Mechanical and Thermal Properties of Thermoplastic Random Copolyesters Made from Lipid- Derived Medium and Long Chain Poly (x-hydroxyfatty acid) s

The physical properties of novel thermoplastic random copolyesters [-(CH2)(n)-COO-/-(CH2)(n)-COO-](x) made of long (n=12) and medium (n=8) chain length -hydroxyfatty esters [HO-(CH2)(n)-COOCH3] derived from bio-based vegetable oil feedstock are described. Poly(-hydroxy tridecanoate/-hydroxy nonanoate) P(-Me13-/-Me9-) random copolyesters (M-n=11,000-18,500 g/mol) with varying molar ratios were examined by TGA, DSC, DMA and tensile analysis, and WAXD. For the whole range of P(-Me13-/-Me9-) compositions, the WAXD data indicated an orthorhombic polyethylene-like crystal packing. Their melting characteristics, determined by DSC, varied with composition suggesting an isomorphic cocrystallization behavior. TGA of the P(-Me13-/-Me9-)s indicated improved thermal stability determined by their molar compositions. The glass transition temperature, investigated by DMA, was also found to vary with composition. The crystallinities of P(-Me13-/-Me9-)s however, were unaffected by the composition. The stiffness (Young's modulus) of these materials was found to be related to their degrees of crystallinity. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40492.

Thermoplastic polyesters and Co-polyesters derived from vegetable oil: synthesis and optimization of melt polycondensation for medium and long chain poly(omega-hydroxyfatty acid)s and their ester derivatives

The synthesis of a series of omega-hydroxyfatty acid (omega-OHFA) monomers and their methyl ester derivatives (Me-omega-OHFA) from mono-unsaturated fatty acids and alcohols via ozonolysis-reduction/crossmetathesis reactions is described. Melt polycondensation of the monomers yielded thermoplastic poly(omega-hydroxyfatty acid)s [-(CH2)(n)-COO-](x) with medium (n = 8 and 12) and long (n = 17) repeating monomer units. The omega-OHFAs and Me-omega-OHFAs were all obtained in good yield (>= 80%) and purity (>= 97%) as established by H-1 NMR, Fourier Transform infra-red spectroscopy (FT-IR), mass spectroscopy (ESI-MS) and high performance liquid chromatography (HPLC) analyses. The average molecular size (M-n) and distribution (PDI) of the poly(omega-hydroxyfatty acid)s (P(omega-OHFA)s) and poly(omega-hydroxyfatty ester) s (P(Me-omega-OHFA) s) as determined by GPC varied with organo-metallic Ti(IV) isopropoxide [Ti(OiPr)(4)] polycondensation catalyst amount, reaction time and temperature. An optimization of the polymerization process provided P(omega-OHFA) s and P(Me-omega-OHFA) s with M-n and PDI values desirable for high end applications. Co-polymerization of the long chain (n = 12) and medium chain (n = 8) Me-omega-OHFAs by melt polycondensation yielded poly(omega-hydroxy tridecanoate/omega-hydroxy nonanoate) random co-polyesters (M-n = 11000- 18500 g mol(-1)) with varying molar compositions.

Development and characterization of biocompatible isotropic and anisotropic oil-in-water colloidal dispersions as a new delivery system for methyl dihydrojasmonate antitumor drug

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Novel bioassay for the discovery of inhibitors of the 2-C-Methyl-D-erythritol 4-Phosphate (MEP) and terpenoid pathways leading to carotenoid biosynthesis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Improvement of Pro-Oxidant Capacity of Protocatechuic Acid by Esterification

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Lisianthus vase life after 1-methylcyclopropene and salicylic acid postharvest treatment

This study evaluated the effects of application of 0.5 µl L-1 1-methyl-cyclopropene (1-MCP), 1000 mg L-1 salicylic acid (SA) and the interaction between the two products at room temperature and pre-exposure at 9±2°C for 24 h in maintaining postharvest quality of lisianthus flowers. After applying the treatment, the flowers were kept in jars with water, stored at 24±2°C. The SA treatments proved ineffective, presenting symptoms of phytotoxicity, with high rate of bent neck and yellowing of petals, both at room temperature and in cold storage, and propitiate the emergence of pathogens. The association between 1-MCP in pre-exposure to 9±2°C for 24 h increased the durability of the stems in six days compared to the control treatment, with less symptoms of bent neck and swelling of stems.

First report on the kinetics of the uncatalyzed esterification of cellulose under homogeneous reaction conditions: a rationale for the effect of carboxylic acid anhydride chain-length on the degree of biopolymer substitution

The kinetics of the homogeneous acylation of microcrystalline cellulose, MCC, with carboxylic acid anhydrides with different acyl chain-length (Nc; ethanoic to hexanoic) in LiCl/N,N-dimethylacetamide have been studied by conductivity measurements from 65 to 85 A degrees C. We have employed cyclohexylmethanol, CHM, and trans-1,2-cyclohexanediol, CHD, as model compounds for the hydroxyl groups of the anhydroglucose unit of cellulose. The ratios of rate constants of acylation of primary (CHM; Prim-OH) and secondary (CHD; Sec-OH) groups have been employed, after correction, in order to split the overall rate constants of the reaction of MCC into contributions from the discrete OH groups. For the model compounds, we have found that k((Prim-OH))/k((Sec-OH)) > 1, akin to reactions of cellulose under heterogeneous conditions; this ratio increases as a function of increasing Nc. The overall, and partial rate constants of the acylation of MCC decrease from ethanoic- to butanoic-anhydride and then increase for pentanoic- and hexanoic anhydride, due to subtle changes in- and compensations of the enthalpy and entropy of activation.

The Effects of Palmitic Acid on Nitric Oxide Production by Rat Skeletal Muscle: Mechanism via Superoxide and iNOS Activation

Background: Increased plasma concentrations of free fatty acids (FFA) can lead to insulin resistance in skeletal muscle, impaired effects on mitochondrial function, including uncoupling of oxidative phosphorylation and decrease of endogenous antioxidant defenses. Nitric oxide (NO) is a highly diffusible gas that presents a half-life of 5-10 seconds and is involved in several physiological and pathological conditions. The effects of palmitic acid on nitric oxide (NO) production by rat skeletal muscle cells and the possible mechanism involved were investigated. Methods: Primary cultured rat skeletal muscle cells were treated with palmitic acid and NO production was assessed by nitrite measurement (Griess method) and 4,5-diaminofluorescein diacetate (DAF-2-DA) assay. Nuclear factor-kappa B (NF-kappa B) activation was evaluated by electrophoretic mobility shift assay and iNOS protein content by western blotting. Results: Palmitic acid treatment increased nitric oxide production. This effect was abolished by treatment with NOS inhibitors, L-nitro-arginine (LNA) and L-nitro-arginine methyl esther (L-NAME). NF-kappa B activation and iNOS content were increased due to palmitic acid treatment. The participation of superoxide on nitric oxide production was investigated by incubating the cells with DAF-2-DA in the presence or absence of palmitic acid, a superoxide generator system (X-XO), a mixture of NOS inhibitors and SOD-PEG (superoxide dismutase linked to polyethylene glycol). Palmitic acid and X-XO system increased NO production and this effect was abolished when cells were treated with NOS inhibitors and also with SOD-PEG. Conclusions: In summary, palmitic acid stimulates NO production in cultured skeletal muscle cells through production of superoxide, nuclear factor-kappa B activation and increase of iNOS protein content. Copyright (C) 2012 S. Karger AG, Basel

Further monoterpene chromane esters from Peperomia obtusifolia: VCD determination of the absolute configuration of a new diastereomeric mixture

A reinvestigation of the monoterpene chromane ester enriched fraction from Peperomia obtusifolia using chiral chromatography led to the identification of a minor peak, which was elucidated by NMR and HRMS as fenchyl-3,4-dihydro-5-hydroxy-2,7-dimethyl-8-(3 ''-methyl-2 ''-butenyl)-2-(4'-methyl-1',3'-pentadienyl)-2H-1-benzopyran-6-carboxylate, the same structure assigned to two other fenchyl esters described previously, pointing out a stereoisomeric relationship among them. Further NMR analysis revealed that it was actually a mixture of two compounds, whose absolute configurations were determined by VCD measurements. Although, almost no vibrational transitions could be assigned to the chiral chromane, the experimental VCD spectrum was largely opposite to that obtained for the average experimental VCD [(2S,1'''R,2'''R,4'''S + 2R,1'''R,2'''R,4'''S)/2] for fenchol derivatives. These results allowed us to assign the putative compounds as a racemic mixture of the chiral chromane esterified with the monoterpene (1S,2S,4R)fenchol, which had not been identified in our early work. (C) 2012 Elsevier Ltd. All rights reserved.

Practical synthesis of a functionalized 1-oxo-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid

The synthesis of a functionalized 1-oxo-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid has been performed in 10 steps from the readily available dimedone. Only three purifications by flash chromatography are required through the whole sequence. The key step is the reaction between a dimedone derivative and a chlorotetrolic ester, that gives a tetrasubstituted benzene ring (through a Diels-Alder/retro- Diels-Alder process) bearing the substituents in the suitable positions for further functionalization. (C) 2012 Elsevier Ltd. All rights reserved.

Oxidation of lysergic acid diethylamide (LSD) by peroxidases: a new metabolic pathway

Lysergic acid diethylamide (LSD) is a potent hallucinogen that is primarily metabolized to 2-oxo-3-hydroxy-LSD (O-H-LSD) and N-desmethyl-LSD (nor-LSD) by cytochrome P450 complex liver enzymes. Due to its extensive metabolism, there still is an interest in the identification of new metabolites and new routes of its metabolism in humans. In the present study, we investigated whether LSD could be a substrate for horseradish peroxidase or myeloperoxidase (MPO). Using liquid chromatography coupled to UV detection and electrospray ionization mass spectrometry (LC-UV-ESI-MS), we found that both peroxidases were capable of metabolizing LSD to the same compounds that have been observed in vivo (i.e., O-H-LSD and nor-LSD). In addition, we found another major metabolite, N,N-diethyl-7-formamido-4-methyl-6-oxo-2,3,4,4a,5,6-hexahydrobenzo[f]quinoline-2-carboxamide (FOMBK), which is an opened indolic ring compound. Hydrolysis of FOMBK led to the deformylated compound 7-amino-N,N-diethyl-4-methyl-6-oxo-2,3,4,4a,5,6-hexahydrobenzo[f]quinoline-2-carboxamide. The reactions of LSD with the peroxidases were chemiluminescent and sensitive to inhibition by reactive oxygen scavengers, which indicated that the classic peroxidase cycle is involved in this new alternative metabolic pathway. Considering that MPO is abundant in immune cells and also present in the central nervous system, the degradation pathway described in this study suggests a possible route of LSD metabolism that may occur concurrently with the in vivo reaction catalyzed by the cytochrome P450 system.

Production of methyl and ethyl biodiesel fuel from pequi oil (Caryocar brasiliensis Camb.)

We studied the physical and chemical characteristics of methyl and ethyl esters (biodiesel) produced by transesterification of pequi oil (Caryocar brasiliensis Camb.) in the presence of potassium hydroxide. The oil extracted from pequi seed comprises 60% of the fruit content. Such characteristics as density, acidity, viscosity, and carbon residue of the biodiesel meet ANP (Brazilian National Petroleum Agency) standards. Our tests demonstrated the feasibility of utilizing pequi oil for biodiesel production.

Stereoselective synthesis of novel diels-alder adducts of p-substituted Methyl Thiocinnamates and Cyclopentadiene

This article describes the Diels-Alder reaction between methyl thiocinnamates, substituted at the para position by electron-donating and electron-withdrawing groups, with cyclopentadiene in the presence of catechol boron bromide (CBB) as a Lewis acid catalyst. The adduct configuration was confirmed by H-1 NMR coupling constants and single-crystal x-ray diffraction. Total endo stereoselectivity was observed in all reactions and was attributed to the effective secondary interaction between the boron atom and the incipient double bond in the norbonene resulting from the planar geometry of the catalyst. C-13 NMR chemical shifts of the coordinated dienophile carbonyl carbons with CBB compared to those of the non coordinated thiocinammates suggest a strong complexation with the catalyst.

Baccharin Prevents Genotoxic Effects Induced by Methyl Methanesulfonate and Hydrogen Peroxide in V79 Cells

Baccharin is one of the major chemical compounds isolated from the aerial parts of Baccharis dracunculifolia DC (Asteraceae), a native plant of South America and the most important botanical source of the Brazilian green propolis that has been used in alternative medicine to treat inflammation, liver disorders, and stomach ulcers. The present study was carried out in V79 cells to determine the possible genotoxic and antigenotoxic activities of baccharin utilizing comet and micronucleus assays, where 2 known mutagenic agents with different mechanisms of DNA damage were used as positive controls. The V79 cells were treated with concentrations of baccharin (0.25, 0.5, 1.0, and 2.0 mu g/mL) and for to investigate the antigenotoxicity these concentrations were associated with methyl methanesulfonate (MMS; 200 mu M-comet assay and 400 mu M-micronucleus assay) or hydrogen peroxide (H2O2; 50 mu M-comet assay and 100 mu M-micronucleus assay). Statistically significant differences in the rate of DNA damage were observed in cultures treated with the highest concentration of baccharin when compared to the control group, but this difference was not found in the micronucleus assay. The results also showed that the frequencies of DNA damage and micronuclei induced by MMS and H2O2 were significantly reduced after treatment with baccharin. The baccharin showed a chemoprevention effect and can be the chemical compound responsible for the antigenotoxicity also demonstrated by the B. dracunculifolia. The antioxidant potential of baccharin may be related to its chemoprevention activity induced against both genomic and chromosomal damages.

Selektive und duale COX-1-, COX-2-Inhibitoren aus der Reihe der Methanone

Zusammenfassung: Prostaglandine (PG) sind wichtige biologische Entzündungsmediatoren, die aus der Arachidonsäure (AA) durch das Enzym Cyclooxygenase (COX) entstehen. Trotz einiger unerwünschter Wirkungen, sind Cyclooxygenase-Hemmer Mittel der Wahl zur Unterdrückung entzündlicher Prozesse. Von der Cyclooxygenase existieren zwei Isoenzyme: COX-1 und COX-2. Eine selektive Hemmung der COX-2 bzw. eine duale Hemmung der COX-1 und COX-2 wird als erfolgversprechendes Prinzip zur Behandlung von entzündlichen Erkrankungen diskutiert.Ziel der Arbeit war die Synthese und in vitro Testung sowie die Erstellung von Struktur-Wirkungs-Beziehungen selektiver bzw. dualer Hemmstoffe der COX-1/-2. Zusätzlich wurden die Substanzen auf inhibitorische Aktivität gegenüber der 5- und 12-Lipoxygenase untersucht.Ausgehend von der Struktur selektiver Hemmstoffe der COX-2 bzw. von dualen COX-1/ COX-2-Inhibitoren sowie von marktüblichen nichtsteroidalen Antirheumatika (NSAR), wurde das Diarylmethanon-Element als Basis gewählt. An diesem Strukturelement wurden Modifikationen vorgenommen, um selektive Hemmstoffe der COX-2 bzw. duale COX-1/ COX-2-Hemmstoffe zu erhalten.Die synthetisierten Verbindungen lassen sich in [4-(Methylsulfanyl)phenyl]- und [4-(Methylsulfonyl)phenyl](aryl)methanone, N-(Aroylphenyl)sulfonamide und -amide sowie (Hydroxyphenyl)(2-thienyl)methanone unterteilen.In der Reihe der [4-(Methylsulfanyl)phenyl](aryl)methanone sind potente Hemmstoffe sowohl der COX-1 als auch der COX-2 erhalten worden. Im Gegensatz dazu zeigen die [4-(Methylsulfonyl)phenyl](aryl)methanone gegenüber COX-1 und COX-2 keine inhibitorische Aktivität. Mit dem 2-Thienylderivat wurde ein potenter, dualer Hemmstoff beider Cyclooxygenase-Isoenzyme identifiziert, dessen Wirkstärke (bezüglich der COX-2) auf den Austausch von Phenyl gegen 2-Thienyl zurückzuführen ist.Die N-(Aroylphenyl)sulfonamide und -amide bilden die umfangreichste Gruppe bei den durchgeführten Untersuchungen, wobei besonders die regioisomeren N-(2-Aroylphenyl)sulfonamide und -amide eingehender studiert wurden. Auf der Basis der (2-Aroylphenyl)sulfonamide läßt sich für die Hemmung der COX-1 eine Struktur-Wirkungs-Beziehungen formulieren, die anhand Hilfe geeigneter Verbindungen überprüft wurde. Die Untersuchungen wurden zum Teil auch auf die 3- und 4-Regioisomeren ausgedehnt, wobei sich die erhaltenen Struktur-Wirkungs-Beziehungen bestätigten. Die Arylsulfonamide inhibieren bevorzugt die COX-1. Auch (4-Aroylphenyl)sulfonamide wurden auf mögliche inhibitorische Aktivität untersucht. Die Einbindung des Amidstickstoffs in ein Indolin- bzw. Tetrahydrochinolin-Ringsystem oder des Sulfonamids in ein 1,3-Propansultam führte in jedem Falle zu wenig aktiven Verbindungen gegenüber der COX-1. N-(2-Aroylphenyl)amide zeigten in Übereinstimmung mit der Hypothese an der COX-1 eine gute inhibitorische Aktivität.Aus der Reihe der (Hydroxyphenyl)(2-thienyl)methanone wurden die freien Alkohole, die Methylether und verschiedene Ester dargestellt und auf COX-1-Aktivität untersucht. Acetate, aber auch Phenole sind die potentesten Inhibitoren der COX-1. Als günstigte Positionen für die 2-Thienylcarbonyl-Einheit am Hydroxyphenylrest erweist sich die ortho- bzw. para-Position.