scholarly journals Substituent Effects of Amines on Genipin Dye Formation – Insights into Dye Origins

2021 ◽  
Author(s):  
Fiona Jeeva ◽  
Chris Caputo
Keyword(s):  
Oxidative Polymerization ◽  
Substituent Effects ◽  
Gel Permeation Chromatography ◽  
Open Shell ◽  
Aliphatic Amines ◽  
Polymerization Reaction ◽  
Unique Reaction ◽  
Dye Absorption ◽  
Interesting Class

<p>Genipin, a naturally occurring iridoid, represents an interesting class of reactive dyes. This colorless molecule produces brilliant blue dyes in the presence of primary aliphatic amines. The mechanism behind this unique reaction has been suggested to proceed via an oxidative polymerization reaction, albeit few studies have investigated this process. By utilizing aromatic amines, we demonstrate that the dye absorption properties can be redshifted to form green dyes as opposed to the blue that is most associated with aliphatic amines. Characterization of the green material with gel-permeation chromatography, mass spectrometry, and electrochemical experiments suggest an alternate structure of the dye molecules and led us to revisit the mechanism behind this reaction. Generation of dyes from the reaction of genipin and methylamine or various aniline derivatives revealed the complete absence of polymeric material and instead revealed a material that contains an open-shell configuration as determined by EPR spectroscopy. Herein we report the first findings that dyes formed from the reaction of genipin with amines form persistent radicals that are likely responsible for their vibrant colors, as opposed to the previously suggested polymer formation. </p>

scholarly journals Substituent Effects of Amines on Genipin Dye Formation – Insights into Dye Origins

2021 ◽  
Author(s):  
Fiona Jeeva ◽  
Chris Caputo
Keyword(s):  
Oxidative Polymerization ◽  
Substituent Effects ◽  
Gel Permeation Chromatography ◽  
Open Shell ◽  
Aliphatic Amines ◽  
Polymerization Reaction ◽  
Unique Reaction ◽  
Dye Absorption ◽  
Interesting Class

<p>Genipin, a naturally occurring iridoid, represents an interesting class of reactive dyes. This colorless molecule produces brilliant blue dyes in the presence of primary aliphatic amines. The mechanism behind this unique reaction has been suggested to proceed via an oxidative polymerization reaction, albeit few studies have investigated this process. By utilizing aromatic amines, we demonstrate that the dye absorption properties can be redshifted to form green dyes as opposed to the blue that is most associated with aliphatic amines. Characterization of the green material with gel-permeation chromatography, mass spectrometry, and electrochemical experiments suggest an alternate structure of the dye molecules and led us to revisit the mechanism behind this reaction. Generation of dyes from the reaction of genipin and methylamine or various aniline derivatives revealed the complete absence of polymeric material and instead revealed a material that contains an open-shell configuration as determined by EPR spectroscopy. Herein we report the first findings that dyes formed from the reaction of genipin with amines form persistent radicals that are likely responsible for their vibrant colors, as opposed to the previously suggested polymer formation. </p>

Structural Characterization of Poly(o-Tolidine)

2005 ◽  
Vol 494 ◽  
pp. 357-362 ◽  
Author(s):  
G. Ćirić-Marjanović ◽  
B. Marjanović ◽  
M. Trchová ◽  
P. Holler
Keyword(s):  
Spectroscopic Analysis ◽  
Platinum Electrode ◽  
Electrochemical Polymerization ◽  
Oxidative Polymerization ◽  
Gel Permeation Chromatography ◽  
Chemical Oxidative Polymerization ◽  
Ammonium Peroxydisulfate ◽  
Gel Permeation ◽  
Ir Spectroscopic

A new polymer of o-tolidine was synthesized by chemical and electrochemical methods from its aqueous solutions in 1M HCl. Chemical oxidative polymerization was performed using ammonium peroxydisulfate as an oxidant. Electrochemical polymerization was carried out using two steps which were successively repeated in a continual process: first, holding the working platinum electrode under a constant anodic potential of +1.6 V, and second, the voltammetric cycle between +0.3 and +1.6 V. During this procedure a polymeric film was formed on the working electrode. Polymerization of o-tolidine was exactly proved by gel permeation chromatography evidencing the chains of molar masses in the range of 1000 – 12600 g mol─1. The structure of poly(o-tolidines) obtained by both chemical and electrochemical procedures was studied by IR spectroscopy. Coupling pathway N–C during polymerization, existence of quinonoid rings and hydrogen bonding involving NH group in polymeric products are revealed by IR spectroscopic analysis. The mechanism of o-tolidine oxidative polymerization is proposed.

scholarly journals Synthesis and Characterization of PSSA-Polyaniline Composite with an Enhanced Processability in Thin Films

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Corneliu Sergiu Stan ◽  
Marcel Popa ◽  
Marius Olariu ◽  
Marius Sebastian Secula
Keyword(s):  
Thin Films ◽  
Oxidative Polymerization ◽  
Polymerization Reaction ◽  
Polar Solvents ◽  
Force Microscopy ◽  
Molar Ratios ◽  
Glass Substrates ◽  
Atomic Force

AbstractThis paper reports the synthesis and investigation of a polymer composite based on poly(4-styrenesulfonic acid) (PSSA) and polyaniline (PANI) directly obtained in an aqueous PSSA medium, with improved conductivity and solubility in polar solvents. The oxidative polymerization reaction of aniline takes place in-situ with PSSA as protonating agent. The synthesis was tested at three PSSA/PANI molar ratios, an intense green colored aqueous composite solution being obtained in each case. For comparison purposes, commercially available polyaniline and PSSA were also investigated. PSSA-PANI composites, PANI and PSSA were investigated through thermal analysis, Fourier Transform Infrared Spectroscopy (FTIR) and Raman spectroscopy. Thin films of PSSA/PANI complex were spin coated on glass substrates which were further investigated through Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). Also, thin films of PSSA-PANI were deposited on interdigitated electrodes for dielectric measurements.

scholarly journals Molar mass determination of lignins and characterization of their polymeric structures by multi-detector gel permeation chromatography

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Evamaria C. Gaugler ◽  
Wolfgang Radke ◽  
Andrew P. Vogt ◽  
Dawn A. Smith
Keyword(s):  
Molar Mass ◽  
Lithium Bromide ◽  
Gel Permeation Chromatography ◽  
Mass Determination ◽  
Organosolv Lignin ◽  
Gel Permeation ◽  
Softwood Kraft Lignin ◽  
Polymeric Structures

AbstractMolar masses, Mark-Houwink-Sakurada (MHS) exponents, and refractive index increments (dn/dc) for three lignins were determined without derivatization by multi-detector gel permeation chromatography (GPC) in dimethylformamide (DMF) with 0.05 M lithium bromide (LiBr). The lack of effectiveness of fluorescence filters on molar mass determination by GPC-multi-angle laser light scattering (MALS) was confirmed for softwood kraft lignin (Indulin AT) and revealed for mixed hardwood organosolv lignin (Alcell) as well as soda straw/grass lignin (Protobind 1000). GPC with viscometry detection confirmed that these lignins were present as compact molecules. The MHS exponent α for Indulin AT and Alcell was in the order of 0.1. Additionally, the intrinsic viscosity of Protobind 1000 for a given molar mass was much lower than that of either Alcell or Indulin AT. This is the first report of dn/dc values for these three lignins in DMF with 0.05 M LiBr.

scholarly journals Grape Seeds Proanthocyanidins: Advanced Technological Preparation and Analytical Characterization

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 418
Author(s):  
Paolo Morazzoni ◽  
Paola Vanzani ◽  
Sandro Santinello ◽  
Antonina Gucciardi ◽  
Lucio Zennaro ◽  
...  
Keyword(s):  
High Resolution Mass Spectrometry ◽  
Industrial Process ◽  
Gel Permeation Chromatography ◽  
Grape Seed ◽  
Direct Infusion ◽  
Grape Seeds ◽  
Flow Filtration ◽  
Process Patent ◽  
Shotgun Approach

A “green” solvent-free industrial process (patent pending) is here described for a grape seed extract (GSE) preparation (Ecovitis™) obtained from selected seeds of Veneto region wineries, in the northeast of Italy, by water and selective tangential flow filtration at different porosity. Since a comprehensive, non-ambiguous characterization of GSE is still a difficult task, we resorted to using an integrated combination of gel permeation chromatography (GPC) and electrospray ionization high resolution mass spectrometry (ESI-HRMS). By calibration of retention time and spectroscopic quantification of catechin as chromophore, we succeeded in quantifying GPC polymers up to traces at n = 30. The MS analysis carried out by the ESI-HRMS method by direct-infusion allows the detection of more than 70 species, at different polymerization and galloylation, up to n = 13. This sensitivity took advantage of the nanoscale shotgun approach, although paying the limit of missed separation of stereoisomers. GPC and MS approaches were remarkably well cross-validated by overlapping results. This simple integrated analytical approach has been used for quality control of the production of Ecovitis™. The emerging feature of Ecovitis™ vs. a popular benchmark in the market, produced by a different technology, is the much lower content of species at low n and the corresponding increase of species at high n.

scholarly journals Chondroitinase ABC digestion of dermatan sulphate. N.m.r. spectroscopic characterization of the oligo- and poly-saccharides

1989 ◽  
Vol 257 (2) ◽  
pp. 347-354 ◽  
Author(s):  
P N Sanderson ◽  
T N Huckerby ◽  
I A Nieduszynski
Keyword(s):  
Gel Permeation Chromatography ◽  
Spectroscopic Characterization ◽  
Repeat Sequence ◽  
Chemical Shift Assignments ◽  
Dermatan Sulphate ◽  
Chondroitinase Abc ◽  
Experimental Conditions ◽  
Full Analysis ◽  
Unsaturated Uronate

Dermatan sulphates, in which iduronate was the predominant uronate constituent, were partially digested by chondroitinase ABC to produce oligosaccharides of the following structure: delta UA-[GalNAc(4SO3)-IdoA]mGalNAc(4SO3) [where m = 0-5, delta UA represents beta-D-gluco-4-enepyranosyluronate, IdoA represents alpha-L-iduronate and GalNAc(4SO3) represents 2-acetamido-2-deoxy-beta-D-galactose 4-O-sulphate], which were fractionated by gel-permeation chromatography and examined by 100 MHz 13C-n.m.r. and 400/500 MHz 1H-n.m.r. spectroscopy. Experimental conditions were established for the removal of non-reducing terminal unsaturated uronate residues by treatment with HgCL2, and reducing terminal N-acetylgalactosamine residues of the oligosaccharides were reduced with alkaline borohydride. These modifications were shown by 13C-n.m.r. spectroscopy to have proceeded to completion. Assignments of both 13C-n.m.r. and 1H-n.m.r. resonances are reported for the GalNAc(4SO3)-IdoA repeat sequence in the oligosaccharides as well as for the terminal residues resulting from enzyme digestion and subsequent modifications. A full analysis of a trisaccharide derived from dermatan sulphate led to the amendment of published 13C-n.m.r. chemical-shift assignments for the polymer.

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