- 24. Note on the Preparation of 1,2-Diketones from Acetylenes
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A mild method for the oxidation of acetylenes to 1,2-diketones using NaIO4/RuO2 is described.An investigation on the compatibility of various functional groups with this oxidizing agent is reported.
- Zibuck, Regina,Seebach, Dieter
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Read Online
- Long-chain fatty acid acylated derivatives of isoflavone glycosides from the rhizomes of Iris domestica
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Six undescribed long-chain fatty acid esters of isoflavone glycosides were obtained from the rhizomes of Iris domestica (L.). Their structures were elucidated by comprehensive spectroscopic data, alkaline hydrolysis, and acid hydrolysis. This is the first report of the long-chain (C14–C18) fatty acid derivatives of isoflavone glycosides from natural products. Belamcandnoate B and D exhibited moderate cytotoxic activities against HCT-116, HepG2, and BGC823 cell lines with IC50 values of 1.69–6.86 μM. Belamcandnoate B and E exhibited 72.27 and 58.98% inhibitory activities, respectively, against Fe2+/cysteine-induced liver microsomal lipid peroxidation at a concentration of 10 μM.
- Li, Jiayuan,Liu, Yanfei,Ni, Gang,Wang, Renzhong,Yu, Dequan
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- Hydrolysis of amides to carboxylic acids catalyzed by Nb2O5
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Hydrolysis of amides to carboxylic acids is an industrially important reaction but is challenging due to the difficulty of cleaving the resonance stabilized amidic C-N bond. Twenty-three heterogeneous and homogenous catalysts were examined in the hydrolysis of acetamide. Results showed that Nb2O5was the most effective heterogeneous catalyst with the greatest yield of acetic acid. A series of Nb2O5catalysts calcined at various temperatures were characterized and tested in the hydrolysis of acetamide to determine the effects of crystal phase and surface properties of Nb2O5on catalytic performance. The high catalytic performance observed was attributed mainly to the facile activation of the carbonyl bond by Lewis acid sites that function even in the presence of basic inhibitors (NH3and H2O). The catalytic studies showed the synthetic advantages of the present method, such as simple operation, catalyst recyclability, additive free, solvent free, and wide substrate scope (>40 examples; up to 95% isolated yield).
- Siddiki,Rashed, Md. Nurnobi,Touchy, Abeda Sultana,Jamil, Md. A. R.,Jing, Yuan,Toyao, Takashi,Maeno, Zen,Shimizu, Ken-Ichi
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p. 1949 - 1960
(2021/03/26)
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- Highly luminescent and multi-sensing aggregates co-assembled from Eu-containing polyoxometalate and an enzyme-responsive surfactant in water
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Hybrid co-assembly of polyoxometalates (POMs) with cationic organic matrices offers a preferable way to greatly enhance POM functionality as well as processability. Thus, multi-stimulus responsive supramolecular materials based on lanthanide-containing POMs with improved luminescence may be fabricated from appropriate components through this convenient strategy. Herein, we reported that the co-assembly of Na9(EuW10O36)·32H2O (EuW10) and a commercially available cationic surfactant, myristoylcholine chloride (Myr), in water could produce enhanced red-emitting luminescent aggregates, with their photophysical properties highly dependent on the molar ratio (R) between Myr and EuW10. The R of 36 was finally selected owing to the displayed superior luminescence intensity and good aggregate stability. The Myr/EuW10 hybrids induced by electrostatic and hydrophobic forces presented practically as multilamellar spheres with diameters varying from 80 to 300 nm. Compared to an aqueous solution of EuW10 nanoclusters, a 12-fold increase in absolute luminescence quantum yield (～23.3%) was observed for the hybrid spheres, which was ascribed to the efficient shielding of water molecules. An unusual aggregation arrangement mechanism and the excellent photophysical properties of these aggregates were thoroughly investigated. Both the enzyme substrate character of Myr and the sensitive coordination structure of EuW10 to the surrounding environment made Myr/EuW10 aggregates exhibit multi-stimulus responsiveness to enzymes, pH, and transition metal ions, thus providing potential applications in fluorescence sensing, targeted-release, and optoelectronics.
- Lei, Nana,Shen, Dazhong,Chen, Xiao
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p. 399 - 407
(2019/01/24)
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- Alteration of Chain Length Selectivity of Candida antarctica Lipase A by Semi-Rational Design for the Enrichment of Erucic and Gondoic Fatty Acids
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Biotechnological strategies using renewable materials as starting substrates are a promising alternative to traditional oleochemical processes for the isolation of different fatty acids. Among them, long chain mono-unsaturated fatty acids are especially interesting in industrial lipid modification, since they are precursors of several economically relevant products, including detergents, plastics and lubricants. Therefore, the aim of this study was to develop an enzymatic method in order to increase the percentage of long chain mono-unsaturated fatty acids from Camelina and Crambe oil ethyl ester derivatives, by using selective lipases. Specifically, the focus was on the enrichment of gondoic (C20:1 cisΔ11) and erucic acid (C22:1 cisΔ13) from Camelina and Crambe oil derivatives, respectively. The pursuit of this goal entailed several steps, including: (i) the choice of a suitable lipase scaffold to serve as a protein engineering template (Candida antarctica lipase A); (ii) the identification of potential amino acid targets to disrupt the binding tunnel at the adequate location; (iii) the design, creation and high-throughput screening of lipase mutant libraries; (iv) the study of the selectivity towards different chain length p-nitrophenyl fatty acid esters of the best hits found, as well as the analysis of the contribution of each amino acid change and the outcome of combining several of the aforementioned residue alterations and, finally, (v) the selection and application of the most promising candidates for the fatty acid enrichment biocatalysis. As a result, enrichment of C22:1 from Crambe ethyl esters was achieved either, in the free fatty acid fraction (wt, 78%) or in the esterified fraction (variants V1, 77%; V9, 78% and V19, 74%). Concerning the enrichment of C20:1 when Camelina oil ethyl esters were used as substrate, the best variant was the single mutant V290W, which doubled its content in the esterified fraction from approximately 15% to 34%. A moderately lower increase was achieved by V9 and its two derived triple mutant variants V19 and V20 (27%). (Figure presented.).
- Zorn, Katja,Oroz-Guinea, Isabel,Brundiek, Henrike,D?rr, Mark,Bornscheuer, Uwe T.
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p. 4115 - 4131
(2018/10/02)
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- Synthesis of α,β-unsaturated aldehydes as potential substrates for bacterial luciferases
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Bacterial luciferase catalyzes the monooxygenation of long-chain aldehydes such as tetradecanal to the corresponding acid accompanied by light emission with a maximum at 490?nm. In this study even numbered aldehydes with eight, ten, twelve and fourteen carbon atoms were compared with analogs having a double bond at the α,β-position. These α,β-unsaturated aldehydes were synthesized in three steps and were examined as potential substrates in vitro. The luciferase of Photobacterium leiognathi was found to convert these analogs and showed a reduced but significant bioluminescence activity compared to tetradecanal. This study showed the trend that aldehydes, both saturated and unsaturated, with longer chain lengths had higher activity in terms of bioluminescence than shorter chain lengths. The maximal light intensity of (E)-tetradec-2-enal was approximately half with luciferase of P. leiognathi, compared to tetradecanal. Luciferases of Vibrio harveyi and Aliivibrio fisheri accepted these newly synthesized substrates but light emission dropped drastically compared to saturated aldehydes. The onset and the decay rate of bioluminescence were much slower, when using unsaturated substrates, indicating a kinetic effect. As a result the duration of the light emission is doubled. These results suggest that the substrate scope of bacterial luciferases is broader than previously reported.
- Brodl, Eveline,Ivkovic, Jakov,Tabib, Chaitanya R.,Breinbauer, Rolf,Macheroux, Peter
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p. 1487 - 1495
(2017/02/18)
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- Fatty acid decarboxylation reaction kinetics and pathway of co-conversion with amino acid on supported iron oxide catalysts
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Fe2O3/Al-MCM-41 nanocomposite catalysts were designed and fabricated to upgrade microalgae hydrothermal liquefaction (HTL)-derived biocrude and its model compounds (palmitic acid and glutamic acid) in the absence of hydrogen. The Fe
- Bian, Junjie,Wang, Yue,Zhang, Qi,Fang, Xudong,Feng, Lijuan,Li, Chunhu
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p. 47279 - 47287
(2017/10/19)
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- CERAMIDE DERIVATIVES AS ANTICANCER AGENTS
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The invention provides a compound of formula (I): (I) wherein R1-R4 have any of the values defined in the specification, as well as compositions comprising a compound of formula (I) and methods for treating diseases (e.g. cancer).
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Page/Page column 23; 24
(2017/02/09)
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- From Alkanes to Carboxylic Acids: Terminal Oxygenation by a Fungal Peroxygenase
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A new heme–thiolate peroxidase catalyzes the hydroxylation of n-alkanes at the terminal position—a challenging reaction in organic chemistry—with H2O2as the only cosubstrate. Besides the primary product, 1-dodecanol, the conversion of dodecane yielded dodecanoic, 12-hydroxydodecanoic, and 1,12-dodecanedioic acids, as identified by GC–MS. Dodecanal could be detected only in trace amounts, and 1,12-dodecanediol was not observed, thus suggesting that dodecanoic acid is the branch point between mono- and diterminal hydroxylation. Simultaneously, oxygenation was observed at other hydrocarbon chain positions (preferentially C2 and C11). Similar results were observed in reactions of tetradecane. The pattern of products formed, together with data on the incorporation of18O from the cosubstrate H218O2, demonstrate that the enzyme acts as a peroxygenase that is able to catalyze a cascade of mono- and diterminal oxidation reactions of long-chain n-alkanes to give carboxylic acids.
- Olmedo, Andrés,Aranda, Carmen,del Río, José C.,Kiebist, Jan,Scheibner, Katrin,Martínez, Angel T.,Gutiérrez, Ana
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supporting information
p. 12248 - 12251
(2016/10/13)
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- Method for the purification of myristic acid
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The invention discloses a myristic acid purification method which comprises the following steps: reacting myristic acid and ammonia in polar solvent to obtain ammonium myristate; and acidifying the ammonium myristate to obtain purified myristic acid. The method has the advantages of no use of toxic solvent, short route, simple operation process, high quality of obtained products, high yield and low cost, and is easy to realize industrial production.
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Paragraph 0021
(2017/03/08)
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- Determination of Key Hydrocarbon Autoxidation Products by Fluorescence
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Hydroperoxides and carboxylic acids are key primary products that arise in the autoxidation of hydrocarbons. We have developed a simple approach to rapidly and simultaneously determine both types of products using hydroperoxide- and acid-sensitive moieties conjugated to nonpolar coumarin- and BODIPY-based fluorophores. The coumarin- and BODIPY-conjugated amine probes described here undergo 38- and 8-fold enhancement, respectively, upon protonation in a solvent system compatible with heavy hydrocarbons. The latter can be used directly with our previously described hydroperoxide-sensitive coumarin-conjugated phosphine probe to enable rapid quantification of both carboxylic acids and hydroperoxides in hydrocarbon samples. The utility of the approach is illustrated by the ready determination of the differing relative rates of hydroperoxide and acid formation with changes in hydrocarbon structure (e.g., n-hexadecane vs 1-hexadecene vs a lubricant base stock). The method offers significant versatility and automation compared with common but laborious titration approaches, and greatly improves screening efficiency and accuracy for the identification of novel radical-trapping antioxidants for high temperature applications. This application was demonstrated by the automated analysis of hydroperoxides and carboxylic acids (by microplate reader) in samples from 24 inhibited autoxidations of a lubricating oil, which were carried out on a parallel synthesizer at 160 °C in triplicate in a single day.
- Shah, Ron,Pratt, Derek A.
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p. 6649 - 6656
(2016/08/16)
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- Selectivity control in oxidation of 1-tetradecanol on supported nano Au catalysts
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Selective oxidation of tetradecanol, a model higher fatty alcohol, on Au/CeO2-Al2O3 catalyst has been investigated to assess the factors that control selectivity. The analysis of the effect of operation conditions (temperature, run time and alcohol/metal (A/M) ratio) on catalytic performance revealed a quite complex reaction network, in which acid formation starts only after a certain level of conversion is reached. This level depends linearly on the total support surface available, indicating that it must be saturated by species generated by the reaction itself to allow acid formation to start. Addition of water to reaction medium did not modify this level, indicating that such species is not adsorbed water, as previously hypothesized, but probably spilled over hydrogen species. The resulting drastic change in the selectivity trends makes the ratio A/M a critical factor to control selectivity to aldehyde and to acid. Selectivity to ester is less sensible to operation parameters. It is noteworthy that aldehyde yields up to 27% with 90% selectivity, and acid yields up to 40% with 81% selectivity can be reached by proper selection of operation parameters.
- Martínez-González,Ivanova, Svetlana,Domínguez, María I.,Cortés Corberán
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p. 113 - 119
(2016/11/05)
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- Activity of neutral and alkaline ceramidases on fluorogenic N -acylated coumarin-containing aminodiols
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Ceramidases catalyze the cleavage of ceramides into sphingosine and fatty acids. Previously, we reported on the use of the RBM14 fluorogenic ceramide analogs to determine acidic ceramidase activity. In this work, we investigated the activity of other amidohydrolases on RBM14 compounds. Both bacterial and human purified neutral ceramidases (NCs), as well as ectopically expressed mouse neutral ceramidase hydrolyzed RBM14 with different selectivity, depending on the N -acyl chain length. On the other hand, microsomes from alkaline ceramidase (ACER)3 knockdown cells were less competent at hydrolyzing RBM14C12, RBM12C14, and RBM14C16 than controls, while microsomes from ACER2 and ACER3 overexpressing cells showed no activity toward the RBM14 substrates. Conversely, N -acylethanolamine-hydrolyzing acid amidase (NAAA) overexpressing cells hydrolyzed RBM14C14 and RBM14C16 at acidic pH. Overall, NC, ACER3, and, to a lesser extent, NAAA hydrolyze fluorogenic RBM14 compounds. Although the selectivity of the substrates toward ceramidases can be modulated by the length of the N -acyl chain, none of them was specific for a particular enzyme. Despite the lack of specificity, these substrates should prove useful in library screening programs aimed at identifying potent and selective inhibitors for NC and ACER3.
- Casasampere, Mireia,Camacho, Luz,Cingolani, Francesca,Casas, Josefina,Egido-Gabás, Meritxell,Abad, José Luís,Bedia, Carmen,Xu, Ruijuan,Wang, Kai,Canals, Daniel,Hannun, Yusuf A.,Mao, Cungui,Fabrias, Gemma
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p. 2019 - 2028
(2015/11/17)
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- Characterization of a novel hormone-sensitive lipase family esterase from Rhizomucor miehei with tertiary alcohol hydrolysis activity
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A novel esterase gene (designated RmEstB) from the thermophilic fungus Rhizomucor miehei was cloned and functionally expressed in Escherichia coli. Sequence analysis revealed a 960-bp open reading frame encoding a protein of 319 amino acids. The deduced protein sequence contained an HGGG motif, suggesting that the enzyme is a hormone-sensitive lipase (HSL) family esterase. It showed highest identity of 52% with the esterase from Pseudomonas mandelii. The recombinant esterase was purified to homogeneity at 5.1-fold purification with a recovery yield of 85%. The molecular mass of RmEstB was estimated to be 37 kDa by SDS-PAGE. RmEstB was most active at pH 7.5 and 50 °C. The enzyme was highly stable in the presence of 30% ethanol, methanol, acetone, isopropanol, dimethyl sulfoxide and acetonitrile. RmEstB showed a broad range of substrate specificities toward various p-nitrophenol (pNP) esters (C2-C10) and triglycerides (C2-C6), with the highest specific activities obtained for pNP acetate (255 U/mg) and triacetin (1330 U/mg), respectively. In addition, RmEstB efficiently catalyzed the hydrolysis of sterically hindered esters of tertiary alcohols. This study presents a novel fungal HSL family esterase with potential for some industrial applications.
- Yan, Qiao-Juan,Yang, Shao-Qing,Duan, Xiao-Jie,Xu, Hai-Bo,Liu, Yu,Jiang, Zheng-Qiang
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- Heterogeneous selective oxidation of fatty alcohols: Oxidation of 1-tetradecanol as a model substrate
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s Selective oxidation of fatty alcohols, i.e., linear long-chain alkanols, has been scarcely investigated to date, despite its potential application in high value chemical's production. We report for the first time the liquid phase heterogeneous oxidation of 1-tetradecanol, used as a model molecule for fatty alcohols, according to green chemistry principles by using a Au/CeO2-Al2O3 catalyst and O2 as oxidant at normal pressure. High selectivity to tetradecanal (ca. 80%) or to tetradecanoic acid (60-70%) are reached at medium conversion (up to 38%), depending on the reaction conditions used. Comparison with similar tests of 1-octanol oxidation shows that the increase of the carbon chain length decreases the alcohol conversion and the formation of ester, probably due to a greater steric effect.
- Corberán, Vicente Cortés,Gómez-Avilés, Almudena,Martínez-González, Susana,Ivanova, Svetlana,Domínguez, María I.,González-Pérez, María Elena
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- Characterization of a novel thermophilic pyrethroid-hydrolyzing carboxylesterase from Sulfolobus tokodaii into a new family
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A novel gene ST2026 encoding a putative carboxylesterase from the thermophilic crenarchaeota Sulfolobus tokodaii (named EstSt7) was cloned and functionally overexpressed in Escherichia coli. The recombinant enzyme was purified to homogeneity after heat treatment, Ni-NTA affinity and Superdex-200 gel filtration chromatography. EstSt7 showed maximum activity at 80 C over 30 min and had a half-life of 180 min at 90 C. Its enzymatic activity was stable in the pH range of 8.0-10.0 with an optimum at 9.0. The enzyme exhibited significant esterase activity toward various p-nitrophenyl esters and the most preferable substrate was p-nitrophenyl butyrate (kcat/Km of 246.3 s-1 mM-1). In addition, EstSt7 showed high activity and stability against organic solvents (20% and 50% v/v) and detergents (1% and 5% v/v). Furthermore, EstSt7 could efficiently hydrolyze a wide range of synthetic pyrethroids including fenpropathrin, permethrin, cypermethrin, cyhalothrin, deltamethrin and bifenthrin, which makes it a potential candidate for the detoxification of pyrethroids for the purpose of biodegradation. Sequence alignment, phylogenetic analysis and comparison of the conserved motif reveal that this novel carboxylesterase EstSt7 should be grouped into a new bacterial lipase and esterase family.
- Wei, Tao,Feng, Shengxue,Shen, Yulong,He, Peixin,Ma, Geli,Yu, Xuan,Zhang, Fei,Mao, Duobin
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p. 225 - 232
(2013/10/21)
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- Nickel-butadiene catalytic system for the cross-coupling of bromoalkanoic acids with alkyl grignard reagents: A practical and versatile method for preparing fatty acids
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The knights who say Ni: A practical and convenient synthetic route to fatty acids involves the Ni-catalyzed alkyl-alkyl cross-coupling of bromoalkanoic acids and alkyl Grignard reagents in the presence of 1,3-butadiene as an additive (see scheme). Copyright
- Iwasaki, Takanori,Higashikawa, Kiyokazu,Reddy, Vutukuri P.,Ho, Willbe W. S.,Fujimoto, Yukari,Fukase, Koichi,Terao, Jun,Kuniyasu, Hitoshi,Kambe, Nobuaki
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supporting information
p. 2956 - 2960
(2013/03/28)
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- Biomimetic flavin-catalyzed aldehyde oxidation
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The oxidation of alkyl and aryl aldehydes to their corresponding carboxylic acids has been achieved through the action of a biomimetic bridged flavin catalyst. The reaction uses readily available 35% aqueous hydrogen peroxide and is operationally simple. The oxidation is a green and sustainable reaction, obviating chlorinated solvents with minimal byproducts.
- Murray, Alexander T.,Matton, Pascal,Fairhurst, Nathan W. G.,John, Matthew P.,Carbery, David R.
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supporting information; experimental part
p. 3656 - 3659
(2012/08/28)
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- Purification and characterization of OleA from Xanthomonas campestris and demonstration of a non-decarboxylative claisen condensation reaction
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OleA catalyzes the condensation of fatty acyl groups in the first step of bacterial long-chain olefin biosynthesis, but the mechanism of the condensation reaction is controversial. In this study, OleA from Xanthomonas campestris was expressed in Escherichia coli and purified to homogeneity. The purified protein was shown to be active with fatty acyl-CoA substrates that ranged from C 8 to C16 in length. With limiting myristoyl-CoA (C 14), 1 mol of the free coenzyme A was released/mol of myristoyl-CoA consumed. Using [14C]myristoyl-CoA, the other products were identified as myristic acid, 2-myristoylmyristic acid, and 14-heptacosanone. 2-Myristoylmyristic acid was indicated to be the physiologically relevant product of OleA in several ways. First, 2-myristoylmyristic acid was the major condensed product in short incubations, but over time, it decreased with the concomitant increase of 14-heptacosanone. Second, synthetic 2-myristoylmyristic acid showed similar decarboxylation kinetics in the absence of OleA. Third, 2-myristoylmyristic acid was shown to be reactive with purified OleC and OleD to generate the olefin 14-heptacosene, a product seen in previous in vivo studies. The decarboxylation product, 14-heptacosanone, did not react with OleC and OleD to produce any demonstrable product. Substantial hydrolysis of fatty acyl-CoA substrates to the corresponding fatty acids was observed, but it is currently unclear if this occurs in vivo. In total, these data are consistent with OleA catalyzing a non-decarboxylative Claisen condensation reactionin the first step of the olefin biosynthetic pathway previously found to be presentin at least 70 different bacterial strains.
- Frias, Janice A.,Richman, Jack E.,Erickson, Jasmine S.,Wackett, Lawrence P.
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experimental part
p. 10930 - 10938
(2012/03/26)
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- Novel 2,2,6,6-tetramethylpiperidine 1-oxyl-iodobenzene hybrid catalyst for oxidation of primary alcohols to carboxylic acids
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Novel bifunctional hybrid-type catalysts bearing 2,2,6,6- tetramethylpiperidine-1-oxyl (TEMPO) and iodobenzene moieties (1a and 1b) were developed and used for the environmentally benign oxidation of primary alcohols to carboxylic acids. Reaction of primary alcohols 2 with a catalytic amount of 1 in the presence of peracetic acid as a co-oxidant under mild conditions gave the corresponding carboxylic acids 3 in excellent yields.
- Yakura, Takayuki,Ozono, Ayaka
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experimental part
p. 855 - 859
(2011/06/26)
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- Bathymodiolamides A and B, ceramide derivatives from a deep-sea hydrothermal vent invertebrate mussel, bathymodiolus thermophilus
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Two ceramide derivatives, bathymodiolamides A (1) and B (2), were isolated from the deep-sea hydrothermal vent invertebrate mussel Bathymodiolus thermophilus. The molecular structures of these compounds were determined using a combination of NMR spectroscopy, mass spectrometry, and chemical degradation. Biological activities were assessed in a ApopScreen cell-based screen for apoptosis induction and potential anticancer activity. To our knowledge, this is the first report of secondary metabolites from the marine hydrothermal vent mussel B. thermophilus.
- Andrianasolo, Eric H.,Haramaty, Liti,McPhail, Kerry L.,White, Eileen,Vetriani, Costantino,Falkowski, Paul,Lutz, Richard
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experimental part
p. 842 - 846
(2011/06/20)
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- Bacillus subtilis spore coat protein LipC is a phospholipase B
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In Bacillus subtilis, the germination-related lipase LipC is located in the spore coat, and mutant spores are defective in L-alanine-stimulated germination. To determine the physiological role of LipC, the recombinant LipC expressed in Escherichia coli wa
- Masayama, Atsushi,Kato, Shiro,Terashima, Takuya,Molgaard, Anne,Hemmi, Hisashi,Yoshimura, Tohru,Moriyama, Ryuichi
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experimental part
p. 24 - 30
(2010/04/24)
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- Chromium(VI) oxide oxidation of non-ethoxylated and ethoxylated alcohols for determination by electrospray ionization mass spectrometry
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A new derivatization procedure to increase the sensitivity of electrospray ionization mass spectrometry (ESI-MS) to non-ethoxylated and ethoxylated alcohols was investigated. The analytes were oxidized with chromium(VI) oxide and the resulting carboxylic and ethoxy-carboxylic acids were isolated by extraction with ethyl acetate; the extracts were alkalinized and infused into the ESI-MS system working in the negative-ion mode. The yields of the combined oxidation-extraction were ca. 100% for non-ethoxylated fatty alcohols dissolved in acetone and they decreased moderately in samples containing increasing amounts of water (e.g., a 75% yield was obtained with 50% water). Ethoxylated alcohols with more than two ethylene oxide units resulted in yields of ca. 60%. Low limits of detection (LODs) were obtained when the procedure was applied to the analysis of body- care products and cosmetics containing fatty alcohols, e.g., in a varicose-vein cream, the LODs were 25 μ cetyl alcohol and 7.5 μ stearyl alcohol (detected as palmitic acid and stearic acid, respectively) per gram of sample. High molecular mass alcohols were also detected in seawater after pre- concentration by solid-phase extraction. Thus, the proposed method is particularly valuable for use in industrial samples having complex matrices and in environmental samples and it is competitive with other methods for the analysis of trace amounts of fatty alcohols.
- Beneito-Cambra, Miriam,Bernabe-Zafon, Virginia,Simo-Alfonso, Ernesto F.,Ramis-Ramos, Guillermo
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experimental part
p. 2093 - 2100
(2011/11/06)
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- Organic reactions promoted by mucin glycoproteins
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(Chemical Equation Presented) Mucins are heavily glycosilated proteins that exhibit a broad range of adhesive interactions with various hydrophobic organic materials. However, there has been no clear evidence that mucins are capable of promoting chemical
- Shraga, Natalie,Belgorodsky, Bogdan,Gozin, Michael
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supporting information; experimental part
p. 12074 - 12075
(2010/01/30)
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- COMMERCIAL METHOD FOR PRODUCTION OF ROOM TEMPERATURE-LIQUID CETYL MYRISTOLEATE
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This invention provides a commercially feasible method to produce ambient-temperature-liquid cetyl myristoleate in commercial quantities. In addition, the invention relates to the use and benefits of the ambient-temperature-liquid CMO product made by this commercial method.
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Page/Page column 8-10
(2008/12/04)
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- Kinetics and mechanism of myristic acid and isopropyl alcohol esterification reaction with homogeneous and heterogeneous catalysts
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The reaction of myristic acid (MA) and isopropyl alcohol (IPA) was carried out by using both homogeneous and heterogeneous catalysts. For a homogeneously catalyzed system, the experimental data have been interpreted with a second order, using the power-law kinetic model, and a good agreement between the experimental data and the model has been obtained. In this approach, it was assumed that a protonated carboxylic acid is a possible reaction intermediate. After a mathematical model was proposed, reaction rate constants were computed by the Polymath program. For a heterogeneously catalyzed system, interestingly, no pore diffusion limitation was detected. The influences of initial molar ratios, catalyst loading and type, temperature, and water amount in the feed have been examined, as well as the effects of catalyst size for heterogeneous catalyst systems. Among used catalysts, p-toluene sulfonic acid (p-TSA) gave highest reaction rates. Kinetic parameters such as activation energy and frequency factor were determined from model fitting. Experimental K values were found to be 0.54 and 1.49 at 60°C and 80°C, respectively. Furthermore, activation energy and frequency factor at forward were calculated as 54.2 kJ mol-1 and 1828 L mol-1 s-1, respectively.
- Yalcinyuva, Tuncer,Deligoez, Hueseyin,Boz, Ismail,Guerkaynak, Mehmet Ali
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p. 136 - 144
(2008/09/18)
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- A simple method for the alkaline hydrolysis of esters
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A very mild and rapid procedure for the efficient alkaline hydrolysis of esters in non-aqueous conditions has been developed, by the use of dichloromethane/methanol (9:1) as solvent. This method conveniently provides both carboxylic acids and alcohols from the corresponding esters and sodium hydroxide in a few minutes at room temperature. A plausible reaction mechanism is proposed.
- Theodorou, Vassiliki,Skobridis, Konstantinos,Tzakos, Andreas G.,Ragoussis, Valentine
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p. 8230 - 8233
(2008/03/14)
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- Process for separating saturated and unsaturated fatty acids for producing cold-tolorant biodiesel fuel from soy oil
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A process for separating a blend of saturated and unsaturated fatty acids or saturated and unsaturated fatty acid alkyl esters into a first fraction enriched with the saturated fatty acids or saturated fatty acid alkyl esters and a second fraction enriched with unsaturated fatty acids or unsaturated fatty acid alkyl esters. When separating fatty acids, the process includes the steps of (a) saponifying a blend of long chain saturated and unsaturated fatty acids to form free fatty acids, (b) complexing the free fatty acids with urea, and (c) separating the urea complexed free fatty acids into a first fraction enriched with saturated free fatty acids and a second fraction enriched with unsaturated free fatty acids. When separating fatty acid alkyl esters, the process includes the steps of (i) complexing the fatty acid alkyl esters with urea, and (ii) separating the urea complexed fatty acid alkyl esters into a first fraction enriched with saturated fatty acid alkyl esters and a second fraction enriched with unsaturated fatty acid alkyl esters.
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Page/Page column 2-3
(2008/06/13)
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- Oxone/sodium chloride: A simple and efficient catalytic system for the oxidation of alcohols to symmetric esters and ketones
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An efficient method for the oxidation of alcohols is presented. The use of catalytic amounts of sodium chloride in combination with oxone allows the conversion primary aliphatic alcohols to symmetric esters. Secondary alcohols can be easily oxidized to ketones, and benzylic alcohols are converted to the corresponding aldehydes. The method is cost effective and enviromentally benign. Copyright Taylor & Francis Group, LLC.
- Schulze, Agnes,Pagona, Georgia,Giannis, Athanassios
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p. 1147 - 1156
(2007/10/03)
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- Molecular cloning, purification, and biochemical characterization of a novel pyrethroid-hydrolyzing esterase from Klebsiella sp. strain ZD112
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The gene encoding pyrethroid-hydrolyzing esterase (EstP) from Klebsiella sp. strain ZD112 was cloned into Escherichia coli and sequenced. A sequence analysis of the DNA responsible for the esfP gene revealed an open reading frame of 1914 bp encoding for a protein of 637 amino acid residues. No similarities were found by a database homology search using the nucleotide and deduced amino acid sequences of the esterases and lipases. EstP was heterologously expressed in E. coli and purified. The molecular mass of the native enzyme was approximately 73 kDa as determined by gel filtration. The results of sodium dodecyl sulfate - polyacrylamide gel electrophoresis and the deduced amino acid sequence of EstP indicated molecular masses of 73 and 73.5 kDa, respectively, suggesting that EstP is a monomer. The purified EstP not only degraded many pyrethroid pesticides and the organophosphorus insecticide malathion, but also hydrolyzed ρ-nitrophenyl esters of various fatty acids, indicating that EstP is an esterase with broad substrates. The Km for trans- and cis-permethrin and kcat/Km values indicate that EstP hydrolyzes both these substrates with higher efficiency than the carboxylesterases from resistant insects and mammals. The catalytic activity of EstP was strongly inhibited by Hg2+, Ag+, and ρ-chloromercuribenzoate, whereas a less pronounced effect (3-8% inhibition) was observed in the presence of divalent cations, the chelating agent EDTA, and phenanthroline.
- Wu, Pei C.,Liu, Yu H.,Wang, Zhuo Y.,Zhang, Xiao Y.,Li, He,Liang, Wei Q.,Luo, Na,Hu, Ji M.,Lu, Jia Q.,Luan, Tian G.,Cao, Li X.
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p. 836 - 842
(2007/10/03)
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- Optically trapping confocal Raman microscopy of individual lipid vesicles: Kinetics of phospholipase A2-catalyzed hydrolysis of phospholipids in the membrane bilayer
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Phospholipase A2 (PLA2)-catalyzed hydrolysis at the sn-2 position of 1,2-dimyristoyl-sn-glycero-3-phosphocholine in optically trapped liposomes is monitored in situ using confocal Raman microscopy. Individual optically trapped liposomes (0.6 μm in diameter) are exposed to PLA2 isolated from cobra (Naja naja naja) venom at varying enzyme concentrations. The relative Raman scattering intensities of C-C stretching vibrations from the trans and gauche conformers of the acyl chains are correlated directly with the extent of hydrolysis, allowing the progress of the reaction to be monitored in situ on a single vesicle. In dilute vesicle dispersions, the technique allows the much higher local concentration of lipid molecules in a single vesicle to be detected free of interferences from the surrounding solution. Observing the local composition of an optically trapped vesicle also allows one to determine whether the products of enzyme-catalyzed hydrolysis remain associated with the vesicle or dissolve into solution. The observed reaction kinetics exhibited a time lag prior to the rapid hydrolysis. The lag time varied inversely with the enzyme concentration, which is consistent with the products of enzyme-catalyzed lipid hydrolysis reaching a critical concentration that allows the enzyme to react at a much faster rate. The turnover rate of membrane-bound enzyme determined by Raman microscopy during the rapid, burst-phase kinetics was 1200 s-1. Based on previous measurements of the equilibrium for PLA2 binding to lipid membranes, the average number of enzyme molecules responsible for catalyzing the hydrolysis of lipid on a single optically trapped vesicle is quite small, only two PLA2 molecules at the lowest enzyme concentration studied.
- Cherney, Daniel P.,Myers, Grant A.,Horton, Robert A.,Harris, Joel M.
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p. 6928 - 6935
(2008/02/12)
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- Use of conjugated linoleic acid (CLA) for the topical treatment of cellulite
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The present invention relates to the use of conjugated linoleic acid (CLA) for the topical treatment of fatty deposits and cellulite and to new topical compositions and to cosmetic and dermatological topical compositions for the treatment of fatty deposits and cellulite comprising CLA as well as kits comprising CLA for said treatment.
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Page/Page column 6; 7
(2008/06/13)
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- Process
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A process for producing a conjugated di- or poly-unsaturated fatty acid having from 12 to 24 carbon atoms, or a salt or ester thereof, comprises reacting a non-conjugated free fatty acid, or a salt or ester thereof with a base in the presence of a solvent comprising a monohydric alcohol having from 1 to 6 carbon atoms, wherein the reaction is carried out at a temperature of from 120° C. to 200° C. in the presence of water in an amount of at least 4% by weight based on alcohol.
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Page/Page column 4-5
(2008/06/13)
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- Thermostable hydrolase
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The present invention relates to a newly identified hydrolase from thermophilic microorganisms having thermostable properties, and more specifically, to a novel thermostable hydrolase showing high activity at high temperatures.
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- Methyltrioxorhenium Catalyzed Oxidative Cleavage of α -Hydroxycarbonyl Compounds to Carboxylic Acids with Hydrogen Peroxide
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Methyltrioxorhenium catalyzed oxidative cleavage of a variety of α-hydroxycarbonyl compounds with hydrogen peroxide selectively yielded corresponding carboxylic acids in excellent yields.
- Jain, Suman L.,Sharma, Vishal B.,Sain, Bir
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p. 3875 - 3878
(2007/10/03)
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- Topical composition having undifferentiated plant seed cells and method for using same
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There is disclosed a topical composition having substantially undifferentiated plant seed cells and, preferably, a pharmaceutically or cosmetically acceptable vehicle. There is also a method for topically applying the composition. There are also methods for delivering a consistent level of an active to skin, nail, lips and/or hair and for enhancing the therapeutic efficacy of a topical composition having substantially undifferentiated plant seed cells.
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- Topical cosmetic composition with skin rejuvenation benefits
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There are provided topical cosmetic compositions for improving the aesthetic appearance of skin and remediating the effects of aging, and methods of use thereof. One composition is a blend of neem seed cell broth and one or more additional botanical ingredients. Another composition has pomegranate fruit extract and, optionally, one or more additional botanical ingredients.
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- Cationic polysaccharide compositions
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The invention provides a polycation composition comprising a polysaccharide chain having an amount of saccharide units ranging from 2 to 2000, at least one oligoamine directly grafted to said polysaccharide chain per each segment of 5 saccharide units, wherein said oligoamine is selected from the group consisting of a linear, branched and cyclic alkyl amine having at least two amino groups, and at least one further grafted group selected from the group consisting of a hydrophobic and an amphiphilic group directly grafted to said polysaccharide chain per each segment of 50 saccharide units, wherein said hydrophobic or amphiphilic group includes an aliphatic chain of at least 4 carbons atoms.
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- Lewis acid assisted permanganate oxidations
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Lewis acids combine with permanganate in acetone solutions to form a complex that has enhanced oxidizing capabilities. The use of Lewis acids under these conditions to promote permanganate oxidations is superior to the use of Bronsted acids because the latter promote enolization of the solvent and subsequent unproductive reduction of the oxidant. The products obtained from a variety of alkenes, alkynes, arenes, sulfides, alcohols and ethers have been identified and probable reaction mechanisms proposed.
- Lai, Sheng,Lee, Donald G.
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p. 9879 - 9887
(2007/10/03)
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- Lipase-catalyzed synthesis of fatty acid diethanolamides.
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Diethanolamides are nonionic emulsifiers widely used in industries such as cosmetics and as corrosion inhibitors. Candida antarctica lipase (Novozym 435) was used to catalyze the amidation of various fatty acids with diethanolamine. Contents of fatty acid
- Liu,Nag,Shaw
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p. 5761 - 5764
(2007/10/03)
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- Mapping the substrate selectivity of new hydrolases using colorimetric screening: Lipases from Bacillus thermocatenulatus and Ophiostoma piliferum, esterases from Pseudomonas fluorescens and Streptomyces diastatochromogenes
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Recent advances in biochemistry and molecular biology have simplified the discovery and preparation of new hydrolases. Although these hydrolases might solve problems in organic synthesis, measuring their selectivity, especially enantioselectivity, remains tedious and time consuming. Recently, we developed a colorimetric screening method to measure the enantioselectivity of hydrolases. Here we apply this rapid screening method to map the substrate selectivity of four new hydrolases: lipases from the thermophilic Bacillus thermocatenulatus (DSM 730, BTL2) and a filamentous fungus Ophiostoma piliferum (NRRL 18917, OPL) and esterases from two bacteria, Pseudomonas fluorescens (SIK-W1, esterase I, PFE) and Streptomyces diastatochromogenes (Tue 20, SDE). We screened a general library of 29 substrates and a chiral library of 23 pairs of enantiomers. All four hydrolases catalysed the hydrolysis of unnatural substrates, but the two lipases accepted a broader range of substrates than the two esterases. As expected, the two lipases favoured more hydrophobic substrates, while the two esterases showed a preference for smaller substrates. Several moderately enantioselective reactions were identified for the solketal esters: BTL2, butyrate, E = 7.9 (R); octanoate, E = 4.9 (R) and 3-bromo-2-methyl propionate methyl esters, PFE, E = 12 (S); SDE, E = 5.6 (S). OPL showed low enantioselectivity toward all substrates tested. The current colorimetric screen could not measure the selectivity for several slow-reacting substrates. Traditional screening identified high enantioselectivity of BTL2 and PFE toward one of these slow substrates, 1-phenylethyl acetate (E>50).
- Liu, Andrew Man Fai,Somers, Neil A.,Kazlauskas, Romas J.,Brush, Terry S.,Zocher, Frank,Enzelberger, Markus M.,Bornscheuer, Uwe T.,Horsman, Geoff P.,Mezzetti, Alessandra,Schmidt-Dannert, Claudia,Schmid, Rolf D.
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p. 545 - 556
(2007/10/03)
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- Contrast media synthesized from polyaldehydes
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Microparticles comprising biodegradable polymers, characterized in that they are synthesized from polymerizable aldehydes, which optionally contain additives and/or crosslinkers capable of copolymerization, optionally surfactants or surfactant mixtures, gases and/or highly volatile liquids in free or bound form, coupling agents, optionally biomolecules or macromolecules bound by these coupling agents as well as optionally diagnostically or therapeutically effective components, are suitable as ultrasonic contrast media.
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- Design, synthesis, and properties of a photoactivatable membrane-spanning phospholipidic probe
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We introduce here a new photochemical probe suitable for labeling deep into the hydrophobic core of membranes: bis-phosphatidylethanolamine (trifluoromethyl)phenyldiazirine 19 (DIPETPD). This is a bipolar phospholipid provided with a covalently bonded chain designed to span the membrane and equipped with a centrally defined attachment point for the photolabeling group (trifluoromethyl)phenyldiazirine (TPD). This molecule was designed to enhance the geometrical resolution of photochemical labeling of membrane proteins by locating the photoreactive functionality in the center of the bilayer. The remarkable chemical stability of the photoreactive group TPD1 allowed the design of a straightforward and convergent synthetic strategy. The key steps developed for molecules of this new general kind are (a) the mild and efficient coupling of two moieties of N-tBOC-protected lysophosphatidylethanolamine methyl ester to the photoreactive symmetric dicarboxylic fatty acid mediated by dicyclohexylcarbodiimide and (dimethylamino)pyridine and (b) the smooth deprotection of the phosphate and amino functionalities with sodium iodide and trifluoroacetic acid, respectively, to yield the final product. DIPETPD has been successfully incorporated into small and large unilamellar vesicles of different lipid composition and prepared by a variety of procedures. The bilayer location of this reagent (transmembrane vs 'U'-shaped conformations) was assayed by reaction of the amino groups at the polar heads of the bipolar phospholipid with selected membrane-impermeable reagents. Photolysis of the probe incorporated into vesicles occurs readily upon irradiation with UV light (near 360 nm). These 'loaded' vesicles show adequate stability and appear uniform and unilamellar in electron micrographs. They undergo the fusion reaction with influenza virus as efficiently as reagent-free vesicles. Evidence is presented here that DIPETPD and a reductively methylated form efficiently label the peptide ion channel form of gramicidin A (and a chemical analogue) and the influenza virus hemagglutinin. DIPETPD may help to identify transmembrane regions of integral membrane proteins and map the lipid - protein interface in a region known to be deep in the membrane. A new radioactive version of this reagent ([3H]-DIPETPD)2 has been recently used to ascertain that the HA2 subunit of influenza virus hemagglutinin inserts into the target membrane prior to fusion.
- Delfino, José M.,Schreiber, Stuart L.,Richards, Frederic M.
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p. 3458 - 3474
(2007/10/02)
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- Method for producing solid lipid microspheres having a narrow size distribution
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Solid lipid microspheres having a diameter lower than one micron and a polydispersion of between 0.06 and 0.90 obtained by adding to a molten lipid substance a mixture consisting of water, a surfactant and possibly a co-surfactant, dispersing in water the obtained microemulsion, washing with water the dispersion microspheres by diafiltration and lyophilizing.
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- Solid lipid microspheres having a narrow size distribution and method for producing them
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Solid lipid microspheres having a diameter lower than one micron and a polydispersion of between 0.06 and 0.90 obtained by adding to a molten lipid substance a mixture consisting of water, a surfactant and possibly a co-surfactant, dispersing in water the obtained microemulsion, washing with water the dispersion microspheres by diafiltration and lyophilizing.
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- N-acylated cyclohexapeptide compounds
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Compounds of the formula wherein R is a residue of a carboxylic acid are described. The compounds are antimicrobial agents.
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- Release of nicotinamide from fatty acid-nicotinamide equimolar complexes
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The release behavior of nicotinamide (NAA) from fatty acid (FA)-NAA equimolar complexes was examined in a JP XI dissolution test apparatus in JP XI disintegration test medium No. 1 (pH 1.2) at 37°C where the carbon number of FA is 14-18. The time required for 50% or 80% of NAA to release (T50 or T80) was measured, and the effect of the constituent FA on T50 or T80 was investigated. The values of T50 or T80 for FA-NAA formed with odd-numbered FA were larger than those for FA-NAA formed with even-numbered FA whose alkyl chain length is one more carbon number longer, though the values of T50 of T80 increased rather regularly with an increase of the alkyl chain length for only even-numbered or odd-numbered FA. The values of T50 and T80 for FA-NAA formed with heptadecanoic acid (C17-NAA) were about 36 and 102 min, respectively, suggesting that C17-NAA may be applicable to the preparaton of a sustained-release drug formulation.
- Yokoyama,Ueda,Fujie
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p. 3075 - 3076
(2007/10/02)
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- Release kinetics of nicotinamide from fatty acid-nicotinamide equimolar complexes. I. Release characteristics of fatty acid complexes
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The rates of release of nicotinamide (NAA) from fatty acid (FA)-NAA complexes, FA-NAA, were determined in a JP XI dissolution test apparatus in 500 ml of JP XI disintegration test medium No. 1 at 37°C. The release rate constant (k) and the activation Gibbs energy (ΔG+) for the release of NAA from FA-NAA were estimated. The results obtained for FA-NAA were compared with previous results obtained for the thiamine disulfide (TDS) complex, (FA)6-(TDS). The plots of log k against the carbon number of the constituent FA (n) presented a zig-zag line which indicates a downward convex at an odd-numbered position. The plots of ΔG+ against n showed a zig-zag line with an upward convex at an odd-numbered position, though the positive value of ΔG± increased rather regularly with an increase of n for either even-numbered or odd-numbered FA. The phenomena that the plots of log k vs. n and ΔG+ vs. n show zig-zag lines due to the difference between even- and odd-numbered FA were the same as observed previously for the release of TDS from (FA)6 (TDS).
- Yokoyama,Ueda,Fujie
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p. 2696 - 2698
(2007/10/02)
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