Pentadienoic Acid Research Articles

Phytoconstituents from Adenanthera pavonina L. as antioxidants and inhibitors of inducible TNF-α production in BV2 cells

Adenanthera pavonina L. has been used traditionally to relieve inflammation. This study aimed to expand the phytochemical knowledge of A. pavonina and evaluate its constituents for their antioxidant and anti-inflammatory potentials as tumor necrosis factor alpha (TNF-α) inhibitors. The antioxidant activity was evaluated using the DPPH radical scavenging assay, and the inhibition of TNF-α was assessed through ELISA and qRT-PCR techniques. Interestingly, five previously undescribed metabolites, including a pentadienoic acid derivative, a triterpenoid glycoside, and three tamarixetin glycosides, were identified alongside seven known compounds. Most compounds evaluated had higher DPPH radical scavenging capabilities than the standard, trolox. Tamarixetin 3-O-(α-ʟ-rhamnopyranosyl)-(1→2)-β-ᴅ-galactopyranoside (11), a previously undescribed compound, was the most effective at suppressing TNF-α protein and m-RNA levels. Other flavonoid glycosides, quercetin 3-O-(α-ʟ-rhamnopyranosyl-(1→2)-β-ᴅ-xylopyranoside (4), isovitixin (5), and quercetin-3-O-[α-ʟ-rhamnopyranosyl-(1→2)]-[α-ʟ-rhamnopyranosyl-(1→6)]-β-ᴅ-galactopyranoside (9), also significantly lowered TNF-α production.

Characterisation of copal resin and amber by negative-ion electrospray ionisation Fourier transform ion cyclotron resonance mass spectrometry.

Copal resin and amber from Columbia were analysed by negative-ion electrospray ionisation (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), with particular focus on polar compounds with relatively high molecular weights. A total of 4038 and 2755 compounds were identified between m/z 150 and 1,000 in the spectra of the copal resin and amber DCM extracts, respectively. The CHO classes were the most abundant species in the detected polar compounds. The petrochemical process of converting copal resin to amber is accompanied by evaporation and dispersion of volatile molecules and polymerisation of relatively smaller molecules. Thus, the most abundant compounds in copal resin comprised more than one C5 basic unit compared to amber, and the relative abundances of compounds with a high number of carbon and oxygen atoms in amber were higher than those in copal resin. There were strong positive correlations between the double-bond equivalence (DBEav ) values and the number of oxygen atoms in both samples. The slopes and y-intercepts of the linear relationship indicated that the C5 pentadienoic acid is the basic structure of heteroatom compound molecules in copal resin and amber. FT-ICR MS analysis focuses on the characterisation of heteroatom compounds with relatively high molecular weight and is helpful to provide supplementary information on the origin and evolution of complex organic mixtures such as copal resin and amber at the molecular level in a fast and convenient way.

Research Advances in Oil Tanning Technology

The conventional process of chamois leather manufacturing for industrial applications utilizes fish oil which contains substantial amounts of pentadienoic fatty acid. The applications of chamois leathers include cleaning polished surfaces, manufacture of gloves and orthopedic uses. However, due to fish oil’s strong odor and high cost, considerable efforts have been made to counter these challenges. Esterification of fish oil has been used as a strategy to address the problem of odor and water absorption but this cannot solve the issue of cost. Oils from plant sources such as linseed, rubber, jatropha, castor and sunflower have been investigated as potential tanning substitutes for fish oil. Linseed has been found to produce chamois leather with mild odor and water absorption characteristics close to those of fish oil compared to other oils obtained from plant sources. Oil from goat fleshing has also been investigated in chamois leather production and has been found to produce chamois leather whose odor compares with that of linseed oil tanned leather. If these tanning oil alternatives are combined with other research advances in chamois leather production such as glutaraldehyde pre-tanning and oxidation using hydrogen peroxide or through ozonation, then the issue of cost, odor and long oxidation period can be resolved.

A Short, Efficient, and Stereoselective Synthesis of Piperine and its Analogues

A quantitative synthesis of piperine from commercially available starting material is presented. The synthesis relies on a stereoselective nucleophilic attack of an in situ generated cuprate onto a cyclobutene lactone. The so-formed aryl-substituted cyclobutene spontaneously undergoes a conrotatory 4π-electrocyclic ring opening to form the 4-aryl pentadienoic acid as a single diastereoisomer. The high-yielding synthesis can be easily modulated on the aryl and on the amide moiety for the synthesis of a wide range of piperine analogues.

Synthesis, optical, electrochemical and photovoltaic properties of donor modified organic dyes for dye-sensitized solar cell (DSSC) applications

The metal-free organic sensitizers 2-cyano 5-(4-dimethylaminophenyl) pentadienoic acid (PR-1) and 2-cyano 5-(4-diphenylaminophenyl) pentadienoic acid (PR-2) have been synthesized by condensation of aldehydes with methyl 2-cyanoacetate. These two dyes have different donor groups and similar (phenyl) π-bridge and (cyanoacetic acid) acceptor group. PR-2 exhibits a broader absorption than the PR-1 due to the intramolecular charge transfer between the donor diphenylamine and the acceptor cyanoacetic acid. With addition of diphenylamine in the PR-2 dye, redshift absorption and suppression of the series resistance were observed. Cyclic voltammetric analysis of the dyes was analyzed through three electrode system at the scan rate of 100 mV s−1. The photovoltaic performance of the synthesized dyes was analyzed and compared with commercially available N719 dye. The overall power conversion efficiency of the PR-1 is 1.32%. The photovoltaic parameters are Voc − 0.67 V, Jsc − 4.54 mA cm−2 and FF − 0.56, respectively. The overall power conversion efficiency of the PR-2 is 2.01%. The photovoltaic parameters are Voc − 0.66 V, Jsc − 5.28 mA cm−2 and FF − 0.57, respectively.

A detailed experimental and theoretical investigation of the role of cyano groups in the π-bridged acceptor of sensitizers for use in dye-sensitized solar cells (DSCs).

Three donor-π conjugated unit-acceptor (D-π-A) type zinc porphyrin sensitizers LX1, LX2 and LX3 bearing meso acrylic acid, α-cyanoacrylic acid, and α-cyanopentadienoic acid, respectively, as the π-bridged acceptors were designed and synthesized for use in dye-sensitized solar cells (DSCs). The interesting role of the cyano group attached to the α position of the acrylic and pentadienoic acid acceptor was investigated. It was shown that even though the introduction of the cyano group and the elongation of the π-bridge can both increase the light-harvesting as indicated by the UV-vis absorption spectra, the relevant cell performance dropped significantly. The photo to power conversion efficiencies (PCEs) of the devices increase in the order of LX1 > LX2 > LX3, with the highest PCE of 6.04% achieved for the LX1-based cell, which bears acrylic acid as the π-bridged acceptor. To further explore the effect of -CN and -CH[double bond, length as m-dash]CH- on the interaction between the absorbed dye and TiO2 substrates, their density of states (DOS) and partial density of states (PDOS), as well as electronic properties were investigated in detail using theoretical calculations. The results suggest that introducing the -CN group into the acceptor and extending the conjugation of the π-bridge have decreased the LUMO levels of the dyes, leading to weak interfacial coupling, low electron injection driving force, low Jsc, and thus poor cell performance.

The Cyclization of 2-Chloro Nicotinic Acid

Studied the craft of synthesize 2-ChloroNicotinicacid, which was 3-Dimethylamino -acrolein and Eethylcyanoacetate as raw materials, synthesized 2,4-pentadienoicacid-2-cyano-5- dimethylaminoethylester, then used HCl gas to cyclize it, the product Ethyl 2-chloronicotinate was hydrolyzed to get 2-chloronicotinicacid. The effects of solvent and catalyst were discussed. The results showed that 2,4- pentadienoi cacid – 2-cyano-5-(dimethylamino) ethyl ester can be dissolved in dimethylethane at low temperature, so that it avoided the own polymerization when cyclization synthesis Ethyl 2-chloronicotinate. The yield was 91.84%. The craft was simple and had less steps and higher yield; there is the potential for industrialization

The solvent-induced collapse of a redox-active conducting polymer and the consequence on its DNA-sensing ability

The synthesis of a novel terthiophene monomer functionalized with pentadienoic acid, 5-(2′:2″, 5″:2″′-terthiophene)-3″-yl)] (2E, 4E)penta-2,4-dienoic acid (TPDA), and its electropolymerization into a conducting polymer is described. The polymer electrochemical stability in aqueous solution was examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). CV revealed PTPDA film displayed good redox activity in an organic solvent (CH2Cl2) and poor electrochemical activity in aqueous PBS buffer. Both techniques revealed that the microstructure of the outer part of PTPDA film collapsed in aqueous solution. The instability is problematic for conducting polymers designed as DNA sensors and affects their DNA-sensing ability. A hybridization response occurred when the PTPDA film was doped with a large hydrophobic dopant but did not occur when the film was doped with a smaller hydrophilic dopant. By attention to both the nature of the polymer and to the choice of dopant anion, the effects on the DNA sensor performance of solvent-induced microstructure collapse in aqueous solution can be mitigated.

The role of Pentadienoic growth regulator acid by number of growth regulators in the initiation, growth and differentiation of Nigella sativa Callus

The effect of Pentadienoic acid (PDA) as a synthetic growth regulator, on the induction, growth and differentiation of callus from stem segments of seedlings of black seed Nigella sativa L. was carried out. PDA was used at the concentrations 10"4, 10 and 10"8 molar alone, or with the optimal concentration of Benzyl Adenine (BA) which is 10"3 molar,and that for Dichlorophenoxyacetic acid (2,4-D) 1 0 molar. The results showed that the addition of PDA alone to the nutritional medium disencourage the induction of callus , However when PDA was added along with the optimal concentrations of the standard growth regulators, the best growth of callus obtained on the medium supplied wHh(10" ) molar of each of 2,4-D and PDA.Thu; fresh weight of callus reached (25.6) gm at 100 days age .it was found also that the addition of BA with PDA encourages growth of shoots since the first stage of the growth, with the stimulation of the callus growth also ,but the presence of 2,4-D with PDA does not encourage any differentiation except the induction and growth of the callus.

Correlation of substituent effects on carbon-13 NMR chemical shifts of side-chain carbons in 5-aryl-2£,4£-pentadienoic acid derivatives by Taft DSP equation

Correlation of substituent effects on carbon-13 NMR chemical shifts of side-chain carbons in 5-aryl-2£,4£-pentadienoic acid derivatives by Taft DSP equation

Rakicidin C, A New Cyclic Depsipeptide fromStreptomycessp.

Chemical screening of extracts of Actinomycetes strains has led to the detection, isolation, and structure elucidation of the new cyclic depsipeptide rakicidin C (1). The secondary metabolite from Streptomyces sp. (strain GT 61042) is built-up from glutamine, N-methyl glycine, 4-amino-(2E,4)-pentadienoic acid, and 3-hydroxy-2,4,6,8-tetramethylnonanoic acid.

Synthesis of labelled 1-azafagomine

(3,4-trans-4,5-trans)-4,5-Dihydroxy-3-(hydroxymethyl)hexahydro-(3-13C)pyridazine (azafagomine, 1a) was synthesised in 7 steps starting from (2-13C) malonic acid 5a through conversion to pentadienoic acid and Diels–Alder reaction with 4-phenyl-1,2,4-triazole-3,5-dione, reduction, epoxidation, epoxide hydrolysis and deprotection.

Straightforward Synthesis of Pyrrolidine Glycosidase Inhibitors via Asymmetric Hetero-Diels-Alder Reaction

Base-catalysed rearrangement of the oxazine-carboxylate 8, obtained from pentadienoic acid 4 by asymmetric hetero-Diels-Alder reaction followed by simple chemical transformations, led to the protected trihydroxy-proline 9. Using various reduction conditions, the potent glycosidase inhibitors 1,4-dideoxy-1,4-imino-D-lyxitol D-1 and 1,4-dideoxy-1,4-imino-L-ribitol L-2 were obtained.

Arohynapenes A and B, new anticoccidial agents produced by Penicillium sp. Taxonomy, fermentation, and structure elucidation.

Penicillium sp. FO-2295, a water isolate, was found to produce a series of new anticoccidial compounds. Two active compounds, designated arohynapenes A and B, were isolated from the fermentation broth of the producing strain by solvent extration and preparative HPLC. Arohynapene A was deduced to be (2E,4E)-5-(5-hydroxy-2,6,8-trimethyl-5,6,7,8-tetrahydronaphtale ne)-2,4- pentadienoic acid, and arohynapene B was (2E,4E)-5-(2-hydroxymethyl-6,8-dimethyl-5,6,7,8-tetrahydronapht alene)-2,4- pentadienoic acid. Arohynapenes inhibited the growth of Eimeria tenella in an in vitro assay using BHK-21 cells as a host. No schizont in the cells was observed at concentrations ranging above 35.0 microM and 7.0 microM for arohynapenes A and B, respectively.

Synthesis of conjugated polyene carbonyl derivatives of nitroxyl spin-labels and determination of their molecular structure and conformation by electron nuclear double resonance

Formic, propenoic, and pentadienoic acid derivatives of the nitroxyl spin-label 2,2,5,5-tetramethyl-1-oxypyrroline and their corresponding ethyl ester and aldehyde analogues have been synthesized and characterized by chemical methods. Because the π-bonding orbitals of the olefinic side chains are conjugated to the vinyl group of the oxypyrrolinyl ring, these spin-labeled derivatives are excellent spectrophotometic probes, exhibiting high molecular absorption extinction in the near ultraviolet. The molecular structures and conformations of these spin-labeled derivatives have been determined by electron nuclear double resonance (ENDOR) spectroscopy and molecular modeling. Conformational analysis based on torsion angle search calculations, constrained by ENDOR-determined electron-proton separations, showed that the polyene chain has an all planar, trans conformation. In the aldehydes the conformation of the C=O group with respect to the alkene chain is found to be s-trans, while in the acids and esters the -OH and -OC 2 H 5 groups were found to be s-trans, placing the C=O group in an s-cis conformation. The different conformations of the carbonyl group in these compounds are explained on the basis of resonance energy and dipolar interactions of the polyene side chain and the carbonyl or carboxyl group

Unsaturated acid derivatives in diels-alder cycloadditions: effect of the extended or cross conjugation.

Behaviour of pentadienoic acid derivatives in Diels-Alder cycloadditions has been examined in the light of experimental results and theoretical calculations. The effect of cross conjugation to an electron-releasing group has also been investigated for these systems and for simple acrylic acid derivatives.

Five doubly unsaturated metabolites of valproic acid in urine and plasma of patients on valproic acid therapy.

The urine and plasma of epileptic patients receiving therapeutic doses of valproic acid (2-propyl- pentanoic acid) was found to contain five doubly unsaturated metabolites of valproic acid, which were identified as their trimethylsilyl derivatives by GC/MS. A series of reference substances was synthesized but only two of them were identical with native metabolites: 2(2-propenyl)-4-pentenoic acid (= 4.4'-diene) and E-2-propyl-2.4- pentadienoic acid (E-2.4-diene). The mass-spectra of the five native metabolites are given. Preliminary quantitative data obtained from four groups of patients indicate increased formation of doubly unsaturated metabolites when valproic acid-induced side-effects are present, and in cases of fatal hepatic failure. The 4.4'-diene has hitherto been found only in fatal cases with hepatic injury. Quantitative data are presented as % of the sum of valproic acid plus all its detected metabolites.

Palladium-catalyzed syntheses of conjugated polyenes

Abstract

Studies on the total synthesis of rifamycin. A method for the stereospecific synthesis of the carbonyl-conjugated 1,3-diene unit [C(15) to C(20)

A new sterespecific process has been devised for the conversion of an aldehyde to a 5-substituted-2-methyl-2 Z , 4 E -pentadienoic acid. This methodology is relevant to the construction of the ansa bridge of the rifamycins.

A novel abscisic acid metabolite from seeds of Robinia pseudacacia

Abstract Abscisic acid and its novel metabolise, which was a conjugated form of hydroxyabscisic acid (Metabolite C), were isolated from seeds of Robinia pseudacacia L. The structure of the conjugate was shown to be (+)-3-methyl-5 - [1( S ),6( R ) - 2,6 - dimethyl - 1 - hydroxy - 6 - (3 - hydroxy - 3 - methyl - 4 - carboxybutanoyloxymethyl) - 4 - oxo-cyclohex-2-enyl]-2- Z -4- E -pentadienoic acid and tentatively named β-hydroxy-β-methylglutarylhydroxyabscisic acid.