The wood and bark of four Acacia species growing in Portugal, namely, A. longifolia, A. dealbata,... more The wood and bark of four Acacia species growing in Portugal, namely, A. longifolia, A. dealbata, A. melanoxylon, and A. retinodes, were investigated for their sterol content. The lipids fractions of the different wood and bark samples were isolated, and the sterols were identified and quantified by GC-MS. Two delta7 sterols, specifically, spinasterol and dihydrospinasterol, were the main sterols found in considerable amounts, particularly in wood tissues (more than 0.5 g/kg of dry wood in the case of A. melanoxylon and A. retinodes). The corresponding unusual steryl glucosides were also identified in significant amounts in the wood and bark extracts.
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
The use of trichloroacetyl isocyanate (TAI) to mark both hydroxyl and carboxyl groups borne by th... more The use of trichloroacetyl isocyanate (TAI) to mark both hydroxyl and carboxyl groups borne by the hydrolysis or methanolysis of suberin fragments (a complex mixture of hydroxy fatty acids), allowed the quantitative assessment of the ratio between carboxyl and hydroxy groups, as well as the ratio between primary and secondary hydroxy groups, to be carried out reliably by 1H nuclear magnetic resonance (NMR) spectroscopy. All the samples thus analyzed displayed an excess of CO2H (or CO2CH3) functions with respect to the OH counterparts, albeit to a variable extent, depending on the procedure adopted to isolate the suberin fragments. The precise knowledge of the molar ratio of these two reactive moieties is fundamental for the correct utilization of suberin monomers in polymerization reactions leading to aliphatic polyesters.
The chemical composition of the epicuticular wax from the fruits of Eucalyptus globulus was studi... more The chemical composition of the epicuticular wax from the fruits of Eucalyptus globulus was studied by GC-MS before and after alkaline hydrolysis. The wax had two main components, ursolic acid and tritriacontan-16,18-dione, together with several other triterpenic acids. After alkaline hydrolysis, a large increase in the amounts of triterpenic acids and fatty acids (particularly in hexadecanoic acid) was observed, suggesting that these components were present predominantly in esterified forms in the fruit wax. Six compounds were isolated from the fruits by preparative chromatography, and were identified as 8-desmethyleucalyptin, sesamin, tritriacontan-16,18-dione, ursolic acid, 3beta-hydroxyurs-11-en-13beta(28)-olide (ursolic acid lactone) and 3beta,11alpha-dihydroxyurs-12-en-28-oic acid, the latter of which was identified for the first time.
Journal of Wood Chemistry and Technology, Feb 16, 2007
... delignification. ACKNOWLEDGMENTS The authors thank FCT-PRAXIS XXI for the financial support o... more ... delignification. ACKNOWLEDGMENTS The authors thank FCT-PRAXIS XXI for the financial support of the research project 3/3.2/PAPEL/2327/95 and for the awarding of a research grant (BIC/3700/96) to Paula Pinto. The authors ...
Separation and Purification Technology, Sep 24, 2010
To explore proper extractive solvents and to design an optimized separation process it is highly ... more To explore proper extractive solvents and to design an optimized separation process it is highly imperative to understand the molecular-based phenomena governing the solutes partitioning. Moreover, the development of new techniques for the biomolecules separation and purification, while maintaining their functional characteristics unchanged, is still ongoing. Therefore, in this work, the partition coefficients of vanillin, a compound with well-known organoleptic
... Andreia F. Sousa, Paula CRO Pinto, Armando JD Silvestre, Carlos Pascoal Neto CICECO and Depar... more ... Andreia F. Sousa, Paula CRO Pinto, Armando JD Silvestre, Carlos Pascoal Neto CICECO and Department of Chemistry, University of Aveiro, 3810-193 Aveiro ... 27. Pelillo, M.; Iafelice, G.; Marconi, E.; Caboni, MF Rap. ... Cordeiro N.; Belgacem MN; Gandini A.; Pascoal Neto C. Ind. ...
... SILVESTRE AJD (1) ; PEREIRA CCL (1) ; NETO C. Pascoal (1) ; EVTUGUIN DV (1) ; CAVALEIROJAS (1... more ... SILVESTRE AJD (1) ; PEREIRA CCL (1) ; NETO C. Pascoal (1) ; EVTUGUIN DV (1) ; CAVALEIROJAS (1) ; ... La liqueur noire de la cuisson de E.globulus a ??t?? extraite de fa??on s??quentielle avec de l'??ther ??thylique ?? des pH de 12, 7 et 2, suivi d'ac??tate d'??thyle ?? un pH de 2. Un ...
This study investigates the effect of pulping time and process parameters on the content of hexen... more This study investigates the effect of pulping time and process parameters on the content of hexenuronic acid (HexA) in Eucalyptus globulus kraft pulps. Under selected standard pulping conditions, the amount of HexA in pulps increases during cooking. This behavior, significantly ...
Acylation of cellulose fibers with fatty acids constitute an interesting way to produce biodegrad... more Acylation of cellulose fibers with fatty acids constitute an interesting way to produce biodegradable plastics,4 as well as to obtain reinforcing materials for composites with common polymeric matrices5 like polyethylene. The cellulose modification reactions can be performed in ...
The wood and bark of four Acacia species growing in Portugal, namely, A. longifolia, A. dealbata,... more The wood and bark of four Acacia species growing in Portugal, namely, A. longifolia, A. dealbata, A. melanoxylon, and A. retinodes, were investigated for their sterol content. The lipids fractions of the different wood and bark samples were isolated, and the sterols were identified and quantified by GC-MS. Two delta7 sterols, specifically, spinasterol and dihydrospinasterol, were the main sterols found in considerable amounts, particularly in wood tissues (more than 0.5 g/kg of dry wood in the case of A. melanoxylon and A. retinodes). The corresponding unusual steryl glucosides were also identified in significant amounts in the wood and bark extracts.
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
The use of trichloroacetyl isocyanate (TAI) to mark both hydroxyl and carboxyl groups borne by th... more The use of trichloroacetyl isocyanate (TAI) to mark both hydroxyl and carboxyl groups borne by the hydrolysis or methanolysis of suberin fragments (a complex mixture of hydroxy fatty acids), allowed the quantitative assessment of the ratio between carboxyl and hydroxy groups, as well as the ratio between primary and secondary hydroxy groups, to be carried out reliably by 1H nuclear magnetic resonance (NMR) spectroscopy. All the samples thus analyzed displayed an excess of CO2H (or CO2CH3) functions with respect to the OH counterparts, albeit to a variable extent, depending on the procedure adopted to isolate the suberin fragments. The precise knowledge of the molar ratio of these two reactive moieties is fundamental for the correct utilization of suberin monomers in polymerization reactions leading to aliphatic polyesters.
The chemical composition of the epicuticular wax from the fruits of Eucalyptus globulus was studi... more The chemical composition of the epicuticular wax from the fruits of Eucalyptus globulus was studied by GC-MS before and after alkaline hydrolysis. The wax had two main components, ursolic acid and tritriacontan-16,18-dione, together with several other triterpenic acids. After alkaline hydrolysis, a large increase in the amounts of triterpenic acids and fatty acids (particularly in hexadecanoic acid) was observed, suggesting that these components were present predominantly in esterified forms in the fruit wax. Six compounds were isolated from the fruits by preparative chromatography, and were identified as 8-desmethyleucalyptin, sesamin, tritriacontan-16,18-dione, ursolic acid, 3beta-hydroxyurs-11-en-13beta(28)-olide (ursolic acid lactone) and 3beta,11alpha-dihydroxyurs-12-en-28-oic acid, the latter of which was identified for the first time.
Journal of Wood Chemistry and Technology, Feb 16, 2007
... delignification. ACKNOWLEDGMENTS The authors thank FCT-PRAXIS XXI for the financial support o... more ... delignification. ACKNOWLEDGMENTS The authors thank FCT-PRAXIS XXI for the financial support of the research project 3/3.2/PAPEL/2327/95 and for the awarding of a research grant (BIC/3700/96) to Paula Pinto. The authors ...
Separation and Purification Technology, Sep 24, 2010
To explore proper extractive solvents and to design an optimized separation process it is highly ... more To explore proper extractive solvents and to design an optimized separation process it is highly imperative to understand the molecular-based phenomena governing the solutes partitioning. Moreover, the development of new techniques for the biomolecules separation and purification, while maintaining their functional characteristics unchanged, is still ongoing. Therefore, in this work, the partition coefficients of vanillin, a compound with well-known organoleptic
... Andreia F. Sousa, Paula CRO Pinto, Armando JD Silvestre, Carlos Pascoal Neto CICECO and Depar... more ... Andreia F. Sousa, Paula CRO Pinto, Armando JD Silvestre, Carlos Pascoal Neto CICECO and Department of Chemistry, University of Aveiro, 3810-193 Aveiro ... 27. Pelillo, M.; Iafelice, G.; Marconi, E.; Caboni, MF Rap. ... Cordeiro N.; Belgacem MN; Gandini A.; Pascoal Neto C. Ind. ...
... SILVESTRE AJD (1) ; PEREIRA CCL (1) ; NETO C. Pascoal (1) ; EVTUGUIN DV (1) ; CAVALEIROJAS (1... more ... SILVESTRE AJD (1) ; PEREIRA CCL (1) ; NETO C. Pascoal (1) ; EVTUGUIN DV (1) ; CAVALEIROJAS (1) ; ... La liqueur noire de la cuisson de E.globulus a ??t?? extraite de fa??on s??quentielle avec de l'??ther ??thylique ?? des pH de 12, 7 et 2, suivi d'ac??tate d'??thyle ?? un pH de 2. Un ...
This study investigates the effect of pulping time and process parameters on the content of hexen... more This study investigates the effect of pulping time and process parameters on the content of hexenuronic acid (HexA) in Eucalyptus globulus kraft pulps. Under selected standard pulping conditions, the amount of HexA in pulps increases during cooking. This behavior, significantly ...
Acylation of cellulose fibers with fatty acids constitute an interesting way to produce biodegrad... more Acylation of cellulose fibers with fatty acids constitute an interesting way to produce biodegradable plastics,4 as well as to obtain reinforcing materials for composites with common polymeric matrices5 like polyethylene. The cellulose modification reactions can be performed in ...
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