Aldehyde Components Research Articles

新規抗菌剤開発を指向したMraY阻害天然物ムライマイシン類の合成研究

This review describes the synthesis and structure-activity relationship (SAR) study of muraymycins (MRYs), which are potent antibacterial nucleoside antibiotics. The key elements of our synthetic approach include the preparation of L-epi-capreomycidine via a C-H amination reaction and a convergent assemblage to construct of the framework of MRYs using Ugi four component reaction. With this approach the first total synthesis of MRY D2 and its epimer, epi-MRY D2, which does not have lipophilic substituents, has been accomplished. The fact that MRY D2 and it's epimer did not show any antibacterial activity indicated the lipophilic substituents of MRYs plays an important role in membrane-permeability. Hence, MRY analogues with lipophilic substituents were designed and synthesized simply by altering the aldehyde component in Ugi four-component assemblage. The MRY analogues with lipophilic substituents exhibited improved antibacterial activity against anti drug-resistant bacteria. It was also suggested that the accessory urea-dipeptide motif might contribute to MraY inhibitory and antibacterial activity. Our synthetic approach would effectively provide a variety of MRY analogues and resultant SAR information brings us directions to create further MRY analogues.

ChemInform Abstract: Development of Chiral Dinitrones as Modular Lewis Base Catalysts: Asymmetric Allylation of Aldehydes with Allyltrichlorosilanes.

Abstract Chiral dinitrones were synthesized by the condensation of a C 2 -symmetrical chiral dihydroxylamine with various aldehydes. The electronic and steric properties of the dinitrones can be modified by changing the aldehyde component. The activity of dinitrones as Lewis base catalysts was examined for the asymmetric allylation of aldehydes with allyltrichlorosilanes. Using DMPU as an additive in chloroform, the reaction proceeded at room temperature to afford allylated products in good yields and good enantioselectivities.

Effect of MAP on Quality of Rice for Super-Long-Term

In this study, effects of Modified Atmosphere (MA) packaging on the quality of rice after a long term storage at room temperature have been investigated. PVC films with different thicknesses and woven bag were used as the package materials for rice samples. Results showed that MA packaging had a significant effect on the quality of the rice. After an extended period of storage, the rice in woven bag showed most severe quality deterioration compared to those stored in PVC packages. Rice packed in 0.05 mm PVC film package has the lowest value of total acid among all samples. The increase of fatty acid content in rice packed in 0.03 mm film, 0.05 mm film, 0.08 mm film and 0.12 mm film was 38.58 mg KOH/100g, 18.96 mg KOH/100g, 26.83 mg KOH/100g and 32.64 mg KOH/100g, respectively. The volatile aldehyde components accumulated in the stored rice are mainly acetaldehyde, valeraldehyde and hexanal. Small package with a MA has obvious benefits in regulating the metabolism and accumulation of volatile aldehyde components in the rice. Rice samples stored in a package of 0.05mm film had the lowest value of volatile aldehyde, while those in 0.03mm film had the highest value. This study suggests that MA packaging with a PVC film of 0.05 mm shows the best effects in maintaining the quality of rice after an extended period of storage (3 to 5 years).

Convergent Route to the Spirohexenolide Macrocycle

Using key functional dissections, the synthesis of spirohexenolides is examined through a three-component strategy that features a 1,2-addition to couple tetronate and aldehyde components forming the C2-C3 bond and a Stille coupling to install the third sulfone-containing component. The macrocycle is completed by an intramolecular Julia-Kocienski reaction to form the C10-C11 trans-disubstituted olefin. Application of this strategy is described in progress toward the synthesis of (±)-spirohexenolide B.

Carbohydrate Building Blocks in the Ugi Three-Component Coupling Reaction: Convenient Annulation of Iminosugars on Imidazoles

An unprecedented version of the Ugi three-component coupling reaction is reported in which isocyanides react with unprotected aldoses as biorenewable aldehyde components and acyclic amidines as amine components. The reaction proceeds through [4 + 1] cycloaddition of a conjugated imine intermediate with the isocyanide followed by dehydrative ring transformation of the resulting 4-amino-5-(polyhydroxyalkyl)imidazole to afford imino sugar-annulated imidazoles in excellent yields (86-95%). The procedure is performed in one pot in the presence of a nanoclay (K-10) catalyst, and can be expeditiously effected under solvent-free microwave-irradiation conditions.

Stability Studies of Oxazolidine-Based Compounds Using 1H NMR Spectroscopy

A series of oxazolidine-based compounds with a variety of substituents in positions 2 and 3 was synthesized and their stability studied. Ring opened intermediates formed on addition of limiting amounts of D(2)O to oxazolidine solutions, as observed by NMR. As the hydrolysis reactions proceeded, a series of novel dimeric beta-amino alcohol compounds formed via an internal reaction between ephedrine and the ring opened intermediates. 2-Phenyl substituted oxazolidine compounds containing electron withdrawing nitro substituents were more rapidly hydrolyzed than the unsubstituted derivative and methoxy substituted compounds, with the nitro substituents appearing to stabilize the ring opened intermediates. Two oxazolidine derivatives, with a methyl and proton at position 2, were found to be more stable to oxazolidine hydrolysis than the 2-phenyl substituted compounds. Oxazolidines incorporating phenyl substituents at position 3 were synthesized and found to be less stable than those incorporating a methyl substituent at position 3. These fundamental structure-activity relationships may be useful when choosing oxazolidine derivatives as synthetic intermediates and as prodrugs for the delivery of compounds containing either beta-amino alcohol or aldehyde components.

Direct Acylation of Aryl Chlorides with Aldehydes by Palladium−Pyrrolidine Co-catalysis

A palladium catalyst system has been developed that allows for the direct acylation of aryl chlorides with aldehydes. The choice of ligand, as well as the presence of pyrrolidine and molecular sieves is shown to be critical to the catalysis, which appears to proceed via an enamine intermediate. The reaction was successful for a wide range of aryl chlorides and tolerant of functionality on the aldehyde component, giving easy access to alkyl aryl ketones in modest to good yields.

Development of chiral dinitrones as modular Lewis base catalysts: asymmetric allylation of aldehydes with allyltrichlorosilanes

Chiral dinitrones were synthesized by the condensation of a C 2-symmetrical chiral dihydroxylamine with various aldehydes. The electronic and steric properties of the dinitrones can be modified by changing the aldehyde component. The activity of dinitrones as Lewis base catalysts was examined for the asymmetric allylation of aldehydes with allyltrichlorosilanes. Using DMPU as an additive in chloroform, the reaction proceeded at room temperature to afford allylated products in good yields and good enantioselectivities.

ChemInform Abstract: An Investigation of Imidazole and Oxazole Syntheses Using Aryl-Substituted TosMIC Reagents.

This article describes efficient and mild protocols for preparing polysubstituted imidazoles in a single pot from aryl-substituted tosylmethyl isocyanide (TosMIC) reagents and imines generated in situ. Traditional imine-forming reactions employing virtually any aldehyde and amine followed by addition of the TosMIC reagent delivers 1,4,5-trisubstituted imidazoles with predictable regiochemistry. Employing chiral amines and aldehydes, particularly those derived from α-amino acids, affords imidazoles with asymmetric centers appended to N-1 or C-5 with excellent retention of chiral purity. 1,4-Disubstituted imidazoles are also readily prepared by a simple variant of the above procedure. Selecting glyoxylic acid as the aldehyde component of this procedure leads to intermediates such as 48, which readily undergo decarboxylation and elimination of the tosyl moiety to deliver 1,4-disubstituted imidazoles in high yields. Alternatively, using NH4OH as the amine component in conjunction with a variety of aldehydes d...

Synthesis and Biological Evaluation of Muraymycin Analogues Active against Anti-Drug-Resistant Bacteria.

Muraymycin analogues with a lipophilic substituent were synthesized using an Ugi four-component assemblage. This approach provides ready access to a range of analogues simply by altering the aldehyde component. The impact of the lipophilic substituent on the antibacterial activity was very large, and analogues 7b-e and 8b-e exhibited good activity against a range of Gram-positive bacterial pathogens including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium. This study also showed that the accessory urea-dipeptide motif contributes to MraY inhibitory and antibacterial activity. The knowledge obtained from our structure-activity relationship study of muraymycins provides further direction toward the design of potent MraY inhibitors. This study has set the stage for the generation of novel antibacterial "lead" compounds based on muraymycins.

10.1007/s11178-008-3023-2

The condensation of dialkyl ketones with α,ω-bis(2-formylphenoxy)- or α,ω-bis(1-formylnaphthalen-2-yloxy)-3-oxapentane and-3,6-dioxaoctane in the presence of ammonium acetate according to Petrenko-Kritchenko gave 14–41% of new bis(areno) aza crowns, bis(areno)piperidinoaza-14-crown-4 and bis(benzo)-piperidinoaza-17-crown-5, having functional substituents in the piperidine fragment. The yield of the aza crown ether appreciably decreases upon extension of the polyether chain in the aldehyde component. The molecular structure of two of the obtained macrocyclic compounds and the relative configuration of asymmetric carbon atoms in the piperidine ring were determined by X-ray analysis, and the size of their internal cavities was estimated.

Non-polar body waxes enhance sex pheromone activity in the yellow peach moth, Conogethes punctiferalis (Guenée) (Lepidoptera: Crambidae)

In the yellow peach moth, a synthetic sex pheromone consisting of (E)-10-hexadecenal and (Z)-10-hexadecenal showed significantly lower attraction than crude pheromone extracts in wind tunnel tests. Synergistic effects of a non-polar fraction (NPF) from the crude pheromone extract on the activity of a polar fraction (PF), including aldehydes, were assessed in wind tunnel tests. NPF itself showed no activity, but the number of males attracted close to the source was significantly increased when it was added to PF. Similar synergistic effects were also observed in a female body wax (FBW) extract and its NPF but not in male body waxes. Effects of NPF from both sources dose-dependently increased and the active dose range of NPF in FBW was larger than that of the crude pheromone extract. New unknown components that synergistically improve the activity of aldehyde components may be non-polar compounds in FBW. The actual sex pheromone system of the yellow peach moth may consist of aldehydes (attractive over a long distance) and non-polar components in female body wax that functions as a cue for the final recognition of females.

중소규모 조선소 인근 주거지역의 유해대기오염물질 농도에 대한 사례연구

We measured ambient concentrations of hazardous air pollutants such as volatile organic compounds (VOCs) and aldehydes in residential areas nearby small and medium scale shipbuilding companies. The VOC concentrations were higher during the normal operation periods than vacation at which almost all operations were shutdown. Concentrations of VOCs was higher, as the sampling site was nearer from shipbuilding companies. The major components of VOCs were m,p-xylene, ethylbenzene, o-xylene, toluene, and 1,3,5-trimethylbenzene which had been found as major VOC compounds emitted from painting processes of shipbuilding in the previous studies. The major components of aldehydes analyzed were benzaldehyde, acrolein, formaldehyde, and acetaldehyde. The concentration of aldehydes was highest at the furthest sampling point from shipbuilding companies because the formation of aldehyde compounds could be occurred by the secondary chemical reactions of VOCs. The results of this study shows a proper counterplan need to be established for the reduction of hazardous air pollutants emitted from small and medium scale shipping companies.

Synthesis of Fluoroalkene Dipeptide Isosteres by an Intramolecular Redox Reaction Utilizing N-Heteorocyclic Carbenes (NHCs)

(Z)-Fluoroalkene dipeptide isosteres (FADIs 16) have served as potential dipeptide mimetics possessing the substitution of fluoroalkenes for parent peptide bonds. Previously, we synthesized FADIs by reduction of gamma,gamma-difluoro-alpha,beta-enoates with organocoppers or SmI(2), which prompted us to use an intramolecular redox reaction mediated by N-heterocyclic carbenes (NHCs) for the preparation of FADIs. Instead of the enoates, gamma,gamma-difluoro-alpha,beta-enal 20 and gamma,gamma-difluoro-alpha,beta-enoylsilane 34 were converted to FADIs by an NHC-mediated intramolecular redox reaction, whereby aldehyde components reduced the allylic difluoride component in an S(N)2' manner with accompanying monodefluorination.

Arylhydrazonals as aldehyde components in Baylis-Hillman reaction: synthesis of 5-hydroxy-2,3,4,5-tetrahydropyridazine-4-carbonitrile and 6,7,8,8a-tetrahydrocinnolin-5(1H)-one

3-Oxo-2-arylhydrazonals reacted with acrylonitrile to yield hydroxyl tetrahydropyridazine derivatives and with cyclohexenone to yield tetrahydrocinnoline.

Volatile Constituents of Turkish Orange (Citrus sinensis (L.) Osbeck) Peel Oils

The compositions of Turkish sweet orange (Citrus cinensis (L.) Osbeck) peel oil samples have been investigated byhigh-resolution gas chromatograph (HRGC) and high-resolution gas chromatography mass spectrometer (HRGC-MS). The orange oils were extracted by the cold-pressing method. In total, 54 components have been identified in orange oil samples. The major monoterpenes of the orange oils were found limonene (91.14 - 92.02 %), myrcene (1.30 - 1.36 %), sabinene (0.95 - 0.98 %) and α-pinene (0.88 - 0.95 %). The major sesquiterpene component was β-caryophyllene (0.05 - 0.07 %). The major oxygenated components of the oils were found; aldehyde components; octanal (1.38 - 1.42 %), decanal (0.23 - 0.28 %) and geranial (0.13 - 0.18 %), alcohol components; linalool (0.37 - 0.39 %), and nerol (0.05 - 0.06 %) and ester components; geranyl acetate (0.06 - 0.09 %) and neryl acetate (0.05 - 0.06 %).

Degradable Dendrimers

The syntheses of various building blocks containing triazaadamantyl (TAA) units, including dendrimer 1, are reported. The TAA units can undergo hydrolysis under physiological conditions to its respective aldehyde and tris(amino­methyl) components. In case of 1, which is non-toxic, the hydrolysis products are also non-toxic, allowing a possible application in drug delivery.

A Facile Method for the Detection of Aldehydes in Oxidized Lipids Using Solid-Phase Microextraction Fiber and Gas Chromatograph Equipped with a Septum-Free Injector

A facile method is described for the detection of volatile odor components from oxidized lipids. The method is based on headspace solid-phase microextraction (HS-SPME) of the compounds in the vial head space and the subsequent analysis of the volatiles by gas chromatography (GC) using a septum-free sample injector. The extraction was done using a 85 microm carboxen-poly(dimethylsiloxane) SPME fiber and the volatiles were desorbed onto a GC instrument with the septum-free injection port. The septum free injector made it possible to analyze the samples without using a conventional silicone rubber septum, that is easily damaged by the repetitive stubs of a relatively thick blunt needle into the septum and a long desorption time after injection. The method was standardized with authentic C(3)-C(10) aldehydes and was applied to the detection of aldehyde components from oxidized fish oil. Several volatiles, including propanal and hexanal, were clearly separated on a polar capillary column (60 m) with reproducible retention times. The present study demonstrates that the method using the GC septum-free injector and the HS-SPME fiber would be useful for the determination of volatile components derived from edible oils.

ChemInform Abstract: Arylhydrazonals as the Aldehyde Component in Baylis—Hillman Reactions.

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Synthesis of Piperidinones via a Multicomponent Condensation

A four-component procedure for the synthesis of polyfunctionalized piperidin-4-ones has been developed. In this reaction, the im­ine is premixed with TiCl4 followed by the addition of diketene and methanol and finally the aldehyde component is added. Reasonable scope in terms of derived substitution patterns was studied. The resulting diastereomeric mixtures of piperidin-4-ones, obtained in good to excellent yields, were successfully converted into single diastereomers under basic conditions (K2CO3/DMF). The ste­reochemistry was assigned by single crystal X-ray structure analysis of a selected piperidinone.