Quinone–amine polymers. II. 1,3‐bis(3‐aminophenoxy) benzene‐<i>p</i>‐benzoquinone oligomers

Kaleem, K.; Chertok, F.; Erhan, Semih

doi:10.1002/pola.1989.080270312

Cited by 36 publications

(14 citation statements)

References 6 publications

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“…When chitosan films were incubated in methanol/buffer solutions containing both tyrosinase and hexyloxyphenol, the film changed from colorless to brown. Figure 3a shows a large increase in the absorbance of this film in the 350-nm region which is consistent with a reaction between the quinone and amino groups (Kaleem et al, 1989;Erhan, 1991, 1998;Yamamoto et al, 1990). Control films incubated with either hexyloxyphenol or tyrosinase did not change color upon incubation, and Fig.…”

Section: Chemical Evidence For the Covalent Modification Of Chitosansupporting

confidence: 69%

Enzymatic grafting of hexyloxyphenol onto chitosan to alter surface and rheological properties

Chen

Kumar

Harris

et al. 2000

Biotechnol. Bioeng.

115

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An enzymatic method to graft hexyloxyphenol onto the biopolymer chitosan was studied. The method employs tyrosinase to convert the phenol into a reactive o‐quinone, which undergoes subsequent nonenzymatic reaction with chitosan. Reactions were conducted under heterogeneous conditions using chitosan films and also under homogeneous conditions using aqueous methanolic mixtures capable of dissolving both hexyloxyphenol and chitosan. Tyrosinase was shown to catalyze the oxidation of hexyloxyphenol in such aqueous methanolic solutions. Chemical evidence for covalent grafting onto chitosan was provided by three independent spectroscopic approaches. Specifically, enzymatic modification resulted in (1) the appearance of broad absorbance in the 350‐nm region of the UV/vis spectra for chitosan films; (2) changes in the NH bending and stretching regions of chitosan's IR spectra; and (3) a base‐soluble material with 1H‐NMR signals characteristic of both chitosan and the alkyl groups of hexyloxyphenol. Hexyloxyphenol modification resulted in dramatic changes in chitosan's functional properties. On the basis of contact angle measurements, heterogeneous modification of a chitosan film yielded a hydrophobic surface. Homogeneously modified chitosan offered rheological properties characteristic of associating water‐soluble polymers. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 70: 564–573, 2000.

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Section: Chemical Evidence For the Covalent Modification Of Chitosansupporting

confidence: 69%

Enzymatic grafting of hexyloxyphenol onto chitosan to alter surface and rheological properties

Chen

Kumar

Harris

et al. 2000

Biotechnol. Bioeng.

115

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“…Natural and synthetic quinone–amine polymers have received considerable attention due to their unique properties and potential applications in various technical fields such as conducting materials, corrosion inhibitors for mild steels, and coating materials 1–6. Three kinds of novel poly(aromatic amino‐2,3‐pyridinedione) oligomers, including poly(4,4′‐methylenedianiline–2,3‐pyridinedione, PMDAP), poly(4,4′‐ethylene dianiline–2,3‐pyridinedione, PEDAP), and poly(4,4′‐sulfonyldianiline–2,3‐pyridinedione, PSDAP), have been synthesized by our cooperative work group.…”

Section: Methodsmentioning

confidence: 99%

Characterization of novel poly(aromatic amine‐2,3‐pyridinedione) oligomers by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

Deng¹,

Zhang²,

Deng³

et al. 2003

Rapid Comm Mass Spectrometry

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“…Thus, the observed absorbance peaks at 305 and 350 nm cannot be attributed to either cresol or its quinone. It has been reported that the reaction of quinones with amines can result in the formation of Michael's-type adducts that have maximum absorptivities between 340 and 400 nm (Nithianandam and Erhan, 1998;Kaleem et al, 1989;Yamamoto et al, 1990). These observations suggest that binding to chitosan may be due to reactions between quinones and chitosan's primary amino groups.…”

Section: Reaction Of Phenol Vapors With Tyrosinase-coated Chitosan Filmsmentioning

confidence: 99%

Enzymatic coupling of phenol vapors onto chitosan

Chen

Wallace

et al. 2001

Biotech & Bioengineering

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Phenols are important industrial chemicals, and because they can be volatile, also appear as air pollutants. We examined the potential of tyrosinase to react with the volatile phenol p-cresol. Three lines of evidence support the conclusion that volatile phenols react with tyrosinase and are coupled (i.e., chemisorbed) onto chitosan films. First, phenol-trapping studies indicated that p-cresol can be removed from vapors if the vapors are contacted with tyrosinase-coated chitosan films. Second, the ultraviolet absorbance of tyrosinase-coated chitosan films changes dramatically when they are contacted with cresol-containing vapors, whereas control films are unaffected by contacting with cresol vapors. Third, pressure measurements indicate that tyrosinase-coated chitosan films only react with cresol vapors if the oxygen cosubstrate is present. Additional studies demonstrate the potential of tyrosinase-coated chitosan films/membranes for the detection and removal of phenol vapors.

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Quinone–amine polymers. II. 1,3‐bis(3‐aminophenoxy) benzene‐p‐benzoquinone oligomers

Cited by 36 publications

References 6 publications

Enzymatic grafting of hexyloxyphenol onto chitosan to alter surface and rheological properties

Enzymatic grafting of hexyloxyphenol onto chitosan to alter surface and rheological properties

Characterization of novel poly(aromatic amine‐2,3‐pyridinedione) oligomers by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

Enzymatic coupling of phenol vapors onto chitosan

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