磷钨杂多酸季铵盐催化脂肪酸甲酯环氧化

以钨酸钠、磷酸、过氧化氢H2O2和氯代十六烷基吡啶为原料制备了磷钨杂多酸季铵盐相转移催化剂.实验发现,采用乙酸乙酯溶解氯代十六烷基吡啶制备的催化剂呈颗粒状析出于油水界面,简单过滤即可分离.该催化剂与H2O2作用体系呈均相,反应速率显著加快.H2O2耗尽并降温后,催化剂以固体颗粒形式沉淀,回收率达90%,重复使用六次活性基本不变.采用FT-IR表征了反应前后催化剂结构的变化.以二氯乙烷为溶剂考察了反应条件对脂肪酸甲酯环氧化反应和H2O2利用率的影响.实验结果表明,在反应时间2.5h,催化剂0.3g,分步加入30%H2O23.5g(30.88mmol),反应温度65℃,二氯乙烷20mL,脂肪酸甲酯5.0g(双键22.84mmol)时,产品环氧值可达5.78%,双键环氧化选择性81.9%,H2O2利用率达86%.     

Montmorillonite K10 catalyzed highly regioselective azidolysis of epoxides: A short and efficient synthesis of phenylglycine

A series of β‐hydroxyazides were effectively synthesized from the regioselective ring opening of epoxides by sodium azide using montmorillonite K10 as a novel heterogeneous catalyst in aqueous acetonitrile in good to excellent yields. The utility of this method has been demonstrated by achieving a short synthesis of phenylglycine in 33.5% overall yield.     

A novel alkenoic acid ester and a new benzophenone from Ranunculus ternatus

A novel alkenoic acid ester,(E)-4-hydroxy-dodec-2-enedioic acid-12-O-methyl ester and a new benzophenone,ethyl (S)-3-[2- (3,4-dihydroxybenzoyl)-4,5-dihydroxyphenyl]-2-hydroxypropanoate,together with a known compound,(E)-4-hydroxy-dodec-2- enedioic acids were isolated from the roots of Ranunculus ternatus.Their structures were elucidated by spectroscopic methods.     

氨基甲酸酯型脱氧胆酸分子钳对氨基酸甲酯的手性识别 研究

以脱氧胆酸为spacer,通过三光气桥连各种芳胺,合成了新的氨基甲酸酯型分子钳受体1～4,这些化合物的结构经IR,^1HNMR和元素分析所证实。利用差光谱滴定法考察了其与D/L氨基酸甲酯的对映选择性识别性能。结果表明,分子钳1～4对所考察的氨基酸甲酯均具有识别能力,其对D-氨基酸甲酯的识别优于对L-氨基酸甲酯的识别。从主客体间的大小形状匹配及几何互补关系等方面对这些受体的识别能力及对映选择性进行了讨论。     

Communication the First Examples of the Coordination Ability of 9-OXO-10-Acridineacetic Ion,an Important Interferon Inducer

Abstract

9-Oxo-10-acridineacetic acid, CMA, has been found to be an interferon inducer.^1-5 Moreover, it has been shown that some analogues of CMA may significantly enhance the titres of serum interferon in mice. Among them, the sodium salt CMANa, (I), was synthesized and its biological activity was recently analysed.⁶ This work presents the results of a study on the interaction of CMA^- with Co(II), Ni(II), Cu(II), and Zn(II).     

An efficient one-pot synthesis of coumarin-amino acid derivatives as potential anti-inflammatory and antioxidant agents

Abstract

A series of seven coumarinyl-amino acid ester conjugates have been synthesized and characterized by NMR (¹H and 13C) and mass spectra. Further, the compounds were investigated for their therapeutic applications such as anti-inflammatory and antioxidant activities. Among the synthesized compounds most of the analogs showed good efficiency compared with the standard.     

A biobased aliphatic polyester derived from 10-hydroxydecanoic acid: Molecular weight dependence of physical properties

Poly(10-hydroxydecanoate) (PHDA) is of interest as a new-type aliphatic polyester due to its bioresource and flexible mechanical property. A series of PHDAs with varied molecular weights (M_n from 27 kg/mol to 74 kg/mol) were prepared by optimized melt polycondensation of 10-hydroxydecanoic acid (HDA). Through DSC, WAXD, POM and tensile tests, the effects of molecular weight on the physical properties, including thermal properties, crystallization behavior, crystal morphology, rheological behavior and mechanical properties of PHDA were studied in detail. The results demonstrated that the physical properties of PHDA largely rely on the molecular weight. In particular, the brittle-ductile transition of PHDA occurred when the molecular weight increased up to 55 kg/mol. With the increase of molecular weight, the elongation at break was largely improved and finally exceeded 1400%. The ultimate tensile strength kept about 20 MPa. Hence, PHDA has a PE-like mechanical property. Our work highlights that PHDA is a polymer with excellent performance, which provides an alternative to durable petroleum resourced packaging materials.     

Dammarane-Type Triterpenoid from the Stem Bark of Aglaia elliptica (Meliaceae) and Its Cytotoxic Activities

Two new dammarane-type triterpenoid fatty acid ester derivatives, 3β-oleate-20S-hydroxydammar-24-en (1) and 3β-oleate-20S,24S-epoxy-25-hydroxydammarane (2) with a known dammarane-type triterpenoid compound, such as 20S-hydroxydammar-24-en-3-on (3), were isolated from the stem bark of Aglaia elliptica (C.DC.) Blume. The chemical structures were determined by spectroscopic methods, including FTIR, NMR (one and two-dimensional), and HRESITOF-MS analysis, as well as chemical derivatization and comparison with previous literature. Furthermore, the synthetic analog resulting from transesterification of 1 and 2 also obtained 3β,20S-dihydroxy-dammar-24-en (4) and 20S,24S-epoxy-3β,25-dihydroxydammarane (5), respectively. The cytotoxic effect of all isolated and synthetic analog compounds was evaluated using PrestoBlue reagent against MCF-7 breast cancer cell and B16-F10 melanoma cell lines. The 20S-hydroxydammar-24-en-3-on (3) showed the strongest activity against MCF-7 breast cancer and B16-F10 melanoma cell, indicating that the ketone group at C-3 in 3 plays an essential role in the cytotoxicity of dammarane-type triterpenoid. On the other hand, compounds 1 and 2 had very weak cytotoxic activity against the two cell lines, indicating the presence of fatty acid, significantly decreasing cytotoxic activity. This showed the significance of the discovery to investigate the essential structural feature in dammarane-type triterpenoid, specifically for the future development of anticancer drugs.     

A new helvolic acid derivative from an endophytic Fusarium sp. of Ficus carica

A new helvolic acid derivative named helvolic acid methyl ester (1), together with two known helvolic acid compounds, helvolic acid (2) and hydrohelvolic acid (3), were isolated from the fermentation of endophytic fungus Fusarium sp. in Ficus carica leaves. Their structures were elucidated and identified by spectroscopic methods. Compounds 1–3 showed potent antifungal and antibacterial activities.     

Exploring the potential of biodiesel derived crude glycerol into high value malic acid: Biosynthesis,process optimization and kinetic assessment

In this study, Zygosaccharomyces rouxii, a sugar tolerant yeast culture was explored for the production of high value malic acid using crude glycerol from biodiesel plant. In addition, the effect of addition of glutamic acid (precursor) (0.25 to 1%), temperature (15 to 30 ​°C) and time (0 to 24 days) of the fermentation process was also investigated by both conventional as well as Response Surface Methodology (RSM). The highest malic acid of 72.1 ​± ​0.05 ​g/L was obtained and RSM predicts the accurate optimized conditions such as 30% crude glycerol concentration in the fermentative media with 0.75% addition of precursor with initial pH 5 ​at 20 ​°C for 20 days. This study reveals that the crude glycerol can be efficiently used and the production of malic acid was raised with 3 folds correspond to no precursor under optimal conditions. The growth and product kinetics were studied by Monod, Logistic, Leudeking Piret as well as Logistic incorporated Leudeking-Piret models with and without precursor and Logistic incorporated Leudeking-Piret model allowed the best fit for the malic acid production.     

A new lupane-type triterpenoid fatty acid ester and other isolates from Ophiorrhiza shendurunii

A new pentacyclic triterpenoid fatty acid ester, lupan-20-ol-3(β)-yl hexadecanoate (1), together with lupan-20-ol-3(β)-yl acetate (2), olean-18-en-3(β)-yl hexadecanoate (3), dotriacontanoic acid (4), stigmasterol (5), rubiadin (6), nonadecanoic acid (7), palmitic acid (8) and camptothecin (9) were isolated from the hexane and chloroform extracts of Ophiorrhiza shendurunii from South India. Structures of the isolates were determined by ¹H, ¹³C, ¹³C DEPT, ¹H–¹H COSY, HMBC, HSQC, NOESY NMR, FT-IR, DART-MS, ESI-MS, alkaline hydrolysis, derivatisation, GC–MS and HPTLC analyses. O. shendurunii hexane and chloroform extracts showed significant activities against Candida albicans and Fusarium oxysporum. Compounds 1 to 3 showed only moderate antiyeast/antifungal activities.     

A new ferulic acid ester from Rhodiola wallichiana var. cholaensis (Crassulaceae)

A new ferulic acid ester, 6-feruloyloxyhexanoic acid (1), was isolated along with 10 known ones (2–11), from the concentrated water extract of Rhodiola wallichiana var. cholaensis. Their chemical structures were elucidated on the basis of extensive spectroscopic methods including Two-dimensional nuclear magnetic resonance (2D NMR) experiments. Compound 3 was isolated from this plant for the first time. The protective effects against H₂O₂-induced myocardial cell injury in cultured H9c2 cells were also evaluated. Compounds 1, 5 and 7–11 provided significant protective effects on H₂O₂-induced H9c2 cells injury at the concentration of 25 μg/mL. And the protective effects of compound 1 was also investigated by the oxygen–glucose deprivation/reperfusion (OGD/R) tests.     

Concurrent esterification and N-acetylation of amino acids with orthoesters: A useful reaction with interesting mechanistic implications

The concurrent esterification and N-acetylation of amino acids has been studied with triethyl orthoacetate (TEOA) and triethyl orthoformate (TEOF). In a surprising finding, only 1 equiv of TEOA in refluxing toluene was necessary to convert l-proline and l-phenylalanine into the corresponding N-acetyl ethyl esters in good yield. The same transformation using TEOF was not effective. Stereochemical outcome and stoichiometric studies as well as structural variation of the amino acids in this reaction provided unexpected mechanistic insight.     

Synthesis of ethyl acetate by esterification of acetic acid with ethanol over a heteropolyacid on montmorillonite K10

In present work, liquid phase esterification of acetic acid with ethanol over dodecatungestophosphoric acid (DTPA) supported on K10 montmorillonite was systematically studied and optimization of process parameters was carried out. The 20% m/m DTPA/K10 was found to be the optimum catalyst with 90% acetic acid conversion and 100% ethyl acetate selectivity. The study was also explored to see the feasibility of 20% m/m DTPA/K10 as a catalyst for the alkylation of acetic acid with other alcohols like methanol, iso-propanol and n-butanol. The 20% m/m DTPA/K10 has shown increased activity with the increase in carbon number, at the same alcohol reflux. The results are novel.     

Melamine Sulfonic Acid: A Recoverable Catalyst for the Ecofriendly Synthesis of Thiocyanohydrins Under Solvent-Free Conditions

Melamine sulfonic acid as a novel and efficient solid acid catalyst has been synthesized and used in the ring opening of epoxides under solvent-free conditions. This catalyst afforded the corresponding thiocyanohydrins with good regioselectivity and very short reaction times. The catalyst can be easily separated and reused several times without appreciable loss of activity. The availability and recoverability of the catalyst with easy operation and workup make this method attractive for organic synthesis.     

新型Sn改性固体酸催化剂SO42-/TiO2催化1,6-己二醇二丙烯酸酯合成

丙烯酸酯单体包括通用丙烯酸酯和特种丙烯酸酯,不仅是高分子化合物的基本单体,也是化工有机反应的原料.特种丙烯酸酯在工业合成中虽然规模小,产量低,但已经应用到皮革、造纸、纺织、涂料、粘合剂和辐射固化技术等许多领域.辐射固化材料主要包括活性稀释剂、光引发剂、齐聚物和添加剂等.其中,齐聚物的主要成分就是丙烯酸酯单体的聚合物.然而,丙烯酸酯的合成工业难度不在合成路线,而是反应所使用的催化剂.浓硫酸和对甲苯磺酸等液体酸催化剂由于后续反应难分离、腐蚀设备、污染环境和催化剂不易回收等缺点,逐渐被固体酸催化剂所替代.而SO42-/MOx固体酸催化剂虽然没有这些缺点,但是催化剂比表面积较小,热稳定性较差,酸性难以调节.为了合成1,6-己二醇二丙烯酸酯,本文首先对多种催化剂进行了筛选,获得了活性高且稳定好的SO42-/TiO2-SnO2改性催化剂.采用N2吸附-脱附、X射线衍射(XRD)、扫描电镜(SEM)、红外光谱(IR)、吡啶红外、氨程序升温脱附和热重等技术考察了催化剂的结构特征、表面酸强度和热稳定性.通过N2吸附-脱附可知,Sn改性后催化剂的比表面积增加到126m2/g,较改性前有明显提高.XRD结果表明,Sn能较好地分散在催化剂载体表面,且随着Sn的加入,催化剂晶粒尺寸逐渐减小.SEM照片进一步证实了N2吸附-脱附和XRD结果.催化剂表面酸性通过吡啶红外和氨程序升温脱附测定.由IR图谱可知,固体酸催化剂SO42-/TiO2-SnO2中SO42-和金属原子的连接方式发生变化,更趋于螯合双齿配位结合.通过吡啶红外可以看出,当Sn添加量为6％时,改性催化剂的酸性位由未改性催化剂的59 μmol/g增加到167 μmol/g.氨程序升温脱附.结果表明,多次使用后催化剂的酸分布几乎不变,但酸量有所下降,这可能与催化剂表面硫源的损失有关.另外,通过热重对催化剂的热稳定性进行了分析,由于高温条件下孔结构容易坍塌导致硫源损失,因此第二个失重峰归属为SO42-的脱除峰.Sn改性后的催化剂中SO42-的脱除峰后移100℃左右,且失重量为5O42-/TiO2的2倍多,说明SO42-/TiO2-SnO2催化剂有更好的热稳定性和更多的酸性位.以1,6-己二醇和丙烯酸酯化反应中1,6-己二醇转化率和1,6-己二醇二丙烯酸酯收率为指标评价了催化剂的催化活性.主要研究了催化剂中Sn含量的影响,并对酯化反应条件进行了优化.结果表明,最适宜的Sn含量为6％,最优的反应条件为:酸/醇比3.5,催化剂添加量7％,酯化温度130℃,酯化时间3h.最后考察了改性催化剂的稳定性.结果表明,催化剂使用10次后,1,6-己二醇转化率仍可达81％以上,固体酸催化剂SO42-/TiO2-SnO2有良好的稳定性.     

A novel reverse worm-like micelle from a lecithin/sucrose fatty acid ester/oil system

We report a novel method for forming reverse worm-like micelles in nonpolar organic solvents. This method requires the addition of trace amounts of a sucrose fatty acid ester (SFE), in addition to lecithin and a nonpolar organic solvent. The region in which these micelles formed increased with lecithin concentration and hydrophobicity of SFE. In addition, zero-shear viscosity (η ₀) of the reverse worm-like micelles increased rapidly upon addition of SFE, reaching 1–3 million times the viscosity of n-decane. Furthermore, the change in η ₀ was examined in detail by performing dynamic viscoelasticity measurements. Results showed that the η ₀ of solution increased upon addition of SFE because both the length and number of reverse worm-like micelles increased along with SFE concentration.     

Synthesis of phosphatidylcholine analogues derived from glyceric acid: a new class of biologically active phospholipid compounds

Synthesis of a new class of phosphatidylcholine analogues derived from glyceric acid is reported for spectroscopic studies of phospholipases and the conformation of phospholipid side-chains in biological membranes, using fluorescence resonance energy transfer (FRET) techniques.     

A new fatty acid ester from Nigella sativa var. hispidula Boiss showing potent anti-protein tyrosine phosphatase 1B activity

A new fatty acid ester (1) and seven known phenolic compounds, i.e. salfredin B₁₁ (2), nigephenol C (3), nigephenol B (4), acetovanillion (5), p-hydroxybenzoic acid (6), p-hydroxy-acetophenone (7) and p-hydroxybenzaldehyde (8), were isolated from the seeds of Nigella sativa var. hispidula. Among them, compounds 5, 7 and 8 were isolated from Nigella for the first time. Their structures were elucidated with HR-ESI-MS, 1D and 2D NMR spectra. Evaluation of the isolated compounds on protein tyrosine phosphatase (PTP1B) assay indicated that although compounds 2–8 show no promising anti-PTP1B activities, compound 1 possess anti-PTP1B activity with an IC₅₀ value of 7.38 ± 0.14 μM in vitro.     

A novel approach to phosphonic acids from hypophosphorous acid

A novel access to phosphonic acids via Pd-catalyzed tandem carbon-phosphorus bond formation-oxidation processes was developed. The procedures involve atom-economical and environmentally friendly functionalization reactions of hypophosphorous acid (H₃PO₂) and H-phosphinic acids [RP(O)(OH)(H)].