2,268 research outputs found

    Phenolic compounds in wine: primary substrates for oxidation

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    Compounds identified on hexane and dichloromethane extracts of Salicornia ramosissima

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    3rd Portuguese Meeting on Medicinal Chemistry and 1st Portuguese-Spanish-Brazilian Meeting on Medicinal Chemistry, Aveiro, 28-30 Novembro 2012.Salicornia ramosissima J. Woods (common purple glasswort) is an annual halophyte, widely distributed in the salt marsh of Ria de Aveiro (Portugal), that belongs to the Salicornia L. genus (Chenopodiaceae).[4] Although phytochemical studies genus on this genus report the presence of compounds which are well-recognized for their biological activities, such as flavonoids, chromones and alkaloids,[3] too little is known about secondary metabolites on purple glasswort. In our previous work we were able to isolate and identify ethyl o-hydroxycinnamate, (E)-fatty alcohol ferulic acid and scopoletin from the dichloromethane extract of S. ramosissima aerial parts. The structure and spectroscopic characterization of some secondary metabolites isolated from dichloromethane crude extract also will be presented and discussed.Thanks are due to the University of Aveiro, Fundação para a Ciência e a Tecnologia (FCT) and FEDER for funding the Organic Chemistry Research Unit (project PEst-C/QUI/UI0062/2011) and Portuguese National NMR Network (RNRMN)

    Some aromatic compounds from dichloromethane extract of Salicornia ramosissima.

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    6th Spanish-Portuguese-Japanese Organic Chemistry Symposium, Lisboa, de 18 a 20 de Julho de 2012 (Poster Communication).Salicornia ramosissima J. Woods, is an annual halophyte, confined to saline habitats, widely distributed in the salt marsh of Ria de Aveiro (Portugal) and also present in many salt marshes of the Iberian Peninsula. Our interest in the phytochemical study of this specie, which belongs to the genus Salicornia and family Chenopodiaceae, is based on previous knowledge that plants of this genus presented compounds such as flavonoids, chromones and alkaloids which are well-recognized for their biological activities. Salicornia ramosissima was subject to some studies of growth conditions and salinity, but its phytochemical composition remains unknown. The analysis of the dichloromethane extract from S. ramosissima aerial parts allowed the isolation of some aromatic compounds, from which we present here their unequivocal structure elucidation.Thanks are due to the University of Aveiro, Fundação para a Ciência e a Tecnologia (FCT) and FEDER for funding the Organic Chemistry Research Unit (project PEst-C/QUI/UI0062/2011) and Portuguese National NMR Network (RNRMN). The authors also wish to acknowledge generous contribution of José M G Pereira for the original photographs of Salicornia in Aveiro region

    Pyrazoles as potential modulators of inflammation through the inhibition of COX2 activity and human leukocytes' oxidative burst

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    The inflammatory process is a complex and tightly regulated cascade of events that involves the production of prostaglandins (PG) by the inducible isoform cyclooxygenase 2 (COX-2) and the production of reactive pro-oxidant species. When the production of these mediators becomes excessive, it can lead to chronic inflammation and associated diseases such as diabetes, rheumatoid arthritis, and cancer. Unfortunately, many existing anti-inflammatory agents are associated with unwanted side effects. Therefore, there is a critical need to discover new and effective compounds that can modulate the inflammatory cascade. In this study, an extensive panel of structurally related pyrazoles holding diverse structures and substitutions were tested in vitro against human COX-2, and ex vivo in human whole blood, through the measurement of prostaglandin E2 (PGE2) production. Their potential inhibitory effect against human leukocytes’ oxidative burst was also studied. The results showed that some of the tested compounds had a significant inhibitory effect on COX2 activity, and pyrazoles 4 and 11 (Figure 1) excelled as the most potent inhibitors, with IC50 < 25 µM. Nonetheless, among the tested compounds only 1 was able to inhibit both the COX-2 activity and the PGE2 production. The tested pyrazoles, namely pyrazole 4, also demonstrated a potential inhibitory effect (IC50 < 5 µM) against human leukocytes’ oxidative burst. These results represent a significant contribution for the design and development of new anti-inflammatory molecules.info:eu-repo/semantics/publishedVersio

    Stability and decolourization ability of trametes villosa laccase in liquid ultrasonic fields

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    We report in this study that the sonication of laccase from Trametes villosa and bovine serum albumin promotes the formation of protein aggregates with high molecular weight. The formation of aggregates leads to the deactivation of the enzyme, fact that was confirmed by the analysis of the enzyme stability (half-life time) upon ultrasound treatment. This inactivation was mainly caused by the radicals formed by the cavitation phenomenon. It was verified that the addition of polyvinyl alcohol to laccase had a protecting effect against enzyme inactivation. The performance of laccase in the decolourization of indigo carmine was studied. It was observed that the best results were attained when the dye solution was treated with ultrasound and enzyme stabilized with polyvinyl alcohol, where more than 65% of decolourization was achieved. This value is remarkably higher than that attained for the enzyme alone, which was only able to decolourize 20% of the dye solution within 1 h of treatment. These results have important implications for the exploitation of sonication in textile industry, where the pollution caused by the release of dyes into effluents is one of the major concerns.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/8651/2002União Europeia - Projecto ULTRATEC (NMP2- CT-2003-505892)

    Immobilization of proteases with a water soluble–insoluble reversible polymer for treatment of wool

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    A commercial protease, Esperase, was covalently linked to Eudragit S-100, a reversible soluble–insoluble polymer by carbodiimide coupling. When compared to the native enzyme, the immobilized form presented a lower specific activity towards high molecular weight substrates but a higher thermal stability at all temperatures tested. The optimum pH of the immobilized protease was shifted towards the alkaline side by about one pH unit while there was no change in optimum temperature between the free and immobilized protease. The immobilized protease exhibited a good storage stability and re-usability. Enzymatic treatment of wool using proteases has been investigated for wool shrink-resist finishing. It was found that using the immobilized protease in the enzymatic treatment of wool there was a reduction of weight and fibre tensile strength loss because the proteolytic attack is only limited to the cuticle surfaces of wool fibres. This novel approach is a promising alternative for wool shrink-resist finishing to replace the conventional chlorine treatments. This environmentally friendly bioprocess needs to be further characterized to a complete understanding and optimization

    An overview of Salicornia genus : the phytochemical and pharmacological profile

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    Copyright © 2014 Daya Publishing House.Salicornia L. (Chenopodiaceae) is a genus of annual, apparently leafless halophytic herb that have articulated and succulent stems. The Salicornia species comprise the most salttolerant land plant and frequently occur in saline areas. The use of glasswort as food is referred by the forensic palynology as a reality at least from 550 years ago. Nowadays it is much appreciated as a gourmet product in Europe but particularly in Asian countries, where is used in fresh salads and pickles. Some of the Salicornia species display applications on folk medicine (for treatment of bronchitis, hepatitis and diarrhea) and showed important biological properties such as antioxidant, anti-inflammatory, hypoglycemic and cytotoxic activities. The phythochemical studies on this genus reported the presence of fatty acids, sterols, saponins, chlorogenic acid derivatives, alkaloids, flavonoids and other kind of phenolic compounds.The purpose of this review is to highlight the advances in Salicornia genus knowledge by presenting its biological and medicinal applications, phytochemical studies and the relationship between the isolated compounds with the described biological and/or medicinal properties.Thanks are due to the Universities of Aveiro and Azores and also to Fundação para a Ciência e a Tecnologia (FCT) and FEDER for funding the Organic Chemistry Research Unit (project PEst-C/QUI/UI0062/2011). The authors also wish to acknowledge generous contribution of José M G Pereira for the original photographs of Salicornia in Aveiro region (Ecomuseu da Troncalhada, 40° 38' 32.32" N, 8° 39' 47.52" W)

    Chemical Modifications on Proteins Using Glutaraldehyde

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    In this work the effect of crosslinking the enzyme esperase (E.C. 3.4.21.62) and the proteins bovine serum albumin and casein with the bifunctional compound glutaraldehyde on molecular mass increase was studied. Two common techniques for measuring molecular mass of proteins were used: SEC and SDS-PAGE. These techniques revealed that the proteins bovine albumin and casein, when subjected to chemical crosslinking with glutaraldehyde, volume fraction 0.25 %, increased their molecular mass by 20- and 40-fold, respectively. It was also observed that Mr increased proportionally to the increase of glutaraldehyde concentration in the solution, and that the addition of glutaraldehyde should be done slowly, in small amounts, in order to attain bigger protein aggregates. When the proteolytic enzyme esperase was subjected to glutaraldehyde, no increase in its Mr was achieved. Several assumptions can be made to explain these results, the most reasonable being the low amount of free lysine groups available for crosslinking. This study confirms that glutaraldehyde is not an adequate crosslinker for esperase

    Structural characterization of lignin from Grape Stalks (Vitis vinifera L.)

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    The chemical structure of lignin from grape stalks, an abundant waste of winemaking, has been studied. The dioxane lignin was isolated from extractive- and protein-free grape stalks (Vitis vinifera L.) by modified acidolytic procedure and submitted to a structural analysis by wet chemistry (nitrobenzene and permanganate oxidation (PO)) and spectroscopic techniques. The results obtained suggest that grape stalk lignin is an HGS type with molar proportions of p-hydroxyphenyl (H), guaiacyl (G) and syringyl (S) units of 3:71:26. Structural analysis by 1H and 13C NMR spectroscopy and PO indicates the predominance of β-O-4′ structures (39% mol) in grape stalk lignin together with moderate amounts of β-5′, β-β, β-1′, 5-5′, and 4-O-5′ structures. NMR studies also revealed that grape lignin should be structurally associated with tannins. The condensation degree of grape stalks lignin is higher than that of conventional wood lignins and lignins from other agricultural residues.N/
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