scholarly journals Zwitterionic Acetylated Cellulose Nanofibrils

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3147 ◽  
Author(s):  
Jowan Rostami ◽  
Aji P. Mathew ◽  
Ulrica Edlund
Keyword(s):  
Acetic Acid ◽  
Schiff Base ◽  
Reaction Time ◽  
Structural Changes ◽  
Glacial Acetic Acid ◽  
Cellulose Nanofibrils ◽  
Periodate Oxidation ◽  
Hydroxyl Groups ◽  
Borohydride Reduction ◽  
Short Reaction Time

A strategy is devised to synthesize zwitterionic acetylated cellulose nanofibrils (CNF). The strategy included acetylation, periodate oxidation, Schiff base reaction, borohydride reduction, and a quaternary ammonium reaction. Acetylation was performed in glacial acetic acid with a short reaction time of 90 min, yielding, on average, mono-acetylated CNF with hydroxyl groups available for further modification. The products from each step were characterized by FTIR spectroscopy, ζ-potential, SEM-EDS, AFM, and titration to track and verify the structural changes along the sequential modification route.

Using Gin Adsorption Model for Assessing the Influence of Algal Powder Bleach Process in Cu(II) Adsorption

2013 ◽  
Vol 295-298 ◽  
pp. 123-128
Author(s):  
Shui Ping Chang ◽  
Yi Chao Lee ◽  
Chih Sheng Lee ◽  
Nien Hsin Kao
Keyword(s):  
Acetic Acid ◽  
Functional Groups ◽  
Binding Sites ◽  
Glacial Acetic Acid ◽  
Cell Structure ◽  
Hydroxyl Groups ◽  
Adsorption Model ◽  
Epiphytic Algae ◽  
Biosorption Process ◽  
Bleaching Procedure

The Cladophora and Spirogyra algae examined in this study belong to the Chlorophyta division. Macro filamentous algae, which are widespread in fresh water worldwide, have high potential to be developed as biological materials because of their large biomass and availability. In this study, we collected fresh algae from where they grew and produced bleached and unbleached algae powder using to adsorb Cu(II) ion solution. After the biosorption process, we noted the following four significant findings: (i) The functional groups and binding sites in the produced algae powder were affected, causing variations in the amount of copper adsorbed. The variations resulted from differences in the cell structure, the cell wall thickness of Cladophora and Spirogyra algae, cell composition, and the types and amount of epiphytic algae. (ii) Common bleaching procedures using glacial acetic acid influenced the binding sites of the functional groups and the biomass of the produced powder. Because of the bleaching, the amount of copper adsorbed by the Cladophora powder declined by 14.2%, and by 15.7% for Spirogyra powder. (iii) The carbonyl and hydroxyl groups of unbleached powder were the main elements affected during the bleaching procedures. Examining whether the biosorption experiment results fit Gin’s biosorption model, we found that the biosorption amount and equilibrium reaction of the two bleached algae powders were inferior to that of the unbleached algae powders. (iv) The bleaching procedure using glacial acetic acid was not suitable for producing algae powder to use as an adsorbent for metal ions.

[4-Iodo-3-(isopropylcarbamoyl)phenoxy]acetic Acid as a Highly Reactive and Easily Separable Catalyst for the Oxidative Cleavage of Tetrahydrofuran-2-methanols to γ-Lactones

Synlett ◽  
2018 ◽  
Vol 29 (17) ◽  
pp. 2316-2320 ◽  
Author(s):  
Takayuki Yakura ◽  
Tomoya Fujiwara ◽  
Hideyuki Nishi ◽  
Yushi Nishimura ◽  
Hisanori Nambu
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Efficient Method ◽  
Product Yield ◽  
Oxidative Cleavage ◽  
Catalyst Loading ◽  
Short Reaction Time ◽  
Phenoxy Acetic Acid ◽  
High Product Yield ◽  
Low Catalyst Loading

[4-Iodo-3-(isopropylcarbamoyl)phenoxy]acetic acid was developed as a highly reactive and easily separable catalyst for the oxidative cleavage of tetrahydrofuran-2-methanols to γ-lactones in the presence of Oxone® (2KHSO5·KHSO4·K2SO4) as the co-oxidant. The reactivity of this new catalyst was considerably greater than that of our previously reported catalyst, 2-iodo-N-isopropylbenzamide. The new catalyst and product were easily separated by only liquid–liquid separation without chromatography. In addition, using a mixture of nitromethane and N,N-dimethylformamide as the solvent and heating enabled a low catalyst loading, a short reaction time, and high product yield. Oxidative cleavage using the new catalyst can be used as a practical and efficient method for synthesizing γ-lactones.

THE BROMINOLYSIS OF CARBOHYDRATE IODIDES: I. ACETYLATED 6-DEOXY-6-IODO AND 2-DEOXY-2-IODO GLYCOSIDES

1964 ◽  
Vol 42 (3) ◽  
pp. 539-546 ◽  
Author(s):  
R. U. Lemieux ◽  
B. Fraser-Reid
Keyword(s):  
Acetic Acid ◽  
Methoxy Group ◽  
Glacial Acetic Acid ◽  
Main Product ◽  
Zinc Dust ◽  
Potassium Acetate ◽  
Borohydride Reduction ◽  
Silver Acetate ◽  
Sodium Borohydride Reduction ◽  
Dust Reduction

Reaction of methyl 6-deoxy-6-iodo-α-D-glucopyranoside triacetate with an excess of bromine in glacial acetic acid; N in potassium acetate, gave a 1.1:1 mixture of the products resulting from replacement of the iodine by bromine and by acetoxy group, respectively. When 2 moles of silver acetate were present per mole of bromine, the reaction was much more rapid and only methyl α-D-glucopyranoside tetraacetate was formed. The brominolysis of methyl 2-deoxy-2-iodo-α-D-mannopyranoside triacetate proceeded at a useful rate only when catalyzed by silver acetate. The main product of the reaction appeared to be methyl 3-acetoxy-2-bromo-2-deoxy-α-D-arabino-hexopyranoside triacetate. The compound could be converted by way of sodium borohydride reduction to methyl 2-bromo-2-deoxy-α-D-altropyranoside and by way of zinc dust reduction to methyl 2-deoxy-α-D-erythro-hexopyranoside-3-ulose diacetate. About 20% of the reaction proceeded with migration of the methoxy group to the 2-position to yield 2-O-methyl-D-glucose tetraacetate. The mechanisms of these reactions are discussed.

Research on Modified Rubbers. Part IV. The Oxidation of Rubber with Aqueous Hydrogen Peroxide-Acetic Acid Mixtures

1934 ◽  
Vol 7 (3) ◽  
pp. 454-461
Author(s):  
G. F. Bloomfield ◽  
E. H. Farmer
Keyword(s):  
Hydrogen Peroxide ◽  
Acetic Acid ◽  
Peracetic Acid ◽  
Glacial Acetic Acid ◽  
Chloroform Solution ◽  
Effective Control ◽  
Acid Mixture ◽  
Hydroxyl Groups ◽  
Derivatives Of ◽  
Degree Of Degradation

Abstract Mair and Todd (J. Chem. Soc., 1932,, 386), in extending the earlier work of Robertson and Mair (J. Soc. Chem. Ind., 46, 41T (1927)), studied the interaction of a chloroform solution of purified rubber with concentrated hydrogen peroxide (100 vols.) dissolved in glacial acetic acid; by this means they obtained a non-acidic substance of the empirical formula C50H92O16, which was unsaturated toward bromine and permanganate, and was considered to have all its oxygen present in the form of hydroxyl groups. Other workers have reported that when peracetic acid dissolved in glacial acetic acid is used in place of the hydrogen peroxide—acetic acid mixture, the products of reaction are acetylated derivatives of rubber (British Patent 369,716). These acetylated derivatives are stated to be obtainable either from solid rubber or from solutions of rubber, but no evidence as to their constitution has been advanced. Now the oxidative degradation of rubber is of considerable interest from two points of view: first, with regard to the light which it may throw on the size, structure, homogeneity, and normality of chemical behavior of the molecules of rubber; and, second, with regard to its efficacy as a means of transforming rubber into derivatives of similar or smaller molecular weight, capable of useful application in industry. The very careful work of Mair and Todd has gone far to show that hydrogen peroxide under the conditions of their experiments attacks the unsaturated centers of the rubber molecule and effects more or less complete hydroxylation of the carbon chain; at the same time it brings about a considerable degree of degradation of the molecule. The product of Mair and Todd, however, is produced under rather restricted conditions of reaction and the reagents employed are costly; consequently the extent to which the character of the product can be modified (i. e., by controlling the degree of degradation, hydroxylation, and acetylation) is left undetermined, and the possibility of producing useful materials at a reasonably low cost by modifying the conditions of reaction and the form of reactants is left unexplored. On the other hand, the employment of peracetic acid as an oxidizing agent, though offering a theoretically elegant way of effecting hydroxylation or acetoxylation at the unsaturated centers of the rubber molecule, is not without drawbacks: the preparation of the reagent is expensive and on a large scale dangerous; moreover, in spite of the fact that it is claimed to be employable either with solutions of rubber or with solid rubber, its reaction with rubber is so vigorous that the prospect of exercising any effective control over the extent of degradation or degree of hydroxylation (acetoxylation) is greatly diminished.

Synthesis and antimicrobial activity of some linear dipeptide pyridine and macrocyclic pentaazapyridine candidates

2016 ◽  
Vol 71 (7) ◽  
pp. 803-810 ◽  
Author(s):  
Mohamed E. Azab ◽  
Eman M. Flefel ◽  
Nermien M. Sabry ◽  
Abd El-Galil E. Amr
Keyword(s):  
Antimicrobial Activity ◽  
Acetic Acid ◽  
Schiff Base ◽  
Carboxylic Acid ◽  
Glacial Acetic Acid ◽  
Antimicrobial Agents ◽  
Acid Hydrazide ◽  
Schiff Base Derivatives ◽  
Carboxylic Acid Hydrazide ◽  
Acid Anhydrides

AbstractA series of tetracarboxamide and macrocyclic tripeptides have been prepared starting from 3,5-bis[N-(1-hydrazinyl-1-oxo-3-phenylpropan-2-yl)]pyridinecarboxamide 4 as starting material, which was synthesized from dinicotinic acid 1. Treatment of 4 with 1,4-diaminobutane, 1,6-diaminohexane, or cycloalkanone derivatives gave the corresponding macrocyclic tetracarboxamides (5a, b) and cycloalkyl hydrazone derivatives (6a–c), respectively. Additionally, the reaction of 4 with acetophenone or acetylpyridine derivatives gave the corresponding Schiff base derivatives 7a–e and 8a–c, respectively. Also, carboxylic acid hydrazide 4 was treated with acid anhydrides in glacial acetic acid to afford the corresponding diimide tetracarboxamide derivatives 9a, b, 10, and 11, respectively. The structures of newly synthesized compounds are established by physical and spectral data evidences. Some of the synthesized compounds were screened as antimicrobial agents.

scholarly journals PEMBUATAN KARBOKSIMETIL SELULOSA DARI KULIT PISANG KEPOK DENGAN VARIASI KONSENTRASI NATRIUM HIDROKSIDA, NATRIUM MONOKLOROASETAT, TEMPERATUR DAN WAKTU REAKSI

2017 ◽  
Vol 6 (3) ◽  
pp. 47-51
Author(s):  
Saputri Ayuningtiyas ◽  
Feni Dwi Desiyana ◽  
Siswarni MZ
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Carboxymethyl Cellulose ◽  
Glacial Acetic Acid ◽  
Raw Materials ◽  
Raw Material ◽  
Banana Peel ◽  
Ftir Analysis ◽  
Substitution Degree ◽  
Materials Used

Carboxymethyl cellulose (CMC) is a derivative cellulose which is soluble an in water (hydrophilic colloid). This material effective to bind water to provide a uniform texture and increase viscosity. The aim  of this study is to utilize banana peel as a raw material to synthesis CMC and determine the best conditions in the process of synthesis CMC from banana peel. The materials used were banana peel, water, aquades, NaOH, Natirum monochloroacetat and glacial acetic acid. The variables in this study were NaOH concentration, natirum monochloroacetat mass, temperature and reaction time. In this  research consists of four stages there are preparation of raw materials, alkalization, carboxymethylation, and neutralization. The results of this research  shows the variatioon NaOH concentration 20%  and  temperature of 45oC degree, mol rasio of  cellulose:sodium monochloroacetat 1:1,6 with a reaction time of 120 minutes obtained the highest substitution degree of 0,73-0.812. The FTIR analysis shows the presence of the O-H, C-H, C = O, C-0, CH2 and 1,4 β-glycoside function groups known to have the same function groups as the commercial carboxymethyl cellulose.

One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H)-Ones Using Cadmium Sulfate as Catalyst

2003 ◽  
Vol 2003 (9) ◽  
pp. 544-545 ◽  
Author(s):  
Shujang Tu ◽  
Fang Fang ◽  
Chunbao Miao ◽  
Hong Jiang ◽  
Daqing Shi ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Biginelli Reaction ◽  
Aromatic Aldehydes ◽  
New Method ◽  
Reaction Conditions ◽  
One Pot ◽  
Cadmium Sulfate ◽  
Short Reaction Time ◽  
Effective Synthesis

A simple effective synthesis of 3,4-dihydropyrimidin-2(1 H)-one derivatives from aromatic aldehydes, 1,3-dicarbonyl compounds and urea in glacical acetic acid using cadmium sulfate as catalyst is described and compared with the classical Biginelli reaction conditions, this new method has the advantage of excellent yields (83–94%) and short reaction time (2-4 h).

Tyrosine-Selective Bioconjugation with Iminoxyl Radicals

2020 ◽  
Author(s):  
Katsuya Maruyama ◽  
Takashi Ishiyama ◽  
Yohei Seki ◽  
Kounosuke Oisaki ◽  
Motomu Kanai
Keyword(s):  
Reaction Time ◽  
Steric Hindrance ◽  
Room Temperature ◽  
Water Soluble ◽  
Light Irradiation ◽  
Sodium Ascorbate ◽  
Iminoxyl Radical ◽  
Short Reaction Time ◽  
Modified Peptides ◽  
The Stability

A novel Tyr-selective protein bioconjugation using the water-soluble persistent iminoxyl radical is described. The conjugation proceeded with high Tyr-selectivity and short reaction time under biocompatible conditions (room temperature in buffered media under air). The stability of the conjugates was tunable depending on the steric hindrance of iminoxyl. The presence of sodium ascorbate and/or light irradiation promoted traceless deconjugation, restoring the native Tyr structure. The method is applied to the synthesis of a protein-dye conjugate and further derivatization to azobenzene-modified peptides.

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