Kinds Of Ketones Research Articles

3,3-Disubstituted 3,4-Dihydro-1,2,4-benzotriazines: Chemistry, Biological Activity, and Affinity to Sigma Receptors.

By reducing the 2-nitrophenylhydrazone of cyclohexanone with sodium dithionite, an unexpected yellow compound was obtained instead of the corresponding colorless amino derivative. Many years later, the structure of this compound, namely, cyclohexane-3-spiro-3,4-dihydro-1,2,4-benzotriazine, was demonstrated. From that time, the reduction of 2-nitrophenylhydrazones of different kinds of ketones, followed by air oxidation of the initially formed amino compounds, has represented a general way to synthesize a variety of 3,3-disubstituted 3,4-dihydro-1,2,4-benzotriazines. Many derivatives have been obtained so far by a single research group, and most of them have demonstrated interesting pharmacological activities, mainly antihypertensive, anti-inflammatory, and diuretic effects and other activities with lower diffusion. Moreover, 3,3-disubstituted 3,4-dihydro-1,2,4-benzotriazines represent a novel class of ligands for sigma receptors, with nanomolar affinity to the σ1 subtype. This property might promote the development of agents for cardiovascular, neurodegenerative, and proliferative pathologies. The present commentary, by collecting compounds and biological results obtained so far, intends to celebrate the centennial of the discovery of the first member of this class of compounds and to promote further investigation in the field.

The Relationship between Microbial Community Succession and Flavor Formation during the Natural Fermentation of Hongqu sufu.

To study the diversity of microbial flora in Hongqu sufu and analyze the characteristics of special flavor compounds, this study took self-made Hongqu sufu as the research object. Dynamic changes in sufu during fermentation were studied. High-throughput sequencing (HTS) was used to analyze changes in the diversity of fungal and bacterial communities during fermentation. The results showed that at the phylum level, the dominant fungal phyla were identified, Mucormyces and Ascomycetes. The dominant bacterial phyla were Proteobacteria and Firmicutes. At the genus level, the dominant fungal genera were identified as Actinomucor, Monascus, and Aspergillus. The dominant bacterial genera were Pseudomonas, Aneurimibacillus, Sphingobacterium, and Bacillus. Headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) combined with technology that can dynamically change flavor compounds was explored to investigate the correlation between microbiota and flavor compounds. In different stages of fermentation, 75 main volatile organic compounds were identified, including seven alcohols, four acids, 16 alkanes, 14 olefins, seven kinds of aldehydes, two kinds of ketones, 10 kinds of esters, one kind of phenol, one kind of sulfur-containing compound, one benzene, and 12 other compounds. The correlation analysis between flora and flavor compounds showed that the fungi genera Alternaria and Pichia were significantly correlated with most flavor compounds. Bacteria genera including Weissella, Hafnia-Obesumbacterium, and Leuconostoc had a strong positive correlation with ethyl oleate.

Ketones in Low-Temperature Oxidation Products of Crude Oil

Ketone compounds are oxidation products of crude oil in the in-situ combustion (ISC) process. Revealing the molecular composition of ketones can provide theoretical guidance for understanding the oxidation process of crude oil and valuable clues for studying the combustion state of crude oil in the reservoir. In this study, low-temperature oxidation (LTO) processes were simulated in thermal oxidation experiments to obtain thermally oxidized oil at different temperatures (170 °C, 220 °C, 270 °C, and 320 °C). A combination of chemical derivatization and positive-ion electrospray (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used to analyze the molecular composition of different kinds of ketones (fatty ketones, naphthenic ketones, and aromatic ketones) in the oxidized oils at different temperatures. The results showed that the concentration of aliphatic ketones and aliphatic cyclic ketones in the product oils decreased with the increase in temperature, while aromatic ketones increased with the increase in temperature. At the same oxidation temperature, the content of ketones follows this order: fatty ketones < cycloalkanes < aromatic ketones. The concentrations of ketones reached their maximum value at 170 °C and decreased at high temperatures due to over-oxidation. It was also found that nitrogen-containing compounds are more easily oxidized to ketone compounds than their hydrocarbon counterparts in the LTO process.

Microbial diversity of milk ghee in southern Gansu and its effect on the formation of ghee flavor compounds.

Ghee is a traditional Tibetan dairy product with high-fat content, low yield, plasticity, caseation, and rich nutrition. In this study, we analyzed the diversity of microbial communities in yak milk and ghee samples at high and low altitudes, especially the Lactobacillus genus, and further used metabolomic techniques to compare the differences in metabolites in yak ghee at different altitudes. The results showed that the increase in altitude had a significant and generally inhibitory effect on the microbial community diversity in milk ghee, and yak milk at high altitude was abundant in nutrients, which could antagonize the negative impact of increased altitude. Using non-targeted metabolomics, we infer the composition of flavor compounds in ghee: nine kinds of carboxylic acids, 11 kinds of esters, six kinds of ketones, two kinds of alcohols, and four kinds of alkene compounds, among which the key flavor compounds are dl-2-(acetylamino)-3-phenylephrine acid, 1-(4-methoxyphenyl)-2-propanone, sebacic acid, Lysope 18:1, and uracil 1-beta-d-arabinofuranoside. These flavor substances are found in Lactococcus, Lactobacillus, and Streptococcus. With the participation of Lactobacillus, it is synthesized through biosynthesis of alkaloids derived from ornithine, lysine, and nicotine acid and glyoxylate and decarboxylate metabolism, among which Lactococcus plays a key role. In this study, a variety of lactic acid bacteria related to ghee fermentation were screened out, revealing the composition of volatile flavor compounds in Gannan yak milk ghee in the Qinghai-Tibet Plateau and providing a reference for further key volatile flavor compounds and the formation mechanism of flavor compounds.

Effects of acetic acid bacteria in starter culture on the properties of sourdough and steamed bread

Sourdough starters for making traditional steamed bread are rich in microbes. Studies have shown that, in addition to yeast and lactic acid bacteria (LAB), acetic acid bacteria (AAB) are other functional species in sourdough, but the influences of AAB on the properties of sourdough and steamed bread were rarely reported. This study aimed to assess the effects of a selected strain of acetic acid bacterium on the properties of sourdough and steamed bread. Sourdoughs and steamed breads were prepared from five different starter cultures, marked as CK (control check, with no starters), Y (only yeast), YL (yeast+LAB), YA (yeast+AAB) and YLA (yeast+LAB+AAB), and their properties were determined. The results of sourdough properties showed that the YLA sourdough had the highest total titratable acid of 14.6 mL and the lowest pH of 3.87 compared with the other groups after fermentation to 8 h; and the YLA sourdough had the greatest elasticity and viscosity. The results of quality properties of steamed bread revealed that the L* value (88.40 ± 0.09) of the YA steamed bread was significantly higher than those of the YLA and YL steamed breads; the YLA steamed bread had the highest specific volume and the highest sensory score of 89.6 ± 3.31 in comparison to those of the other groups; the hardness and chewiness of YLA and YA steamed breads were significantly lower than those of the other groups. Volatile compounds in the steamed breads were also determined by SPME–GC–MS. A total of 42 flavor substances were detected, including 3 kinds of alcohols, 8 kinds of aldehydes, 7 kinds of ketones, 2 kinds of acids, 15 kinds of esters, 1 furan, and 6 kinds of other types of compounds, mainly alkanes and esters, followed by alcohols and aldehydes. The YLA steamed bread was richer in esters, aldehydes, and acids than those from the other treatment groups. By contrast, alkanes and aldehydes were dominant in the Y and YL steamed breads. Therefore, the flavor and quality of the steamed bread made from the YLA sourdough could be improved obviously. These results could provide references for the application of AAB in dough fermentation and the improvement of new kinds of starters.

Determination of Liquid−Liquid equilibria of ethylene glycol + 1,2-Butanediol + 5-Methyl-2-hexanone/Di-isobutyl ketone ternary systems

Two kinds of ketones, 5-methyl-2-hexanone and di-isobutyl ketone were selected as the extraction agents for separating the azeotrope of ethylene glycol (EG)and 1,2-butanediol (1,2-BDO). By comparing the results of preliminary extraction experiments under 303.15 K and normal pressure, 5-methyl-2-hexanone was the better one. And the Liquid-liquid equilibrium data of EG + 1,2-BDO + 5-methyl-2-hexanone ternary system were successively measured at 293.15 K and 313.15 K. The distribution coefficient (K2) and selectivity coefficient (S) of 1,2-BDO were calculated from the experimental data. The LLE data were correlated by NRTL and UNIQUAC activity models with the authorized Aspen Plus software. The root mean square deviations (RD) between the experimental and calculated values were all less than 0.7%, which means they were consistent with each other very well.

Analysis of Volatile Components in Gui Qi Mango Fruit Wine

The volatile components in Gui Qi Mango fruit wine analyzed by headspace solid-phase microextraction-gas chromatography-mass spectrometry. Results showed that 32 kinds of volatile components were detected in Gui Qi Mango fruit wine, including 7 kinds of alcohols (65.69%), 17 kinds of esters (28.92%), 4 kinds of alkanes (2.16%), 3 kinds of aldehydes (0.36%), 2 kinds of olefins (0.32%), 1 kinds of ketones (0.41%), 1 kinds of phenols (0.2%). In the all of the volatile components, the relative content of alcohols and esters were 94.61%. The fermentation process had an effect on the Gui Qi Mango fruit wine, and alcohols and esters played a positive role in the aroma of Gui Qi Mango fruit wine.

Functional Poly(ester–amide)s with Tertiary Ester Linkages via the Passerini Multicomponent Polymerization of a Dicarboxylic Acid and a Diisocyanide with Different Electron-Deficient Ketones

We describe a straightforward synthetic strategy for a new family of functional poly(ester–amide)s (PEAs) with tertiary ester linkages via the Passerini multicomponent polymerization (Passerini-MCP) of a diacid (A2), 1,6-diisocyanohexane (B2), and four kinds of electron-deficient ketones. First, Passerini three-component reactions (Passerni-3CR) of hexanoic acid and tert-butyl isocyanide with nine kinds of ketones were investigated to evaluate the reactivities of these ketones toward Passerni-3CR. Four electron-deficient ketones, 1,1,1-trifluoroacetone (1), 1,1,1-trifluoroacetophenone (2), ethyl pyruvate (3), and 2,3-butanedione (4), were found to be excellent oxo-compounds for this Passerini-3CR. Then, the Passerini-MCP of A2 and B2 with 1, 2, 3, and 4 in CH2Cl2 was performed to generate polymers P1–P4 with tertiary ester linkages and different electron-withdrawing substituents. Polymer P5 was also prepared by the Passerini-MCP of A2 and B2 with phenylacetaldehyde (5) for comparison. Size exclusion chrom...

Detection of Ketones by a Novel Technology: Dipolar Proton Transfer Reaction Mass Spectrometry (DP-PTR-MS).

Proton transfer reaction mass spectrometry (PTR-MS) has played an important role in the field of real-time monitoring of trace volatile organic compounds (VOCs) due to its advantages such as low limit of detection (LOD) and fast time response. Recently, a new technology of proton extraction reaction mass spectrometry (PER-MS) with negative ions OH- as the reagent ions has also been presented, which can be applied to the detection of VOCs and even inorganic compounds. In this work, we combined the functions of PTR-MS and PER-MS in one instrument, thereby developing a novel technology called dipolar proton transfer reaction mass spectrometry (DP-PTR-MS). The selection of PTR-MS mode and PER-MS mode was achieved in DP-PTR-MS using only water vapor in the ion source and switching the polarity. In this experiment, ketones (denoted by M) were selected as analytes. The ketone (molecular weight denoted by m) was ionized as protonated ketone [M + H]+ [mass-to-charge ratio (m/z) m + 1] in PTR-MS mode and deprotonated ketone [M - H]- (m/z m - 1) in PER-MS mode. By comparing the m/z value of the product ions in the two modes, the molecular weight of the ketone can be positively identified as m. Results showed that whether it is a single ketone sample or a mixed sample of eight kinds of ketones, the molecular weights can be detected with DP-PTR-MS. The newly developed DP-PTR-MS not only maintains the original advantages of PTR-MS and PER-MS in sensitive and rapid detection of ketones, but also can estimate molecular weight of ketones. Graphical Abstract ᅟ.

Aromatic components produced by non-Saccharomyces Cerevisiae derived from natural fermentation of grape

Aromatic components are important functional products during the wine fermentation process. In the current study, nine strains (Y10, Y5, Y21, Y2, Y19, Y16, Y3, Y13 and Y4) of non-Saccharomyces were isolated from Cabernet Sauvignon grape wine. Aromatic components from Cabernet sauvignon-fermented wine were determined the phylogenetic evolution status of different non-Saccharomyces based on 26S rDNA and D1/D2 sequence analysis and analysed by a gas chromatography–mass spectrometry analysis, and they were grouped into one category with four different yeast genus which were Meyerozyma guilliermondii, Brettanomyces naardenensis, Pichia guilliermondi and Candida fermentati. A total of 102 kinds of aroma components were detected, including 39 kinds of esters, 31 kinds of alcohols, 8 kinds of ketones, 10 kinds of alkanes, 15 kinds of acids and 4 kinds of other aroma substances.

Screening and identification of Acinetobacter junii for Apocynum vernetum L. fiber enzymatic retting

There are many kinds of ketones with antisepsis functions in the Apocynum vernetum L. fiber (ALF), but its enzymatic retting is difficult. In order to select the appropriate ALF enzymatic retting strain, wastewater from ALF retting was analyzed to screen a strain with high pectinase activity. Of the analyzed strains, the maximum pectinase activity measured was of the #2 strain: 103.2 IU/ml at a zymogenic time of 12 hrs at 37°C. The retting experiments verified that this strain was well suited for ALF; the residual gum rate of ALF was 15.26% and its fiber physicochemical properties were similar to those fibers which were chemically retted. The strain was determined to be a new retting strain, Acinetobacter junii, according to a 16S rDNA sequence analysis in combination with morphology, and biophysical and biochemical tests using fermentation, catalase, methyl red and gelatin liquefaction. As a new pectinase‐producing strain, Acinetobacter junii could be utilized in industrial enzymatic retting productions after further process optimization and can replace the conventional chemical retting process due to its improved fiber quality and reduced environmental pollution.

Synthesis, structures and inclusion properties of tetranaphthalides: new macrocyclic clathrate hosts

Novel tetranaphthalide host compounds 3 and 4 bearing isomeric naphthalene moieties have been synthesized and their inclusion properties were investigated. These host compounds enclathrated several kinds of ketones, cyclic ethers, amides, sulfoxides and aromatic compounds. The structures of two representative inclusion compounds containing different host molecules and a common guest (dimethyl sulfoxide) were investigated by X-ray diffraction to determine the nature of guest inclusion and to rationalize their distinctly different thermal decomposition profiles.

Low-n Rydberg Transitions of Liquid Ketones Studied by Attenuated Total Reflection Far-Ultraviolet Spectroscopy

Far-ultraviolet (FUV) spectra in the 8.55-6.20 eV (145-200 nm) region were measured for several kinds of ketones in the liquid phase to investigate low-n Rydberg transitions using a uniquely developed technique of attenuated total reflection (ATR) FUV spectrometry. Assignments of the transitions are attempted for absorptions in this region by comparing the spectra for the liquid phase with those for the gas phase and ab initio calculations at the equation-of-motion coupled cluster theory with single and double substitutions at the aug-cc-pVDZ level. The transition from a nonbonding electron (n) to the 3s Rydberg orbital was found at around 6.7 eV for all investigated liquid ketones. Another intense band also appeared in the higher-energy region (ca. 8.5 eV) for all the ketones. A significant shoulder was found at around 7.4 eV for branched ketones. This shoulder band near 7.4 eV was assigned to the n-3p Rydberg transition. Band broadening and higher energy shifts were observed in the spectra of the liquid phase ketones in comparison with those of the gas phase ketones.

An efficient dipeptide‐catalyzed direct asymmetric aldol reaction of equimolar reactants in solid media

The direct asymmetric aldol reactions of equivalent molar amounts of aldehydes and ketones were carried out at -20 degrees C over alkaline Al(2)O(3) with 20 mol % of Pro-Trp as catalyst and 20 mol % of N-methylmorpholine or 1,4-diazabicyclo[2.2.2]octane as additive. After simple and environmentally friendly work-up, moderate to high isolated yields (up to 95%), good diastereoselectivities (>99:1), and enantioselectivities (up to 98% ee) have been achieved for the reactions of different kinds of ketones with various aldehydes. The catalytic system could be reused without decrease of activity by addition of 10 mol % catalyst and base in the catalytic system.

Asymmetric Addition to Ketones: Enantioselective Formation of Tertiary Alcohols

The stereoselective formation of chiral tertiary alcohols is of great importance for the synthesis of enantiomerically pure natural products and pharmaceuticals. The simplest approach for the preparation of chiral alcohols is the enantioselective addition of organometallic reagents to carbonyl compounds. Hundreds of catalysts promote nucleophilic additions of organometallic compounds to aldehydes with high enantioselectivities. However, the use of ketones as group acceptors under similar conditions has proven much more challenging. The chemistry of catalytic asymmetric additions to ketones is progressing, especially since 1998. This review attempts to cover advances in this field which have occurred between 1994-2004. Particular attention is paid to chiral auxiliaries, reagents and catalysts used for the addition to different kinds of ketones (aromatic and aliphatic ketones, α, β-unsaturated ketones, α-ketoesters) as well as the enantiomeric excesses of the chiral tertiary alcohols obtained for each case. In addition, a discussion about the progress in the catalytic asymmetric addition to ketoimines in order to generate enantiomerically enriched tertiary amines will be presented. Finally, recent applications of the asymmetric addition to ketones chemistry in the synthesis of natural products and related compounds are reported. © 2006 Bentham Science Publishers Ltd.

A Novel Synthesis of 2,4,4‐Trisubstituted 2‐Cyclopentenones by Consecutive Reaction of 1‐Chlorovinyl p‐Tolyl Sulfoxides with Acetonitrile and Its Homologues.

AbstractFor Abstract see ChemInform Abstract in Full Text.

A novel synthesis of 2,4,4-trisubstituted 2-cyclopentenones by consecutive reaction of 1-chlorovinyl p-tolyl sulfoxides with acetonitrile and its homologues

1-Chlorovinyl p-tolyl sulfoxides were synthesized from several kinds of ketones and chloromethyl p-tolyl sulfoxide in three steps in high overall yields. Treatment of the 1-chlorovinyl p-tolyl sulfoxides with cyanomethyllithium (lithium α-carbanion of acetonitrile) at low temperature gave the adducts in almost quantitative yields. The adducts were then treated with LDA followed by excess lithium α-carbanion of the homologues of acetonitrile to afford 3,5,5-trisubstituted cyclopentadienyl enaminonitriles, which were hydrolyzed and heated under acidic conditions to give 2,4,4-trisubstituted 2-cyclopentenones in good overall yields.

Novel moisture‐curable epoxy resins and their characterization

AbstractThe shelf‐life stability and curability of a moisture‐curable epoxy resin system were evaluated with ketimines, which were used as moisture‐latent hardeners and were derived from different kinds of ketones as protective groups. Both the shelf‐life stability and curability of the compounds were mainly influenced by the steric hindrance of the ketimines. The theoretical results calculated by MOPAC showed good agreement with the experimental results. Methyl i‐propyl ketone and methyl t‐butyl ketone, having a narrow space (<4.2 Å) around ketimine N and a wide space (>3.7 Å) around ketimine C, were demonstrated to be the optimum ketones for the ketimines. The lap shear strength, with respect to the adhesive properties of the ketimines, was higher with a large‐volume ketone than with a small‐volume ketone as the protective group. This was due to the higher reaction conversion of the epoxide for the system. In addition, the large plasticizing effect of the large ketone volume could lead to a large relaxation of the stress generated at the bonding interface. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 91–95, 2003

Photoinitiation performance of some ketones in the LDPE–acrylic acid surface photografting system

The photoinitiating performance of four kinds of ketones (alkyl-, alkyl phenyl-, phenyl- and di-ketones) and two aldehydes (formaldehyde and acetaldehyde) were examined by measuring their polymerization reactivity, grafting efficiency and surface wetting time with a simple technique, film interlayer photopolymerization (FIP), with LDPE as film substrate, acrylic acid as monomer and an HPM-15 Lamp (2 kW) as UV radiation source. Benzophenone, xanthone, acetophenone and 9-fluorenone are shown to be efficient photografting initiators for obtaining thick grafted layers, while anthraquinone, 4,4-dichlorobenzophenone, 4-benzylbenzophenone, benzoylformic acid and biacetyl are suitable photoinitiators for obtaining thin grafted layers. These results and subsequent analysis show that high triplet state energy, strong UV absorption, stable molecular structure and low initiating reactivity of the resulting ketyl free radical are decisive factors making the ketones efficient initiators for grafting applications.

Volatile compounds produced by the fungus Aspergillus oryzae in rice Koji and their changes during cultivation

The volatile compounds produced by growing the fungus Aspergillus oryzae on steamed rice, during koji making, were collected with a Tenax-TA column and analyzed by GC and GC-MS. Eight kinds of alcohols, three kinds of aldehydes, five kinds of ketones, and an ester were identified. The production of volatile compounds was affected by the oxygen concentration. Alcohols and aldehydes were especially increased by a deficiency of oxygen. The production of volatile compounds was maximum at the middle stage of growth and decreased thereafter. The results of semicontinuous analysis of mycelial growth and the production of volatile compounds showed that the tendency of the almost volatile compounds corresponded better with the mycelial growth rate than the mycelial weight. The tendency of 1-octen-3-ol was different from other volatile compounds; it increased with the cultivation time and didn't decrease.