through co-solvation strategy.The interfacial compatibility between TBP and electrode is effectively improved using a short-chain ether(glycol dimethyl ether,DME),and a specially competitive solvation structure is further constructed using lithium borate difluorooxalate(LiDFOB)to form the stable and inorganic-rich electrode interphases.Benefiting from the presence of the cathode electrolyte interphase(CEI)and solid electrolyte interphase(SEI)enriched with LiF and Li_(x)PO_(y)F_(z),the electrolyte demonstrates excellent cycling stability assembled using a 50μm lithium foil anode in combination with a high loading NMC811(15.4 mg cm^(-2))cathode,with 88%capacity retention after 120 cycles.Furthermore,the electrolyte exhibits excellent high-temperature characteristics when used in a 1-Ah pouch cell(N/P=0.26),and higher thermal runaway temperature(238℃)in the ARC(accelerating rate calorimeter)demonstrating high safety.This novel electrolyte adopts long-chain phosphate as the main solvent for the first time,and would provide a new idea for the development of extremely high safety and high-temperature electrolytes. 展开更多
关键词 Non-flammable electrolyte Long chain phosphate ester Solvation structure Lithium metal batteries Battery safety
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Research progress on classification,source,application of phytosterol esters,and their thermal oxidation stability
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作者 Dami Li Shangde Sun Jingnan Chen 《Grain & Oil Science and Technology》 CAS 2024年第1期1-11,共11页
Phytosterol esters can effectively decrease serum cholesterol concentration in the human body and prevent cardio-cerebrovascular diseases.It was found that phytosterol esters exhibited better solubility and bioavailab... Phytosterol esters can effectively decrease serum cholesterol concentration in the human body and prevent cardio-cerebrovascular diseases.It was found that phytosterol esters exhibited better solubility and bioavailability than free phytosterols.In recent years,phytosterol esters have attracted increasing attention.However,during food processing,phytosterol esters are susceptible to degradation at high temperatures,resulting in certain losses and formation of potentially harmful substances for humans.This paper reviews the relevant literatures and updates on the thermal oxidation stability of phytosterol esters in recent years from the following aspects:(i)Sources,physiological activities,and applications of phytosterol esters;(ii)Oxidation mechanism of phytosterol esters;(iii)Effects of phytosterols species,the volume of addition,food matrix,heating temperature and time,and antioxidants on the thermal loss and oxidation stability of phytosterol esters.The research progress on the safety of phytosterol esters is also discussed in detail.Additionally,the prospects for future research are highlighted. 展开更多
关键词 Thermal stability Loss rate Oxidation mechanism Phytosterol esters
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Removal of Dye Using Lignin-Based Biochar/Poly(ester amide urethane)Nanocomposites from Contaminated Wastewater
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作者 Annesha Kar Niranjan Karak 《Journal of Renewable Materials》 EI CAS 2024年第9期1507-1540,共34页
The pursuit of incorporating eco-friendly reinforcing agents in polymer composites has accentuated the exploration of various natural biomass-derived materials.The burgeoning environmental crisis spurred by the discha... The pursuit of incorporating eco-friendly reinforcing agents in polymer composites has accentuated the exploration of various natural biomass-derived materials.The burgeoning environmental crisis spurred by the discharge of synthetic dyes into wastewater has catalyzed the search for effective and sustainable treatment technologies.Among the various sorbent materials explored,biochar,being renewable,has gained prominence due to its excellent adsorption properties and environmental sustainability.It has also emerged as a focal point for its potential to replace other conventional reinforcing agents,viz.,fumed silica,aluminum oxide,treated clays,etc.This study introduces a novel class of polymer nanocomposites comprising of lignin-based biochar particles and poly(ester amide urethane)matrix via a feasible method.The structural evaluation of these nanocomposites was accomplished using Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,and powder X-ray diffraction.The polymer nanocomposites exhibited superior mechanical properties with an increment in tensile strength factor by 45%in comparison to its pristine matrix,along with an excellent toughness value of 90.22 MJm^(−3)at a low loading amount of only 1 wt%.The composites showed excellent improvement in thermal properties with a sharp rise in the glass transition temperature(Tg)value from−28.15℃to 84℃,while also championing sustainability through inherent biodegradability attributes.Beyond their structural prowess,these polymer nanocomposites demonstrated excellent potential as adsorbents,displaying efficient removal of malachite green and tartrazine dyes from aqueous systems with a removal efficiency of 87.25%and 73.98%,respectively.The kinetics study revealed the pseudo second order model to be the precision tool to assess the dye removal study.Complementing this,the Langmuir adsorption isotherm provided a framework to assess the sorption features of the polymer nanocomposites.Overall,these renewable biochar integrated polymer matrices boast remarkable recovery capabilities up to seven cycles of usage with an excellent dye recovery percentage of 95.21%for the last cycle,thereby defining sustainability as well as economic feasibility. 展开更多
关键词 Reinforcing agents BIOCHAR polymer nanocomposites poly(ester amide urethane) dye removal adsorption kinetics pseudo second order model langmuir isotherm
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Study on the regulatory effect of liver X receptor in HEK293 cells by six main diterpene esters in Semen Euphorbiae
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作者 Si-Yuan Ma Fan-Miao Kong +8 位作者 Xiao-Tong Wei Jun-Li Zhang Hai-Ting Zhu Xin-Ning Zhang Yu-Feng Hu Ming-Rui Jiang Hui-Nan Wang Yi-Cen Xu Ying-Zi Wang 《TMR Modern Herbal Medicine》 CAS 2024年第2期35-40,共6页
Background:To study the effects of the main diterpene esters in Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)on the transcriptional activity and protein expression of liver X receptor(LXR).Methods:The effe... Background:To study the effects of the main diterpene esters in Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)on the transcriptional activity and protein expression of liver X receptor(LXR).Methods:The effect of the main diterpene ester components in Semen Euphorbiae on the viability of HEK293 cells were studied by MTT assay.The LXR-Luc plasmid vector was transfected into HEK293 cells and treated with Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)for 24 h.The effect of the main diterpene ester components of Semen Euphorbiae on LXR-Luc luciferase activity was investigated by dual luciferase reporter gene system,and the expression of LXRαprotein was detected by Western Blot.Results:Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)could significantly reduce the relative luciferase activity(RLU)of LXRα,and the expression level of LXRαprotein was significantly down-regulated.Conclusion:Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)can inhibit the expression of LXR protein level,which may be achieved by inhibiting the transcriptional activity of LXR. 展开更多
关键词 Semen Euphorbiae diterpene esters HEK293 LXR dual luciferase reporter gene system
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Recent Advances of Sensitive Electrochemical Sensing Platforms for Rapid Detection of Phthalate Acid Esters
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作者 Xiuxiu Dong Lili Zhang +2 位作者 Meicai Ge Minfu Wu Qijian Niu 《Instrumentation》 2024年第2期9-23,共15页
As a kind of plasticizer,phthalic acid esters(PAEs)are often added to plastics to enhance elasticity,transparency,durability and prolong service life.However,it does not chemically bind to plastics and is easy to migr... As a kind of plasticizer,phthalic acid esters(PAEs)are often added to plastics to enhance elasticity,transparency,durability and prolong service life.However,it does not chemically bind to plastics and is easy to migrate to the environment.It is difficult to degrade in the environment,and it is also enriched in the human body through the food chain and respiration,which will lead to obvious adverse reactions such as decreased learning and memory function and neurobehavioral disorders.Due to the toxicity,universality and low concentration limitations of PAEs in the environment and food,it is essential to achieve rapid and sensitive detection of PAEs in soil,atmosphere,water and food.Electrochemical(EC)sensors have the advantages of simplicity,fast,low cost,portability,easy operation,high specificity and high sensitivity,so they are applied for the detection of PAEs.Although there are a large number of studies on the detection of PAEs by EC sensors,there is no review on this aspect.In this review,we introduce the detection of PAEs from classical EC sensors,electrochemiluminescence(ECL)sensors and photo-electrochemical(PEC)sensors in the past five years.This review is beneficial to understanding the construction of EC sensors and the detection mechanism of PAEs.We also propose that the development of rapid,accurate and real-time detection methods of PAEs is key to assessing risk and preventing related diseases. 展开更多
关键词 phthalate acid esters electrochemical sensor DETERMINATION
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Pollution characteristics and risk assessment of organophosphate esters in aquaculture farms and natural water bodies adjacent to the Huanghe River delta
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作者 Jinyu CHAO Song FENG +2 位作者 Yingdong HAO Jianing LIN Bin ZHANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第1期251-266,共16页
To date,little attention has been paid to the effects of organophosphate esters(OPEs)pollution on aquacultural environment and aquatic product safety.Huanghe(Yellow)River delta area is one of the largest aquaculture c... To date,little attention has been paid to the effects of organophosphate esters(OPEs)pollution on aquacultural environment and aquatic product safety.Huanghe(Yellow)River delta area is one of the largest aquaculture centers in China,where ecological security protection is crucial in the national strategy of China.To explore the pollution characteristics,bioaccumulation,and health risks of OPEs in aquaculture farms in the Huanghe River delta and natural water bodies in the adjacent seas,five species of organisms from different farm types nearby the Huanghe River delta,and the corresponding culture water and sediments were sampled in this study.The total concentrations of Σ_(13)OPEs in water,sediments,and organisms were 51.53-272.18 ng/L,52.63-63.17 ng/g dry weight(dw),and 46.82-108.90 ng/g dw,respectively.Among the five types of culture ponds,the water samples from the swimming crab and hairy crab culture ponds exhibited higher OPEs,the concentration of OPEs in the sediments from the few ponds was relatively balanced,and the OPEs in the organism from the holothurian ponds was higher.Tris(1,3-dichloro-2-isopropyl pho sphate)(TDCP)was the main contaminant in water samples and tripropyl phosphate(TPrP)in sediments and organisms.However,trisphenyl phosphate(TPhP)showed the strongest bioaccumulation ability,followed by 2-ethylhexyl diphenyl phosphate(EHDPP)and TPrP.The bioaccumulation capacities of the five species were as follows:prawn>holothurian>hairy crab>swimming crab>carp.These five types of organisms,as main seafood in human consumption,were at low risk of negative impacts of pollution.However,the risk from the mixture of organophosphate flame retardants(OPFRs)still requires more attention due to the increasing consumption and production in the world. 展开更多
关键词 organophosphate esters(OPEs) aquaculture farms BIOACCUMULATION health risk assessment
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Breakdown Voltage Prediction by Utilizing the Behavior of Natural Ester for Transformer Applications
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作者 P.Samuel Pakianathan R.V.Maheswari 《Intelligent Automation & Soft Computing》 SCIE 2023年第3期2717-2736,共20页
This research investigates the dielectric performance of Natural Ester(NE)using the Partial Differential Equation(PDE)tool and analyzes dielectric performance using fuzzy logic.NE nowadays is found to replace Mineral ... This research investigates the dielectric performance of Natural Ester(NE)using the Partial Differential Equation(PDE)tool and analyzes dielectric performance using fuzzy logic.NE nowadays is found to replace Mineral Oil(MO)due to its extensive dielectric properties.Here,the heat-tolerant Natural Esters Olive oil(NE1),Sunflower oil(NE2),and Ricebran oil(NE3)are subjected to High Voltage AC(HVAC)under different electrodes configurations.The break-down voltage and leakage current of NE1,NE2,and NE3 under Point-Point(P-P),Sphere-Sphere(S-S),Plane-Plane(PL-PL),and Rod-Rod(R-R)are measured,and survival probability is presented.The electricfield distribution is analyzed using the Partial Differential Equation(PDE)tool.NE shows better HVAC with stand capacity under all the electrodes configuration,especially in the S-S shape geometry.The exponential function is developed for the oils under different elec-trode geometry;NE shows a higher survival probability.Likewise,the most influ-ential dielectric properties such as breakdown voltage,kinematic viscosity,and water content are used to develop a Mamdani-based control system model that combines two variables to produce the surface model.The surface model indi-cates that the NE subjected for investigation is less susceptible to moisture effect and higher kinematic viscosity.Based on the surface models of PDE and fuzzy,it is concluded that NE possesses a high survival rate since its breakdown voltage does not react to changes in water content.Hence the application of NE in the transformer application is highly safe and possesses extended life. 展开更多
关键词 Power transformer fuzzy logic prediction partial differential equation natural ester exponential function
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Adsorption of Phthalic Acid Esters by Humic Acid and Its Research Progress
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作者 Ying LI Xiuqin KONG +6 位作者 Dongxia LUO Yinghai LUO Tong CHEN Fengyu WANG Huaxiu XING Fuqiang LI Miantao LEI 《Meteorological and Environmental Research》 CAS 2023年第4期63-66,共4页
Humic acid is rich in highly electronegative oxygen-containing organic functional groups,so it has high reactivity and can adsorb phthalic acid ester(PAEs)in the environment to reduce the risk of environmental polluti... Humic acid is rich in highly electronegative oxygen-containing organic functional groups,so it has high reactivity and can adsorb phthalic acid ester(PAEs)in the environment to reduce the risk of environmental pollution from PAEs.In this paper,the extraction,characterization and adsorption models of humic acid were reviewed,and the research status of adsorption of PAEs by humic acid was further summarized.Based on these,the feasibility and observable application prospect of humic acid as a cheap adsorbent were analyzed. 展开更多
关键词 Humic acid EXTRACTION CHARACTERIZATION Phthalic acid esters ADSORPTION
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Insights into biobased epoxidized fatty acid isobutyl esters from biodiesel:Preparation and application as plasticizer
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作者 Xiaojiang Liang Fengjiao Wu +5 位作者 Qinglong Xie Zhenyu Wu Jinjin Cai Congwen Zheng Junhong Fu Yong Nie 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第4期41-50,共10页
Biodiesel was used to prepare epoxidized fatty acid isobutyl esters(Ep-FABEs)as a biobased plasticizer in this work.Transesterification of biodiesel with isobutanol catalyzed by tetrabutyl titanate was carried out in ... Biodiesel was used to prepare epoxidized fatty acid isobutyl esters(Ep-FABEs)as a biobased plasticizer in this work.Transesterification of biodiesel with isobutanol catalyzed by tetrabutyl titanate was carried out in a gas-liquid tower reactor.The conversion achieved nearly 100%within 5 h under the reaction temperature,the mass ratio of catalyst to fatty acid methyl esters(FAMEs),and isobutanol to FAMEs total molar ratio of 180℃,0.4%(mass),and 5.4:1,respectively.In addition,kinetic model of the transesterification reaction was developed at 150–190℃.The calculated activation energy was 48.93 kJ·mol^(-1).Then,the epoxidation of obtained fatty acid isobutyl esters(FABEs)was conducted in the presence of formic acid and hydrogen peroxide.The Ep-FABEs was further analyzed for its plasticizing effectiveness to replace dioctyl phthalate(DOP)and compared with conventional epoxy plasticizer epoxidized fatty acid methyl esters(Ep-FAMEs).The results indicated that the thermal stability and mechanical properties of PVC films with Ep-FABEs plasticizer were significantly improved compared with those plasticized with DOP.In addition,the extraction resistance and migration stability of Ep-FABEs were better than those of EpFAMEs.Overall,the prepared Ep-FABEs via structural modification of biodiesel proved to be a promising biobased plasticizer. 展开更多
关键词 BIODIESEL TRANSesterIFICATION Isobutyl esters Epoxidized isobutyl esters Biobased plasticizer
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Anticancer Activities of Substituted Cinnamic Acid Phenethyl Esters on Human Cancer Cell Lines 被引量:4
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作者 李树春 李辉 +2 位作者 张法 李中军 崔景荣 《Journal of Chinese Pharmaceutical Sciences》 CAS 2003年第4期184-187,共4页
Caffeic acid phenethyl ester (CAPE) and sixteen substituted cinnamic acid phenethyl esters were prepared via conventional procedures in order to test their in vitro anticancer activities by either MTT assay or SRB... Caffeic acid phenethyl ester (CAPE) and sixteen substituted cinnamic acid phenethyl esters were prepared via conventional procedures in order to test their in vitro anticancer activities by either MTT assay or SRB assay on six different human cancer cell lines. The results indicated that in the concentration of 10 μmol·L -1 the lead compound CAPE possessed anticancer activities against human HL 60, Bel 7402, and Hela cell lines, and two other compounds possessed potent anticancer activities against Bel 7402 and Hela cell lines. 展开更多
关键词 medicinal chemistry cinnamic acid phenethyl esters chemical synthesis anticancer activity
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Effect of linear carboxylic ester on low temperature performance of LiMn_2O_4-graphite cells 被引量:3
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作者 洪树 李劼 +2 位作者 王冠超 张治安 赖延清 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第1期206-210,共5页
To improve the low-temperature performances of Li-ion cells, three types of linear carboxylic ester-based electrolyte, such as EC/EMC/EA(1:1:2, mass ratio), EC/EMC/EP(1:1:2, mass ratio) and EC/EMC/EB(1:1:2,... To improve the low-temperature performances of Li-ion cells, three types of linear carboxylic ester-based electrolyte, such as EC/EMC/EA(1:1:2, mass ratio), EC/EMC/EP(1:1:2, mass ratio) and EC/EMC/EB(1:1:2, mass ratio), were prepared to substitute for industrial electrolyte(EC/EMC/DMC). Then, 18650-type Li Mn2O4-graphite cells(nominal capacity of 1150 mA ·h) were assembled and studied. Results show that the cells containing three types of electrolyte are able to undertake 5C discharging current with above 93% capacity retention at-20 °C. Electrochemical impedance spectra show that the discharge capacity fading of Li-ion cells at low temperature is mainly ascribed to the charge transfer resistance increasing with temperature decreasing. In comparison, the cells containing electrolyte of 1.0 mol/L LiPF6 in EC/EMC/EA(1:1:2, mass ratio) have the highest capacity retention of 90% at-40 °C and 44.41% at-60 °C, due to its lowest charge-transfer resistance. 展开更多
关键词 Li-ion cells low temperature performance ELECTROLYTE linear carboxylic ester ionic conductivity charge-transfer resistance
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Short communication Catalytic synthesis of butyric esters with TiSiW_(12)O_(40)/TiO_2 被引量:46
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作者 YANGShuijin CHENLuchun SUNJutang 《Rare Metals》 SCIE EI CAS CSCD 2003年第1期75-77,共3页
The catalytic activities of TiSiW_(12)O_(40)/TiO_2 in synthesizing ethylester; propyl ester, n-butyl ester; and amyl ester were reported. It was demonstrated thatTiSiW_(12)O_(40)/TiO_2 is an excellent catalyst. Variou... The catalytic activities of TiSiW_(12)O_(40)/TiO_2 in synthesizing ethylester; propyl ester, n-butyl ester; and amyl ester were reported. It was demonstrated thatTiSiW_(12)O_(40)/TiO_2 is an excellent catalyst. Various factors concerned with esterification wereinvestigated. The optimum conditions were found: the mole ratio of alcohol to acid is 1.3:1, themass ratio of catalyst to reactants is 1.5 percent, and the reaction time is 1.0 h. Under theoptimum conditions, the yields are 88.0 percent for ethyl ester, 94.5 percent for propyl ester, 98.6percent for n-butyl ester, 99.1 percent for n-amyl ester, and 96.7 percent for iso-amyl ester,respectively. 展开更多
关键词 butyric ester TiSiW_(12)O_(40)/TiO_2 esterIFICATION CATALYST
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采用Fluo-3 AM-ester探针研究桃不同组织的Ca^2+信号分布 被引量:2
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作者 鲁振华 王志强 +3 位作者 彭斌 牛良 崔国朝 刘淑娥 《果树学报》 CAS CSCD 北大核心 2011年第5期915-917,I0001,共4页
钙作为植物最重要的矿质元素之一,在植物生理和生化活动中起重要作用。采用激光扫描共聚焦显微镜,以Fluo-3 AM-ester为荧光探针研究了桃果肉和叶柄组织中Ca2+的分布,结果表明Fluo-3 AM-ester可作为荧光探针对桃不同组织中游离的Ca2+信... 钙作为植物最重要的矿质元素之一,在植物生理和生化活动中起重要作用。采用激光扫描共聚焦显微镜,以Fluo-3 AM-ester为荧光探针研究了桃果肉和叶柄组织中Ca2+的分布,结果表明Fluo-3 AM-ester可作为荧光探针对桃不同组织中游离的Ca2+信号强度和分布特征进行分析。不同的物镜观察(10×和20×)下,Ca2+荧光信号相对强度差异不大;在叶柄中Ca2+荧光信号主要分布于维管束,在果实中多分布于细胞壁;但叶柄中荧光信号分布明显高于果肉组织,这与钙在不同组织中的功能有关。 展开更多
关键词 Ca2+信号 激光扫描共聚焦显微镜 Fluo-3AM-ester
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Determination of phthalate esters in fat-containing foods by packed nanofiber solid-phase extraction column and gas chromatography 被引量:1
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作者 邱金丽 王羽 +1 位作者 周小玲 康学军 《Journal of Southeast University(English Edition)》 EI CAS 2016年第3期322-326,共5页
A new method for simultaneous determination of four phthalate esters ( PAEs) in commercial fat-containing foods was developed by the combination of a packed nanofibers column based on solid-phase extraction with gas... A new method for simultaneous determination of four phthalate esters ( PAEs) in commercial fat-containing foods was developed by the combination of a packed nanofibers column based on solid-phase extraction with gas chromatography-flame ionization detector ( GC-FID ). Conditions for obtaining optimum extraction efficiency such as extraction solvents, morphologies of adsorbent, ion strength and pH were investigated and optimized in detail. Under the optimized conditions, the limits of detection (LODs) found for dibutyl phthalate (DBP) , butyl benzyl phthalate (BBP), diethyl hexyl phthalate (DEHP) and di-n-octyl phthalate (DNOP) were 50, 25, 50 and 25 ng/g, respectively. Good linearity of four PAEs was achieved in the range of 50 to 4 000 ng/g. The proposed method was applied for analyzing different kinds of fat-containing samples. PAEs in commercial fat-containing samples can be highly extracted by a packed solid-phase extraction column of 5 mg polystyrene ( PS) nanofibers. The satisfactory average recoveries were obtained in the range of 96. 7% to 102. 3% , and the relative standard deviations (RSDs) below 5% were achieved. The proposed method reduces the organic solvent consumption, the complex and tedious procedures for sample pretreatment, and achieves high sensitivity and reproducibility for the investigated PAEs. 展开更多
关键词 phthalate esters (PAEs nanofibers solid-phase extraction gas chromatography fat-containing foods
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Detailed investigation of optimized alkali catalyzed transesterification of Jatropha oil for biodiesel production 被引量:5
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作者 Waqas Ahmed Muhammad Faizan Nazar +2 位作者 Syed Danish Ali Usman Ali Rana Salah Ud-Din Khan 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2015年第3期331-336,共6页
The non-edible oils are believed to be one of the major feedstock for the production of biodiesel in future.In the present study,we investigated the production of Jatropha oil methyl esters(JOMEs) via alkali-catalyz... The non-edible oils are believed to be one of the major feedstock for the production of biodiesel in future.In the present study,we investigated the production of Jatropha oil methyl esters(JOMEs) via alkali-catalyzed transesterification route.The biophysical characteristics of Jatropha oil were found within the optimal range in accordance with ASTM standards as a substitute diesel fuel.The chemical composition and production yield of as-synthesized biodiesel were confirmed by various analytical techniques such as FT-IR,1H NMR,13 C NMR and gas chromatography coupled with mass spectrometry.A high percentage conversion,~96.09%,of fatty acids into esters was achieved under optimized transesterification conditions with 6 :1 oil to methanol ratio and 0.9 wt% Na OH for 50 min at ~60°C.Moreover,twelve fatty acids methyl esters(FAME) were quantified in the GC/MS analysis and it was interesting to note that the mass fragmentation pattern of saturated,monounsaturated and diunsaturated FAME was comparable with the literature reported values. 展开更多
关键词 Jatropha oil methyl esters TRANSesterIFICATION biodiesel fuel gas chromatography mass spectrometry
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Synthesis of insecticidal sucrose esters 被引量:9
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作者 Song Zi-juan Li Shu-jun Chen Xi Liu Li-mei Song Zhan-qian 《Forestry Studies in China》 CAS 2006年第3期26-29,共4页
Some synthetic sucrose esters (SE) are a relatively new class of insecticidal compounds produced by reacting sugars with fatty acids, which are safe for the environment. Especially, sucrose esters composed of C6-C12... Some synthetic sucrose esters (SE) are a relatively new class of insecticidal compounds produced by reacting sugars with fatty acids, which are safe for the environment. Especially, sucrose esters composed of C6-C12 fatty acids have desirable insecticidal properties against many soft-bodied arthropod pests. In our study, sucrose octanoate which has the highest activity against a range of arthropod species was synthesized by a trans-esterification method and proved its insecticidal property. Under the condition of a homogeneous liquid, sucrose octanoate was prepared by reacting ethyl octanoate with sucrose at reduced pressure; the yield was 79.11%. Sucrose octanoate synthesized was identified and its property analyzed by IR, TLC and spectrophotometric analysis. It was shown that the ratio of monoester to polyester in sucrose octanoate was 1.48:1. The insecticidal activity of the synthetic sucrose octanoate was evaluated at a concentration of 4 and 8 mg.mL^-1. The mortality of first-instar larvae ofLymantria dispar from its contact toxicity was 72.5% after 36 hours, the revision insect reduced rate of Aphis glycines reached above 80% at 4 and 8 mg.mL^-1 after being treated for 5 days. Since the SE products are nontoxic to humans and higher animals, fully biodegradable and hydrolyzed to readily metabolizable sucrose and fatty acid, they are not harmful to crops and appear to be good insecticide candidates. 展开更多
关键词 INSECTICIDAL sucrose ester transesterification method
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Studies on Production of Biodiesel by Esterification of Fatty Acids by a Lipase Preparation from Candida sp. 99-125 被引量:8
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作者 DENG Li(邓利) +5 位作者 NIE Kaili(聂开立) WANG Fang(王芳) TAN Tianwei(谭天伟) 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2005年第4期529-534,共6页
A self-made lipase preparation from Candida sp. 99-125 was used for the production of biodiesel through enzymatic esterification of fatty acids. The crude lipase powder and fermentation broth were immobilized on a che... A self-made lipase preparation from Candida sp. 99-125 was used for the production of biodiesel through enzymatic esterification of fatty acids. The crude lipase powder and fermentation broth were immobilized on a cheap fiber cloth carrier. The conditions of lipase-catalyzed esterification between long-chain fatty acids and methanol in a solvent system were investigated in detail, including the temperature, pH value, substrate concentration, solvent, absorbent agent, enzyme dosage and purity, immobilization method, the mode of addition of substrate. The results show that reaction temperature, pH of lipase micro-environment, substrate concentration, enzyme dosage and purity affect the esterification strongly. Several new methods and enzymatic procedures for improving the enzymatic reaction involving the process cost are also discussed, such as fossil diesel fuel as reaction solvent, immobilization method, multi-step gradient addition of methanol. The esterification degree of 92.8% was obtained with oleic acid and methanol under the optimal reaction condition after 12.5 h reaction time. The half-life of the immobilized lipase preparation from crude free lipase powder for esterification was 15 days. 展开更多
关键词 BIODIESEL fatty acid short-chain alcohol ester immobilized lipase CATALYSIS esterIFICATION
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