scholarly journals Potential of Kale and Lettuce Residues as Natural Adsorbents of the Carcinogen Aflatoxin B1 in a Dynamic Gastrointestinal Tract-Simulated Model

Toxins ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 771
Author(s):  
Alma Vázquez-Durán ◽  
María de Jesús Nava-Ramírez ◽  
Daniel Hernández-Patlán ◽  
Bruno Solís-Cruz ◽  
Víctor Hernández-Gómez ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Gastrointestinal Tract ◽  
Aflatoxin B1 ◽  
Electrostatic Interactions ◽  
Hydrophobic Interactions ◽  
Maximum Adsorption Capacity ◽  
Promising Alternative ◽  
Simulated Model ◽  
Dipole Interactions ◽  
Natural Adsorbents

Adsorption of the carcinogen aflatoxin B1 (AFB1) onto agro-waste-based materials is a promising alternative over conventional inorganic binders. In the current study, two unmodified adsorbents were eco-friendly prepared from kale and lettuce agro-wastes. A dynamic gastrointestinal tract-simulated model was utilized to evaluate the removal efficiency of the sorptive materials (0.5%, w/w) when added to an AFB1-contaminated diet (100 µg AFB1/kg). Different characterization methodologies were employed to understand the interaction mechanisms between the AFB1 molecule and the biosorbents. Based on adsorption results, the biosorbent prepared from kale was the best; its maximum adsorption capacity was 93.6%, which was significantly higher than that of the lettuce biosorbent (83.7%). Characterization results indicate that different mechanisms may act simultaneously during adsorption. Non-electrostatic (hydrophobic interactions, dipole-dipole interactions, and hydrogen bonding) and electrostatic interactions (ionic attractions) together with the formation of AFB1-chlorophyll complexes appear to be the major influencing factors driving AFB1 biosorption.

scholarly journals Physicochemical characterization of three natural clays used as adsorbent for the humic acid removal from aqueous solution

2018 ◽  
Vol 37 (1-2) ◽  
pp. 77-94 ◽  
Author(s):  
Soumahoro Gueu ◽  
Gisèle Finqueneisel ◽  
Thierry Zimny ◽  
Danièle Bartier ◽  
Benjamin Kouassi Yao
Keyword(s):  
Humic Acid ◽  
Adsorption Capacity ◽  
Ligand Exchange ◽  
Electrostatic Interactions ◽  
Hydrophobic Interactions ◽  
Physicochemical Characterization ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Natural Clays

Adsorption behaviours of humic acid on three natural clays from Ivory Coast were studied. In order to investigate the adsorption mechanism, characterization of clays and the humic acid–clay complex was conducted by using various analytical methods (attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), specific surface area analysis (BET) and chemical composition). As a result, adsorption process showed that the maximum adsorption capacity of humic acid was achieved at pH = 3 and was found to be to 115 mg/g obtained for the best sample. For all clays, the adsorption was found to be strongly dependent on pH and well fitted by the Langmuir model. In addition, it was shown that the adsorption capacity was linked to the kaolinite content of each sample. The results showed that humic acid adsorption onto clay was made via electrostatic interactions, ligand exchange and hydrophobic interactions. This study showed that clays are valuable adsorbents for the removal of humic acid.

scholarly journals A triple-binding-domain model explains the specificity of the interaction of a sphingolipid activator protein (SAP-1) with sulphatide, GM1-ganglioside and globotriaosylceramide

1986 ◽  
Vol 240 (3) ◽  
pp. 921-924 ◽  
Author(s):  
C H Wynn
Keyword(s):  
Hydrogen Bonding ◽  
Methyl Ester ◽  
Energy Minimization ◽  
Electrostatic Interactions ◽  
Hydrophobic Interactions ◽  
Binding Domain ◽  
Domain Model ◽  
Gm1 Ganglioside ◽  
Gm2 Ganglioside ◽  
Activator Proteins

The conformations of the neutral glycosphingolipid, globotriaosylceramide, and of the methyl ester of GM1-ganglioside have been predicted by energy-minimization techniques and compared with those previously obtained for GM1- and GM2-ganglioside. A triple-binding-domain model is put forward to explain known specificities of binding between these glycosphingolipids and activator proteins. This model suggests that hydrophobic interactions, electrostatic interactions and hydrogen-bonding between sugar residues are important. The model is discussed in relation to previous studies on the effect of chemical modification of glycosphingolipids on their ligand properties.

scholarly journals Interactions between adsorbents and adsorbates in aqueous solutions

2020 ◽  
Vol 92 (10) ◽  
pp. 1655-1662
Author(s):  
Zhijian Wu ◽  
Xiushen Ye ◽  
Haining Liu ◽  
Huifang Zhang ◽  
Zhong Liu ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Ionic Strength ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Electrostatic Interactions ◽  
Hydrophobic Interactions ◽  
Solution Ph ◽  
Electrostatic And Hydrophobic Interactions

AbstractAdsorption is one of the most widely used processes in physicochemical operations. To design an adsorbent for a specific adsorbate, it is important to understand the interactions between adsorbents and adsorbates, which are very important for both adsorption capacity and selectivity. Electrostatic interactions, hydrogen bonding, hydrophobic interactions, complexation, and precipitation are comprehensively discussed. Adjusting solution pH and ionic strength is an effective method to improve the adsorption, especially when electrostatic and hydrophobic interactions are main interactions. With the increase in ionic strength, the hydrophobic interactions between adsorbents and adsorbates increase, while the electrostatic interactions decrease.

scholarly journals Adsorptive and Coagulative Removal of Trace Metals from Water Using Surface Modified Sawdust-Based Cellulose Nanocrystals

J ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 193-205
Author(s):  
Opeyemi A. Oyewo ◽  
Sam Ramaila ◽  
Lydia Mavuru ◽  
Taile Leswifi ◽  
Maurice S. Onyango
Keyword(s):  
Trace Metals ◽  
Adsorption Capacity ◽  
Cellulose Nanocrystals ◽  
Inductively Coupled Plasma ◽  
Electrostatic Interactions ◽  
Natural Waters ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Major Drawback ◽  
Surface Modified

The presence of toxic metals in surface and natural waters, even at trace levels, poses a great danger to humans and the ecosystem. Although the combination of adsorption and coagulation techniques has the potential to eradicate this problem, the use of inappropriate media remains a major drawback. This study reports on the application of NaNO2/NaHCO3 modified sawdust-based cellulose nanocrystals (MCNC) as both coagulant and adsorbent for the removal of Cu, Fe and Pb from aqueous solution. The surface modified coagulants, prepared by electrostatic interactions, were characterized using Fourier transform infrared, X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive spectrometry (SEM/EDS). The amount of coagulated/adsorbed trace metals was then analysed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). SEM analysis revealed the patchy and distributed floccules on Fe-flocs, which was an indication of multiple mechanisms responsible for Fe removal onto MCNC. A shift in the peak position attributed to C2H192N64O16 from 2θ = 30 to 24.5° occurred in the XRD pattern of both Pb- and Cu-flocs. Different process variables, including initial metal ions concentration (10–200 mg/L), solution pH (2–10), and temperature (25–45 °C) were studied in order to investigate how they affect the reaction process. Both Cu and Pb adsorption followed the Langmuir isotherm with a maximum adsorption capacity of 111.1 and 2.82 mg/g, respectively, whereas the adsorption of Fe was suggestive of a multilayer adsorption process; however, Fe Langmuir maximum adsorption capacity was found to be 81.96 mg/g. The sequence of trace metals removal followed the order: Cu > Fe > Pb. The utilization of this product in different water matrices is an effective way to establish their robustness.

Influence of Electrostatic Interactions and Hydrogen Bonding on the Activity of Cyclodextrin-based Superoxide Dismutase Models

2001 ◽  
Vol 13 (5) ◽  
pp. 619-625 ◽  
Author(s):  
Alex Fragoso ◽  
Roberto Cao ◽  
Alicia Díz ◽  
Ileana Sånchez ◽  
Leticia Sånchez
Keyword(s):  
Superoxide Dismutase ◽  
Hydrogen Bonding ◽  
Electrostatic Interactions

scholarly journals The N-atom in [N(PR3)2]+ cations (R = Ph, Me) can act as electron donor for (pseudo) anti-electrostatic interactions

CrystEngComm ◽  
2015 ◽  
Vol 17 (20) ◽  
pp. 3768-3771 ◽  
Author(s):  
Antonio Bauzá ◽  
Antonio Frontera ◽  
Tiddo J. Mooibroek ◽  
Jan Reedijk
Keyword(s):  
Hydrogen Bonding ◽  
Electron Donor ◽  
Molecular Hydrogen ◽  
Electrostatic Interactions ◽  
Lone Pair ◽  
Dft Study ◽  
Nitrogen Lone Pair

A CSD analysis and DFT study reveal that the nitrogen lone-pair in [N(PPh3)2]+ is partially intact and involved in intramolecular hydrogen bonding.

scholarly journals Characterization of Virus Adsorption by Using DEAE-Sepharose and Octyl-Sepharose

2002 ◽  
Vol 68 (8) ◽  
pp. 3965-3968 ◽  
Author(s):  
Patricia A. Shields ◽  
Samuel R. Farrah
Keyword(s):  
Sodium Chloride ◽  
Electrostatic Interactions ◽  
Hydrophobic Interactions ◽  
Chloride Concentration ◽  
Sodium Chloride Concentration ◽  
Virus Adsorption ◽  
Nacl Concentration

ABSTRACT Viruses were characterized by their adsorption to DEAE-Sepharose or by their elution from octyl-Sepharose by using buffered solutions of sodium chloride with different ionic strengths. Viruses whose adsorption to DEAE-Sepharose was reduced most rapidly by an increase in the sodium chloride concentration were considered to have the weakest electrostatic interactions with the solids; these viruses included MS2, E1, and φX174. Viruses whose adsorption to DEAE-Sepharose was reduced least rapidly were considered to have the strongest electrostatic interactions with the column; these viruses included P1, T4, T2, and E5. All of the viruses studied adsorbed to octyl-Sepharose in the presence of 4 M NaCl. Viruses that were eluted most rapidly following a decrease in the concentration of NaCl were considered to have the weakest hydrophobic interactions with the column; these viruses included φX174, CB4, and E1. Viruses that were eluted least rapidly from the columns after the NaCl concentration was decreased were considered to have the strongest hydrophobic interactions with the column; these viruses included f2, MS2, and E5.

Preparation of the copper-containing metallogels based on chitosan for biomedical and agricultural applications

2020 ◽  
Vol 1 (8) ◽  
pp. 60-70
Author(s):  
A. A. Vikhrov ◽  
◽  
V. P. Zubov ◽  
S. Yu. Zaytsev ◽  
◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Animal Husbandry ◽  
Chitosan Solution ◽  
Additional Treatment ◽  
Feed Additives ◽  
Farm Animals ◽  
Cross Linking ◽  
Improved Method ◽  
Polymer Complexes ◽  
Promising Alternative

It is well-known, due to the geological features in a number of regions of the Russian Federation, there may be a shortage of certain microelements and other important “nutrients” in animal diets. The main approach to solve this problem is to use special feed additives. At present, preparations based on organic sources, for example, metal-polymer complexes, are considered a promising alternative. The purpose of this study is to develop an improved method for preparation of the copper-containing polysaccharide complexes and to study their most important parameters. Using CuCl2 as an example, it was shown that the formation of chitosan hydrogels is possible without the usage of potentially hazardous cross-linking agents (for example, glutaraldehyde) or polyvalent anions (for example, SO4 2–), which provide non-covalent cross-linking of chitosan due to electrostatic interactions with NH3 + in its composition. It was found that, upon frontal «gelation» of a 2% chitosan solution (MM 400±100 kDa) in acetic acid (1 vol%), the formation of stable metal gels is observed provided that the content of CuCl2 and ethanol in the precipitant solution is more than 40 mg/ml or more than 24 vol.%, respectively (Vchitosan = Vprecipitant). The obtained complexes are stable in aqueous-alcoholic solutions and swell in water up to destruction (pH 5,5). After additional treatment with an aqueous 1,5% ammonia solution, complexes practically do not swell in solutions with ≥ pH 5,5 (at least τ = 6 days) and dissolve at pH ≤ 4,2. Thus, the use of these complexes is able to provide the release of Cu2 + not in the rumen (pH 6,3–7,2), but in the abomasum (pH ~ 3), which can increase the bioavailability of copper. The development of an improved method for obtaining metal-polysaccharide complexes in a gel form that does not contain «ballast» (in terms of nutritional value and physiology of farm animals) anions (for example, SO4 2–) opens up new opportunities for the development of highly effective feed additives for animal husbandry.

Sign in / Sign up

Export Citation Format

Share Document