Synthesis and Properties of Novel Cationic Maleic Diester Polymerizable Surfactants

Three new cationic polymerizable surfactants are synthesized by the reaction of alkylmaleic hemiester with glycidyltrimethylammonium chloride. Their structures are confirmed by H-1 NMR, IR and elements analysis. The values of CMC and gamma (CMC) of these surfactants have been measured. One can obtain nearly monodisperse polystyrene latex by emulsion polymerization using the polymerizable surfactant.

Comparison of the Digestion and Absorption Characteristics of Docosahexaenoic Acid-Acylated Astaxanthin Monoester and Diester in Mice

Docosahexaenoic acid-acylated astaxanthin(DHA-AST)esters exhibit distinct bioactivities in improving brain function.However,the digestion and absorption characteristics of DHA-AST esters in vivo are unclear,thereby restricting the molecular mechanism analysis of their superior activities.This study compared the digestion and absorption characteristics of DHA-AST monoester and diester by determining the levels of AST and DHA in the serum,liver,small intestinal content and wall,and feces at different time points after a single-dose oral administration of the esters.After oral gavage with 2 mg AST equivalent of the DHA-AST monoester and diester for 18 h,the excretion rates were approximately 51%and 84%,respectively.This result indicates that DHA-AST monoester was better than diester for the absorption of AST.The results in serum,liver,and small intestinal content and wall also agreed with this finding.Moreover,the excretion rates of DHA in the feces at 24 h in the DHA-AST monoester and diester groups were approximately 40%and 36%after gavage with 5 mg DHA equivalent,respectively.This result indicates that DHA-AST diester exhibited a better tendency than monoester for the absorption of DHA.Interestingly,the results in the liver and small intestinal wall showed an apparent difference,indicating that DHA-AST diester was better than monoester for the absorption of DHA.These findings provide a scientific basis for the molecular mechanism analysis and utilization of DHA-AST monoester and diester as functional ingredients.

Diester Derivatives from Chemically Modified Waste Cooking Oil as Substitute for Petroleum Based Lubricating Oils

In order to provide a new way for waste cooking oil(WCO) resource utilization, several diester derivatives were obtained from WCO through a three-step chemical modifications, viz.: transesterification, epoxidation and oxirane ring opening with carboxylic acids. The effects of the chain length of side chain groups on the viscosity, acid value, low temperature fluidity, thermo-oxidative stability, tribological properties and surface tension of diester derivatives were investigated. The results showed that increasing the chain length of side chain groups had a positive influence on the viscosity, viscosity index, acid value, pour point, friction coefficient and wear scar diameter along with a negative influence on the oxidation onset temperature, volatile loss, insoluble deposit, maximum non-seizure load and surface tension. These diester derivatives exhibited improved physicochemical and tribological properties that make themselves promising environmentally friendly biolubricant basestocks.

Transformation of phthalic acid diesters in an anaerobic/anoxic/oxic leachate treatment process

Transformations of di-n-butyl phthalate(DBP) and di(2-ethylhexyl) phthalate(DEHP) have been investigated in anaerobic/anoxic/oxic(A/A/O) leachate treatment processes. Although the DBP removal processes are different when the DBP initial concentration is different, the overall system DBP removal efficiencies are high(N 94%).DEHP is much more difficult to remove than DBP. The removal efficiency of DEHP is approximately 75%–78%.The results of mass balance calculations indicate that approximately 33.7%–50.7% of the DBP is degraded by the activated sludge, 48.9%–64.9% accumulates in the system, and 0.4%–1.4% is contained in the final effluent. Approximately 15.0%–19.0% of the DEHP is degraded by activated microcosms, 75.8%–79.0% accumulates in the system, and 5.2%–6.0% is contained in the final effluent. Biodegradation and adsorption to the activated sludge are the main mechanisms for DBP removal and adsorption to the activated sludge is the main mechanism for DEHP removal. The different removal mechanisms of the two PAEs may be related to their different molecular structures. However, PAEs are not really removed when they adsorb onto the sludge. Therefore, methods for decreasing PAEs adsorption and increasing the biodegradation efficiencies of the leachate treatment processes should be further investigated.

Phosphate Diester Hydrolysis by Dinuclear Tb(III) Complexes with BDBPH in Second-order Dependence

The kinetic study on the hydrolysis reaction of bis（4-nitrophenyl） phosphate （BNPP） catalyzed by Tb-BDBPH system（2：1） was carried out in 50% ethanol solution （pH 7.0-10.0） at 35℃ with I=0.10NaNO3. The second-order rate constant kBNPP, 2.3×10.3 （mol^-1L S^-1）, was determined. The dinuclear monohydroxo species, L-2Tb-OH, is kinetically mainly active species. The hydrolysis rate of BNPP by the complex is increased almost 2.6 million-fold compared with the background hydroxide rate at the same condition.

Aqueous Diels-Alder Reactions of Cyclopentadicnc with Symmetric Diester of Fumarate or Maleate

Symmetric, diesters of cis- or trans- bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylate were prepared by aqueous Diels-Alder reaction of cyclopentadiene with symmetric diester of fumarate or maleate.

A Facile Synthesis of N-Substituted Spirocyclic Diester of α-Aminophosphonic Acid

A simple and direct method for preparation of N-substituted spirocyclic dieSter of □-amino phosphonic acid (4) in high yield is introduced. The reaction consists of the threecomponent reachon of phenylurea (1), an aromatic aldehyde (2), and 3,9-dichloro-2,4,8,10-tetraoxa- 3, 9 -diphosphaspiro [5,5] undecane (3) in anhydrous benzene.

A New Chromogenic Diester-calix[4]crown Receptor for Ca^(2+)

A diester-calix[4]crown-4-ether bearing mono (azophenol) moiety shows a larger spectral change toward Ca2+ than other alkali and alkaline eafth cations.

含饱和烷烃和芳烃结构的聚非对称交酯的高效合成与性能研究

非对称交酯合成效率低,开环聚合(ROP)产物分子量小,因此很少有研究报道聚非对称交酯的流变行为与力学性能.本研究采用N,N-二异丙基乙胺(DIPEA)作为缚酸剂,通过均相反应体系高效合成了多种非对称交酯,经ROP得到数均分子量70 kg/mol的聚非对称交酯;并对聚合物的化学结构、热学性能、流变行为和力学性能进行了表征.热学测试和力学性能测试结果表明5种聚酯材料均为非晶聚合物,在单体结构中引入高支化度饱和烷烃取代基和芳香族取代基可以提高聚合物玻璃化转变温度,而聚合物侧链的低支化度饱和烷烃取代基会降低其玻璃化转变温度并提高断裂伸长率.流变测试结果表明,不同取代基的聚非对称交酯的零切黏度均低于聚乳酸,并且聚合物的缠结分子量受取代基影响.本研究为聚酯材料结构设计与性能调控提供了有益参考.

Dichloromethane as a methylene synthon for regioselective linkage of diverse carboxylic acids:Direct access to methylene diesters under metal-free conditions

A metal-free cross coupling between common CH2Cl2 and carboxylic acids has been achieved with K2CO3 as the sole additive. This simple protocol is a convenient and cost-effective route to synthesize methylene diesters from a wide scope of carboxylic acids substrates with good functional group tolerance. Several gram-scale reactions have been performed to evaluate the effectiveness and practicality of this protocol.

Chemoselective synthesis of novel aminoindolizines using aminopyridines, acetylenic diesters and α-halo ketones

A chemoselective synthesis of novel indolizine derivatives were reported via three-component reactions of aminopyridines, acetylenic diesters and a-halo ketones. In these reactions, the zwitterion generated from aminopyridines and acetylenic diesters reacted with a-halo ketones to produce indolizine skeleton in good to high yields under mild reaction conditions.

An Unusual Acceleration of Amination Reactivity by the Proximal Ester Groups in Catechol Diesters: An Efficient Way for Peptide Synthesis

Peptide bond formation has drawn more and more attention due to its importance in medicinal chemistry and drug discovery.Using active esters to construct peptide bonds is an indispensable strategy in this field.We herein report a fast and efficient amination reaction to synthesize peptides from catechol diesters.Catechol monoesters are good active esters in peptide synthesis due to the anchimeric assistance effect.In previously reported work,the amination reaction was inactivated if the 2-hydroxyl group in the catechol esters was functionalized.However,we found an unusual acceleration of the amination reactivity when the 2-hydroxyl group was functionalized as an ester group.The reaction can be complete in 2−3 min in some cases.This acceleration was found through experimental studies to not result from the anchimeric assistance effect.We proposed aπ*−π*interaction pathway between the two proximal ester groups.Some computational studies were made to support this assumption.

Aggregation of deuteroporphyrin IX diesters in aqueous-organic binary solution

The aggregation properties of a series of deuteroporphyrin IX diesters in the THF-Buffer (0.1 mol·L?l Tris-HCl) aquiorgano solvent have been studied by means of UV-Vis and fluorescence spectrometers. Experimental data show that the dimerization of porphyrins is mainly determined by π-π interaction in pure organic solution while further aggregation of porphyrins with long hydro-carbon chains is more likely driven by hydrophobic-lipophilic interaction in aqueous-organic binary solution. The appearance of the aggregates induces a red shift in absorption spectra and fluorescence quenching in fluorescence spectra. The chain-length effect and chain-foldability effect have also been observed.

Lipophilicity determination of N-( benzothiazol-2-yl )-α-amino alkyl phosphonic diesters by RP-HPLC and RP-HPTLC

Using methanol-water mixtures as the mobile phase, the chromatographic retention parameters k' and Rf were determined by reversed-phase high-performance liquid chromatography (RP-HPLC) and reversed-phase high-performance thin-layer chromatography (RP-HPTLC) for N-(benzothiazol-2-yl)-α-amino alkyl phosphoric diesters and the correlation with lipophilicity parameter (Clog P) was established. Log Kw values obtained from RP-HPLC and Rm values obtained from RP-HPTLC can be used to evaluate the lipophilicity of this kind of compounds. Chromatographic method is a good alternative for lipophilicity measurement.

可控微波促进对称1,n-亚甲基二酯的环境友好合成

采用可控微波加热技术,在水作溶剂或无溶剂条件下芳甲酸与1,n-二溴代烷发生双酯化反应,“一锅”法高效地合成了系列亚甲基二羧酸酯类化合物.考察了反应温度、时间、碱、溶剂对双酯化产率的影响,在优化实验条件下合成了31种亚甲基二羧酸酯,底物适用范围广,并提出了合理的反应机理.该方法操作简单、时间短,产率较高,同时符合绿色化学的原则.

变异系数法-AHP复合加权联用TOPSIS模型优选白附片降毒增效炮制工艺

目的:运用变异系数法-层次分析法(AHP)复合加权联用TOPSIS优选白附片炮制工艺参数,为白附片规范化炮制提供参考。方法:以煮制时间、浸漂时间和蒸制时间为考察因素,以穷举寻根法开展试验设计,以苯甲酰新乌头原碱、苯甲酰乌头原碱、苯甲酰次乌头原碱、新乌头碱、次乌头碱、乌头碱、水分、灰分和胆巴残留量为评价指标,以变异系数法-AHP复合加权计算权重系数,通过TOPSIS模型优选白附片炮制工艺参数。结果:白附片最优炮制工艺参数为煮制20 min、浸漂48 h、蒸制3 h。结论:该工艺稳定、可行,可为白附片的规模化加工炮制提供参考。

1,2-环己烷二甲酸双酯在空气压缩机油中的应用

对比考察了邻苯二甲酸二异辛酯和1,2-环己烷二甲酸二异辛酯,邻苯二甲酸二异癸酯和1,2-环己烷二甲酸二异癸酯的理化性能及其相应成品油的综合性能,环己烷二元酸酯及其成品油40℃黏度相对略低,但是黏度指数相对较高;其高低温性能略差,但是其成品油的高温性能、黏度指数以及低温性能均表现良好。

藻酸双酯钠片与阿司匹林联合治疗短暂性脑缺血发作的疗效观察

目的探讨藻酸双酯钠片联合阿司匹林治疗短暂性脑缺血发作(TIA)的临床疗效。方法选择2023年1月至2023年12月北京市大兴区人民医院收治的94例TIA患者,以随机数字表法分为对照组和研究组,各47例。在常规对症治疗基础上,对照组采用阿司匹林治疗,研究组采用阿司匹林+藻酸双酯钠片。比较两组患者临床疗效、糖尿病评分(ABCD2)评分、血脂指标、甲襞微循环、凝血功能、用药不良反应,以及随访3个月时临床结局。结果研究组治疗有效率93.62%(44/47)高于对照组74.47%(35/47),差异有统计学意义(P<0.05);治疗后,与对照组比较,研究组ABCD2评分、总胆固醇(TC)、三酰甘油(TG)、低密度脂蛋白胆固醇(LDL-C)、管袢形态、管袢流态、袢周状态评分、纤维蛋白原(FIB)均降低(P均<0.05);高密度脂蛋白胆固醇(HDL-C)、活化部分凝血活酶时间(APTT)、凝血酶原时间(PT)均升高(P<0.05);研究组不良反应发生率与对照组比较,差异无统计学意义(P均>0.05);随访3个月研究组进展为脑梗死的发生率与对照组比较,差异无统计学意义(P>0.05)。结论TIA患者应用藻酸双酯钠片联合阿司匹林治疗效果显著,能提升疗效,降低脑梗死发生率,改善患者的血脂、微循环和凝血功能。

蒙药复方制剂孟根·沃斯-18丸质量标准研究

目的建立蒙药复方制剂孟根·沃斯-18丸质量标准。方法对制剂进行显微鉴别,采用薄层色谱(TLC)法定性鉴别制剂中枫香脂;采用滴定法测定热制水银的含量;采用高效液相色谱法测定6种生物碱含量,色谱柱为Agilent Eclipse Plus C18柱(250 mm×4.6 mm,5μm),流动相为乙腈-0.2%磷酸水溶液(梯度洗脱),流速为1.0 mL/min,检测波长为232 nm,柱温为40℃,进样量为10μL。结果制剂显微鉴别特征明显;枫香脂的TLC图斑点清晰,分离度好,阴性对照无干扰;热制水银重复性试验结果的RSD为1.63%,平均加样回收率为100.50%(RSD=1.99%,n=9);苯甲酰新乌头原碱、苯甲酰次乌头原碱、苯甲酰乌头原碱、新乌头碱、次乌头碱、乌头碱进样量分别在45.19~293.72μg、4.73~30.73μg、6.33~41.17μg、9.28~60.33μg、8.78~57.09μg、9.31~60.52μg范围内与峰面积线性关系良好(r=0.9999),精密度、稳定性、重复性试验结果的RSD均小于3.0%,平均加样回收率分别为93.24%,95.68%,92.13%,89.59%,88.30%,89.82%,RSD分别为2.34%,2.45%,3.13%,2.61%,2.69%,3.22%(n=9)。10批次制剂中热制水银含量为9.42%~13.83%,转移率为96.97%;单酯型生物碱(苯甲酰新乌头原碱、苯甲酰次乌头原碱、苯甲酰乌头原碱)总量为7.7~62.0μg/g、双酯型生物碱(新乌头碱、次乌头碱、乌头碱)总量为9.0~49.0μg/g。结论所建方法操作简便,专属性强,可为含草乌中蒙药制剂标准的建立提供参考。

棕榈酸虾青素酯的合成分离及抗氧化活性分析

以虾青素与棕榈酸作为反应底物酯化合成棕榈酸虾青素双酯,优化出最佳反应条件为:虾青素50 mg、棕榈酸45 mg、二氯甲烷1 mL、1-乙基-3(3-二甲基丙胺)碳二亚胺(EDCI)80 mg和4-二甲氨基吡啶(DMAP)40 mg,氮气保护下25℃避光反应12 h。通过柱层析纯化获得棕榈酸虾青素双酯和棕榈酸虾青素单酯,纯度分别为98.9%和97.4%,利用红外、核磁、高分辨质谱等对产品进行了结构表征。抗氧化实验表明,抗氧化效果总体为棕榈酸虾青素单酯>虾青素>棕榈酸虾青素双酯。