Carbaryl insecticide conjugation onto chitosan via iodochitosan and chitosan carbonyl imidazolide precursors

Chirachanchai, Suwabun; Lertworasirikul, Amornrat; Tachaboonyakiat, Wanpen

doi:10.1016/s0144-8617(00)00275-7

Cited by 17 publications

(8 citation statements)

References 19 publications

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“…N,N -Carbonyldiimidazole (CDI) was used for activation of hydroxyls in 2 towards subsequent coupling with propargylamine to yield 3; CDI is a cheap and efficient coupling agent used in industrial production of peptides (Montalbetti & Falque, 2005), which has been successfully employed in the modification of polysaccharides as cellulose, dextran or chitosan for multiple applications (Chirachanchai, Lertworasirikul, & Tachaboonyakiat, 2001;Oh, Lee, & Park, 2009;Önal & Telefoncu, 2003). Propargylamine was selected as the alkyne donor, as it provides a hydrophilic and stable, yet chemo-reversible, carbamate group linked to the terminal alkyne through a flexible methylene.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of an O-alkynyl-chitosan and its chemoselective conjugation with a PEG-like amino-azide through click chemistry

Oliveira

Martins

Mafra

et al. 2012

Carbohydrate Polymers

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a b s t r a c t N-Phthaloyl-chitosan O-prop-2-ynyl carbamate was prepared as a biopolymer amenable to undergo chemoselective conjugation by azide-alkyne coupling, while allowing upturn of chitosan's amines after dephthaloylation. N-phthaloylchitosan was prepared according to previously described methods and, due to its low solubility in current organic media, subsequent modifications were run in heterogeneous conditions. Activation of hydroxyls with carbonyl-1,1 -diimidazole and coupling to propargylamine yielded N-phthaloyl-chitosan O-prop-2-ynyl carbamate, then coupled to a model PEG-like azide by azide-alkyne coupling, giving the expected triazolyl conjugate. N-Dephthaloylation allowed recovery of the free amines, responsible for chitosan's bioadhesion and tissue-regeneration properties.The structures of all polymers were confirmed by Fourier-transformed infra-red (FT-IR) and X-ray photoelectron (XPS) spectroscopies, as well as by solid-state nuclear magnetic resonance (SSNMR). All chitosan derivatives were poorly soluble in both aqueous and organic media, which makes them suitable for topical applications or for removal of toxic substances from either the gastric intestinal tract or environmental sources.

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Section: Resultsmentioning

confidence: 99%

Synthesis of an O-alkynyl-chitosan and its chemoselective conjugation with a PEG-like amino-azide through click chemistry

Oliveira

Martins

Mafra

et al. 2012

Carbohydrate Polymers

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“…Sua estrutura química é formada pelos copolímeros β-(1→4)-2-amino 2-desoxi-D-glicose e β-(1→4)-2-acetamida 2-desoxi-D-glicose com a presença de grupos amino e grupos hidroxila primário e secundário. A quitosana vem sendo estudada como biomaterial de potencial aplicação principalmente nas áreas médica e farmacêutica [4][5][6] . Yamaguchi, et al [7] observaram compósitos de quitosana e suas aplicações na regeneração de nervos.…”

Section: Produção E Caracterização De Microesferas De Quitosana Modifunclassified

Produção e caracterização de microesferas de quitosana modificadas quimicamente

et al. 2005

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Resumo: Microesferas de quitosana podem ser empregadas na área de biomaterias, em processos biotecnológicos e como adsorventes. Neste trabalho, foi empregada a técnica de atomização e coagulação para produção dessas microesferas, que permitiu o controle dos parâmetros de operação e por conseqüência a obtenção de microesferas de tamanho e faixas de tamanho específicos. Após a sua obtenção, as microesferas foram modificadas quimicamente com objetivo de estudar as resistências térmica, mecânica e química. Para isso foram empregadas três rotas distintas: a-) reticulação com glutaraldeído; b-) reticulação com epicloridrina e c-) acetilação. As microesferas preparadas apresentaram distribuição de tamanho da ordem de 140 µm com desvio padrão de 11,9 µm. Após as modificações químicas, as microesferas apresentaram temperatura de degradação térmica em torno de 300 °C, aumento da estabilidade química à solução de HCl, e diminuição da resistência mecânica.Palavras-chave: Quitosana, microesferas, atomização, modificação química. Production and Characterization of Chemically Modified Chitosan MicrospheresAbstract: Chitosan microspheres can be used as biomaterial, in biotechnology processes and as adsorbents. This work is concerned with the production of chitosan microspheres using spraying and coagulation processes, which allows us to control the operating parameters and to produce chitosan microspheres of several ranges and sizes. The microspheres were modified chemically in order to study their thermal, mechanical and chemical resistance. The methods used were: 1) crosslinking with glutaraldehyde; 2) crosslinking with epichlorohydrin; 3) acetylation. The microspheres obtained presented mean particle size of 140 µm and standard deviation of 11.9 µm. The modified microspheres showed thermal degradation around 300 °C, an increase of chemical stability using HCl solution and a decrease of mechanical resistance.

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“…In the second step, between 120 and 323 °C, 63.5% mass loss was observed. This mass should be due to the breaking of intermolecular hydrogen bonding and the glycoside linkages [ 28 ]. DQCS showed a 7.9% loss of mass between 41 and 138 °C during the first step.…”

Section: Resultsmentioning

confidence: 99%

Preparation and Characterization of Quaternized Chitosan Derivatives and Assessment of Their Antioxidant Activity

et al. 2018

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Chitosan (CS) is an abundant and renewable polysaccharide that is reported to exhibit a great variety of beneficial properties. However, the poor solubility of chitosan in water limits its applications. In this paper, we successfully synthesized single N-quaternized (QCS) and double N-diquaternized (DQCS) chitosan derivatives, and the resulting quaternized materials were water-soluble. The degree of quaternization (DQ) of QCS and DQCS was 0.8 and 1.3, respectively. These derivatives were characterized by FTIR, 1H NMR, 13C NMR, TGA, and SEM. Moreover, the antioxidant activity of the chitosan was evaluated by free radical scavenging ability (against DPPH-radical, hydroxyl-radical, and superoxide-radical) and ferric reducing power. Our results suggested that the antioxidant abilities were in the order of DQCS > QCS > CS, which was consistent with the number of quaternized groups. These data demonstrate that the number of quaternized groups of chitosan derivatives contributes to their antioxidant activity. Therefore, DQCS, with a higher number of quaternized groups and higher positive charge density, is endowed with high antioxidant activity, and can be used as a candidate material in food and pharmaceutical industries.

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Carbaryl insecticide conjugation onto chitosan via iodochitosan and chitosan carbonyl imidazolide precursors

Cited by 17 publications

References 19 publications

Synthesis of an O-alkynyl-chitosan and its chemoselective conjugation with a PEG-like amino-azide through click chemistry

Synthesis of an O-alkynyl-chitosan and its chemoselective conjugation with a PEG-like amino-azide through click chemistry

Produção e caracterização de microesferas de quitosana modificadas quimicamente

Preparation and Characterization of Quaternized Chitosan Derivatives and Assessment of Their Antioxidant Activity

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