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.

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.

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.

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.

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.

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.

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。

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.

固体酸CuCo_(2)S_(4)催化制备呋喃基二酯化合物

采用2,5-四氢呋喃二甲醇(THFDM)与不同碳链长度脂肪酸(正丁酸、正癸酸和棕榈酸)为原料,以新型多孔状金属有机骨架材料固体酸CuCo_(2)S_(4)为催化剂,催化合成呋喃基二酯化合物。通过单因素实验研究醇酸摩尔比、催化剂添加量、反应温度以及反应时间对脂肪酸转化率的影响。实验结果表明,在醇酸摩尔比1∶1、催化剂添加量1.25%(以THFDM质量计)、反应温度140℃、反应时间7 h条件下,正丁酸、正癸酸和棕榈酸转化率分别达到84.57%、94.22%与87.20%。通过傅里叶红外光谱和核磁共振碳谱对提纯后的产物进行分析,证明产物为具有对称结构的呋喃基二酯化合物。理化性质表明2,5-四氢呋喃二丁酸酯在润滑油助剂领域具有潜在的应用价值。

佛波双酯对照品的制备研究

目的研究佛波双酯(TPA)对照品的制备方法及质量标准,为佛波双酯原料和相关制剂的质量控制提供依据。方法利用硅胶柱制备色谱和反相制备色谱对巴豆油的甲醇-水提取物进行分离纯化,分别以高效液相色谱法(HPLC)和气相色谱对佛波双酯对照品进行纯度检查和含量测定,用紫外光谱(UV)、红外图谱(IR)、质谱(MS)、核磁共振氢谱(1H-NMR)、碳-13核磁共振(13C-NMR)等方法进行图谱分析及结构确证,确认分子式为C36H56O8。结果纯化制备得到的佛波双酯对照品,紫外最大吸收波长为232 nm,MS结果为高分辨电喷雾质谱(HRESI-MS)m/z 615.4120(M-H)-,HPLC检查纯度>99.5%。结论本制备方法科学有效,制备的对照品纯度符合中药化学对照品的相关要求,可作为佛波双酯原料及相关制剂质量控制的化学对照品。

不同灭菌工艺对生川乌中乌头类双酯型生物碱成分及产品质量影响研究

目的:在保证生川乌药效的前提下,筛选最优灭菌工艺。方法:分别采用热压灭菌、干热灭菌、钴-60辐照灭菌三种方法进行灭菌处理,采用HPLC法考察灭菌后乌头类双酯型生物碱含量变化情况,同步考察药材及其产品微生物数量是否符合标准,以综合评估大生产适用工艺。结果:3种灭菌方法均能使产品符合成品质量标准,综合考虑灭菌后样品微生物数量、指标成分含量、效率等因素,干热灭菌工艺是最优工艺。结论:在干热灭菌条件下,产品微生物限度符合要求,乌头类双酯型生物碱转移率较优,生产效率可接受,可作为工业生产最优工艺。

紫外-可见分光光度法测定舒筋消肿散中双酯型生物碱限量

目的建立舒筋消肿散中双酯型生物碱的限量测定方法。方法应用紫外-可见分光光度法,采用改良盐酸羟胺-高氯酸铁法显色,在520 nm波长处测定乌头碱对照液和供试品溶液的吸光度,计算供试品溶液中双酯型生物碱的含量。结果乌头碱对照液浓度在23.1~231.0μg·mL^(-1)范围内线性关系良好,回归方程A=0.00705C+0.000134,r=0.999891。乌头碱平均回收率92.42%,RSD=1.20%(n=9)。测得10批舒筋消肿散中双酯型生物碱限量,以乌头碱计分别为:0.131%、0.065%、0.077%、0.117%、0.108%、0.081%、0.097%、0.122%、0.103%、0.092%。结论建立的测定方法简便、准确、灵敏、重现性良好,适用于舒筋消肿散中双酯型生物碱限量的测定。

人参再造丸中6种乌头类生物碱的含量测定方法研究

建立人参再造丸(浓缩丸)中6种乌头类生物碱含量的检测方法。采用超高效液相色谱-质谱联用法(UPLC-MS)对人参再造丸(浓缩丸)中双酯型生物和单酯型生物碱的含量进行测定,梯度洗脱模式下,以0.1%甲酸溶液-乙腈为流动相,电喷雾离子源(正离子模式),监测模式为多反应监测。结果表明,6种生物碱均有良好的线性关系,精密度试验、稳定性试验、重复性试验中RSD均低于5%,平均回收率和RSD分别为97.27%~108.29%和1.99%~4.01%。所建立的方法能同时准确、快速地测定人参再造丸(浓缩丸)中6种乌头类生物碱成分的含量,专属性强、灵敏度高、重复性好,能为全面有效管控人参再造丸(浓缩丸)质量提供参考。

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.