25618-55-7Relevant articles and documents
STUDY OF NITRATION EQUILIBRIUM IN THE GLYCERIN-AQUEOUS NITRIC ACID SYSTEM. 1. DEPENDENCE OF THE EQUILIBRIUM CONSTANTS OF NITRATION REACTIONS ON THE TEMPERATURE, ACIDITY OF THE MEDIUM, AND STRUCTURE OF THE NITRATED COMPOUND
Kazakov, A. I.,Lagodzinskaya, G. V.,Andrienko, L. P.,Yunda, N. G.,Korolev, A. M.,et al.
, p. 1560 - 1565 (1990)
The equilibrium constants of seven sequential-parallel reactions of conversion of glycerin into glycerin trinitrate in aqueous HNO3 were measured.The effect of the acidity of the medium on the equilibrium nitration constants is correlated with processes of protonation of glycerin and its nitrates.The equilibrium nitration constants are higher for primary hydroxides than for secondary hydroxides, and they decrease in both series in going from glycerin to its dinitrates.
Reduction of nitroglycerin with elemental iron: Pathway, kinetics, and mechanisms
Oh, Seok-Young,Cha, Daniel K.,Kim, Byung J.,Chiu, Pei C.
, p. 3723 - 3730 (2004)
Nitroglycerin (NG) is a nitrate ester used in dynamites, propellants, and medicines and is therefore a common constituent in propellant-manufacturing and pharmaceutical wastewaters. In this study we investigated the reduction of NG with cast iron as a potential treatment method. NG was reduced stepwise to glycerol via 1,2- and 1,3-dinitroglycerins (DNGS) and 1- and 2-mononitroglycerins (MNGs). Nitrite was released in each reduction step and was further reduced to NH4+. Adsorption of NG and its reduction products to cast iron was minimal. A reaction pathway and a kinetic model for NG reduction with cast iron were proposed. The estimated surface area-normalized reaction rate constants for NG and NO2- were (1.65 ± 0.30) × 10-2 (L·m -2·h-1) and (0.78 ± 0.09) × 10 -2 (L·m-2·h-1), respectively. Experiments using dialysis cell with iron and a graphite sheet showed that reduction of NG to glycerol can be mediated by graphite. However, reduction of NO2- mediated by graphite was very slow. NG and NO 2- were also found to reduce to glycerol and NH 4+ by Fe2+ in the presence of magnetite but not by aqueous Fe2+ or magnetite alone. These results indicate that in a cast iron-water system NG may be reduced via multiple mechanisms involving different reaction sites, whereas nitrite is reduced mainly by iron and/or adsorbed Fe2+. The study demonstrates that iron can rapidly reduce NG to innocuous and biodegradable end products and represents a new approach to treat NG-containing wastewaters.
A Kinetic Model for the Epoxidation of Allyl Alcohol with Hydrogen Peroxide on Titanium Silicate TS-1
Sulimov,Danov,Ovcharova,Flid,Bruk
, p. 673 - 678 (2017)
The kinetic regularities of the oxidation of allyl alcohol into glycidol in the presence of titanium silicate are studied at varied initial concentrations of the reagents, products, and temperature. The probable mechanism is used as the basis to develop a substantial kinetic model, which adequately describes the obtained experimental data.
Permanganate oxidation of unsaturated alcohols in alkaline media
Jaky, Miklos,Simon-Trompler, Edit
, p. 561 - 567 (2002)
A study was made on permanganate oxidation of olefinic and acetylenic alcohols in aqueous alkali media. Deprotonation constants of alcohols can be calculated from the kinetic data. The rate constant of alkoxide group oxidation exceeded that of the unsaturated bond. For oxidation of the alcoholic group a mechanism based on hydride ion transfer is proposed.
Drummond,Baker
, p. 286 (1929)
Dual mechanism of zinc-proline catalyzed aldol reactions in water
Kofoed, Jacob,Darbre, Tamis,Reymond, Jean-Louis
, p. 1482 - 1484 (2006)
The aldol reaction of acetone with aldehydes in aqueous medium under catalysis by zinc-proline (Zn(l-Pro)2) and secondary amines such as proline, (2S,4R)-4-hydroxyproline (Hyp) and (S)-(+)-1-(2-pyrrolidinomethyl) pyrrolidine (PMP) is shown to proceed by an enamine mechanism, as evidenced by reductive trapping of the iminium intermediate, while the aldol reaction of dihydroxyacetone (DHA) under catalysis by zinc-proline and by general bases such as N-methylmorpholine (NMM) is shown to occur under rate-limiting deprotonation of the α-carbon and formation of an enolate intermediate. The Royal Society of Chemistry 2006.
Lysophospholipases cooperate to mediate lipid homeostasis and lysophospholipid signaling
Wepy, James A.,Galligan, James J.,Kingsley, Philip J.,Xu, Shu,Goodman, Michael C.,Tallman, Keri A.,Rouzer, Carol A.,Marnett, Lawrence J.
, p. 360 - 374 (2019)
Abstract Lysophospholipids (LysoPLs) are bioactive lipid species involved in cellular signaling processes and the regulation of cell membrane structure. LysoPLs are metabolized through the action of lysophospholipases, including lysophospholipase A1 (LYPLA1) and lysophospholipase A2 (LYPLA2). A new X-ray crystal structure of LYPLA2 compared with a previously published structure of LYPLA1 demonstrated near-identical folding of the two enzymes; however, LYPLA1 and LYPLA2 have displayed distinct substrate specificities in recombinant enzyme assays. To determine how these in vitro substrate preferences translate into a relevant cellular setting and better understand the enzymes’ role in LysoPL metabolism, CRISPR-Cas9 technology was utilized to generate stable KOs of Lypla1 and/or Lypla2 in Neuro2a cells. Using these cellular models in combination with a targeted lipidomics approach, LysoPL levels were quantified and compared between cell lines to determine the effect of losing lysophospholipase activity on lipid metabolism. This work suggests that LYPLA1 and LYPLA2 are each able to account for the loss of the other to maintain lipid homeostasis in cells; however, when both are deleted, LysoPL levels are dramatically increased, causing phenotypic and morphological changes to the cells.—Wepy, J. A., James J. Galligan, P. J. Kingsley, S. Xu, M. C. Goodman, K. A. Tallman, C. A. Rouzer, and L. J. Marnett. Lysophospholipases cooperate to mediate lipid homeostasis and lysophospholipid signaling.
OXIDATION OF ALLYL ALCOHOL BY HYDROGEN PEROXIDE IN THE PRESENCE OF PHOSPHOTUNGSTIC HETEROPOLY ACID
Kuznetsova, L. I.,Maksimovskaya, R. I.,Fedotov, M. A.
, p. 488 - 493 (1985)
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Influence of impurities on the epoxidation of allyl alcohol to glycidol with hydrogen peroxide over titanium silicate TS-1
Harvey, Luke,Kennedy, Eric,Dlugogorski, Bogdan Z.,Stockenhuber, Michael
, p. 241 - 246 (2015)
The epoxidation of allyl alcohol to glycidol by hydrogen peroxide over titanium silicate TS-1 ZSM-5 has been studied under conditions relevant for an industrial-scale process. In particular, the effects of different solvents, impurities and some side reactions known to occur due to those impurities have been examined. It was found that certain aldehydes (in particular, acrolein) are especially detrimental to glycidol yield. Conversely, some of the impurities added to the reaction mixture were found to promote the conversion of allyl alcohol. Possible mechanisms for this are discussed.
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Raciszewski
, p. 1267,1268 (1960)
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Molecular analysis of NAD+-dependent xylitol dehydrogenase from the zygomycetous fungus Rhizomucor pusillus and reversal of the coenzyme preference
Yamasaki-Yashiki, Shino,Komeda, Hidenobu,Hoshino, Kazuhiro,Asano, Yasuhisa
, p. 1943 - 1953 (2014)
The zygomycetous fungus Rhizomucor pusillus NBRC 4578 is able to ferment not only D-glucose but also D-xylose into ethanol. Xylitol dehydrogenase from R. pusillus NBRC 4578 (RpXDH), which catalyzes the second step of D-xylose metabolism, was purified, and its enzymatic properties were characterized. The purified RpXDH preferred NAD+ as its coenzyme and showed substrate specificity for xylitol, D-sorbitol, and ribitol. cDNA cloning of xyl2 gene encoding RpXDH revealed that the gene included a coding sequence of 1,092 bp with a molecular mass of 39,185 kDa. Expression of the xyl2 in R. pusillus NBRC 4578 was induced by D-xylose, and the expression levels were increased with accumulation of xylitol. The xyl2 gene was expressed in Escherichia coli, and coenzyme preference of the recombinant RpXDH was reversed from NAD+ to NADP+ in the double mutant D205A/I206R by site-directed mutagenesis.
Synthesis and biological properties of dicationic arginine-diglycerides
Perez,Pinazo,Vinardell,Clapes,Angelet,Infante
, p. 1221 - 1227 (2002)
A novel family of dicationic arginine-diglyceride surfactants, 1,2-diacyl-3-O-(L-arginyl)-rac-glycerol·2HCl (XXR) with alkyl chain lengths in the range of C8-C14 was prepared. These new surfactants can be regarded as analogues of lecithins. They have two hydrophobic tails of identical fatty acid chains attached to the glycerol through ester bonds and a dicationic polar head from arginine instead of the zwitterionic on the lecithins. These new compounds can be classified as multifunctional surfactants with self-aggregation behaviour comparable to that of short-chain lecithins. They have antimicrobial activity similar to that of the conventional cationic surfactants and are as harmless as amphoteric betaines.
Production and characterization of Escherichia coli glycerol dehydrogenase as a tool for glycerol recycling
Piattoni, Claudia Vanesa,Figueroa, Carlos María,Asención Diez, Matías Damián,Parcerisa, Ivana Lorna,Antu?a, Sebastián,Comelli, Raúl Alberto,Guerrero, Sergio Adrián,Beccaria, Alejandro José,Iglesias, Alberto álvaro
, p. 406 - 412 (2013)
NAD+-dependent glycerol (Gro) dehydrogenase (GroDHase) catalyzes the conversion of Gro into dihydroxyacetone (DHA), the first step for fermentative Gro metabolism in Escherichia coli. In this work, we cloned the gldA gene that codes for the E. coli GroDHase and homologously expressed, purified, and kinetically characterized the recombinant protein. To achieve this, the enzyme was over-produced using Gro supplemented growth medium and lactose as the inducer. The enzyme was highly purified using either pseudo-affinity chromatography or a simple heat-shock treatment, which is potentially valuable for industrial production of GroDHase. We detected efficient oxidation of Gro derived from biodiesel production to DHA by gas chromatography. The results presented in this work support recombinant GroDHase production in a biorefinery setting as a relevant tool for converting Gro into DHA for future biotechnological applications.
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Neuberg,Faerber
, p. 246 (1917)
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Buchner,Meisenheimer
, p. 1782 (1910)
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Tomita
, p. 166 (1921)
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Selective Formation of Triose from Formaldehyde catalysed by Ethylbenzothiazolium Bromide
Matsumoto, Toshihiko,Inoue, Shohei
, p. 171 - 172 (1983)
Dihydroxyacetone was obtained selectively by condensation of formaldehyde using 3-ethylbenzothiazolium bromide as a catalyst in the presence of base.
Functional investigation and applications of the acetylesterase activity of the Citrus sinensis (L.) Osbeck peel
Fontana, Gianfranco,Bruno, Maurizio,Maggio, Antonella,Rosselli, Sergio
supporting information, p. 4502 - 4507 (2020/03/16)
The hydrolysis of acetyl moieties on a set of commercially relevant substrates was performed by employing the whole tissue of Citrus sinensis (L.) Osbeck peel as an efficient biocatalyst in mild reaction conditions with high degree of regioselectivity. The reaction is done in aqueous media and the product is easily recovered. Optimal reaction conditions were deduced and two practical applications were investigated: the elaboration of acetylglicerols and the preparation of vitamin K1 precursor. Peel waste (flavedo and albedo) from orange juice manufacturing was successfully employed as a biocatalyst.
Product Control and Insight into Conversion of C6 Aldose Toward C2, C4 and C6 Alditols in One-Pot Retro-Aldol Condensation and Hydrogenation Processes
Gao, Lou,Hou, Wenrong,Hui, Yingshuang,Tang, Yi,Zhan, Yulu,Zhang, Yahong
, p. 560 - 566 (2021/06/25)
Alcohols have a wide range of applicability, and their functions vary with the carbon numbers. C6 and C4 alditols are alternative of sweetener, as well as significant pharmaceutical and chemical intermediates, which are mainly obtained through the fermentation of microorganism currently. Similarly, as a bulk chemical, C2 alditol plays a decisive role in chemical synthesis. However, among them, few works have been focused on the chemical production of C4 alditol yet due to its difficult accumulation. In this paper, under a static and semi-flowing procedure, we have achieved the product control during the conversion of C6 aldose toward C6 alditol, C4 alditol and C2 alditol, respectively. About C4 alditol yield of 20 % and C4 plus C6 alditols yield of 60 % are acquired in the one-pot conversion via a cascade retro-aldol condensation and hydrogenation process. Furthermore, in the semi-flowing condition, the yield of ethylene glycol is up to 73 % thanks to its low instantaneous concentration.
