scholarly journals Synthesis of selectively modified cellulose derivatives via reductive amination of 2-oxy- and 3-oxy-cellulose intermediates

1984 ◽  
Vol 62 (2) ◽  
pp. 260-262 ◽  
Author(s):  
Manssur Yalpani ◽  
Laurance D. Hall ◽  
Jacques Defaye ◽  
Andrée Gadelle
Keyword(s):  
Crown Ether ◽  
Reductive Amination ◽  
Ammonium Acetate ◽  
Water Soluble ◽  
Cellulose Derivatives ◽  
Oxidized Cellulose ◽  
Sodium Cyanoborohydride ◽  
Chromium Tricarbonyl ◽  
Derivatives Of ◽  
Modified Cellulose

Diamagnetic and paramagnetic amine derivatives of cellulose have been prepared from selectively oxidized cellulose precursors via the reductive amination method using sodium cyanoborohydride. 4-Amino-2,2,6,6-tetramethylpiperidine-1-oxyl was employed in the syntheses of nitroxide spin labelled cellulose derivatives 4 and 5 from 3-oxy-cellulose (1) and 6-O-triphenylmethyl-2-oxy-cellulose (2). Conversion of the linear polymer 1 into a highly branched, water soluble 3-deoxy-cellulose derivative 6 was accomplished by attachment of glucosamine side chains. 3-Amino-3-deoxy-cellulose 7 was obtained using ammonium acetate. A novel type of organometallic cellulose conjugate 8 was prepared by condensation of 2 and p-toluidine chromium tricarbonyl. Similarly, 1,10-diazo-18-crown-6 was added to 2 to form the crown ether derivative 9. The synthetic strategies involving either 6-O protected or unprotected oxy-cellulose intermediates are compared in terms of reaction yields and product properties.

Fractionation of wood polymers by carboxymethylation: Exploring the strategy

TAPPI Journal ◽  
2012 ◽  
Vol 11 (1) ◽  
pp. 29-37 ◽  
Author(s):  
SHANG-NING CHIEN ◽  
THOMAS E. AMIDON ◽  
YUAN-ZONG LAI
Keyword(s):  
Industrial Applications ◽  
Water Soluble ◽  
Hot Water ◽  
Insoluble Residue ◽  
Cellulose Derivatives ◽  
Initial Water ◽  
Pre Treatment ◽  
Cellulose Component ◽  
Derivatives Of

We explored the feasibility of fractionating wood polymers in situ by carboxymethylation to yield the carboxymethyl derivatives of cellulose (CMC), hemicelluloses, and lignin for potential industrial applications. The initial water-soluble materials formed were a mixture of hemicelluloses and cellulose derivatives, and also contained some lignin (3%–5%). Interestingly, the water-insoluble residue after another carboxymethylation treatment gave essentially a CMC product containing less than 1% of residual lignin. Thus, the bulk of wood lignin is less reactive than the polysaccharide components under typical carboxymethylation conditions. Also, a hot water pre-extraction or dilute acid pre-treatment of wood samples was found to significantly enhance the reactivity of the cellulose component. A preextraction approach would facilitate CMC preparation and also provide the flexibility to convert the extracted hemicelluloses to other bio-based fuels or materials.

scholarly journals Easy assembly of ligands for glycosidase affinity chromatography

1990 ◽  
Vol 270 (2) ◽  
pp. 539-540 ◽  
Author(s):  
R C Bernotas ◽  
B Ganem
Keyword(s):  
Amino Acids ◽  
Affinity Chromatography ◽  
Enzyme Purification ◽  
Reductive Amination ◽  
Water Soluble ◽  
High Yield ◽  
Glycosidase Inhibitors ◽  
Neutral Ph ◽  
Sepharose 4B ◽  
Derivatives Of

An improved, high-yield synthesis of the corresponding N-carboxypentyl derivatives of three iminoalditol glycosidase inhibitors has been developed for affinity chromatography enzyme purification. Reductive amination of 1-deoxynojirimycin (or its D-manno or D-galacto analogues) with methyl 5-formylvalerate and NaBH3CN at neutral pH afforted an aminoester which upon hydrolysis with aqueous 5% HCl gave the desired aminoacid in 97% overall yield. These amino acids could then be covalently attached using water-soluble carbodi-imide to 6-aminohexyl Sepharose 4B.

scholarly journals SYNTHESIS AND ANTIRADICAL ACTIVITY OF HINDERED PHENOLIC DERIVATIVES OF FLAX CELLULOSE

2020 ◽  
pp. 47-54
Author(s):  
Sergey Vladimirovich Bukharov ◽  
Yuliya Maskhutovna Sadykova ◽  
Timur Erkinovich Umarov ◽  
Aleksandr Romanovich Burilov ◽  
Gul'nara Nailovna Nugumanova ◽  
...  
Keyword(s):  
Antiradical Activity ◽  
Acid Hydrazide ◽  
Analysis Data ◽  
Degree Of Substitution ◽  
Elemental Analysis Data ◽  
Cellulose Derivatives ◽  
Hindered Phenol ◽  
The Difference ◽  
Derivatives Of ◽  
Modified Cellulose

The modification of powdered ultradisperse cellulose by hindered phenol fragments was carried out. The modification was carried out by reacting cellulose tosylate with 3-(3',5'-ditert-butyl-4'-hydroxyphenyl) propionic acid hydrazide and 3,5-ditert-butyl-4-hydroxybenzyl dimethylamine in DMF at 100 ○C for 16–30 hours. Samples of modified cellulose were characterized by spectroscopy IR and 1H NMR. From the of elemental analysis data, the degree of substitution of cellulose derivatives by hindered phenol units was calculated. The antiradical activity of the obtained samples in their reactions with a stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) was determined. The reactions of modified cellulose with DPPH were carried out under the pseudo first-order conditions with respect to the radical. From the values of the effective constants, the second-order rate constants were calculated. It was established that the modification of cellulose by hindered phenol fragments leads to a sharp increase in its antiradical activity, which depends on the degree of substitution of the sample and the method of substitution. The difference in the activity of hydrazide and benzyl derivatives of cellulose may indicate their different spatial structure, resulting in different availability of phenol fragments. The antiradical activity of the hydrazide derivative of cellulose exceeds that of the antioxidant Ionol (2,6-ditert-butyl-4-methylphenol).

Potential anticonvulsants: Substituted N-benzylidene derivatives of 10-(4-aminopiperazino)-10,11-dihydrodibenzo[b,f]thiepins

1983 ◽  
Vol 48 (4) ◽  
pp. 1173-1186 ◽  
Author(s):  
Václav Bártl ◽  
Jiří Holubek ◽  
Emil Svátek ◽  
Marie Bartošová ◽  
Miroslav Protiva
Keyword(s):  
Acute Toxicity ◽  
Water Soluble ◽  
Hypotensive Activity ◽  
Anticonvulsant Effect ◽  
Maximal Electroshock ◽  
Soluble Salts ◽  
Sleeping Time ◽  
Central Depression ◽  
Derivatives Of ◽  
Electroshock Seizures

Reactions of 10-(4-aminopiperazino)-10,11-dihydrodibenzo[b,f]thiepins XIVa-XIVd with benzaldehyde, 3,4-dimethoxybenzaldehyde, 4-dimethylaminobenzaldehyde, salicylaldehyde, 3-ethoxy-4-hydroxybenzaldehyde, 2-(2-dimethylaminoethoxy)benzaldehyde, 3-(2-dimethylaminoethoxy)benzaldehyde and 3-ethoxy-4-(2-dimethylaminoethoxy)benzaldehyde afforded a series of 19 hydrazones IIIa-Xc. Some of them showed the expected anticonvulsant effect but only towards pentetrazole; antagonism of maximal electroshock seizures was not observed. In general, the products have a character of tranquillizers: in higher does they produce central depression, potentiate the thiopental sleeping time, have hypothermic action; in single cases antiamphetamine, antireserpine, antihistamine and cataleptic effects were observed. The water-soluble salts of the basic hydrazones VIIIa, VIIIc, IXc and Xc, administered parenterally, showed a rather high acute toxicity and revealed also adrenolytic and hypotensive activity.

scholarly journals Antioxidant Network Based on Sulfonated Polyhydroxyalkanoate and Tannic Acid Derivative

2021 ◽  
Vol 8 (1) ◽  
pp. 9
Author(s):  
Laura Brelle ◽  
Estelle Renard ◽  
Valerie Langlois
Keyword(s):  
Gallic Acid ◽  
Tannic Acid ◽  
Water Soluble ◽  
Gel Formation ◽  
Ene Reaction ◽  
Inorganic Cations ◽  
Medium Chain Length ◽  
Physically Crosslinked ◽  
The Stability ◽  
Derivatives Of

A novel generation of gels based on medium chain length poly(3-hydroxyalkanoate)s, mcl-PHAs, were developed by using ionic interactions. First, water soluble mcl-PHAs containing sulfonate groups were obtained by thiol-ene reaction in the presence of sodium-3-mercapto-1-ethanesulfonate. Anionic PHAs were physically crosslinked by divalent inorganic cations Ca2+, Ba2+, Mg2+ or by ammonium derivatives of gallic acid GA-N(CH3)3+ or tannic acid TA-N(CH3)3+. The ammonium derivatives were designed through the chemical modification of gallic acid GA or tannic acid TA with glycidyl trimethyl ammonium chloride (GTMA). The results clearly demonstrated that the formation of the networks depends on the nature of the cations. A low viscoelastic network having an elastic around 40 Pa is formed in the presence of Ca2+. Although the gel formation is not possible in the presence of GA-N(CH3)3+, the mechanical properties increased in the presence of TA-N(CH3)3+ with an elastic modulus G’ around 4200 Pa. The PHOSO3−/TA-N(CH3)3+ gels having antioxidant activity, due to the presence of tannic acid, remained stable for at least 5 months. Thus, the stability of these novel networks based on PHA encourage their use in the development of active biomaterials.

1,3-dipolar cycloaddition in the synthesis of glycoconjugates of natural chlorins and bacteriochlorins

2009 ◽  
Vol 13 (03) ◽  
pp. 336-345 ◽  
Author(s):  
Mikhail A. Grin ◽  
Ivan S. Lonin ◽  
Anna A. Lakhina ◽  
Elena S. Ol'shanskaya ◽  
Alexey I. Makarov ◽  
...  
Keyword(s):  
Triple Bond ◽  
Tautomeric Form ◽  
Click Reaction ◽  
Copper Cation ◽  
Water Soluble ◽  
Dipolar Cycloaddition ◽  
Nmr Studies ◽  
Metal Free ◽  
Cu Complex ◽  
Derivatives Of

Glucose-, galactose- and lactose-containing photosensitizers based on derivatives of chlorophyll a and bacteriochlorophyll a were synthesized with the use of [3+2] cycloaddition between sugar azides and triple bond derivatives of chlorins and bacteriochlorins. Unlike bacteriochlorin cycloimide, chlorin was detected to form a Cu -complex during the click reaction. An approach to the synthesis of metal-free glycosylated chlorins was developed with the use of "protection" by Zn 2+ cation and subsequent demetalation. It is based on the action of alkynyl chlorin e6 derivative Zn -complex, which is resistant to the substitution by copper cation. Bacteriochlorin p cycloimide conjugate with per-acetylated β-D-lactose was obtained and shown to become water-soluble after unblocking of the lactose hydroxy functions. NMR studies allowed for the elucidation of structure, tautomeric form and conformation of the obtained compounds.

Influence of water-soluble derivatives of [60]fullerene on therapeutically important targets related to neurodegenerative diseases

MedChemComm ◽  
2014 ◽  
Vol 5 (11) ◽  
pp. 1664-1668 ◽  
Author(s):  
R. A. Kotelnikova ◽  
A. V. Smolina ◽  
V. V. Grigoryev ◽  
I. I. Faingold ◽  
D. V. Mischenko ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Cognitive Functioning ◽  
Water Soluble ◽  
Neuroprotective Agents ◽  
Fullerene Derivatives ◽  
Influence Of Water ◽  
Derivatives Of

Water soluble fullerene derivatives I and II were shown to behave as promising neuroprotective agents that improve cognitive functioning in animals.

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