- A short synthesis of (±)-methylenolactocin
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A short synthesis of the antitumor antibiotic methylenolactocin 1 and the first synthesis of the methyl ester of its cis analogue 7 are described.
- Sarkar, Subrata,Ghosh, Subrata
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- Redox silencing of the Fenton reaction system by an alkylitaconic acid, ceriporic acid B produced by a selective lignin-degrading fungus, Ceriporiopsis subvermispora
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The selective lignin-degrading fungus, Ceriporiopsis subvermispora secretes alkylitaconic acids (ceriporic acids) during wood decay. We reported that ceriporic acid B (hexadecylitaconic acid) was protective against the depolymerization of cellulose by the Fenton reaction. To understand the redox silencing effects, we analyzed the physicochemical and redox properties of itaconic, octylitaconic and hexadecylitaconic acids. The initial rate of HO production by the Fenton system with Fe3+, H2O2 and l-cysteine was suppressed by hexadecylitaconic and octylitaconic acids by 0.04 and 0.16 of the reaction rate without chelators. ESR, O2 uptake and the assay of Fe2+ with BPS demonstrated that Fe3+ reduction by l-cysteine was suppressed by hexadecylitaconic and octylitaconic acids while the reaction of Fe2+ with H2O2 was not suppressed by the two alkylitaconic acids. Ligand exchange experiments with NTA demonstrated that Fe3+ chelation by two carboxyl groups of alkylitaconic acids is a critical step in iron redox modulation. In stark contrast, the production of HO and reduction of Fe3+ were not suppressed by itaconic acid due to HO-initiated degradation of the chelator. The strong redox silencing effects by a series of alkylitaconic acids have attracted interest in controlling microbial plant cell wall degradation and chemoprotection against cellular oxidative injury. This journal is The Royal Society of Chemistry.
- Ohashi, Yasunori,Kan, Yoshihiko,Watanabe, Takahito,Honda, Yoichi,Watanabe, Takashi
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- A concise synthesis of (±)-methylenolactocin and the formal synthesis of (±)-phaseolinic acid
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(±)-Methylenolactocin was prepared in five steps involving an indium-mediated allylation reaction as the key step.
- Loh, Teck-Peng,Lye, Pek-Ling
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- Chemical synthesis, iron redox interactions and charge transfer complex formation of alkylitaconic acids from Ceriporiopsis subvermispora.
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In 1999, we first reported that a white rot fungus, Ceriporiopsis subvermispora produced a series of novel alkylitaconic acids (ceriporic acids). In the present paper we synthesized the metabolite, 1-nonadecene-2,3-dicarboxylic acid (ceriporic acid B) by Grignard reaction to analyze chemical properties of the alkylitaconates. Mass spectrometer (MS) and nuclear magnetic resonance (NMR) spectra of the synthetic compound was identical to those of the fungal metabolite isolated. The dicarboxylic acid inhibited autoxidation of Fe(2+) to Fe(3+) as well as reduction of Fe(3+) to Fe(2+) by the strong natural reductants, cysteine, glutathione, and ascorbic acid. The formation of charge transfer complexes (CTCs) between 1-heptadecene-2,3-dicarboxylic acid and oxidized intermediates from phenolic substrates were also observed. Thus, we herein report that the new class of lipid-related metabolites produced by C. subvermispora are potential metabolites participating in the control of iron redox reactions and CTCs formation from oxidized lignin fragments.
- Enoki, Makiko,Honda, Yoichi,Kuwahara, Masaaki,Watanabe, Takashi
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- Phase-Transfer-Catalyzed Asymmetric Annulations of Alkyl Dihalides with Oxindoles: Unified Access to Chiral Spirocarbocyclic Oxindoles
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A general phase-transfer-catalyzed asymmetric (n+1) (n = 4 or 5) annulation reaction, featuring the direct coupling of simple oxindoles with alkyl dihalides that are allylic/benzylic and non-allylic/benzylic, has been developed to provide previously inacc
- Gao, Min,Hu, Lin,Li, Xuemin,Li, Yongyi
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supporting information
p. 875 - 880
(2022/02/05)
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- Synthesis and Bioactivity of Polymer-Based Synthetic Mimics of Antimicrobial Peptides (SMAMPs) Made from Asymmetrically Disubstituted Itaconates
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A series of asymmetrically disubstituted diitaconate monomers is presented. Starting from itaconic anhydride, functional groups could be placed selectively at the two nonequivalent carbonyl groups. By using 2D NMR spectroscopy, it was shown that the first functionalization step occurred at the carbonyl group in the β position to the double bond. These monomers were copolymerized with N,N-dimethylacrylamide (DMAA) to yield polymer-based synthetic mimics of antimicrobial peptides (SMAMPs). They were obtained by free radical polymerization, a metal-free process, and still maintained facial amphiphilicity at the repeat unit level. This eliminates the need for laborious metal removal and is advantageous from a regulatory and product safety perspective. The poly(diitaconate-co-DMAA) copolymers obtained were statistical to alternating, and the monomer feed ratio roughly matched that of the repeat unit content of the copolymers. Investigations of varied R group hydrophobicity, repeat unit ratio, and molecular mass on antimicrobial activity against Escherichia coli and on compatibility with human keratinocytes showed that the polymers with the longest R groups and lowest DMAA content were the most antimicrobial and hemolytic. This is in agreement with the biological activity of previously reported SMAMPs. Thus, the design concept of facial amphiphilicity has successfully been transferred, but the selectivity of these polymers for bacteria over mammalian cells still needs to be optimized.
- Boschert, David,Schneider-Chaabane, Alexandra,Himmelsbach, Andreas,Eickenscheidt, Alice,Lienkamp, Karen
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p. 8217 - 8227
(2018/05/30)
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- Synthesis of functionalized 2-isoxazolines as three-dimensional fragments for fragment-based drug discovery
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Abstract The design of new sp3 and spiro-enriched fragments has been achieved from 1,3-dipolar cycloaddition between alkenes and chloro-oximes. The selection of reagents was performed to afford a panel of 2-isoxazoline-containing fragments that show desirable three dimensional (3D) characteristics to allow the probing of biologically-relevant chemical space. Principal moments of inertia (PMI) were calculated to evaluate the 3D diversity. The resulting 3D fragments with suitable physicochemical properties, especially a good solubility, will be used to improve the hit rate of our fragment-based screening.
- Tran, Ngoc Chau,Dhondt, Heleen,Flipo, Marion,Deprez, Benoit,Willand, Nicolas
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supporting information
p. 4119 - 4123
(2015/08/03)
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- Esterification of itaconic acid using Ln~SO4 2-/TiO2-SiO2 (Ln = La3+, Ce 4+, Sm3+) as catalysts
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A series of itaconate esters, e.g. dimethyl itaconate, dibutyl itaconate and diisooctyl itaconate, were synthesized using solid acid SO4 2-/MxOy (M = Ti4+, Fe3+, Zr4+, Al3+) and SO42-/TiO2-SiO2 modified with lanthanide ion (Ln = La3+, Ce4+, Sm 3+) as catalysts. It was found that SO4 2-/TiO2-SiO2 modified with lanthanide ion were of the same excellent catalytic activity as sulfuric acid (H2SO 4). Moreover, Ln~SO42-/TiO 2-SiO2 is of excellent stability. Take La 3+~SO42-/TiO2-SiO2 for example, the influence of the preparation conditions on catalytic performance was in detail examined by Py-FTIR, NH3-FTIR, XRD and NH3-TPD, and the optimum preparation conditions were obtained. Furthermore, the effective separation of product combined with the recyclable catalyst is expected to contribute to the development of clean and environmental friendly strategy for the synthesis of itaconate esters.
- Li, Lu,Liu, Shiwei,Xu, Junming,Yu, Shitao,Liu, Fusheng,Xie, Congxia,Ge, Xiaoping,Ren, Jianyun
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- Nicotinamide-dependent Ene reductases as alternative biocatalysts for the reduction of activated alkenes
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Four NAD(P)H-dependent non-flavin ene reductases have been investigated for their ability to reduce activated C=C bonds in an asymmetric fashion by using 20 structurally diverse substrates. In comparison with flavin-dependent Old Yellow Enzyme homologues, a higher degree of electronic activation was required, because the best activities were obtained with enals and nitroalkenes rather than enones and carboxylic esters. Although FaEO from Fragaria x ananassa (strawberry) and its homologue SlEO from Solanum lycopersicum (tomato) exhibited a narrow substrate spectrum, progesterone 5β-reductase (At5β-StR) from Arabidopsis thaliana (thale cress) and leukotriene B4 12-hydroxydehydrogenase (LTB4DH/PGR) from Rattus norvegicus (rat) appear to be promising candidates, in particular for the asymmetric bioreduction of open-chain enals, nitroalkenes and α,β-unsaturated γ-butyrolactones. Competing nitro reduction and non-enzymatic Weitz-Scheffer epoxidation were largely suppressed. Electronically activated alkenes have been stereoselectively reduced by using a single-enzyme-cofactor system employing nicotinamide-dependent non-flavin ene reductases. Copyright
- Durchschein, Katharina,Wallner, Silvia,MacHeroux, Peter,Schwab, Wilfried,Winkler, Thorsten,Kreis, Wolfgang,Faber, Kurt
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supporting information
p. 4963 - 4968
(2013/01/14)
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- Asymmetric bioreduction of activated C=C bonds using Zymomonas mobilis NCR enoate reductase and old yellow enzymes OYE 1-3 from yeasts
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The asymmetric bioreduction of C=C-bonds bearing an electron-withdrawing group, such as an aldehyde, ketone, imide, nitro, carboxylic acid, or ester moiety by a novel enoate reductase from Zymomonas mobilis and Old Yellow Enzymes OYE 1-3 from yeasts furnished the corresponding saturated products in up to >99%ee. Depending on the substrate type, stereocontrol was achieved by variation of the substrate structure, by switching the (E/Z) geometry of the alkene or by choice of the appropriate enzyme. This substrate- or enzyme-based stereocontrol allowed access to the opposite enantiomeric products. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Hall, Melanie,Stueckler, Clemens,Hauer, Bernhard,Stuermer, Rainer,Friedrich, Thomas,Breuer, Michael,Kroutil, Wolfgang,Faber, Kurt
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supporting information; experimental part
p. 1511 - 1516
(2009/04/11)
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- DBU-CH3I, a potential substitute for CH2N2 in the preparation of methyl esters and methyl aryl ethers: Studies with assorted acids
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DBU-CH3I has been poised to be a substitute for diazomethane in the preparation of methyl esters from carboxylic acids. The reactions can be carried out in commercial untreated acetone and acetonitrile, which have been exemplified with several methyl esters, otherwise it is difficult to prepare. Bis-esterification using diiodomethane can also be achieved in a similar fashion. Sufficiently acidic phenols are also conveniently O-methylated by the method. Copyright Taylor & Francis Group, LLC.
- Mal, Dipakranjan,Jana, Amit,Ray, Sutapa,Bhattacharya, Sourav,Patra, Asit,De, Saroj R.
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experimental part
p. 3937 - 3946
(2009/04/11)
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- Stereocomplementary bioreduction of α,β-unsaturated dicarboxylic acids and dimethyl esters using enoate reductases: Enzyme- And substrate-based stereocontrol
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Asymmetric bioreduction of α,β-unsaturated dicarboxylic acids, such as 2-methylmaleic/fumaric and 2-methylenesuccinic acid, as well as the corresponding dimethyl esters, using three cloned enoate reductases furnished 2-methylsuccinic acid or dimethyl 2-methylsuccinate, respectively. Opposite stereoisomeric products were obtained in up to >99% ee either by choice of the enzyme or by using E/Z-configurated substrates. Cofactor-recycling systems (NADH/FDH/formate, NADH/GDH/glucose or NADPH/G6PDH/glucose-6-phosphate) only worked in presence of a divalent metal ion, such as Ca2+, Mg 2+, or Zn2+.
- Stueckler, Clemens,Hall, Melanie,Ehammer, Heidemarie,Pointner, Eva,Kroutil, Wolfgang,Macheroux, Peter,Faber, Kurt
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p. 5409 - 5411
(2008/09/18)
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- Borohydride reduction of acetophenone and esters of dehydrocarboxylic acids in the presence of chiral cobalt(II) diamine complexes
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The catalytic reduction of acetophenone, methyl α-acetamidocinnamate, and dimethyl itaconate with alcohol-modified sodium borohydride was studied in the presence of complexes CoCl2·L2 (L2 are chiral C 2-symmetric diamines: (4S,5S)-2,2-dimethyl-4,5- bis(aminomethyl)-1,3-dioxolane, (4S, 5S)-2,2-dimethyl-4,5-bis(methylaminomethyl) -1,3-dioxolane, (4S, 5S)-2,2-dimethyl-4,5-bis(dimethylaminomethyl)-1,3- dioxolane, and (4S, 5S)-2,2-dimethyl-4,5-bis(diphenylaminomethyl)-1,3-dioxolane) . The maximum enantiomeric excess of (S)-1-phenylethanol was 24%, that of dimethyl α-methylsuccinate was 38%.
- Nindakova,Shainyan
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p. 348 - 353
(2007/10/03)
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- A simple method for the preparation of monomethyl esters of dicarboxylic acids by selective esterification of the nonconjugated carboxyl group in the presence of an aromatic or conjugated carboxyl group
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Various dicarboxylic acids have been converted selectively into monomethyl esters in which the nonconjugated carboxyl group is selectively esterified in the presence of an aromatic or conjugated carboxyl group at room temperature (~ 25-27°C) in methanol using a catalytic amount of thionyl chloride.
- Ram, Ram N.,Meher, Nabin Kumar
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p. 282 - 283
(2007/10/03)
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- Selective esterification of aliphatic nonconjugated carboxylic acids in the presence of aromatic or conjugated carboxylic acids catalysed by NiCl2.6H2O
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Unhindered aliphatic nonconjugated carboxylic acids were esterified selectively in the presence of aromatic or conjugated acids on heating in the corresponding alcoholic solutions at reflux for 3-13 hr with 10 mol% of NiCl2.6H2O catalyst.
- Ram, Ram N.,Charles
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p. 7335 - 7340
(2007/10/03)
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- Synthesis and Radical Polymerization of Itaconates Containing an Adamantyl Ester Group
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Itaconates containing a 1-adamantyl or a 3,5-dimethyl-1-adamantyl ester group were prepared and polymerized in the presence of a radical initiator.The polymerization reactivity has been investigated in relation to the structure of ester alkyl groups of the monomer.It has been clarified that the adamantyl-containing polyitaconates show high thermal stability, i.e., high glass transition temperatures and decomposition temperatures.The relationship between polymer structures and thermal properties of polymers from some α- and β-substituted acrylic esters, i.e., acrylates, methacrylates, crotonates, fumarates, and itaconates was discussed .
- Matsumoto, Akikazu,Watanabe, Hiroyuki,Otsu, Takayuki
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p. 846 - 852
(2007/10/02)
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- A New Synthesis of Trimethyl Aconitate by Palladium-catalysed Triple Carbonylation of Propynyl Alcohol
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A two-step palladium-catalysed carbonylation, consisting of an oxidative carbonylation of propynyl alcohol, followed by a substitutive carbonylation, leads to E and Z aconitic trimethyl esters in high yield.
- Gabriele, Bartolo,Costa, Mirco,Salerno, Giuseppe,Chiusoli, Gian Paolo
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p. 1007 - 1008
(2007/10/02)
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- TROPANE ALKALOIDS FROM SCHIZANTHUS PINNATUS
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From Schizanthus pinnatus Ruiz et Pav. we have isolated seven new tropan-3α,6β-diol diesters, schizanthines F (1), G (2), H (3), I (4), K (8), L (9), and M (10), together with tropin, (-)-6β-angeloyloxytropan-3α-ol (5), (-)-6β-tigloyloxytropan-3α-ol (6), and (-)-3α-senecionyloxytropan-6β-ol (7).The structures of the new alkaloids were determined mainly by spectroscopic methods comprising 2-D and 1-D nmr lond-range heteronuclear correlations.
- Fuente, Gabriel de la,Reina, Matias,Munoz, Orlando,Martin, Aurelio San,Girault, Jean-Pierre
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p. 1887 - 1898
(2007/10/02)
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- INVESTIGATIONS IN THE SYNTHESIS OF AZIDO DERIVATIVES OF DICARBOXYLIC ACIDS
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The synthesis of azido derivatives of dicarboxylic acids was investigated.It was established that the corresponding mono- and diazido acids can be obtained by the hydrolysis of esters of 2-azidomethylsuccinic, 2-azidoglutaric, 2,4-diazidoglutaric, 2,5-diazidoadipic, and 2,6-diazidopimelic acids.During the azidation of 2,3-dibromosuccinic and 2-methyl-2,3-dibromosuccinic acids decomposition of the diazido esters occurs at the moment of formation with the quantitative release of nitrogen and partial decarboxylation.
- Kovaleva, L. I.,Kabanova, E. P.
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p. 918 - 923
(2007/10/02)
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- NEW C-C BOND FORMATION WITH PYRIDINIUM METHYLIDE: HYDROMETHYLENATION OF OLEFIN
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New C-C bond formation with pyridinium methylide is presented: Pyridinium methylide reacts with electron-deficient olefins providing the next higher homologs of olefins, in which the double bond of starting olefin is saturated and, instead, a C=C double bond is newly formed.This reaction mode has been never reported before in the study of nitrogen ylide and is to be referred to as hydromethylenation of olefin.In the presence of base, 1,2-double bond migration occurs leading to the methylated derivatives of starting olefins.
- Tsuge, Otohiko,Kanemasa, Shuji,Kuraoka, Satoru,Takenaka, Shigeori
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p. 281 - 284
(2007/10/02)
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