scholarly journals Chemoselective Attachment of the Water-Soluble Dark Quencher Hydrodabcyl to Amino Groups in Peptides and Preservation of Its Spectroscopic Properties over a Wide pH Range

ACS Omega ◽  
2021 ◽  
Author(s):  
Oxana Kempf ◽  
G. Matthias Ullmann ◽  
Rainer Schobert ◽  
Karl Kempf ◽  
Elisa Bombarda
2015 ◽  
Vol 18 (3) ◽  
pp. 170-180
Author(s):  
Anh Thi Tram Tu ◽  
Huy Thuc Ha

Highly deacetylated chitosan (CS) reacted with anhydride acetic (Ac2O) to produce chitosan with various degree of deacetylation (DDA) depending on the CS/Ac2O ratios. The structure of products was characterized by FT-IR, 1H NMR, 13C NMR, and the molecular weight was identified by GPC. The DDA of products decreases as the CS/Ac2O ratio increases. The products with less than 80 % DDA were soluble in water with a wide pH range. The water-soluble chitosan can be used in many biomedical applications such as manufacturing drug delivery systems or functionalized iron oxide nanoparticles.


2016 ◽  
Vol 65 (15) ◽  
pp. 751-758 ◽  
Author(s):  
Srijita Basumallick ◽  
Maria Gabriela Nogueira Campos ◽  
David Richardson ◽  
Andre Gesquiere ◽  
Swadeshmukul Santra

2019 ◽  
Vol 55 (82) ◽  
pp. 12312-12315 ◽  
Author(s):  
Lei Qin ◽  
James R. Wright ◽  
Jakob D. E. Lane ◽  
Stuart N. Berry ◽  
Robert B. P. Elmes ◽  
...  

Water soluble macrocyclic squaramides bind selectively to sulfate in aqueous–DMSO mixtures across a pH range from 3.2–14.


1997 ◽  
Vol 488 ◽  
Author(s):  
Xiaobo Shi ◽  
DeQuan Li ◽  
M. Lütt ◽  
M. R. Fitzsimmons ◽  
G. P. Van Patten

AbstractThis paper reports the synthesis and characterizations of a new water-soluble poly(paraphenylene) (PPP) and its applications in preparing self-assembled multi-layer films. This new water-soluble conducting polymer was prepared through the sulfonation reaction of poly(pquarterphenylene- 2,2'-dicarboxylic acid). The incorporation of sulfonate groups has dramatically improved PPP's solubility in water at a wide pH range, whereas previous PPP is only slightly soluble in basic solutions. Dilute aqueous solutions of this polymer with acidic, neutral or basic pH emit brilliant blue light while irradiated with UV light. The sulfonated PPP emits from 350 nm to 455 nm with a maximum intensity at 380 nm. Self-assembled multilayers of this sulfonated PPP were constructed with a positively charged polymer poly(diallyl dimethyl ammonium chloride) and characterized with various surface analyses. Conductive (RuO2 and ITO), semiconductive (Si wafer), and non-conductive (SiO2) substrates were used in the preparation of self-assembled multilayers. Electrical, optical and structural properties of these novel self-assembled thin films will be discussed.


RSC Advances ◽  
2014 ◽  
Vol 4 (43) ◽  
pp. 22651-22659 ◽  
Author(s):  
Wenchao Ding ◽  
Yong Liu ◽  
Yijing Li ◽  
Qiurong Shi ◽  
Houshen Li ◽  
...  

We present a simple strategy for synthesis of water-soluble, monodisperse, highly fluorescent gold nanoclusters (Au NCs) with sizes of 1.8 nm by co-reduction of glutathione and citrate for 24 h at 50 °C. The fluorescence intensity of the GS/C–Au NCs obtained is pH-dependent and can be reversibly adjusted in the pH range from 4.1 to 8.6.


2014 ◽  
Vol 10 ◽  
pp. 3007-3018 ◽  
Author(s):  
Milo Malanga ◽  
Mihály Bálint ◽  
István Puskás ◽  
Kata Tuza ◽  
Tamás Sohajda ◽  
...  

The fluorescent tagging of cyclodextrin derivatives enlarges their spectroscopic properties thus generating chemosensors, biological tools for visualization and sophisticated photoresponsive devices. Cyclodextrin polymers, due to the cooperative interactions, exhibit additional properties compared to their monomeric counterpart. These macromolecules can be prepared either in well water-soluble form or as gels of high swelling. Two versatile synthetic strategies for introducing a fluorescent tag (rhodamine, fluorescein, nitrobenzofuran or coumarin) into the water-soluble epichlorohydrin branched cyclodextrin polymers were worked out and compared. The fluorescent labeling was realized in three steps: 1) building in azido moieties, 2) transforming the azido groups into amino groups and 3) coupling the proper fluorescent compound to the amino groups. The other strategy started by functionalization of the monomer prior to the branching. Either the fluorescent-labeled monomer or the intermediate azido derivative of the monomer was branched. Further tuning of the properties of the polymer was achieved via branching of the methylated cyclodextrin derivative. The key intermediates and the fluorescent final products were characterized by various spectroscopic techniques and capillary electrophoresis. The applied synthetic routes were evaluated based on the molecular weight, cyclodextrin content of the products and the efficiency of labeling.


1967 ◽  
Vol 45 (6) ◽  
pp. 1225-1234 ◽  
Author(s):  
M. F. Li ◽  
Carol Flemming

Oyster hemolymph hemagglutinin agglutinated fish, rabbit, and human, red blood cells, was active over a wide pH range (optimum pH 7.5), and was heat-labile. Dialysis caused a greater reduction in the activity in the aged hemolymph than it did in the fresh hemolymph. Ultracentrifugation removed 90% of the protein; the remaining 11% retained all the activity. Gel filtration revealed two distinct hemagglutinins associated with two main protein peaks. Fractionation according to solubility gave seven different protein fractions, but only the salt-soluble and a very minor water-soluble Fraction possessed hemagglutinating activity. Agar-gel diffusion tests on the protein fractions showed a complexity of patterns which was partially resolved by immunoelectrophoretic techniques.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Atinuke O. Idowu ◽  
Adeola M. Alashi ◽  
Ifeanyi D. Nwachukwu ◽  
Tayo N. Fagbemi ◽  
Rotimi E. Aluko

Abstract This work evaluated the functional properties of sesame protein fractions in order to determine their potential in food applications. Sesame seed protein fractions were prepared according to their solubility: water-soluble (albumin), salt-soluble (globulin), alkaline-soluble (glutelin) and ethanol-soluble (prolamin). Globulin was the most abundant fraction, consisting of 91% protein, followed by glutelin, albumin and prolamin in decreasing order. Non-reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed polypeptides of sizes ≥20 kDa for albumin while glutelin and globulin had similar polypeptide sizes at 19, 85 and 100 kDa. Prolamin had polypeptide sizes 20, 40 and 100 kDa. The albumin and globulin fractions had higher intrinsic fluorescence intensity (FI) values than the glutelin. Albumin had a higher solubility (ranging from 80 to 100%) over a wide pH range when compared with the other fractions. Water holding capacity (g/g) reduced from 2.76 (glutelin) to 1.35 (prolamin) followed by 0.42 (globulin) and 0.08 (albumin). Oil holding capacity (g/g) reduced from: 4.13 (glutelin) to 2.57 (globulin) and 1.56, 1.50 for albumin and prolamin respectively. Gelling ability was stronger for prolamin and glutelin than albumin and globulin, while higher emulsion (p < 0.05) quality was obtained for prolamin and albumin than for glutelin and globulin. Graphical abstract


1991 ◽  
Vol 56 (12) ◽  
pp. 2791-2799 ◽  
Author(s):  
Juan A. Squella ◽  
Luis J. Nuñez-Vergara ◽  
Hernan Rodríguez ◽  
Amelia Márquez ◽  
Jose M. Rodríguez-Mellado ◽  
...  

Five N-p-phenyl substituted benzamidines were studied by DC and DP polarography in a wide pH range. Coulometric results show that the overall processes are four-electron reductions. Logarithmic analysis of the waves indicate that the process are irreversible. The influence of the pH on the polarographic parameters was also studied. A UV spectrophotometric study was performed in the pH range 2-13. In basic media some variations in the absorption bands were observed due to the dissociation of the amidine group. A determination of the pK values was made by deconvolution of the spectra. Correlations of both the electrochemical parameters and spectrophotometric pK values with the Hammett substituent constants were obtained.


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