Iodine-catalyzed Efficient Synthesis of β-Keto Esters from Aldehydes and Ethyl Diazoacetate Under Solvent-free Conditions

An efficient procedure for the synthesis ofβ-keto esters from the reaction of aldehydes and ethyl diazoacetate catalyzed by iodine at room temperature under solvent-free conditions has been described. The catalytic procedure has the advantages of easily available catalyst, mild reaction conditions, high yields, and easy work-up.

Synthesis and Physicochemical Properties of L-(+)-a-(Positive Butyl)-Leucine Ethyl Ester Chiral Ionic Liquids

L-（＋）-α-（positive butyl）-leucine ethyl ester bromide chiral ionic liquid was synthesized by using microwave-assisted synthesis method and L-（＋）-α-（positive butyl）-leucine ethyl ester terafluoroborate and hexafluorophosphate chiral ionic liquids were synthesized by the anion exchange reaction. The structures were characterized by IR, ~1HNMR and structure optimization calculation. The results of studies on physicochemical properties show that they possess better thermal stability, solubility, bio-solubility and high conductivity. They can serve as effective reaction media as well as chiral catalysts. They are presently being investigated as dispersion agents in molecular imprinting ployer.

Design,Synthesis,and Biological Evaluation of 5H-Thiazolo[3,2-a]pyrimidine-6-carboxylic Acid Ethyl Ester Derivatives as a Novel Series of Acetylcholinesterase Inhibitors

Acetylcholinesterase inhibitors are the most frequently prescribed anti-Alzheimer＇s drugs. A series of 5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester derivatives as the novel acetylcholinesterase inhibitors was designed based on virtual screening methods. The target compounds were synthesized with Biginelli reaction and Hantzsch-type condensation of dihydropyrimidines with substituted phenacyl chlorides, and were characterized with elemental analysis, IR, MS, ^1H NMR, and ^13C NMR. The biological evaluation against human acetylcholinesterase in vitro indicated all the target compounds show more than 50% inhibition at 10μmol/L by means of the Ellman method. The results provide a starting point for the development of novel drugs to treat Alzheimer＇s disease and lay the foundation of searching for improved acetylcholinesterase inhibitors with the novel scaffolds.

Synthesis, Crystal Structure and Inhibition of N-2-Thiophenesulfonyl-α-L-phenylalanine Ethyl Ester on K562 Cell Proliferation

The title compound N-2-thiophenesulfonyl-a-L-phenylalanine ethyl ester has been synthesized. Complete assignments were achieved by IR, MS, ^1H NMR and single-crystal X-ray diffraction analyses. Using MTT assay, the inhibitory rate of the title compound on K562 cells （chronic myeloid leukemic cells） was measured and the result of preliminary bioassay showed that the title compound possesses antiproliferation effects on K562 cells. In order to investigate the relationship between structure and activity of the target compound, we report its crystal structure and biological behavior in the present paper. Crystallographic data： C15H17NO4S2, Mr = 339.42, monoclinic, space group P21, flack = -0.15（12）, a = 5.7916（10）, b = 11.5078（19）, c = 12.924（2） A, β = 97.781（3）°, Z = 2, V = 853.4（2） A^3, De = 1.321 g/cm^3, F（000） = 356, -7≤h≤7, -10≤k≤14, -15 ≤ l≤15, R = 0.0628, wR = 0.1540 and μ（MoKa） = 0.327 mm^-1. The molecule comprises a benzene and a thiofuran rings, and the intramolecular N（1）-H（1A）…O（1） makes a five-membered ring of O（1）--C（6）-C（5）--N（1）--H（1A）.

Supercritical Synthesis of Ethyl Esters via Transesterification from Waste Cooking Oil Using a Co-Solvent

Biofuels became more promising alternative to the fossil fuels because of the depletion of fossil resources, renewability, environmental benefits, and energy security. Ethanolysis of waste cooking oil with hexane as co-solvent was carried out for the production of fatty acid ethyl ester (FAEE). This process reduced the severity of process parameters with high purity biodiesel yield. Process variables such as co-solvent ratio, ethanol to oil molar ratio, reaction temperature and reaction time were optimized. The maximum biodiesel yield of 88% was obtained at ethanol/oil molar ratio of 40:1, co-solvent (hexane) to oil ratio of 0.2% (v/v), reaction temperature of 300°C in 20 min of reaction time. Fatty acid ethyl ester (biodiesel) samples produced from this process were measured and evaluated using GC-MS analytical instrument. Thermo gravimetric analysis (TGA) was also performed to examine the thermal stability of waste cooking oil, ethyl esters and fuel blends. Fuel properties of ethyl esters were determined and compared with the ASTM standards for biodiesel, regular diesel and ethyl esters from different feedstock.

Synthesis and Characterization of 2-cetyl-3-20 keto acid(N-ethyl perfluorinated octyl sulfonamide) N-ethyl ester

2-Cetyl-3-20 keto acid（N-ethyl perfluorinated octyl sulfonamide） N-ethyl ester was synthesized by the reaction of N-ethyl-N-hydroxyethyl perfluorinated octyl sulfonamide and alky ketene dimer. The experimental results show that the yield of products can be 89% when the molar ratio of perfluorinated octyl sulfonamide to ketene dimer is 1 ： 1.1 and the reaction lasts about four hours at 80 ℃. The structure of the product was characterized by FTIR and ^1HNMR. The product can dissolve in polar solvents such as NMP, DMAC, THF, DMSO, CHCl3, and 10% weight-loss temperature measured by TGA is 202℃.

An Alternative Synthesis and Crystal Structure Characterization of Nutrient Fortifier N-(1-(Phenylacetyl)-L-prolyl) Glycine Ethyl Ester

A nutritional fortifier N-(1-(phenylacetyl)-L-prolyl)glycine ethyl ester(4)was successfully synthesized through two synthetic schemes and characterized by IR,^1H-NMR,^13C-NMR,elemental analysis and X-ray single-crystal diffraction.The intermediate N-phenylacetyl-L-proline(2)was synthesized by the solid-liquid reaction of L-proline and phenylacetyl chloride directly.Compound 2(C13 H15 NO3,Mr=233.26)belongs to the orthorhombic system,space group P212121 with a=8.9468(3),b=9.3190(3),c=14.0453(4)A,V=1171.03(6)A^3,Z=4,Dc=1.323 g/cm^3,μ=0.773 mm^-1,F(000)=496.0,the final R=0.0313 and wR=0.0797 for all data.Compound 4(C17 H22 N2 O4,Mr=318.36)is of orthorhombic system,space group P212121 with a=6.5831(2),b=8.5536(2),c=28.9138(9)A,V=1628.11(8)A^3,Z=4,Dc=1.299 g/cm3,μ=0.763 mm-1,F(000)=680.0,the final R=0.0353 and wR=0.0816 for all data.

Extraction Separation of Scandium，Iron and Lutetium with Isopropyl Phosphonic Acid Mono（1－hexyl－4－ethyl）OctylEster

The extraction and stripping of scandium from its sulfate solutions by isopropyl phosphonic acid mono (1-hexyl-4-ethyl) octyl ester (PT-2, HL) diluted with n-hexane are reported. A high efficiency of separation between scandium, iron and lutetium can be achieved by controlling aqueous acidity. Different mechanisms of Sc3+ with PT-2 in various acid range have been proposed.At lower aqueous acidity, it is a cation exchange reaction, while at higher acidity. a solvation reaction was ascertained. Its IR and NMR spectra have been discussed. The effect of temperature on extraction of Sc3+ was observed and thermodynamic functions were calculated.

Synthesis and Crystal Structure of 4-(4,6-Dimethoxylpyrimidin-2-yl)-3-thiourea Carboxylic Acid Ethyl Ester

4-（4,6-Dimethoxyl-pyrimidin-2-yl）-3-thiourea carboxylic acid ethyl ester was synthesized by the reaction of 2-amino-4,6-dimethoxyl pyrimidine, potassium thiocyanate and methyl chloroformate in ethyl acetate. Single crystals suitable for X-ray measurement were obtained by recrystallization with the solvent of dimethyl formamide at room temperature. The crystal structure was determined by X-ray diffraction analysis. Crystallographic data： C10H14N4O4S, M, = 286.31, monoclinic, space group C2/c with a = 2.5309（3）, b = 0.67682（6）, c = 1.74237（19） nm, β = 114.744（3）°, V= 2.7106（5） nm3, Dc = 1.403 g/cm3, p = 0.225 mm-1, F（000） = 1200, Z= 8, R= 0.0514 and wR= 0.1529.

A new caffeic ester from Incarvillea mairei var.granditlora (Wehrhahn) Grierson

A new cafferic ester, （＋）-2-（1-hydroxyl-4-oxocyclohexyl） ethyl caffeate, was isolated from the 80% ethanol extract of the whole plants of Incarvillea mairei var. granditlora （Wehrhahn） Grierson. The structure of the compound was established by spectroscopic methods.

Vapor-Liquid Equilibrium of Ethyl Acetate+C_nH_(2n+1)OH(n=1,2,3) Binary Systems at 0.3 MPa

Vapor-liquid equilibrium data for the binary systems of ethyl acetate + methanol,ethyl acetate + ethanol and ethyl acetate + 1-propanol at 0.3 MPa were determined.The experimental data were verified with the point-to-point test of van Ness(1973).All these systems present an azeotropic point at 0.3 MPa that increases in ester composition for longer alcohol chains.The UNIFAC in different versions and ASOG prediction models were applied.

Synthesis, Spectroscopic and Crystal Structure Studies on Ethyl 5,7-Dimethyl Coumarin-4-Acetate

Ethyl ester of 5,7-dimethyl coumarin-4-acetic acid has been synthesized from 3,5-Xylenol in a two step sequence of reaction involving Pechmann cyclisation and acid catalyzed esterification. The title compound 2 crystallizes in Monoclinic form, space group P 1 21/c 1, with a = 8.6248(4) ?, b = 18.9103(8) , c = 8.4204(4)?, β = 101.241(2)?, V = 1347.00(11) ?, D cal = 1.283 Mg/cm3, Z = 4. The molecule is stabilized by intermolecular C-H … O bonds.

Lipase-Catalyzed Synthesis and Characterization of 6-O-(11-Dodecenoic)-Glucose Ester in Ionic Liquids

Novozym-435 Lipase-catalyzed transesterification of glucose with 11-dodecenoic ethyl ester in ionic liquids was investigated. The effect of substrate ratio, lipase content, and temperature on the activity and stability of lipase was also studied. The highest yield of sugar ester was obtained in 1-buty-3-methyl imidazolium tetrafluoroborate [Bmim][BF4] under such conditions as the reaction temperature of 55℃, the enzyme concentration of 20 mg/mL, the mole ratio of glucose/11-dodecenoic ethyl ester of 1:2, the water content of the system of 2%, Lipase Novozym-435 can use repeatedly 7 times. The structure of production was characterized by FTIR, HPLC, MS and NMR. The results show that the production is 6-O-(11-dodecenoic)-glucose ester.

Optimization of Lipase Catalyzed Synthesis of Ethyl Valerate, a Green Apple Flavor Using Response Surface Methodology （RSM）

Ethyl valerate, a green apple flavor is short-chain ester with fruity notes is widely used in food, cosmetic and pharmaceutical industries. Traditionally, flavor esters are produced by chemical method or extracted by natural sources. However, with the steadily growing demand for natural flavor compounds, the biosynthesis of such esters by lipase under mild conditions has been receiving much attention for producing these valuable products. In this study, enzymatic synthesis of ethyl valerate in solvent free system, was successfully optimized via response surface method （RSM） based on 5-level, 4-variable of central composite rotatable design （CCRD）. The parameters were reaction time （30-60 min）, reaction temperature （30-60 ℃）, amount of enzyme （10-25%, w/w） and shaking speed （50-150 rpm）. The optimum condition derived via RSM for the reaction was reaction time of 48 min, reaction temperature of 30 ℃, enzyme amount of 25%, （w/w） and shaking speed of 51 rpm. The actual experimental yield was 84.28 % under the optimum condition, which compared well with the maximum predicted value of 84.61%. Comparison of predicted and experimental values reveals good correspondence between them, implying that empirical models derived from RSM can be used to adequately describe the relationship between the factors and response in the synthesis of ethyl valerate.

乙基香兰素人工抗原的合成及鼠源多克隆抗体的制备

为研究检测乙基香兰素(EV)的免疫学方法,采用活性酯(AE)和混合酸酐(MA)2种方法,将乙基香草酸(EVA)与牛血清白蛋白(BSA)偶联,制备乙基香兰素人工免疫抗原BSA-EV(AE)和BSA-EV(MA),并采用紫外扫描(UV)和凝胶电泳(SDS-PAGE)对人工抗原进行鉴定。将BSA-EV(AE)和BSA-EV(MA)分别免疫BALB/c小鼠,3免后10 d断尾采血并分离血清制备鼠源多克隆抗体。采用间接ELISA法测定血清抗体效价,间接竞争ELISA法测定血清抗体敏感性和特异性。结果显示,乙基香兰素人工抗原制备成功,BSA-EV(AE)和BSA-EV(MA)的偶联比分别为1∶2.92和1∶37.95。BSA-EV(AE)免疫组3号血清效价最高为1∶51 200,对EV的半数抑制浓度(IC_(50))为173.78μg/L,线性范围为14.79~2 041.74μg/L。BSA-EV(MA)免疫组1号血清效价最高为1∶102 400,对EV的IC_(50)为617.00μg/L,线性范围为42.66~8 709.64μg/L。2个免疫组的血清抗体与香兰素、甲基香兰素、麦芽酚、乙基麦芽酚、BSA、鸡卵清蛋白(OVA)的交叉反应率均小于1%。综上,人工抗原BSA-EV合成成功,并成功制备了对EV灵敏特异的鼠源多克隆抗体。

月桂酰精氨酸乙酯的不同应用形式对干酪贮藏期间品质变化的影响

研究构建月桂酰精氨酸乙酯的水溶液、乳状液、固体脂质粒、壳聚糖可食性涂膜等不同形式应用于干酪保藏,通过对贮藏过程中干酪的菌落总数、色差、质构和感官进行测定和分析,评估最适合干酪贮藏的应用形式。实验结果表明,月桂酰精氨酸乙酯能够有效抑制干酪表面英诺克李斯特菌的生长,延长贮藏时间。在4℃贮藏20 d后,对照组菌落数增加了7.02 log CFU/g,月桂酰精氨酸乙酯能有效抑制李斯特菌生长,小尺寸颗粒乳状液处理组抑菌效果最好,菌落数仅增加了2.44 log CFU/g。在色差、质构及感官分析中,发现月桂酰精氨酸乙酯并不会影响干酪的品质。作为新型保鲜剂,月桂酰精氨酸乙酯在干酪贮藏中具有广阔的应用前景,小尺寸颗粒乳状液具有更好的保藏效果。

磁性固相萃取-气质联用-同位素内标法精准检测白酒中8种高级脂肪酸乙酯

高级脂肪酸乙酯是引起酒体浑浊的关键因素之一。为系统分析白酒中的高级脂肪酸乙酯以改善白酒生产过程中的浑浊问题,建立了一种基于氨基化四氧化三铁(Fe_(3)O_(4)-NH_(2))磁性固相萃取结合气质联用技术的方法,用以同时测定白酒中8种高级脂肪酸乙酯。通过考察酒样的pH值、离子强度、吸附剂用量、吸附时间、解吸溶剂种类、解吸溶剂酸碱度、解吸时间等因素,确定了较佳的萃取条件。结果表明:这8种高级脂肪酸乙酯在各自的质量浓度范围内线性关系良好,相关系数R 2均大于0.99;方法检出限和定量限分别为9.1~42.9μg/L和5.2~200.0μg/L;回收率为79.6%~99.3%,相对标准偏差(n=3)为8.0%~10.7%。应用此方法,并结合同位素内标法对24种不同香型和品牌的白酒样品中8种高级脂肪酸乙酯进行精准定量,发现它们的种类和质量浓度存在显著差异。其中,在酱香型白酒中,高级脂肪酸乙酯的检出率最高,达到100%。该方法简便快捷,样品萃取只需10 min,具有高灵敏度和准确性,能够有效避免传统液-液萃取技术的背景干扰问题,可为实现白酒中高级脂肪酸乙酯的精准检测提供一种新的方法。

血浆脂肪酸乙酯与酒精性急性胰腺炎炎症和疾病严重程度的相关性研究

目的分析血浆脂肪酸乙酯(FAEE)与酒精性急性胰腺炎(AAP)炎症和疾病严重程度的相关性。方法回顾性分析2017年1月至2022年1月该院收治的227例AAP患者及213例非酒精性急性胰腺炎(AP)组患者数据。根据Bathazar计算机断层扫描严重指数将AAP患者的疾病严重程度分为轻度、中度、重度。通过气相色谱分析患者血浆FAEE和游离脂肪酸(NEFA)水平。结果AAP组患者血浆FAEE(P<0.001)和NEFA(P=0.019)水平相较于非酒精性AP组更高。然而,经受试者工作特征(ROC)曲线分析,血浆FAEE对鉴别诊断AAP与非酒精性AP有良好效能,曲线下面积(AUC)为0.926(95%CI:0.901~0.951)。中度[158.77(127.01~230.55)nmol/L]和重度[274.49(208.32~309.31)nmol/L]AAP患者血浆FAEE水平高于轻度患者[126.15(84.37~166.52)nmol/L],而且重度患者较中度患者更高(H=64.069,P<0.001)。血浆FAEE水平>146.61 nmol/L为重度AAP发生的危险因素(P<0.05),且其对重度AAP有较好的预测价值,AUC为0.786(95%CI:0.705~0.867)。Spearman秩相关分析结果显示,AAP患者血浆FAEE水平与白细胞介素(IL)-1β、IL-6及NEFA水平呈正相关(rS=0.298、0.475、0.302,均P<0.001)。结论血浆FAEE有可能成为AAP鉴别诊断和预测疾病严重程度的潜在生物标志物。

产酯酵母在清香型白酒中的发酵应用研究

为丰富清香型白酒的香气成分,对清香型白酒酿造系统中分离得到的产酯酵母进行发酵产酯、产香特征研究,优选菌种进行扩大化生产应用。从19株产酯酵母中筛选出3株产香丰富、产酯能力强的菌株,对优良菌株进行放大生产实验,对原酒进行主要风味成分定量检测,特征性香气成分采用顶空固相微萃取-全二维气相色谱-飞行时间质谱技术检测并结合PLS-DA等方法进行差异化分析,并进行感官品评。结果显示,实验酒样主要风味成分中乙酸乙酯、总酯含量有较大提升,乙酸乙酯含量由1.51 g/L提升到了2.12 g/L,提升了40.4%,总酯含量由2.02 g/L提升到了2.67 g/L,提升了32.18%,出酒率差异不明显;实验酒样共检测到1356种风味化合物,共13类,其中实验酒样风味化合物含量明显高于对照酒样的微量成分有癸酸乙酯、苯乙酸乙酯、苯丙酸乙酯、十二烷酸乙酯、十四烷酸乙酯、苯乙醇、1,2-丙二醇、2-壬醇等;实验酒样香气较对照酒样酯香明显,香气馥郁,酒质醇甜柔和。本研究为产酯酵母在清香型白酒生产中的应用提供了理论依据。

叉枝蒿对粘虫杀虫活性成分及作用机制研究

【目的】探究叉枝蒿对粘虫的杀虫活性及杀虫机制,为粘虫的高效绿色防控提供理论依据。【方法】采用浸虫浸叶法测定10种蒿属植物提取物及叉枝蒿不同极性4部分萃取物对粘虫3龄幼虫的杀虫活性;分别采用小叶碟添加法、浸叶法和浸虫法确定叉枝蒿石油醚萃取物对粘虫的主要杀虫方式;通过浸虫法测定叉枝蒿石油醚萃取物、馏分及主要成分对粘虫3龄幼虫的触杀活性。叉枝蒿石油醚萃取物经柱层析分离及气相色谱—质谱分析,确定其活性成分,并测定活性成分对粘虫体内4种酶活力的影响。【结果】叉枝蒿石油醚萃取物对粘虫3龄幼虫的触杀活性最好,处理第7 d时对粘虫的致死中浓度(LC_(50))为6.85 mg/mL。经硅胶柱色谱分离,从叉枝蒿石油醚萃取物中得到21个馏分,其中馏分8表现出最好的触杀活性;气相色谱—质谱分析结果显示,馏分8的主要化合物为棕榈酸乙酯(49.57%)、十三烷(14.55%)、硬脂酸乙酯(4.86%)和壬烷(4.74%),4种化合物中以棕榈酸乙酯的触杀活性最好,处理后第7 d时对粘虫的LC_(50)为1.82 mg/mL。棕榈酸乙酯LC_(50)处理粘虫第7 d时扫描电镜显示,粘虫表皮蜡质层颗粒排列疏松,间隙增大。棕榈酸乙酯LC_(50)处理粘虫1、3、5和7 d时,粘虫体内乙酰胆碱酯酶(AChE)和Na^(+)-K^(+)-ATP酶随时间的推移表现出抑制作用,羧酸酯酶(CarE)表现出先激活后抑制作用,过氧化氢酶(CAT)表现出先抑制后激活作用。【结论】叉枝蒿对粘虫具有良好的杀虫活性。叉枝蒿石油醚萃取物中的棕榈酸乙酯对粘虫的触杀活性最好,可作为粘虫生物防治的潜力化合物进行开发利用。