A Fourier transform infrared study of the electrophilic attack at the N7-site of guanosine-5′-monophosphate

1984 ◽  
Vol 62 (2) ◽  
pp. 266-272 ◽  
Author(s):  
H. A. Tajmir-Riahi ◽  
T. Theophanides
Keyword(s):  
Fourier Transform ◽  
Infrared Spectra ◽  
Fourier Transform Infrared ◽  
Divalent Metal ◽  
Ring System ◽  
Disodium Salt ◽  
Divalent Metal Ions ◽  
Electrophilic Attack ◽  
Infrared Study ◽  
Spectral Changes

Fourier transform infrared spectra of several N7-bound cations of guanosine-5′monophosphate disodium salt (5′-GMPNa2), such as N7-H+GMP, N7-MeGMP, and N7-MGMP, where Me = CH3+ and M = divalent metal ions, Cd, Mn, Co, Ni, Cu, Pt, and Mg, have been recorded and a correlation between the spectral changes and the nature of the electrophile (H+, CH3+, and M2+) bound has been established. Spectroscopic evidence shows that methylation of the N7-position of 5′-GMPNa2 causes larger perturbation on the guanine ring system than protonation or metalation, in the order Me+ > H+ > M2+. The effect of an N7-electrophilic attack on the vibrational frequencies of the purine, the sugar, and the phosphate group is discussed.

Synthesis, characterization, and their some chemical and biological properties of PVA/PAA/nPS hydrogel nanocomposites: Hydrogel and wound dressing

2020 ◽  
Vol 35 (3) ◽  
pp. 203-215
Author(s):  
Mehmet Emin Diken ◽  
Berna Koçer Kizilduman ◽  
Begümhan Yilmaz Kardaş ◽  
Enes Emre Doğan ◽  
Mehmet Doğan ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Acrylic Acid ◽  
Infrared Spectra ◽  
Vinyl Alcohol ◽  
Fourier Transform Infrared ◽  
Poly Vinyl Alcohol ◽  
Seed Particles ◽  
Fourier Transform Infrared Spectra ◽  
Hydrogel Nanocomposites ◽  
Poly Acrylic Acid

The nanocomposite hydrogels were prepared by dispersing of the nanopomegranate seed particles into poly(vinyl alcohol)/poly(acrylic acid) blend matrix in an aqueous medium by the solvent casting method. These hydrogels were characterized using scanning electron microscopy, Fourier transform infrared spectra, differential scanning calorimetry, and optical contact angle instruments. The nanopomegranate seed, blend, and hydrogel nanocomposites were tested for microbial activity. In addition, cytocompatibilities of these blend and hydrogel nanocomposites/composites were tested on human lymphocyte with in vitro MTS cell viability assays. Fourier transform infrared spectra revealed that esterification reaction took place among functional groups in the structure of poly(vinyl alcohol) and poly(acrylic acid). The hydrophilic properties of all hydrogels decreased with increasing nanopomegranate seed content. The mean diameters of the nanopomegranate seed particles were about 88 nm. Nanopomegranate seed particles demonstrated antibacterial properties against gram-positive bacteria, Staphylococcus aureus, and gram-negative bacteria, Escherichia coli. The lymphocyte viabilities increased after addition of nanopomegranate seeds into the polymer blend. The swelling behavior of blend and hydrogels was dependent on the cross-linking density created by the reaction between poly(vinyl alcohol)/poly(acrylic acid) blend and nanopomegranate seed. Scanning electron microscopy images were highly consistent with Fourier transform infrared spectra, differential scanning calorimetry, and antibacterial activity results.

A Practical Real-Time Fourier Transform Infrared Detector for Liquid Chromatography

1978 ◽  
Vol 32 (5) ◽  
pp. 502-506 ◽  
Author(s):  
D. Warren Vidrine ◽  
David R. Mattson
Keyword(s):  
Fourier Transform ◽  
Liquid Chromatography ◽  
Real Time ◽  
Infrared Spectra ◽  
Infrared Detector ◽  
Fourier Transform Infrared ◽  
Paraffin Oil ◽  
Chromatographic Detection ◽  
Liquid Chromatographic ◽  
System Capability

A practical Fourier transform infrared system for real-time liquid chromatographic detection is described. Simple flowcell detection with automatic solvent subtraction is used, and detection of 500 ng of injected paraffin oil is demonstrated. Results from several chromatographic runs illustrate the system capability to serve as a real time infrared detector and simultaneously acquire infrared spectra.

Fourier transform infrared study of high-purity maceral types

Fuel ◽  
1984 ◽  
Vol 63 (4) ◽  
pp. 536-542 ◽  
Author(s):  
Gary R. Dyrkacz ◽  
Carol A.A. Bloomquist ◽  
Peter R. Solomon
Keyword(s):  
Fourier Transform ◽  
High Purity ◽  
Fourier Transform Infrared ◽  
Infrared Study

Fourier transform infrared study of coal tar pitches

Fuel ◽  
1995 ◽  
Vol 74 (11) ◽  
pp. 1595-1598 ◽  
Author(s):  
Maria D. Guillén ◽  
Maria J. Iglesias ◽  
Antonio Domínguez ◽  
Carlos G. Blanco
Keyword(s):  
Fourier Transform ◽  
Coal Tar ◽  
Fourier Transform Infrared ◽  
Infrared Study

A fourier transform infrared study of the coagel to micelle transitions of sodium laurate and sodium oleate

1982 ◽  
Vol 4 (2) ◽  
pp. 131-145 ◽  
Author(s):  
David G. Cameron ◽  
Junzo Umemura ◽  
Patrick T.T. Wong ◽  
Henry H. Mantsch
Keyword(s):  
Fourier Transform ◽  
Sodium Oleate ◽  
Fourier Transform Infrared ◽  
Sodium Laurate ◽  
Infrared Study

Fourier-Transform Infrared Spectroscopy of Environmentally Weathered Textile Fabrics for Enhanced Microplastic Identification

2021 ◽  
Author(s):  
Shreyas Patankar ◽  
Ekaterina Vassilenko ◽  
Mathew Watkins ◽  
Anna Posacka ◽  
Peter Ross
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Infrared Spectra ◽  
Environmental Fate ◽  
Uv Light ◽  
Natural Fibers ◽  
Fourier Transform Infrared ◽  
Ambient Conditions ◽  
Selection Of

<p>Microplastic pollution in oceans is among the global environmental concerns of our time. Emerging research on ocean environments indicates that microfibers, such as those originating from textiles, are some of the most commonly occurring type of microplastic contaminants. While Fourier-transform infrared spectroscopy (FTIR) is commonly used to identify and characterize pollutant samples obtained from the environment, this identification is challenging because infrared spectra of materials can be modified by exposure to the ocean, air, UV light, and other ambient conditions, in a process referred to as “weathering”. We report preliminary efforts in improving FTIR characterization of microplastics by building a library of infrared spectra of common textile fibers weathered under a selection of ambient conditions. Consumer textile materials including polyester, nylon, cotton, and other, were exposed to a selection of ambient conditions: ocean, air, and wastewater treatment stages, in a controlled weathering experiment. Infrared spectra were monitored for up to 52 weeks, with the resulting data illuminating on the environmental fate and longevity of synthetic and natural fibers. Spectral changes caused by weathering were found to depend strongly on both the composition of the material and the specific ambient conditions. This library of weathered material spectra is useful not only in easier identification of environmental microfibers, but also in helping us estimate the duration and manner of weathering that a given environmental microfiber may have experienced.</p>

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