New hydrophobically modified carboxymethylcellulose derivatives

Charpentier, D.; Mocanu, Georgeta; Carpov, A.; Chapelle, Stella; Merle, L.; Müller, G.

doi:10.1016/s0144-8617(97)00031-3

Cited by 89 publications

(43 citation statements)

References 13 publications

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“…The amidated derivative of CMC with a degree of substitution of 63.1 mol% was prepared using the modified method of Charpentier et al (1997). First, the methylester was prepared via esterification with methanol.…”

Section: Methodsmentioning

confidence: 99%

Comparative Study on the Hypocholesterolemic Activity of Amidated Polysaccharides and Psyllium

et al. 2015

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The effects of amidated carboxymethylcellulose, amidated pectin, and psyllium on serum and hepatic cholesterol, hepatic fat, and fecal output of sterols were examined in female rats. Rats were fed a diet supplemented with cholesterol (0 or 10 g/kg) and palm fat. Amidated cellulose at 30 g/kg significantly decreased the serum and hepatic concentration of cholesterol by 28.1% and 64.6%, respectively. Corresponding values in rats fed amidated pectin were 28.9% and 72.4%. The effects of psyllium were similar, but less pronounced. Amidated pectin significantly increased the fecal output of cholesterol, total neutral sterols, and total sterols by 49.1%, 31.9%, and 31.0%, respectively. Amidated cellulose and psyllium increased the fecal excretion of total sterols by 1.1% and 5.5%, respectively. In the feces of rats fed amidated cellulose, a small amount of conjugated bile acids was detected (0.83% of total bile acids). In these rats, the lowest expression of hepatic cholesterol 7α-hydroxylase was detected, corresponding to the low fecal output of bile acids. We conclude that the hypocholesterolemic effects of both amidated polysaccharides were similar in spite of their different affinity to sterols.

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Section: Methodsmentioning

confidence: 99%

Comparative Study on the Hypocholesterolemic Activity of Amidated Polysaccharides and Psyllium

et al. 2015

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“…The DA values of the prepared derivatives varied from 13 to 59 mol%. CMC derivatives obtained by the direct amidation of the carboxyl group with N-hexadecylamine were described by Charpentier et al (1997), but the DA values of these derivatives were significantly lower (from 0.9 to 6% per monomeric unit).…”

Section: Preparation and Characterisation Of Cellulose Derivativesmentioning

confidence: 99%

“…The methodology of preparation of hydrophobic cellulose derivatives was based on the modified methods of Charpentier et al (1997) and Taubner et al (2013). MCC, CMC, and their derivatives were analysed for their carbon, hydrogen, and nitrogen contents using the EL III Universal CHNOS Elemental Analyser (Elementar Analysensysteme GmbH, Germany).…”

Section: Preparation and Characterisation Of Modified Cellulosesmentioning

confidence: 99%

Hydrophobically Modified Celluloses as Novel Cholesterol-lowering Polymers

Tůma¹,

Volek²,

Synytsya³

et al. 2014

BioResources

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Hydrophobically modified celluloses were prepared by the esterification of monocarboxycellulose (MCC) and carboxymethylcellulose (CMC) with methanol, followed by the amino-de-alkoxylation of the methyl esters with n-octadecylamine. These cellulose derivatives were fed at 30 and 60 g/kg for 4 weeks to female rats. The diets were supplemented with palm fat (60 or 50 g/kg) and cholesterol (0 or 10 g/kg). There was no significant effect of amidated celluloses on the feed intake or body weight of rats. Both MCC and CMC derivatives significantly decreased the concentrations of cholesterol present in the serum and liver. The supplementation of diets with hydrophobically modified celluloses tended to increase fecal concentrations of cholesterol and coprostanol and significantly increased fecal concentrations of total neutral sterols. In rats fed diets containing cholesterol, the total serum cholesterol correlated negatively with the fecal concentrations of neutral sterols. It can be concluded that MCC-C18 and CMC-C18 are effective cholesterollowering agents.

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“…22 This method relies on the esterification reaction of the cellulose fractions of RH with MCA, furnishing carboxylate groups as shown in Scheme 3, that occurs preferentially at the C2 position. 25,26 The degree of functionalization, known as the number of hydroxyl groups that can be substituted (maximum 3) can lead to dissolution in water (above 0.4), 22 which is not interesting herein. Hence, we used a milder condition for carboxymethlyation to guarantee heterogeneous catalysts and indeed the functionalized samples maintained Orth 1763 Vol.…”

mentioning

confidence: 99%

“…9, 2017 overall characteristics (i.e., color and appearance; Figure 1). Unfortunately, the reported procedures 22,[25][26][27] for determining the degree of carboxymethylation were inapplicable for our samples since they usually require dissolution of the material and high cellulose composition (> 90%) or even advanced techniques such as solid nuclear magnetic resonance. We attempted colorimetric analysis for quantifying carboxylic 20 and IMZ groups, 28 but the complex nature of RH interfered in the analyses and no concrete conclusion was possible.…”

mentioning

confidence: 99%

Degrading Pesticides with Waste Product: Imidazole-Functionalized Rice Husk Catalyst for Organophosphate Detoxification

Ferreira

Orth

2017

J. Braz. Chem. Soc.

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Rice husk (RH) is one the largest agricultural waste products worldwide, and rice is one of the crops that use the most pesticides. Among these, organophosphates have been of increasing concern due to their high toxicity. Herein, we report the functionalization of RH with imidazole groups (RHIMZ) to obtain sustainable catalysts from waste for organophosphate degradation. The waste-derived catalyst showed prominent catalytic activity in dephosphorylation reactions with the model substrate diethyl 2,4-dinitrophenyl phosphate (DENDPP), over 10 5 -fold, compared to the spontaneous reaction (lifetime = 1 month). Finally, RHIMZ was also effective in degrading the pesticide Paraoxon (spontaneous lifetime = 1 million years), degrading 60% in 20 days, giving a 10 7 -fold enhancement. Overall, the proposed approach is environmentally friendly for reusing the waste for a noble cause, i.e., degrading toxic pesticides, which is promising for designing sensors and detoxification processes.Keywords: rice husk, sustainable catalyst, imidazole, pesticide degradation, organophosphate, rice husk functionalization IntroductionRice husk (RH) comprises one of the largest agricultural waste products, with the inherent waste management concerns.1 Notwithstanding, while rice feeds more than half of the human population, about 0.22 kg of RH is produced for each 1 kg of rice cropped, i.e., an estimated production of 164 million tons of RH only in 2013, according to data of FAOSTAT.2,3 Furthermore, RH leads as the most underused cellulosic source in contrast to wood, textile fibers and papers. RH is composed of 75-80% of organic matter, which corresponds nearly to 44% of cellulose, 31% of hemicellulose and 25% of lignin. 4,5 When burned (550-600 °C), RH ash configures as the cereal residue with the highest percentage of Si (94.38, 2.29 and 0.97% of SiO 2 , K 2 O and CaO, respectively, and traces of P 2 O 5 , Al 2 O 3 , MgO, Fe 2 O 3 , Na 2 O and TiO 2 ).5 Despite these facts, research and use of cellulosic residues such as raw RH in the chemical industry is still a relatively unexplored field, thus the main destination of these materials is to burn as biomass or use as fertilizer. 1The RH waste awareness is potentiated by some facts: rice is among the major crops worldwide, which is also one that most applies agrochemicals.6,7 Specifically concerning Brazil's scenario, while it occupies fourth place in worldwide agricultural production, Brazil is one of the largest consumers of agrochemicals. This has become a serious public health issue, since poisoning by pesticides is alarmingly high, losing only to medical drug. Moreover, studies show that nearly 30% of food samples (2011)(2012) contain prohibited substances or are present in abusive amounts.8 This scenario along with the worldwide concern in preventing hunger and assuring safe food has increased the interest in studies regarding reactions with toxic pesticides, especially organophosphates, with potential for developing efficient monitoring and detoxifying procedures. Curiously, abando...

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New hydrophobically modified carboxymethylcellulose derivatives

Cited by 89 publications

References 13 publications

Comparative Study on the Hypocholesterolemic Activity of Amidated Polysaccharides and Psyllium

Comparative Study on the Hypocholesterolemic Activity of Amidated Polysaccharides and Psyllium

Hydrophobically Modified Celluloses as Novel Cholesterol-lowering Polymers

Degrading Pesticides with Waste Product: Imidazole-Functionalized Rice Husk Catalyst for Organophosphate Detoxification

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