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Enzymes as ultimate green catalysts for polymer synthesis and biodegradation / Vrijeshkumar Singh in PAINTINDIA, Vol. LXVIII, N° 5 (05/2018)
[article]
Titre : Enzymes as ultimate green catalysts for polymer synthesis and biodegradation Type de document : texte imprimé Auteurs : Vrijeshkumar Singh, Auteur ; Vivek L. Patil, Auteur Année de publication : 2018 Article en page(s) : p. 53-64 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Biodégradation
Encapsulation
EnzymesUne enzyme est une protéine dotée de propriétés catalytiques. Pratiquement toutes les biomolécules capables de catalyser des réactions chimiques dans les cellules sont des enzymes ; certaines biomolécules catalytiques sont cependant constituées d'ARN et sont donc distinctes des enzymes : ce sont les ribozymes.
Une enzyme agit en abaissant l'énergie d'activation d'une réaction chimique, ce qui accroît la vitesse de réaction. L'enzyme n'est pas modifiée au cours de la réaction. Les molécules initiales sont les substrats de l'enzyme, et les molécules formées à partir de ces substrats sont les produits de la réaction. Presque tous les processus métaboliques de la cellule ont besoin d'enzymes pour se dérouler à une vitesse suffisante pour maintenir la vie. Les enzymes catalysent plus de 5 000 réactions chimiques différentes2. L'ensemble des enzymes d'une cellule détermine les voies métaboliques qui peuvent avoir lieu dans cette cellule. L'étude des enzymes est appelée enzymologie.
Les enzymes permettent à des réactions de se produire des millions de fois plus vite qu'en leur absence. Un exemple extrême est l'orotidine-5'-phosphate décarboxylase, qui catalyse en quelques millisecondes une réaction qui prendrait, en son absence, plusieurs millions d'années3,4. Comme tous les catalyseurs, les enzymes ne sont pas modifiées au cours des réactions qu'elles catalysent, et ne modifient pas l'équilibre chimique entre substrats et produits. Les enzymes diffèrent en revanche de la plupart des autres types de catalyseurs par leur très grande spécificité. Cette spécificité découle de leur structure tridimensionnelle. De plus, l'activité d'une enzyme est modulée par diverses autres molécules : un inhibiteur enzymatique est une molécule qui ralentit l'activité d'une enzyme, tandis qu'un activateur de cette enzyme l'accélère ; de nombreux médicaments et poisons sont des inhibiteurs enzymatiques. Par ailleurs, l'activité d'une enzyme décroît rapidement en dehors de sa température et de son pH optimums.
Polymères -- Biodégradation
Polymères -- Synthèse
Polymérisation enzymatique
Solvants organiquesIndex. décimale : 667.9 Revêtements et enduits Résumé : Enzymes are biological molecules which catalyse biological reactions. Enzymes and their biological reactions include study of bio-polymerisation by chemical kinetics of enzymatic ring opening polymerisation and radical initiated polymerisation mechanism. Enzyme also catalyses grafting of bio materials like lignin, starch and chitosan. However enzymatic polymerisation has limitations of enzyme activity and stability. Hence approaches like immobilisations, encapsulation and use of organic media were reviewed to enhance reactivity of enzymes. Various challenges in industrial applications and troubleshooting are established. Enzyme not only polymerises but also shows degradation mechanism for polymers which opens area of sustainability for coating industry. Note de contenu : - ENZYMES AS CATALYSTS IN POLYMER CHEMISTRY : Michaelis-Menten kinetics - Application of Michaelis-Menten kinetics
- ENZYMATIC POLYMERIZATION MECHANISM : Enzymatic ring opening polymerisation (e-ROP) - Enzyme initiated radical polymerizations - Candila Antartica lipase B (CALB) - Enzyme catalysis in polymer end-functionalization - Enzyme initiated polymerisation of chitosan - HRP initiated polymerisation of poly(acrylamide) grafting of starch - Laccase/hydroperoxide polymerisation grafting of acrylamide with lighin - Enzymatic grafting-artificial urushi - Enzyme catalysed chemo selective polymerisation - Immobilisation of enzyme - Encapsulation of enzyme - Organic solvent tolerant enzyme
- PROSPECT OF ENZYMATIC POLYMERIZATION CURRENT STATUS
- ENZYMATIC DEGRADATION OF POLYMER
- INDUSTRIAL APPLICATION
- CHALLENGES AND TROUBLESHOOTING IN INDUSTRIAL APPLICATION OF ENZYMATIC POLYMERISATION : Limitations of enzymatic ATRP (atomic transfer radical polymerisation and enzymatic ring-opening polymerization (e-ROP) - Limitations for CALB initiated reaction
- TABLES : 1. Kinetic constants for different enzymes - 2. Selective enzymes for degradation of polymer
- FIGURES : 1. Categories of enzyme - 2. Representation of an amino acid in a chain of amino acids, all together forming a protein - 3. Proposed mechanism for enzymatic trans-esterification - 4. Scanning electron microscopy (SEM) image of Candida Antartica Lipase B (CALB) macro porous cross-linked acrylic resin
- SCHEMES : 1. Resting state ofheme peroxidases - 2. Schematic mechanism for laccase-catalyzed radical formation - 3. Schematic representation of laccase mediator systems (LMSs) and peroxidase mediator systems (PMSs) initiated polymerization reactions. Upper : the mediator is used as true catalyst transferring the radical to a monomer ; lower : the oxidized mediator radical itself initiates the polymerization process - 4. Structures of the amino acid residues forming the catalytic triad and the oxyanion hole of CALB - 5. Trans-esterification of esters with alcohols : reversible with an alkyl ester or a halogenated alkyl ester, and irreversible with a vinyl ester - 6. Enzymatic Michael addition of diethylamine to (A) α-acrylated, ω-methacrylated EG in bulk (B) α-acrylated, ω-crotonated EG in bulk - CALB catalyzed epoxidation of olefins in the presence of hydrogen peroxide - 8. Functionalized PEGs vial CALB-catalyzed trans-esterification - 9. Enzymatic of PIB-OH and glissopal-OH - 10. CALB catalyzed methacrylation of PDMS - 11. Modification of chitosan with enzyme-generated quinones - 12. Proposed mechanism for the HRP-initiated poly(acrylamide)-grafting of starch - 13. Proposed mechanism of laccase/hydroperoxide polymerization grafting of acrylamide onto lignin - 14. Bienzymatic formation of artificial urushi with tailored properties - 15. Chemo selective polymerization of bifunctional (phenol/vinyl) monomer units using HRP - 16. Complementary conversion of m-ethinylphenol using HRP or CuClEn ligne : https://drive.google.com/file/d/1COMqb_QtcfdM4Nn03XVPSzpHWzAti8oP/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=30706
in PAINTINDIA > Vol. LXVIII, N° 5 (05/2018) . - p. 53-64[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 19993 - Périodique Bibliothèque principale Documentaires Disponible Ethylated analogue of Zingerone : A new and eco-respectful preservative in cosmetics / Patricio Guerreiro in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 45, N° 2 (03-04/2023)
[article]
Titre : Ethylated analogue of Zingerone : A new and eco-respectful preservative in cosmetics Type de document : document électronique Auteurs : Patricio Guerreiro, Auteur ; Sylvie Cupferman, Auteur ; Jacques Lharidon, Auteur ; Roger Rozot, Auteur ; Maria Dalko-Csiba, Auteur Année de publication : 2023 Article en page(s) : p. 187-197 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Biodégradation
Composés organiques -- Synthèse
Conservateurs (chimie)
Cosmétiques
Curcuma et constituants
Eco-conception
Extraits de plantes:Extraits (pharmacie)
Formulation (Génie chimique)
Gingembre et constituants
Ingrédients cosmétiques
Matériaux bio-inspirés
MicrobiologieIndex. décimale : 668.5 Parfums et cosmétiques Résumé : - Objective : This article describes the eco-design of a new preservative in cosmetics based on bio-inspiration of natural extracts from traditional medicines. In order to reach the multiple specification targets, various structures have been synthesized and evaluated to select the one demonstrating broad antimicrobial spectrum with favorable environmental profile and application potential to a wide variety of formulas.
- Methods : In order to evaluate the antimicrobial activity of the synthesized structures, the method of the challenge test consisting in an artificial contamination of the sample with collection microbial strains and evaluation of the number of revivable microorganisms was used to select the most promising candidate. Validation of its antimicrobial potential was later confirmed on Gram positive and Gram negative bacteria, yeast and mold with measurement of its Minimum Inhibitory Concentration (MIC) in comparison with known preservatives. Environmental impact assessment of the selected candidate was achieved with the help of ready biodegradability and aquatic ecotoxicity tests performed according to appropriate Organization tes a strfor Economic Co-operation and Development (OECD) and European Union (EU) guidelinesy.
- Results : Bio-inspired from turmeric and ginger extracts, an ethylated analog of Zingerone (EZ) with the chemical name 4-(3-ethoxy-4-hydroxyphenyl)butan-2-one demonstrates the strongest activity on Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans. Moreover, EZ shows a solubility in water two times higher than that of Zingerone thus increasing its interest as a potential preservative. Finally, its assessment of ready biodegradability and aquatic ecotoxicity in OECD-EU tests with a favorable environmental profile confirms its unique interest and fully justifies its use in cosmetic formulas as an eco-respectful preservative.
- Conclusion : Bio-inspiration based on technologies without noteworthy side effects but also on eco-design, particularly through the use of measures of potential environmental impact very upstream of a development, are two fundamental elements for the launching of new eco-friendly cosmetic ingredients. This approach has thus validated the strong potential of EZ as a preservative of eco-respectful formulas. The selection of EZ is also a very good example of the achievement of two key objectives targeted by cosmetic companies for the development of a novel active ingredient : environmental performance and technical performance.Note de contenu : - MATERIALS AND METHODS : Antimicrobial tests - ENVIRONNEMENTAL tests
- RESULTS AND DISCUSSION : Bio-inspiration : From natural extracts of turmeric and ginger to an eco-designed ethylated analogue of Zingerone (EZ) with antimicrobial activity - Environnemental favourable profile of ethylated analogue of Zingerone (EZ)
Strong potential of an ethylated analogue of Zingerone (EZ), as a preservative with no bacterial cross-resistance to antimicrobials
- Table 1 & 2 : Culture conditions
- Table 3 : Antimicrobial activity of five molecules close to Zingerone structure on five strains
- Table 4 : Results of MIC measurements of EZ on five strains in comparison with preservatives approved by organic standards
- Table 5 : Challenge test results of EZ formulated in a simplex formula (carbopol gel), pH = 5.5DOI : https://doi.org/10.1111/ics.12830 En ligne : https://drive.google.com/file/d/1xUR5XyuizpfF-kNXwC5ABRBa0UBSl9FL/view?usp=share [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39169
in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 45, N° 2 (03-04/2023) . - p. 187-197[article]Evaluation of environmental impact of typical leather chemicals. Part 2 : Biodegradability of organic tanning agents by activated sludge / Danhong Sun in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 92, N° 2 (03-04/2008)
[article]
Titre : Evaluation of environmental impact of typical leather chemicals. Part 2 : Biodegradability of organic tanning agents by activated sludge Type de document : texte imprimé Auteurs : Danhong Sun, Auteur ; Qiang He, Auteur ; Zhang Wenjun, Auteur ; Yulu Wang, Auteur ; Bi Shi, Auteur Année de publication : 2008 Article en page(s) : p. 59-64 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Acrylique
Agents de tannage
AldéhydesUn aldéhyde est un composé organique, faisant partie de la famille des composés carbonylés, dont l'un des atomes de carbone primaire (relié au plus à 1 atome de carbone) de la chaîne carbonée porte un groupement carbonyle.
L'aldéhyde le plus simple est le formaldéhyde (ou méthanal), aussi appelé formol lorsqu'il est en solution aqueuse.
Un aldéhyde dérive formellement d'un alcool primaire (oxydation) dont le groupement hydroxyde -OH est en bout de chaîne et se forme suite à l'enlèvement de deux atomes H d'où le nom "alcool déshydrogéné" ou aldéhyde.
Biodégradation
Boues résiduaires -- Analyse
Composés aromatiques
Composés organiques
Cuirs et peaux -- Industrie -- Aspect de l'environnement
Environnement -- Etudes d'impact
Evaluation
SyntansIndex. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The biodegradability of typical organic tanning agents, including aromatic syntans, aldehydic tanning agents and acrylic tanning agents, were investigated. The results showed that the biodegradation behaviours of these leather chemicals are closely associated with their chemical structures, molecular weights and compositions. Therefore, different organic tanning agents might result in different environmental impacts even though they belong to the same type of tanning agent. The four aromatic syntans tested exhibited low biodegradability in general. Among them, a phenol-based syntan was not biodegradable and the phenol-sulphone based syntan produced a strong inhibitory effect on respiration of activated sludge. Comparatively, the naphthalene-based syntan was somewhat easier to biodegrade than other aromatic syntans. In the cases of aldehydic tanning agents, both formaldehyde and glutaraldehyde were not biodegradable and were toxic to organisms in activated sludge. Thus, they are potential inhibitors to biodegradation of other organic compounds in wastewater. However, an aliphatic aldehydic tanning agent was biodegradable and showed no toxicity to microorganisms in activated sludge. As for acrylic tanning agents, results indicated that commercial anionic products do not have any negative effect on biodegradation activity of activated sludge but they themselves were hardly biodegraded. Whereas, cationic acrylic tanning agents have the potential to inhibit the activated sludge process when presented at a high concentration. Note de contenu : - Biodegradability of aromatic syntans
- Biodegradability of aldehydic tanning agents
- Biodegradability of acrylic tanning agents
- Table 1 : The types and main properties of organic tanning agents used in experiments
- Table 2 : BOD5 /COD values of aromatic syntans
- Table 3 : BOD5 /COD values of aldehydic tanning agentsEn ligne : https://drive.google.com/file/d/1O2b7myavpoCSbVBi0--SckW-RKh98-ca/view?usp=share [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=38931
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 92, N° 2 (03-04/2008) . - p. 59-64[article]Evaluation of environmental impact of typical leather chemicals. Part 3 : Biodegradability of vegetable tannin extracts by activated sludge / Qiang He in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 92, N° 3 (05-06/2008)
[article]
Titre : Evaluation of environmental impact of typical leather chemicals. Part 3 : Biodegradability of vegetable tannin extracts by activated sludge Type de document : texte imprimé Auteurs : Qiang He, Auteur ; Danhong Sun, Auteur ; Xin Liu, Auteur ; Lin Wei, Auteur ; Bi Shi, Auteur Année de publication : 2008 Article en page(s) : p. 103-106 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Biodégradation
Boues résiduaires -- Analyse
Cuirs et peaux -- Industrie -- Aspect de l'environnement
Déchets industriels -- Elimination
Environnement -- Etudes d'impact
Tanins végétauxIndex. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The short-term (5 day) and long-term (30 day) biodegradation behaviours of black wattle, bayberry, valonia and chestnut tannin extracts were systematically investigated in this paper. The results indicated that all of these four vegetable tannin extracts are biodegradable although they might retard the biodegradation process to some extent owing to the inhibitory effect of tannins on the activated sludge process. Short-term biodegradabilities of the four tannin extracts were concentration-dependent. These tannin extracts could be effectively biodegraded in 5 days at concentrations of 0.25g/L, but the biodegradation process was retarded remarkably when the concentrations were increased to 5.00g/L. In general, short-term biodegradabilities of the four tannin extracts follow the sequence of valonia tannin>chestnut tannin>bayberry tannin>wattle tannin, implying that the hydrolysable tannins are easier to biodegrade than the condensed tannins. The results of long-term biodegradation showed that all of the four vegetable tannin extracts can be completely biodegraded by prolonging the activated sludge process, even if they are present at high concentration. Therefore, the encouraging findings in this research suggest that vegetable tannin extracts are environmentally friendly leather chemicals. Note de contenu : - BOD5/COD values of vegetable tannin extracts
- Respiration of activatedslud ge in the presence of vegetable tannin extracts
- COD removals of vegetable tannin extracts by the activatedslud ge process
- COD removals (%) of vegetable tannin extracts at different concentrations
- Table 1 : Type andtannin content of vegetable tannin extracts tested in experiments
- Table 2 : BOD5 /COD values of vegetable tannin extracts at different concentrationsEn ligne : https://drive.google.com/file/d/1rkdcAB3YoMjEm3urqqTf-HjnXnzkK-x3/view?usp=share [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=38954
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 92, N° 3 (05-06/2008) . - p. 103-106[article]Exploring sustainabilty claims : biodegradable fragrances / Stampa Alberto in SOFW JOURNAL, Vol. 148, N° 10 (10/2022)
[article]
Titre : Exploring sustainabilty claims : biodegradable fragrances Type de document : texte imprimé Auteurs : Stampa Alberto, Auteur ; Marta Pajaro, Auteur Année de publication : 2022 Article en page(s) : p. 53-55 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Allégations (droit) Une allégation est l’affirmation d'un fait par une partie dans une plaidoirie, que la partie prétend pouvoir prouver. Les allégations restent des affirmations sans la preuve, jusqu'à ce qu'elles puissent être prouvées.(Wikipedia)
Biodégradation
Durée de vie (Ingénierie)
Essais (technologie)
ParfumsIndex. décimale : 668.5 Parfums et cosmétiques Résumé : With consumers increasingly concerned about sustainability, and new claims constantly arriving on the market, Kao Chemicals Europe investigates what should be taken into account to create a biodegradable fragrance. The differences between anaerobic and aerobic biodegradation are stated, as well as the different aerobic biodegradation methods that can be used and the classification according to the results of this test. The OECD Ready Biodegradability tests are explained in more detail to better understand how to determine the biodegradation of a substance. After all of this, it is explored when a fragrance can be considered biodegradable, although it is not currently implemented at a legislative and mandatory level, and what should be done to pursue and push this kind of claim into the market. Finally, some actions taken in the regulatory field regarding the biodegradation topic in personal care and home care formulations are outlined to exemplify how this type of claim is gaining momentum. Note de contenu : - Anaerobic and aerobic biodegradation
- Aerobic biodegradation test
- Biodegradable categories for chemicals
- The OECD biodegradable test
- Biodegradable fragrances
- Table : Applicability of ready biodegradability test methods, from OECD guidelinesEn ligne : https://drive.google.com/file/d/1BmKTiXPoBeA_ysE_uHAl7JuYPN1jcsFG/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=38251
in SOFW JOURNAL > Vol. 148, N° 10 (10/2022) . - p. 53-55[article]Réservation
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