Carboxylic Acid Ethyl Ester Research Articles

THE INVESTIGATION OF THE CHEMICAL AND TECHNOLOGICAL PROPERTIES OF BIOMASS WASTE FROM PLANT RAW MATERIALS

The aim of this work is to study the technical, chemical and group composition of biomass of the cotton crop (Cozipiym) and Shyralzhyn (Artemisia Dracunculus), to establish their suitability for obtaining chemical products. The results of the study established that the physical and chemical characteristics of Cotton crop and Shyralzhyn biomass is not inferior to oak wood and can be used for obtaining valuable chemical products and adsorbents. The study of the group composition of the analyzed plants showed that they can be used later on to produce cellulose, lignin and hemicellulose. The biomass of cotton crop and Shiralzhyn waste contains from 6.64 to 11% of pectin substances, which makes it possible to use as a sorbent against to ions of heavy metals and radionuclides. We isolated vegetable oil (fats) from the seed of tarragon polynyas – Shyralzhyn for the first time, the yield is 15.7%. The development of technology for the complex processing of waste from the cotton crop and Shyralzhyn (wormwood - tarragon) biomass are in prospective. Isolation of triglycerides (oils) from wormwood-tarragon kernels, by transesterification of esters, to produce methyl and ethyl esters of higher carboxylic acids, which can be used as additives to diesel fuels. Establish the main regularities of the recycling process. The extraction of extractive substances, such as tanning, natural dyes, lipids (waxes), antioxidants-polyphenols and pectins.

ANTIMICROBIAL ACTIVITIES OF COMPOUNDS ISOLATED FROM PYCNANTHUS ANGOLENSIS (WELW.) WARB AND BRYOPHYLLUM PINNATUM (LAM) OKEN

In the present study a semi-pure residue each from Pycnanthus angolensis (Welw.) Warb and Bryophyllum pinnatum (Lam) for the presence of biologically active compound(s) were investigated. This exercise led to two compounds whose identities have been established to be 1,6-dihydro-2-methyl-4-hydroxy-6-oxo-3-pyridine carboxylic acid ethyl ester (1,6-dihydro-2-methyl-4-hydroxy-6-oxo-3-nicotinic acid ethyl ester) (5-ethoxycarb, NG5-a ) and 1-ethoxy-2-hydroxy-4-prophenylguaethol (vanitrope, KF-1a ), respectively using MS and IR spectral techniques. NG - 5a was proved to be bacteriostatic against Escherichia coli but recorded no activity against Staphylococcus aureus and Candida albicans. KF - 1a recorded only minimal activity against S. aureus but demonstrated no activities against E. coli or C. albicans.

Rum classification using fingerprinting analysis of volatile fraction by headspace solid phase microextraction coupled to gas chromatography-mass spectrometry

In this study, targeted and untargeted analyses based on headspace solid phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME-GC-MS) method were developed for classifying 33 different commercial rums. Targeted analysis showed correlation of ethyl acetate and ethyl esters of carboxylic acids with aging when rums of the same brand were studied, but presented certain limitations when the comparison was carried out between different brands. To overcome these limitations, untargeted strategies based on unsupervised treatments, such as hierarchical cluster analysis (HCA) and principal component analysis (PCA), as well as supervised methods, such as linear discriminant analysis (LDA) were applied. HCA allowed distinguishing main groups (with and without additives), while the PCA method indicated 40 ions corresponding to 13 discriminant compounds as relevant chemical descriptors for the correct rum classification (PCA variance of 88%). The compounds were confirmed based on the combination of retention indexes and low and high-resolution mass spectrometry (HRMS). Using the obtained results, LDA was carried out for the analytical discrimination of the remaining rums based on manufacturing country, raw material type, distillation method, wood barrel type and aging period and 94%, 91%, 92%, 95% and 94% of rums, respectively, were correctly classified. The proposed methodology has led to a robust analytical strategy for the classification of rums as a function of different parameters depending on the rum production process.

Synthesis and structure-activity relationships of quinolinone and quinoline-based P2X7 receptor antagonists and their anti-sphere formation activities in glioblastoma cells

Screening a compound library of quinolinone derivatives identified compound 11a as a new P2X7 receptor antagonist. To optimize its activity, we assessed structure-activity relationships (SAR) at three different positions, R1, R2 and R3, of the quinolinone scaffold. SAR analysis suggested that a carboxylic acid ethyl ester group at the R1 position, an adamantyl carboxamide group at R2 and a 4-methoxy substitution at the R3 position are the best substituents for the antagonism of P2X7R activity. However, because most of the quinolinone derivatives showed low inhibitory effects in an IL-1β ELISA assay, the core structure was further modified to a quinoline skeleton with chloride or substituted phenyl groups. The optimized antagonists with the quinoline scaffold included 2-chloro-5-adamantyl-quinoline derivative (16c) and 2-(4-hydroxymethylphenyl)-5-adamantyl-quinoline derivative (17k), with IC50 values of 4 and 3 nM, respectively. In contrast to the quinolinone derivatives, the antagonistic effects of the quinoline compounds (16c and 17k) were paralleled by their ability to inhibit the release of the pro-inflammatory cytokine, IL-1β, from LPS/IFN-γ/BzATP-stimulated THP-1 cells (IC50 of 7 and 12 nM, respectively). In addition, potent P2X7R antagonists significantly inhibited the sphere size of TS15-88 glioblastoma cells.

A copper(II) complex of an asymmetrically N-functionalized derivative of 1,4,7-triazacyclononane: synthesis, crystal structure and SOD activity

A copper(II) complex chlorido-{1-carboxylic acid ethyl ester-4, 7-bis[1-(carboxylic acid ethyl ester) benzimidazole-2-yl-methyl]-1,4,7-triazacyclononane}copper(II) hexafluorophosphate ethanol solvate ([CuClL]·PF6·EtOH) was synthesized and crystallographically characterized {where L = 1-carboxylic acid ethyl ester-4,7-bis[1-(carboxylic acid ethyl ester) benzimidazole-2-yl-methyl]-1,4,7-triazacyclononane}. X-ray structure analysis shows that the copper(II) adopts a distorted square pyramidal coordination geometry. The activity of dismutation of superoxide () of the complex in riboflavin–methionine–nitroblue tetrazolium was studied. The result shows that the complex possesses a high superoxide dismutase (SOD) activity in comparison to some reported SOD mimics. Its redox behavior was studied by cyclic voltammetry with the aim of elucidating the reason that the complex reduces superoxide radicals.

Physicochemical studies on bioactive Cr(III) coordination compounds with esters of hydrazine carboxylic acid as hetero donor ligands

Reaction between hydrazine derivative ligands (HrzE) or (HrzB) and chromium salt in 1:2 (metal:ligand) molar ratio yielded monometallic trivalent coordination compounds with general formula [Cr(HrzE)2X2]X and [Cr(HrzB)2X2]X, where (HrzE) = hydrazine carboxylic acid ethyl ester, (HrzB) = hydrazine carboxylic acid tert-butyl ester, and X = Cl−, Br− or F−. Elemental analysis, conductivity measurements, magnetic moment measurements, and various spectroscopic techniques, viz. infrared, ultraviolet–visible, and electrospray ionization mass spectrometry, were applied to illustrate the structure and composition of the coordination compounds. Analytic and conductivity results were consistent with 1:1 electrolytic behavior and the proposed formulas of the coordination compounds. Electronic absorption data and magnetic moment parameters indicated octahedral geometry surrounding the metal ion in the coordination compounds. The in vitro antimicrobial behavior of the ligands and coordination compounds was screened using four bacterial strains (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Salmonella typhi) and two fungal strains (Candida parapsilosis and Saccharomyces cerevisiae). The results indicated improved activity of the coordination compounds compared with the free ligands against the studied bacteria and fungi.

Spectroscopic validation and biological screening of new iron(III) complexes with N, O donor ligands

Monometallic trivalent complexes of iron were synthesized by reaction between N, O type donor ligands (L) or (L′) and metal salt in a 1:2 (metal:ligand) molar ratio. Structure and composition of metal complexes were evaluated by elemental analysis, conductance measurements, magnetic moment measurements, and various spectroscopic studies viz. FTIR, UV–visible, and ESI–MS. Analytical and molar conductance data are consistent with the formulation of complexes as [Fe(L)2X2]·X and [Fe(L′)2X2]·X (where; L = Hydrazine carboxylic acid ethyl ester, L′ = Hydrazine carboxylic acid tert-butyl ester and X = Cl−, Br− or NO3 −) due to their 1:1 electrolytic nature. IR spectral data revealed bi-dentate coordination behavior of ligands. An octahedral geometry may be assigned for metal complexes on the basis of electronic absorption data and magnetic moment parameters. The compounds were evaluated for their biological activity by in vitro antimicrobial screening against bacteria Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Salmonella typhi and fungi Candida parapsilosis and Saccharomyces cerevisiae. The results indicate that metal complexes exhibit more activity than free ligands against studied microbes.

Bis azide–triphenylphosphine as a reagent for esterification at room temperature

Modified Staudinger reaction is a well-established reaction for the amide synthesis from organic azides and carboxylic acids in the presence of phosphorous reagents. In contrary to this, it is notable that bis azide in the presence of triethylphosphite or trimethylphosphite does not afford the expected bis amides but affords the ethyl or methyl esters of the carboxylic acids respectively. This serendipitous observation when further investigated results in the discovery of bis azide–triphenylphosphine as an efficient reagent for esterification at room temperature.

Anti-nociceptive and anti-inflammatory activities of 4-[(1-phenyl-1H-pyrazol-4-yl) methyl] 1-piperazine carboxylic acid ethyl ester: A new piperazine derivative

Piperazine compounds possess anti-infective, anti-carcinogenic, anxiolytic, hypotensive, anti-hypertensive and vasorelaxant properties and are attractive candidates for the development of new analgesic and anti-inflammatory drugs. This study investigates the anti-nociceptive and anti-inflammatory effects of piperazine derivative 4-[(1-phenyl-1H-pyrazol-4-yl) methyl]1-piperazine carboxylic acid ethyl ester (LQFM-008) and the involvement of the serotonergic pathway. In the formalin test, treatments with LQFM-008 (15 and 30mg/kg p.o.) reduced the licking time in both neurogenic and inflammatory phases of this test. In the tail flick and hot plate tests, LQFM008 treatment (15 and 30mg/kg p.o.) increased latency to thermal stimulus, suggesting the involvement of central mechanisms in the anti-nociceptive effect of LQFM-008. In the carrageenan-induced paw edema test, LQFM-008 (p.o.) at the doses of 15 and 30mg/kg reduced the edema at all tested time points, while the dose of 7.5mg/kg reduced the edema only for the first hour. LQFM-008 (30mg/kg p.o.) reduced both cell migration and protein exudation in the carrageenan-induced pleurisy test. Furthermore, pre-treatment with NAN-190 (0.6mg/kgi.p.) and PCPA (100mg/kgi.p.) antagonized the anti-nociceptive effect of LQFM-008 in both phases of the formalin test. Our data suggest that LQFM-008 possesses anti-inflammatory and anti-nociceptive effects mediated through the serotonergic pathway.

Kinetically Inert Bispidol-Based Cu(II) Chelate for Potential Application to (64/67)Cu Nuclear Medicine and Diagnosis.

A family of 2,4-pyridyl-disubstituted bispidol derivatives bearing methylene carboxylic acid ethyl esters (L1-L3), methylene carboxylic acids (L4 and L5), or methylenethiophene (L6) groups were synthesized. In water, all ligands form rigid 1:1 complexes in the presence of Zn(II) in which the bicycle adopts a chair-chair conformation (cis isomer), as observed by (1)H NMR and, in the case of ligand L1, by an X-ray diffraction crystal structure. Interestingly, addition of Zn(II) ions on ligand L1 induces a metal-mediated selective hydrolysis of the ethyl esters. This selective hydrolysis was not observed upon addition of other cations such as Na(+), Mg(+), and Ca(2+). Reduction of the central ketone was achieved to prevent ring opening via retro Diels-Alder reactions and to afford highly stable and water-soluble ligands (L4, L5, L6). The complexation properties of L4 and L6 were studied in solution, with a particular interest for ligand L4. Fast complexation occurs in strongly acidic media (pH = 1), with a high affinity toward Cu(II) (log KCuL4 = 19.2(3), pCu = 17.0 at pH 7.4, pCu = -log[Cufree], [Cu] = 1 × 10(-6) M, [L] = 1 × 10(-5) M) and high selectivity versus Co(II), Ni(II), and Zn(II), as shown by the values of the binding constants obtained from potentiometric and spectrophotometric titrations. Reversible redox potential with E1/2 = -430 mV (vs normal hydrogen electrode) was measured. The complex was found to be fairly inert from acid-assisted dissociation experiments in 5 M HClO4 (t1/2 = 110 d at 25 °C).

Hypotensive and antihypertensive potential of 4-[(1-phenyl-1H-pyrazol-4-yl) methyl]1-piperazine carboxylic acid ethyl ester: A piperazine derivative

AimsClinical complaints on the first-line of cardiovascular medications make continuous search for new drugs a necessity. This study evaluated the cardiovascular effects and mechanism of 4-[(1-phenyl-1H-pyrazol-4-yl)methyl]1-piperazine carboxylic acid ethyl ester (LQFM008). Main methodsNormotensive male Wistar or spontaneously hypertensive rats (anesthetized or conscious) were used to evaluate the effect of LQFM008 on the mean arterial pressure (MAP), heart rate (HR), arterial blood flow (ABF), arterial vascular conductance (AVC), baroreflex effectiveness index (BI), systolic blood pressure (SBP), diastolic blood pressure (DBP) and vascular function. Key findingsIn anesthetized normotensive rats, LQFM008 (7.3, 14.3 or 28.6μmol/kg, iv) reduced MAP (−21.1±2.7; −23.9±4.7 or −32.4±8.3mmHg, respectively) and AVC (22%, 32% or 38%) in a dose-dependent manner. LQFM008 elicited a temporal reduction in the SBP and DBP without changes to the BI of conscious normotensive rats. In hypertensive rats, LQFM008 (7.3, 14.3 or 28.6μmol/kg, iv) reduced MAP (−2.3±2.6; −29.3±2.7 or −38.4±2.8mmHg, respectively) and increased HR (1.6±3.7; 15.4±4.9 or 25.5±6.2 bmp, respectively) in a dose-dependent manner. A week of oral administration of LQFM008 47.7μmol/kg elicited a temporal reduction in SBP of hypertensive rats. Pretreatments with atropine, WAY-100635 or L-NAME blocked the effect of LQFM008. In addition, LQFM008-induced endothelium-dependent vascular relaxation was inhibited by L-NAME. SignificanceOur findings showed hypotensive, antihypertensive and vasorelaxant effects of LQFM008 and suggest the participation of nitric oxide, 5-HT1A and muscarinic receptors.

Synthesis of 2-(4-methyl-1,3-thiazol-5-yl)ethyl esters of acridone carboxylic acids and evaluation of their antibacterial activity

2-(4-Methyl-1,3-thiazol-5-yl)ethyl acridone carboxylates were synthesized by the transesterification of the corresponding butyl esters. The kinetic characteristics of these reactions were determined, and the antimicrobial activity of a number of reaction products was investigated.

MODIFIED METHOD FOR THE SYNTHESIS OF ISOMERIC N -SUBSTITUTED (1 H -PYRAZOLYL)PROPANE-1,3-DIONES

The condensation reaction of isomeric N -substituted (1 H -pyrazol-4-yl)ethanones with the ethyl esters of pyrazole carboxylic acids and fluoroacetic acids has been studied using NaH as the base. Under optimized conditions, it proved to be a convenient and preparative method for the synthesis of N -substituted (1 H -pyrazolyl)propane-1,3-diones and (1 H -pyrazolyl)-4-polyfluorobutane-1,3-diones. Authors: I. V. Taydakov and S. S. Krasnoselsky English translation in Chemistry of Heterocyclic Compounds , 2011, 47 (6), pp 695-699 http://link.springer.com/article/10.1007/s10593-011-0821-1

One-pot synthesis of dihydropyrano[c]chromene derivatives by using BF3•SiO2 as catalyst

Abstract Silica-supported boron trifluoride (BF3•SiO2) is an efficient, readily available, and reusable catalyst for the synthesis of 2-amino-5-oxo-4-aryl-4H,5H-pyrano[3,2-c]chromene-3-carbonitrile or carboxylic acid ethyl ester derivatives by condensation of 4-hydroxycoumarin, an aldehyde, and an alkylnitrile.

N-H...O hydrogen bonding and π- π interactions in 2-Amino-1- (4-methoxy-phenyl)-5-oxo-4,5-dihydro-1H-pyrrole-3- carboxylic acid ethyl ester

The pyrrole derivatives show a broad spectrum of biological activities such as anticancer, antidiabetic, aldose reductase inhibition, anti-inflammatory and analgesic activities and therefore these derivatives attracted much attention. The title compound, 2-Amino-1-(4-methoxy-phenyl)-5-oxo-4,5- dihydro-1H-pyrrole-3-carboxylic acid ethyl ester, C14H16N2O4, a novel Pyrrole derivative has been synthesized and characterized by NMR. The crystal structure of it is determined using X-ray crystallographic technique. It crystallizes in to monoclinic space group P21/n with lattice parameters a = 4.088, b = 27.696, c = 11.763 A and β = 93.76(0)°. In the title compound, the pyrrole ring is planar. The configuration of the substituted ethoxy carbonyl moiety is an extended zigzag chain lying parallel along b-axis. N-H…O (intra) and N-H…O (inter) interactions along with C-H…O interactions form a ring and chain of (14) graph-set motifs respectively. Another C-H…O interactions interlinked the rings forming molecular chain along [001] direction. An off-centric π-π interaction involving pyrrole ring and symmetry related phenyl ring of the superimposed molecular chain responsible for the stability of the molecule along [100] direction.

ИЗУЧЕНИЕ ТЕРМИЧЕСКОГО РАСТВОРЕНИЯ В ЭТАНОЛЕ САПРОПЕЛЕЙ ОЗЕР КАЧКУЛЬНЯ И БАРЧИН НОВОСИБИРСКОЙ ОБЛАСТИ

The thermal dissolution in ethanol of organic type sapropel (Kachkulnya lake) and organo-mineral type sapropel (Barchin lake) from Novosibirsk region was studied. It was shown that the rising of the temperature of thermal dissolution process from 200 to 400 °C results in an increase the conversion of sapropel organic matter of Lake Kachkulnya from 39,9 wt.% to 69,7 wt.% and in a decrease of extractable products yield from 40,1 wt .% to 27,4 wt.%. According to GC-MS data the extractable products obtained at 200°C mainly (up to 68,1%) consist of ethyl esters of monobasic aliphatic saturated carboxylic acids with an even number of carbon atoms in the chain (from hexadecanoic to heptacosanoic acids). In addition, they contain phenols, nitrogen and sulfur compounds, aliphatic hydrocarbons, ketones and aldehydes. The rise of the temperature of sapropel dissolution reduces the ester content in the extractable products from 68,1 to 8,0%, and increases the content of aliphatic hydrocarbons and phenols from 3,2 to 26,9% and from 14,0 to 42,3%, respectively. Products of thermal dissolution in ethanol of organo-mineral sapropel (Barchin lake) at 300°C have a higher content of alkanes and alkenes (by 4.6 times), lower content of phenols (by 2,1 times) and nitrogencontaining compounds (by 2,8 times) as compare to products from organic sapropel (Kachkulnya lake).

Effect of pH on the photophysical properties of two new carboxylic-substituted iridium(iii) complexes

Two cyclometalated iridium(III) complexes have been prepared based on 2-(4-diphenylamino-phenyl)-quinoline and incorporating carboxylic acid ethyl ester (–COOC(2)H(5), (TPAQCE)(2)Irpic and carboxylic acid (–COOH, (TPAQCOOH)(2)Irpic) substituents at the 4-position of the quinoline ligand, respectively. The absorption, emission and (1)H NMR spectra of (TPAQCE)(2)Irpic and (TPAQCOOH)(2)Irpic under alkaline or acidic conditions demonstrate that they respond to the pH of the surrounding solvent environment. The deprotonation of the carboxylic acid group significantly blue-shifts the metal-to-ligand charge transfer absorption band of (TPAQCOOH)(2)Irpic by 48 nm and enhances the emission quantum-yield in DMSO. In addition, (1)H-NMR titration reveals that (TPAQCOOH)(2)Irpic is deprotonated into negatively charged (TPAQCOO(−))(2)Irpic in free DMSO-d(6) solution, and the acid-induced N^O ancillary ligands cleavage or replacement in (TPAQCOOH)(2)Irpic could be ignored. A water-soluble near-neutral optical pH probe (TPAQCOOH)(2)Irpic with pK(a) of ~7 is also reported. In aqueous buffer, (TPAQCOOH)(2)Irpic possesses an obvious emission response with an excellent linearity in the pH range of 6.50–8.00, showing a promising application in bioprocessing.

Amination of quinolones with morpholine derivatives

The aromatic nucleophilic substitution reaction of 7-chloroquinolone carboxylic acid and its ethyl ester with cyclic amines under microwave irradiation conditions was investigated. 1H NMR spectroscopy was used to monitor the progress of the substitution reaction. The reaction proceeded in high yield with simple cyclic amines and was less efficient for sterically more demanding bimorpholine derivatives. A Pd-catalyzed amination of quinolone carboxylic acid ethyl ester with bimorpholine derivatives provided new C-7 bimorpholino-substituted quinolone derivatives.

Impact of Nitrogen Source and Trinexapac-ethyl Application on Creeping Bentgrass (Agrostis stolonifera L.) Physiology under Neutral Shade, Deciduous Tree Shade, and Full Sunlit Conditions

Decreased light quantity or quality affects the growth of turfgrass plants. Shade causes thinning of turfgrass stands and loss in surface quality. Plant changes include increased chlorophyll levels, lower soluble sugars, and loss of canopy cover. The objective of this research was to investigate if applications of foliar nitrogen and trinexapac-ethyl [4-(cyclopropyl-α-hydroxy-methylene)-3,5-dioxo-cyclohexane carboxylic acid ethyl ester] (TE) would result in beneficial biochemical changes in creeping bentgrass (Agrostis stolonifera L. cv. Penncross) grown in different shaded environments. Foliar applications of three nitrogen treatments, (NH2)2CO, Ca(NO3)2, or (NH4)2SO4, were made weekly at 0.43 g N/m2. Growth regulator treatments consisted of an untreated control or TE applied biweekly at an a.i. rate of 0.057 kg·ha−1. Plots were established in full sun (FS), neutral shade (NS), and deciduous shade (DS). Chlorophyll content, soluble carbohydrates, flavonoids, clipping yield, and color were measured. Nitrogen treatments caused some variation in levels of soluble carbohydrates in shaded conditions. Chlorophyll (Chl) levels varied between TE treatments, with increased levels of chlorophyll b (Chl b) found in TE-treated plots under FS. Application of TE resulted in higher flavonoid concentrations in leaf tissue in shaded conditions. Repeated applications of (NH2)2CO significantly improved color (P = 0.05). Turfgrass managers maintaining creeping bentgrass in shade may benefit from applications of TE and (NH2)2CO.

Temperature-Dependant Volumetric and Compressibility Studies of Drug-Surfactant Interactions in Dimethylsulfoxide (DMSO) Solutions

In this work we present apparent molar volume, � v and apparent molar adiabatic compressibility, � � values of sodium dodecyl sulphate (SDS) in DMSO and in DMSO solution of 0.25 % w/v 6-methyl-4(2-hydroxy3-methoxyphenyl)-2-thioxo-1,2,3,4-tetrahydro pyrimidine-5 carboxylic acid ethyl ester (a pyrimidine derivative drug). The study was carried out over a temperature range (20–40 � C) covering a wide range of SDS concentration (2 - 11 mmol dm −3 � . Being highly sensitive to the extrinsic experimental conditions, a difference observed