Conventionally, two consecutive enzymatic reactions catalyzed by γ-glutamylcysteine synthetase and glutathione synthetase are most commonly used for glutathione production. Here we demonstrate that the bacterial bi-functional GshF can be used for glutathione production in an eukaryotic system, without the accumulation of the intermediate γ-glutamylcysteine.

An ambipolar ternary deep-blue emitter with CIE coordinates of (0.15, 0.07) and high electroluminescent performance was constructed on the basis of an insulated donor-π-acceptor system through an indirect linkage.

A highly efficient catalyst system assembled from enantiomerically pure diaminocyclohexane and Ni(OAc)(2) is, for the first time, used to catalyze the cascade Michael-Henry reaction of various diones and substituted nitroalkenes. A series of polyfunctionalized bicyclo[3.2.1]octane derivatives containing four stereogenic centers are prepared with excellent enantioselectivities (up to >99% ee) and ...

An efficient and rapid synthesis of the CDEF ring system of lactonamycinone is reported via a highly chemo- and diastereoselective intermolecular Diels-Alder cycloaddition between trans-1,2-disilyloxybenzocyclobutene and the appropriate γ-alkylidenebutenolide. The feasibility and the total chemoselectivity of the [4 + 2] cycloaddition for the construction of a spirolactone moiety via an ...

Thiostrepton (TSR), often referred as to a parent compound in the thiopeptide family, is a bimacrocyclic member that features a quinaldic acid (QA) moiety-containing side ring appended to the characteristic core system. QA biosynthesis requires an unusual ring-expanding conversion, showing a methyl transfer onto and a rearrangement of the indole ...

The combination of carbaboranylmercuric chloride (new type of bulky Lewis acid) and silver triflate efficiently catalyzes cycloisomerization of 1,3-dienes at room temperature. The catalytic system gives allyl-substituted azacycles and cycloalkanes in excellent yields with high to complete regioselectivity.

Closing in on azacines: We have developed a new six step approach for the rapid and enantioselective synthesis of indolizidine, pyrrolo[1,2-a]azepine, and pyrrolo[1,2-a]azocine azabicyclic systems and their respective lactam congeners, which are found in a host of natural products as well as pharmaceutical preparations. This protocol enables a concise enantioselective ...

The incredible bulk: The first palladium-catalyzed amidation of five-membered heterocyclic bromides with multiple heteroatoms was achieved using the Pd/1 catalyst system. N-Arylated imidazoles, pyrazoles, thiazoles, pyrroles, and thiophenes were synthesized in moderate to excellent yield. Experimental results and DFT calculations point to the need for an electron-rich and sterically demanding ...

A benzo[a]anthraquinone ring system, common to a group of angucycline antibiotics, has been prepared by a unique cascade of reactions. The reaction sequence was initiated by a Suzuki-Miyaura cross-coupling between a bromoquinone and vinyl boronic anhdyride. The reaction product is proposed to undergo a 6π-electron cyclization triggered by reductive activation ...

The single-step synthesis of fused tricyclic pyridazino[1,2-a]indazolium ring systems is described. Structural details revealed by crystallography explain the unexpected reactivity. The method is applied to the gram scale synthesis of nigeglanine hydrobromide.

Nitrocylcohexadienones have been applied as nitration reagents for mild, mono-nitrating reactions. The original synthesis of 2,3,5,6-tetrabromo-4-methyl-4-nitrocylcohexa-2,5-dien-1-one appeared to be difficult to pursue due to both the solvent system and reaction conditions. Therefore, we applied a modified solvent system and optimized the reaction conditions to prepare the dienone at 0°C, eventually ...

Highly efficient, deep desulfurization of model oil containing dibenzothiophene (DBT), benzothiophene (BT), or 4,6-dimethyldibenzothiophene (4,6-DMDBT) has been achieved under mild conditions by using an extraction and catalytic oxidative desulfurization system (ECODS) in which a lanthanide-containing polyoxometalate Na(7) H(2) LnW(10) O(36) ⋅32 H(2) O (LnW(10) ; Ln=Eu, La) acts as catalyst, [bmim]BF(4) ...

A domino approach of Heck coupling was used to synthesize β-trifluoromethylstyrene derivatives from iodoarenes and 1-iodo-3,3,3-trifluoropropane in moderate to good yields. This method avoids the use of low-boiling, gaseous reagents such as 3,3,3-trifluoropropene, and additives and phosphines in the catalytic system.

Safeners are so-called "inert" constituents of herbicide formulations added to protect crops from the toxic effects of herbicides. We examined the reactivity of three dichloroacetamide safeners and 12 structural analogues [all neutral compounds of the form Cl(2)CXC(═O)NRR'; X = H, Cl; R-groups include alkyl, branched alkyl, n-allyl, and cyclic moieties] ...

Reactive Oxygen Species (ROS) are quintessential inflammatory compounds with oxidizing behaviour. We have successfully developed a micellar system with responsiveness at the same time to two of the most important ROS: superoxide and hydrogen peroxide. This allows for an effective and selective capture of the two compounds and, in perspective, ...

The heterogeneous system TBD/Al(2)O(3) is an efficient catalyst for the intermolecular aldol reaction between ketones and aromatic aldehydes. This system operates with low catalysts loading (10%), in water or organic solvents, and with short reaction times. The desired aldol products are rendered cleanly. Experiments confirmed that this aldol protocol is ...

New synthetic strategies have been explored for the synthesis of the structural core of liposidomycins and caprazamycins, an intriguing class of complex nucleoside-type antibiotics. This structural core is comprised of a cyclic diazepanone system linked to an uridyl fragment. The various synthetic approaches have in common that they originate from ...

Leprosy may present acute/subacute inflammatory processes (leprosy reactions). The study characterized the reactional states of patients at health clinics in Vitória, Espírito Santo State, Brazil, and associated them with sociodemographic factors and clinical/nutritional variables. between January and December 2009, longitudinal follow-up of patients with leprosy continued until leprosy reactions occurred ...

Oxidative stress is detrimental to life process and is particularly responsible for aging and age-related diseases. Thus, most organisms are well equipped with a spectrum of biological defense mechanisms against oxidative stress. The major efficient antioxidative mechanism is the glutathione system, operating a redox cycling mechanism for glutathione utilization, which ...

The nutritional and antioxidant composition of four tomato Portuguese farmer' varieties widely cultivated in homegardens was determined. The analysed components included macronutrients, individual profiles of sugars and fatty acids by chromatographic techniques, hydrophilic antioxidants such as vitamin C, phenolics, flavonols and anthocyanins, and lipophilic antioxidants such as tocopherols, β-carotene and ...

A general strategy for fast decarboxylative difunctionalization to gem-dihalohydrin, gem-dihaloether, gem-dibromoester and cyclized bromo-1,4-dioxane synthons with outstanding regio- and stereoselectivity is demonstrated.

Potassium Boc-protected aminomethyltrifluoroborate, a primary aminomethyl equivalent, was synthesized successfully through a "one-pot" process. With this trifluoroborate, Suzuki-Miyaura cross-coupling reactions were investigated with a variety of both aryl and hetaryl chlorides in good to excellent yields.

Potassium tungsten oxide nanofibers have been successfully synthesized via a facile hydrothermal reaction route in the presence of sulfate. After reduction under a reductive atmosphere of H2(5vol.%)/N2, the potassium tungsten oxide transformed to potassium tungsten bronze. Due to the lacking of free electrons, the potassium tungsten oxide (KxWO3+x/2) showed no ...

Although vitamin C deficiency and scurvy are generally considered as pure nutritional disorders, only a minority of the vitamin C concentration is determined by food intake. In the presence of transition metals (iron and copper), the antiscorbutic factor shifts from an antioxidant to a pro-oxidant function. Haptoglobin (Hp) is a ...

Here, we show the one-step synthesis of N-alkylated anilines from nitrobenzenes and alcohols catalyzed by nano-gold catalyst. The yields to N-alkylated anilines were ∼90% under mild conditions. The mechanism of this reaction was explored. It shows promise for clean and simple synthesis of N-alkylated anilines.

The development of an enantioselective allylic alcohol dichlorination catalyzed by dimeric cinchona alkaloid derivatives and employing aryl iododichlorides as chlorine sources is reported. Reaction optimization, exploration of the substrate scope, and a model for stereoinduction are presented.

Tandem Au(iii)-catalyzed heterocyclization/Nazarov cyclizations leading to substituted carbocycle fused furans are described. An interesting dichotomy of reaction pathways as a function of solvent, confirmed by the isolation and trapping of reaction intermediates, provided a basis for computational studies that supported the experimental findings.

Carbonyl rhenium(i) complexes are efficient catalysts for the regioselective isomerization of terminal propargylic alcohols into α,β-unsaturated aldehydes or ketones which can be used as an unprecedented recyclable catalytic system (up to 10 consecutive runs) in the ionic liquid [BMIM][PF(6)].

Sulfur-, selenium-, and nitrogen-containing compounds bearing leaving groups in the β-position undergo facile substitution chemistry enabled by anchimeric assistance. Here we provide direct comparisons between such systems in the rigid bicyclo[3.3.1]nonane framework easily derived from 1,5-cyclooctadiene. For a series of dichloride electrophiles of this type, the relative reactivities were found ...

First syntheses of C6,7 and C7 enantiopure cocaine analogues were achieved from d-(-)-ribose via a trans-acetonide controlled endo-selective intramolecular nitrone-alkene cycloaddition (INAC) as the key step. This synthetic scheme allows practical preparation of cocaine analogues for bioevaluation as potential candidates for the treatment of cocaine addiction and as potential conjugates ...

A family of furoquinolines were efficiently obtained through a tandem acetalization/cycloisomerization process catalyzed by (5 mol%) silver imidazolate polymer and triphenylphosphine, and diversity was brought by the use of 7 different alcohol groups. From these furoquinolines, 3 examples of reduced derivatives could be obtained (d.r. up to 94 : 6), 10 different ...

To gain access to 3-propoxy-β-carboline hydrochloride (3-PBC·HCl) (1·HCl) and β-carboline-3-carboxylate-tert-butyl ester (βCCt) (2), potential clinical agents active against alcohol self-administration, a two-step route was developed. This process involves a palladium-catalyzed Buchwald-Hartwig coupling and an intramolecular Heck reaction. This two-step route provides rapid access to multigram quantities of 3-PBC (1) and ...

We have examined the catalytic activity of an iron(iii) complex bearing the 14,28-[1,3-diiminoisoindolinato]phthalocyaninato (diiPc) ligand in oxidation reactions with three substrates (cyclohexane, cyclooctane, and indan). This modified metallophthalocyaninato complex serves as an efficient and selective catalyst for the oxidation of cyclohexane and cyclooctane, and to a far lesser extent indan. ...

Based on the structures of natural sphingolipids, we designed heterocyclic sphingoid base mimetics in which the conformational restriction is introduced by incorporation of a pyrrolidine moiety between the 2-amino group and the C-4 carbon atom of the sphingoid base. Our synthesis features a regioselective nucleophilic ring opening of a cyclic ...

The Paternò-Büchi (PB) reaction of geraniol derivatives 1, which contain allylic alcohol functionality and unfunctionalized double bonds, with benzophenone was investigated to see the effect of the hydroxyl group on the regioselectivity of the oxetane formation, i.e., 2/3. At low concentration of geraniol (1a), oxetanes 2a and 3a were formed ...

The chemical tropospheric dimethyl sulfide (DMS, CH(3) SCH(3) ) degradation involves several steps highly dependent on the environmental conditions. So, intensive efforts have been devoted during the last years to enhance the understanding of the DMS oxidation mechanism under different conditions. The reaction of DMS with OH is considered to ...

Rhodococcus jostii RHA1, a PCB1-degrading soil bacterium whose genome has been sequenced, shows lignin-degrading activity in two recently developed spectrophotometric assays. Bioinformatic analysis reveals two unannotated peroxidase genes present in the genome of R. jostii RHA1 with sequence similarity to ORFs in other lignin-degrading microbes. They are members of the ...

Inter- and intramolecular palladium-catalyzed allyl cross-coupling reactions, using allylindium generated in situ from allyl halides and indium, is demonstrated. Allylindium compounds may be effective nucleophilic coupling partners in palladium-catalyzed cross-coupling reactions. A variety of allyl halides, such as allyl iodide, allyl bromide, crotyl bromide, prenyl bromide, geranyl bromide, and 3-bromocyclohexene ...

Biosynthesis of the molybdenum cofactor in bacteria is described with a detailed analysis of each individual reaction leading to the formation of stable intermediates during the synthesis of molybdopterin from GTP. As a starting point, the discovery of molybdopterin and the elucidation of its structure through the study of stable ...

The aim of the present study is to predict and evaluate the probable nootropic activity of novel nicotine analogs with the help of computer program, PASS (prediction of activity spectra for substances). Two compounds from differently substituted pyridines were selected for synthesis and evaluation of nootropic activity based on their ...

An autoregressive error term model was applied to examine the dynamic oscillation of ammonia-oxidizing bacterial (AOB) lineages found in an activated sludge bioreactor. The current abundance of AOB lineages was affected by the past abundance of AOB lineages and past environmental and operational factors as well as current influencing factors.

Cu-catalyzed methods for site-selective hydroboration of terminal alkynes, where the internal or α-vinylboronate is generated predominantly (up to >98%) are presented. Reactions are catalyzed by 1-5 mol % of N-heterocyclic carbene (NHC) complexes of copper, easily prepared from N-aryl-substituted commercially available imidazolinium salts, and proceed in the presence of commercially ...

This Review describes the application of nitroxides to synthesis and polymer chemistry. The synthesis and physical properties of nitroxides are discussed first. The largest section focuses on their application as stoichiometric and catalytic oxidants in organic synthesis. The oxidation of alcohols and carbanions, as well as oxidative CC bond-forming reactions ...

The computational analysis of the rhodium-catalyzed Pauson-Khand reaction indicates that the key transition state is highly charge-polarized, wherein different diastereoisomers have distinctively different charge polarization patterns. Experimental studies demonstrate that chloro-enynes provide the optimal σ-electron-withdrawing group to promote polarization and thereby reduce the activation barrier to provide a highly diastereoselective ...

A racemic synthesis of the ABCD ring core of the ambiguines that preserves the tertiary alcohol has been accomplished in convergent synthesis in 10 synthetic steps, in an overall yield of 46% from commercially available 4-bromoindole and m-methylanisole.

In the solvent-free oxidation of benzyl alcohol to benzaldehyde using supported gold-palladium nanoparticles as catalysts, two pathways have been identified as the sources of the principal product, benzaldehyde. One is the direct catalytic oxidation of benzyl alcohol to benzaldehyde by O(2) , whereas the second is the disproportionation of two ...

Conducting reactions using water as solvent is a highly prized goal for the organic chemist. Based upon recent literature and our continuing interest in the field of aqueous organocatalysis, we tested the scope of an enamine based Diels-Alder reaction using (±)-nornicotine, proline and a proline derivative as aqueous organocatalysts. Unfortunately, ...

The ruthenium-catalyzed hydroamidation of terminal alkynes has evolved to become a broadly applicable tool for the synthesis of enamides and enimides. Depending on the catalyst system employed, the reaction leads chemo-, regio-, and stereoselectively to a single diastereoisomer. Herein, we present a comprehensive mechanistic study of the ruthenium-catalyzed hydroamidation of ...

A one-pot, three-step strategy for the regioselective semihydrogenation of dienes is described. This procedure uses 9-BBN-H as a temporary protective group for alkenes. Yields range from 55% to 95%, and the reaction is tolerant of a variety of common functional groups. Additionally, the final elimination step of the sequence can ...

Titanate nanosheets and nanotubes have first been introduced into cigarette filter, a great range of harmful compounds including tar, nicotine, ammonia, hydrogen cyanide, selected carbonyls and phenolic compounds can be reduced efficiently.