scholarly journals A Fast and Convenient Synthesis of New Water-Soluble, Polyanionic Dendrimers

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4754
Author(s):  
Grzegorz M. Salamończyk

Reasonably simple, efficient, and possessing aspects of generality, the methodology for the synthesis of new, water-soluble, dendrimeric polyesters with great potential applications as antiviral drugs in their own right is described. The essential aspect of the presented approach is a quite unique, immediate access to the polyanionic material at each generation during divergent synthesis. Six target polyanionic dendrimers (generations 1, 2, and 3) have been synthesized. The key monomers applied in this project were 1,3,5-benzenetricarboxylic acid derivatives, which also worked as direct precursors of the charged dendrimer surface.

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Xiaodi Wang ◽  
Yongchao Zhang ◽  
Luyao Wang ◽  
Xiaoju Wang ◽  
Qingxi Hou ◽  
...  

AbstractAn efficient separation technology for hydrolysates towards a full valorization of bamboo is still a tough challenge, especially regarding the lignin and lignin-carbohydrate complexes (LCCs). The present study aimed to develop a facile approach using organic solvent extraction for efficiently fractionating the main components of bamboo hydrolysates. The high-purity lignin with only a trace of carbohydrates was first obtained by precipitation of the bamboo hydrolysate. The water-soluble lignin (WSL) fraction was extracted in organic solvent through a three-stage organic solvent extraction process, and the hemicellulosic sugars with increased purity were also collected. Furthermore, a thorough characterization including various NMR techniques (31P, 13C, and 2D-HSQC), GPC, and GC-MS was conducted to the obtained lignin-rich-fractions. It was found that the WSL fraction contained abundant functional groups and tremendous amount of LCC structures. As compared to native LCC of bamboo, the WSL fraction exhibited more typical LCC linkages, i.e. phenyl glycoside linkage, which is the main type of chemical linkage between lignin and carbohydrate in both LCC samples. The results demonstrate that organic phase extraction is a highly efficient protocol for the fractionation of hydrolysate and the isolation of LCC-rich streams possessing great potential applications.


Food Research ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 557-562
Author(s):  
M.D. Lieu ◽  
T.T.H. Hoang ◽  
H.N.T. Nguyen ◽  
T.K.T. Dang

Anthocyanin is a water-soluble color compound of the flavonoid which was successfully encapsulation in Saccharomyces cerevisiae by plasmolysis, ethanol, and ultrasound treatments using alone or in combination in the first time. Treatment agents significantly enhanced the encapsulation efficiency of anthocyanin fluid. The encapsulation yield (EY) of the combined factors was higher than the individual impact factors. Ethanol 10% (v/v) and ultrasound 180 seconds for the highest EY 40.22±0.67%, then ethanol 10% (v/v) and NaCl 10% (w/v) for EY 36.45±0.35%, NaCl 10% and ultrasound for EY 32.14±0.98% lowest. The color stability evaluation of the capsules was carried out at 80°C for 30 minutes. The color lost rate was determined by the spectrometer. The color loss of samples with the un-treatment yeast was 20.45±1.21%, higher than the treated sample. This suggests that anthocyanin encapsulation by yeast cell is efficient in overcoming the effects of high temperatures and having potential applications in food processing.


2011 ◽  
Vol 183-185 ◽  
pp. 1219-1223 ◽  
Author(s):  
Xiang Yu ◽  
Min Wang ◽  
Qun Hui Wang ◽  
Xu Ming Wang

Poly γ-glutamic acid (γ-PGA) is a kind of water soluble and biodegradable polymer, which is nontoxic toward humans and the environment. Therefore, the potential applications of γ-PGA and its derivatives have been of interest in a broad range such as food, cosmetics, medicine, water treatment and agriculture. This paper summarizes γ-PGA synthesis pathways in microorganisms, producing strains, fermentation parameters, as well as separation and purification methods. In addition, the prospect of γ-PGA application on agriculture was introduced, pointing out the problems and the future trends in research and application of γ-PGA.


2019 ◽  
Vol 91 (6) ◽  
pp. 983-995
Author(s):  
Thi-Thanh-Tam Nguyen ◽  
Sabrina Belbekhouche ◽  
Rémi Auvergne ◽  
Benjamin Carbonnier ◽  
Daniel Grande

Abstract Polyelectrolytes (PEs) bearing easily derivatizable functions for possible post-modification under mild conditions can find a broad range of applications in various fields. The present paper describes the successful controlled side-chain allylation of two types of PEs: polyamine-based polycations, i.e. poly(allylamine hydrochloride) (PAH) and branched polyethyleneimine (PEI), and strong polyanions, i.e. poly(sodium vinyl sulfonate) (PVS) and poly(sodium 4-styrene sulfonate) (PSS). PSS has been largely investigated in the literature, while PVS is much less commonly explored. The allylation of each type presents its own drawback, i.e. heterogeneous reaction in the case of strong polyanions and instability of partially protonated allylated polyamine products. Nevertheless, all encountered difficulties could be solved and thoroughly elucidated by different experimental tests. This partial allyl-functionalization does not affect the electrolytic properties of the newly allylated PEs, as evidenced by the effective construction of two series of polyelectrolyte multilayer (PEM) films, namely PEI-ene (PSS-ene/PAH-ene)4 and PEI-ene (PVS-ene/PAH-ene)4, the latter being one of the rare examples developed in the literature. The presence of allyl groups on the PE side-chains allows for the stabilization of the resulting PEM films via thiol-ene photo-crosslinking in the presence of a water-soluble dithiol crosslinker. In order to fix permanently the resulting crosslinked PEM films on substrates, the covalent crosslinking occurs not only between different C=C bonds on PE layers but also with those present on substrates preliminarily functionalized with allyl groups via sulfur–gold chemistry. The robustness of both resulting crosslinked PEM films under strongly basic solution (pH 14) is validated by Quartz Crystal Microbalance (QCM) measurements. The versatility and effectiveness of the present approach is expected to find potential applications in different scientific and technological fields.


Holzforschung ◽  
2007 ◽  
Vol 61 (3) ◽  
pp. 247-253 ◽  
Author(s):  
Ivo Safarik ◽  
Petra Lunackova ◽  
Ewa Mosiniewicz-Szablewska ◽  
Frantisek Weyda ◽  
Mirka Safarikova

Abstract A magnetically responsive composite material based on lignocellulose and magnetic nanoparticles has been prepared. Spruce sawdust was magnetically modified by contact with water-based magnetic fluid stabilised with perchloric acid. Electron spin resonance and transmission electron microscopy measurements indicated the presence of both individual magnetic nanoparticles and clusters precipitated on the surface of sawdust particles. The material prepared was used to study the adsorption of selected water-soluble organic dyes. The adsorption isotherms followed Langmuir, generalised Freundlich, generalised Langmuir, and Langmuir-Freundlich adsorption patterns. Maximum adsorption capacities for acridine orange, Bismarck brown, crystal violet, malachite green, methyl green, Nile blue, safranin O and Saturn blue LBRR 200 ranged between 34 and 59 mg g-1 dry adsorbent. A change in pH value can increase the dye adsorption. Ferrofluid-modified sawdust is thus an interesting material for further study and potential applications.


1986 ◽  
Vol 75 (7) ◽  
pp. 648-653 ◽  
Author(s):  
Richard A. Kenley ◽  
Stuart E. Jackson ◽  
John S. Winterle ◽  
Yelena Shunko ◽  
Gary C. Visor

2011 ◽  
Vol 89 (2) ◽  
pp. 122-129 ◽  
Author(s):  
Jaclyn A. O’Brien ◽  
Yin Lu ◽  
Emma N. Hooley ◽  
Kenneth P. Ghiggino ◽  
Ronald P. Steer ◽  
...  

The aggregation of metalloporphyrins is believed to play a crucial role in the excited-state annihilation process known as triplet–triplet annihilation, which in turn has significant potential applications in photon upconversion schemes. In this work, the propensity of the water-soluble metalloporphyrin zinc (II) meso-tetra(4-sulfonatophenyl)porphine to undergo aggregation when adsorbed to glass cover slips was investigated by single-molecule fluorescence microscopy. In proof-of-principle experiments, it was demonstrated (1) that individual molecules of the metalloporphyrin can be directly visualized in spite of their very weak fluorescence emission, and (2) that at low concentrations (10−8 mol/L), the molecule has a strong tendency to form multimolecular aggregates. A subset of the multimolecular aggregates shows a significant blue-shift in fluorescence emission, though at present the precise nature of the molecular aggregates remains unclear.


NANO ◽  
2016 ◽  
Vol 11 (07) ◽  
pp. 1650073 ◽  
Author(s):  
Lu Liu ◽  
Hu Xu ◽  
Bing Shen ◽  
Xinhua Zhong

Pentaerythritol tetrakis 3-mercaptopropionate (PTMP) grafted poly(acryl acid) (PAA) ionic hydrophilic oligomer PAA-PTMP (PP) and dihydrolipoic acid (DHLA) grafted methoxypoly(ethylene glycol) (mPEG) nonionic hydrophilic oligomer mPEG-DHLA (PD) have been designed, synthesized and used as co-capping ligands in water-solubilization of hydrophobic quantum dots (QDs) via ligand exchange. The obtained oligomers with multi-thiol groups could bind strongly to the surface atoms of QDs. Meanwhile, the carboxyl groups (from PP) and mPEG segment (from PD) can render QDs water-soluble, and the free carboxylic groups can possibly be used for the further bioconjugation. The resulting water-soluble QDs have been characterized by ultraviolet-visible (UV-Vis), fluorescence, Fourier transform infrared (FTIR) spectroscopy as well as transmission electron microscopy (TEM) and dynamic light scattering (DLS) techniques. The water-soluble QDs have relatively small hydrodynamic size (10[Formula: see text]12 nm), and importantly, retain high fluorescence quantum yields (up to 45%) compared with that of the originally hydrophobic QDs (49%). In addition, they have tunable surface charges and show excellent colloidal stability over a relatively broad pH range ([Formula: see text]), in high salt concentration, and even after thermal treatment at 100[Formula: see text]C. These results indicate that the water-soluble QDs coated by PP and PD oligomers have potential applications in cellular imaging and biosensor.


Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3195
Author(s):  
Hong Chen ◽  
Mehdi Vahdati ◽  
Pu Xiao ◽  
Frédéric Dumur ◽  
Jacques Lalevée

The development of visible-light 3D printing technology by using water-soluble initiating systems has attracted widespread attention due to their potential applications in the manufacture of hydrogels. Besides, at present, the preparation of water-soluble photoinitiators suitable for visible light irradiation (such as LEDs) still remains a challenge. Therefore, this work is devoted to developing water-soluble photoinitiators (PI)/photoinitiating systems (PIS) upon irradiation with a LED @ 405 nm. In detail, a new water-slightly-soluble chalcone derivative dye [(E)-3-(4-(dimethylamino) phenyl)-1-(4-(2-(2-(2-methoxyethoxy) ethoxy) ethoxy) phenyl) prop-2-en-1-one] was synthesized here and used as a PI with a water-soluble coinitiator, i.e., triethanolamine (TEA) which was also used as an electron donor. When combined together, a charge transfer complex (CTC) formed immediately which exhibited excellent initiating ability for the free radical photopolymerization of poly(ethyleneglycol)diacrylate (PEG-DA). In light of the powerful CTC effect, the [dye-TEA] CTC could not only exhibit enhanced water solubility and mechanical properties but could also be effectively applied for 3D printing. This CTC system is environmentally friendly and cost-saving which demonstrates a great potential to prepare hydrogels via photopolymerization.


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