Propionic Acid Ester Research Articles

Impact of the aliphatic side chain length on photovoltaic properties of fullerenes functionalized with 3-(1-indenyl)propionic acid esters

10 Indene C60 and C70 derivatives have been synthesized and characterized, and solar cells fabricated using them gave the best efficiency for hexyl derivatives.

Torulaspora delbrueckii Strain Behaviour within Different Refermentation Strategies for Sparkling Cider Production

Torulaspora delbrueckii is known for improving the aroma quality in wine and beer, but information for cider manufacturing is scarce. We explored the behaviour of two commercial strains of T. delbrueckii in apple juice fermentation to produce cider and sparkling cider. The influence of the strain, method, and strain–method interaction on the physicochemical parameters of cider was analysed by enzymatic and chromatographic assays. The data were subjected to an analysis of variance and a principal component analysis. Both strains also showed regular fermentation kinetics under pressure. Ethanol, lactic acid, acetic acid, and glycerol were produced with significant differences between strains and production methods. Then, 26 volatile compounds were identified, with higher alcohols being the quantitatively most abundant group. Strain A was associated with a higher production of methyl butanol, 2-phenyl ethanol, and butyric, propionic, and succinic acid esters, while strain B was associated with higher amounts of hexanoic acid, and acetate and valerate esters. In addition, 13 compounds showed significant differences between methods, and 14 were influenced by the method–strain interaction. Our findings encourage the further investigation of the application of T. delbrueckii as a solo player to produce ciders with a unique flavour.

Breath indeed carries significant information about a disease: Potential biomarkers of cerebral palsy.

Objective and reliable noninvasive medical diagnostics of a large variety of diseases is still a dream. As a step in the direction of realization, a spectroscopic breath study of cerebral palsy (CP) was performed. Principal component analysis revealed data clustering for a healthy group and CP individuals was observed, with a P-value below 10-5 . Learning algorithms resulted in 91% accuracy in distinguishing the groups. With the help of manual analysis of absorption spectral features of breath samples, two volatile organic compounds were identified that demonstrate significant deviations in the groups. These represent two esters of propionic acid (PPAE). A transportation scheme was hypothesized that links the gut where propionic acid (PPA) and PPAE are produced, the brain of CP patients, through which PPA and PPAE transmit, and the lungs where PPAE releases. The results show a possibility to detect one more brain-related disorder via breath, in this case CP.

Enzymatic Enantioselective Hydrolysis of 2-(3-Chlorophenyl) Propionic Acid Ester Enhanced by PEG: Experiment and Optimization

Chiral resolution of 2-(3-chlorophenyl) propionic acid (CPA) via the hydrolysis of CPA ester catalyzed by lipase PS from Pseudomonas cepacia is reported. With polyethylene glycol (PEG 400) as a cos...

Optimisation of fermentation process for production of black rice wine and evaluation of its phenolic and volatile compounds

A statistical model was developed to describe the fermentation process using Saccharomyces cerevisiae ATCC 9763 in the production of black rice (cv. Poireton) wine from Manipur, India. Fermentation process parameters were optimised by response surface methodology and experiments were conducted according to a three-level and three-variable central composite rotatable design. The combination of pH, temperature and time was the most promising for achieving a high ethanol yield. With the use of the developed quadratic model equation, alcohol production (11.1%, v/v) was obtained in a batch fermentation process at the optimum operating condition of pH (6.96), temperature (26.2°C) and incubation time (74 h). GC–MS analysis of the wine revealed volatile aromatic compounds, namely 1-methyl-2-pyrrolidine ethanol, propionic acid, 3-mercapto and ethyl ester. © 2018 The Institute of Brewing & Distilling

How Much Does the Hybridization of a Carbon Atom Affect the Transmission of the Substituent Effect on the Chemical Shift?

1H and 13C NMR spectra of aryl esters of propionic acid, acrylic acid, and propiolic acid were systematically examined to find out the substituent effect on the chemical shift. The values of the chemical shift of the carbonyl carbon showed an inverse correlation with the Hammett σ values, and the magnitude of the slope was the largest with the propiolates. The α carbons of acrylates and propiolates also showed an inverse correlation with much smaller values of the slopes than those of the carbonyl carbons; but those of the propionates showed absolutely no correlation. However, the β carbons of acrylates and propiolates showed normal correlation with larger values of the slopes. The signs and the magnitudes of the slopes may be understood by the transmission of the substituent electronic effect through bonds as well as through space. The propiolyloxy group also showed a significantly large effect on the 13C chemical shift values of the benzene ring.

A general method for the synthesis of enantiopure aliphatic chain alcohols with established absolute configurations. Part 2, via catalytic reduction of acetylene alcohol MαNP esters

A general method for synthesizing enantiopure (100% ee) aliphatic alcohols with established absolute configurations has been developed and applied to alcohols CH3(CH2)n–CH(OH)–(CH2)mCH3, the enantiomeric discrimination of which is the most difficult, if m=n+1 and n is large. Racemic saturated alcohols with short chains could be directly enantioresolved as (S)-(+)-2-methoxy-2-(1-naphthyl)propionic acid (MαNP acid) esters by HPLC on silica gel, and their absolute configurations were simultaneously determined by 1H NMR diamagnetic anisotropy. However, the application of this powerful MαNP ester method to alcohols with long chains was difficult, because of smaller values of the separation factor α. In such cases, the use of the corresponding acetylene alcohol MαNP esters was crucial. Acetylene alcohol MαNP esters were largely separated by HPLC on silica gel, and their absolute configurations were unambiguously determined by 1H NMR as reported in the Part 1 paper. The MαNP esters obtained with established absolute configurations were catalytically hydrogenated to yield saturated alcohol MαNP esters. It was evidenced that no racemization occurred at the stereogenic center of the alcohol moiety during catalytic hydrogenation, by the coinjection of MαNP esters in HPLC. From the MαNP esters obtained, enantiopure (100% ee) aliphatic chain alcohols with established absolute configurations were recovered. Although the [α]D values of these alcohols were too small for the identification of the enantiomers, it was clarified that the analytical HPLC of MαNP esters is useful for identification in most cases.

Structural Effect of Thiol-Compounds on the Thiol-Ene Based UV Curable Adhesive

Three thiol-compounds with different functionalities were synthesized through esterification reaction which was prepared by 1, 4-butanediol, trimethylolpropane, and pentaerythritol and 3-mercapto propionic acid respectively. Thiol-compounds and polyurethane-acrylate prepolymer were blended with addition of photo-initiator in certain proportions in order to form polyurethane curing film under UV irradiation. The structure and properties of the thiol-compounds and the polyurethane curing film were characterized by NMR, FT-IR, and TG. The results showed that the thiol-ene addition reaction between the urethane acrylates and the thiol-compounds was preceeded. With the increase of functionality of mercaptopropionic acid ester, the thermal stability improved, and the T-peel strength enhanced. When the moral ratio of urethane acrylates and trimethylolpropane-3-mercapto propionic acid ester was 1:1, the adhesive showed the best mechanical properties and thermal stability with curing time 40s, T-peel strength 88N/m and 50 % mass loss at 369°C, respectively.

Synthesis, antimicrobial evaluation and QSAR studies of propionic acid derivatives

A series of Schiff bases (1–17) and esters (18–24) of propionic acid was synthesized in appreciable yield and characterized by physicochemical as well as spectral means. The synthesized compounds were evaluated in vitro for their antimicrobial activity against Gram-positive bacteria Staphylococcus aureus, Bacillus subtilis, Gram negative bacterium Escherichia coli and fungal strains Candida albicans and Aspergillus niger by tube dilution method. Results of antimicrobial screening indicated that besides having good antibacterial activity, the synthesized compounds also displayed appreciable antifungal activity and compound 10 emerged as the most active antifungal agent (pMICca and pMICan=1.93). The results of QSAR studies demonstrated that antibacterial, antifungal and overall antimicrobial activities of synthesized propionic acid derivatives were governed by the topological parameters, Kier’s alpha first order shape index (κα1) and valence first order molecular connectivity index (1χv).

A computational proof toward correlation between the theoretical chemical concept of electrophilicity index for the acceptors of C60 and C70 fullerene derivatives with the open-circuit voltage of polymer-fullerene solar cells

A quantum chemical computational study has been performed at B3LYP/6-311G(d, p) level to investigate electronic structures of the C60 and C70 fullerene derivatives, as electron acceptor in bulk heterojunction solar cells, seeking ways to improve their efficiency in corresponding photovoltaic devices. The key point of the present survey is to achieve a significant linear correlation between the electrophilicity index calculated for the fullerene derivatives and the corresponding open-circuit voltage of the photovoltaic device. This index is a prominent feature in determining tendency of the fullerene derivative towards acquiring an additional electron from the adjacent electron-rich donor molecule, and also its resistance to give the electron back transfer. The results reveal that replacing butyric acid ester by propionic acid ester in the aliphatic part or increasing the donating strength of the substituent in the esteric part will cause an increase in electrophilicity. Considering the derivatives of C70 generally yields higher electrophilicity than those of C60 derivatives. Also for indene-C60 derivatives a significant increase in the electrophilicity is observed by increasing the number of adducts, leading to raise in the VOC values.

A facile synthesis of novel optically active R,R-2-(4-(2-(4-(5-chloro-3-halo-pyridin-2-yloxy)-phenoxy)-propionyloxy)-phenoxy)-propionic acid esters using cyanuric chloride as potential herbicide

Abstract A facile method for the synthesis of a new series of R , R -2-(4-(2-(4-(5-chloro-3-halopyridin-2-yloxy)-phenoxy)-propionyloxy)-phenoxy)-propionic acid ester derivatives containing a halo-substituted pyridine carrying two R , R chiral centers from ( R )-2-(4-hydroxyphenoxy)propionic acid, halopyridines and alcohols using base/cyanuric chloride/catalyst system is reported. Their herbicidal activities against grass weeds and crops selectivity were evaluated.

Disassembly of preformed amyloid beta fibrils by small organofluorine molecules

A potential therapeutic approach for Alzheimer's disease is to reduce the amount of toxic amyloid-beta oligomers and fibrillar amyloid plaques. In order to contribute to this approach the ability of small organofluorine compounds that were previously reported as successful inhibitors of fibrillogenesis to destabilize preformed fibrils of the amyloid-beta peptide was studied. These organofluorine molecules including chiral compounds were tested in vitro using standard methods based on Thioflavin-T (THT) fluorescence spectroscopy, atomic force microscopy (AFM) and Fourier-transform infrared spectroscopy (FTIR). It was observed that 5'-halogen substituted 3,3,3-trifluoromethyl-2-hydroxyl-(indol-3-yl)-propionic acid esters showed significant activity in the disassembly of the preformed fibrils. Since the same compounds were identified as strong fibrillogenesis inhibitors as well, this dual action makes them promising candidates for further drug development.

Hydroesterification of 2-vinyl-6-methoxynaphthalene using palladium complexes containing chelating nitrogen ligands

Hydroesterification of 2-vinyl-6-methoxynaphthalene (VMN) to methyl ester of 6-methoxy naphthyl propionic acid (ester of naproxen) has been investigated using palladium complexes containing the chelating N ∩O and N ∩N ligands (pyridine-2-carboxylate, 2-acetylpyridine, 2-pyridine-carboxaldehyde, and bipyridine) as catalysts. Palladium complex containing 2-acetylpyridine as the ligand was found to be superior to other Pd-complexes. Both acid and halide promoters were necessary for high activity and selectivity. As an acid promoter, benzenesulfonic acid was found to be more effective compared to p-toluenesulfonic acid. Formation of ether 2-methoxy-6-(1-methoxyethyl)naphthalene and a polymer of VMN was observed in all the reactions. It was observed that active catalytic species generated during carbonylation reaction was responsible for the polymer formation. The effect of various parameters such as solvents, CO pressure, and alcohols on the catalytic activity as well as the selectivity was investigated. The turnover frequency using the complex Pd(acpy)(PPh 3)(OTs) 2 (acpy = 2-acetylpyridine) catalyst was found to be 42 h −1, which is the highest for the hydroesterification of VMN.

Selective synthesis of α-substituted β-keto esters from aldehydes and diazoesters on mesoporous silica catalysts

The titled reactions are effectively catalyzed on mesoporous silica MCM-41 but not on amorphous silica prepared from the same starting materials as those of MCM-41. The ordered porous structure was essential to generate the acid catalysis. Planting of Al or Ti ion improved not only the catalytic activity but also the tolerance to basic functional groups of substrates. The catalytic activity of Al- or Ti-MCM-41 was better than that of SnCl 2 and NbCl 5 in the homogeneous phase. In particular, Al (or Ti)-MCM-41 was characteristically active for the reaction of aldehydes with α-substituted diazoesters to give 2-substituted-3-oxo propionic acid esters.

Synthesis of bridged piperazines with σ receptor affinity

Bridged piperazines 4 were designed as conformationally restricted piperazine σ receptor ligands. The chiral pool synthesis started from ( S)-glutamate, which was transformed in five reaction steps into the piperazinediones 5 bearing a propionic acid ester side chain. A two-step Dieckmann analogous cyclization provided the bicyclic ketones 7 as key intermediates. The alcohols 8 were prepared by LiAlH 4 reduction of the ketones 7. NaBH 4 reduction, Williamson ether synthesis and LiAlH 4 reduction led to the methyl and benzyl ethers 12 and 13. High σ 1 affinity is attained when one large substituent is introduced either at N-8 or O-2. The most potent σ 1 ligand in this series of compounds is the methyl ether 12b with the N-butyl substituent ( K i = 13.2 nM, selectivity σ 2:σ 1 = 16). Moreover, the N-methyl derivatives 13a (σ 2: K i = 30.4 nM) and 12a (σ 2 preference) represent promising starting points for the development of potent and selective σ 2 ligands.

Excited States and Two-Photon Absorption of Some Novel Thiophenyl Pt(II)−Ethynyl Derivatives

The photophysical characterization of two new compounds related to bis((4-(phenylethynyl)phenyl)ethynyl)bis(tributylphosphine)platinum(II), here abbreviated Pt1, is reported. For the first new compound ATP1, the inner phenyl rings (closer to the Pt atom) in Pt1 are replaced by thiophene rings bridging at the 2,5-positions. In compound ATP2, the outer phenyl groups are replaced by thiophene rings bonded at the 2-position. Specifically, we report on the fluorescence quantum yield, two-photon absorption, triplet decay times and two-photon absorption induced emission spectra of the molecules in THF solutions. The results were compared with those of Pt1 and Pt1 capped with an acetonide-protected 2,2-bis(methylol)propionic acid (bis-MPA) ester group (Pt1-G1). The photophysical properties of the organic dye 7-(diethylamino)coumarin (Coumarin 110) were determined and used as a reference material. The two-photon absorption cross section around 720-740 nm of ATP1 and ATP2 was found to be of the same order of magnitude as for Pt1-G1, i.e., between 5 and 10 GM, but slightly larger for ATP1 than for ATP2 (1 GM = 1 Göppert-Mayer = 10(-50) (cm(4) s)/photon). The fluorescence decay time of all compounds was found to be very short (subnanosecond) with quantum yields 0.0045, 0.0007, 0.0011 and 0.0020 for ATP1, ATP2, Pt1-G1 and Pt1, respectively, measured at excitation wavelength 373 nm. Just as Pt1 and Pt1-G1, both thiophenyl derivatives showed large intersystem crossing capabilities and phosphorescence, characteristic for a triplet state that can enhance the nonlinear absorption and optical power limiting by triplet state absorption. The phosphorescence emission of the thiophenyl derivatives was red-shifted in comparison with Pt1 and Pt1-G1, and the phosphorescence decay times were on the order of 200-500 ns, as for the Pt1 compound.

The temperature dependence of the retention index for n-alkyl esters of acetic, propionic, cyclohexanecarboxylic, benzoic and phenylacetic acid on DB-1 and DB-5 capillary columns

The temperature dependence of the retention index was studied for n-alkyl esters of acetic, propionic, cyclohexanecarboxylic, benzoic and phenylacetic acid on DB-1 and DB-5 capillary columns. The study was performed over various temperature ranges depending on the volatility of the ester. Two linear equations of the temperature dependence of the retention data on the column temperature and its reciprocal as variables were studied. Agood linearity of the retention index versus column temperature was found.

Angularly Substituted Octahydroindoles, Decahydroquinolines, Octahydropyrindines, and Octahydrocyclopenta[b]pyrroles by Bruylants Reaction.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Angularly Substituted Octahydroindoles, Decahydroquinolines, Octahydropyrindines, and Octahydrocyclopenta[b]pyrroles by Bruylants Reaction

The easily available cycloalkanoyl acetic- and propionic acid esters are transformed to the corresponding amines by standard procedures. These in turn provided an efficient access to cyclic α-aminonitriles, which were reacted with a series of Grignard reagents yielding stereoselectively the cis-configured title compounds; the scope and limitation of this route were investigated. The stereochemical assignment was achieved by X-ray crystallography and NMR spectroscopy.

Stereoselective Michael addition of trimethyl aluminium to nitro acrylates: a route to 2-methyl-3-amino propionic acid

The copper(I)-catalysed Michael addition of trimethyl aluminium to nitro acrylates yields 2-methyl-3-nitro propionic acid esters on a 200 g scale with enantiomeric excesses up to 92%.