Role of Humic Acid Chemical Structure Derived from Different Biomass Feedstocks on Fe(III) Bioreduction Activity: Implication for Sustainable Use of Bioresources

Humic acids (HAs) are redox-active components that play a crucial role in catalyzing relevant redox reactions in various ecosystems. However, it is unclear what role the different compost-derived Has play in the dissimilatory Fe(III) bioreduction and which chemical structures could accelerate Fe reduction. In this study, we compared the effect of eighteen HAs from the mesophilic phase, thermophilic phase and mature phase of protein-, lignocellulose- and lignin-rich composting on catalyzing the bioreduction of Fe(III)-citrate by Shewanella oneidensis MR-1 in temporarily anoxic laboratory systems. The chemical composition and structure of different compost-derived HAs were analyzed by UV–Vis spectroscopy, excitation-emission matrices of the fluorescence spectra, and 13C-NMR. The results showed that HAs from lignocellulose- and lignin-rich composting, especially in the thermophilic phase, promoted the bioreduction of Fe(III). They also showed that HA from protein-rich materials suppressed significantly the Fe(II) production, which was mainly affected by the amount and structures of functional groups (e.g., quinone groups) and humification degree of the HAs. This study can aid in searching sustainable HA-rich composts for wide-ranging applications to catalyze redox-mediated reactions of pollutants in soils.

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Surface-induced formation and redox-dependent staining of outer membrane extensions inShewanella oneidensisMR-1

10.1101/689703 ◽

2019 ◽

Author(s):

Grace W. Chong ◽

Sahand Pirbadian ◽

Mohamed Y. El-Naggar

Keyword(s):

Outer Membrane ◽

Shewanella Oneidensis ◽

Medium Composition ◽

Extracellular Electron Transfer ◽

Active Components ◽

Transmission Electron ◽

Redox Active ◽

Redox Centers

AbstractThe metal-reducing bacteriumShewanella oneidensisMR-1 produces extensions of its outer membrane (OM) and periplasm that contain cytochromes responsible for extracellular electron transfer (EET) to external redox-active surfaces, including minerals and electrodes. While the role of multi-heme cytochromes in transporting electrons across the cell wall is well established, their distribution alongS. oneidensisOM extensions is also thought to allow lateral electron transport along these filaments. These proposed bacterial nanowires, which can be several times the cell length, would thereby extend EET to more distant electron acceptors. However, it is still unclear why these extensions form, and to what extent they contribute to respiration in living cells. Here, we investigate physical contributors to their formation usingin vivofluorescence microscopy. While previous studies focused on the display ofS. oneidensisouter membrane extensions (OMEs) as a response to oxygen limitation, we find that cell-to-surface contact is sufficient to trigger the production of OMEs, including some that reach >100 µm in length, irrespective of medium composition, agitation, or aeration. To visualize the extent of heme redox centers along OMEs, and help distinguish these structures from other extracellular filaments, we also performed histochemical redox-dependent staining with transmission electron microscopy on wild type and cytochrome-deficient strains. We demonstrate that redox-active components are limited to OMEs and not present on other extracellular appendages, such as pili and flagella. We also observed that the loss of 8 functional periplasmic and outer membrane cytochromes significantly decreased both the frequency and intensity of redox-dependent staining found widespread on OMEs. These results will improve our understanding of the environmental conditions that influence the formation ofS. oneidensisOMEs, as well as the distribution and functionality of EET components along extracellular appendages.

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Active Components from Cassia abbreviata Prevent HIV-1 Entry by Distinct Mechanisms of Action

International Journal of Molecular Sciences ◽

10.3390/ijms22095052 ◽

2021 ◽

Vol 22 (9) ◽

pp. 5052

Author(s):

Yue Zheng ◽

Xian-Wen Yang ◽

Dominique Schols ◽

Mattia Mori ◽

Bruno Botta ◽

...

Keyword(s):

Crude Extract ◽

Female Genital Tract ◽

Binding Activity ◽

Sub Saharan Africa ◽

Active Components ◽

Chemical Structures ◽

3D Space ◽

In Silico Study ◽

Sub Saharan ◽

Hiv 1

Cassia abbreviata is widely used in Sub-Saharan Africa for treating many diseases, including HIV-1 infection. We have recently described the chemical structures of 28 compounds isolated from an alcoholic crude extract of barks and roots ofC. abbreviata, and showed that six bioactive compounds inhibit HIV-1 infection. In the present study, we demonstrate that the six compounds block HIV-1 entry into cells: oleanolic acid, palmitic acid, taxifolin, piceatannol, guibourtinidol-(4α®8)-epiafzelechin, and a novel compound named as cassiabrevone. We report, for the first time, that guibourtinidol-(4α®8)-epiafzelechin and cassiabrevone inhibit HIV-1 entry (IC50 of 42.47 µM and 30.96 µM, respectively), as well as that piceatannol interacts with cellular membranes. Piceatannol inhibits HIV-1 infection in a dual-chamber assay mimicking the female genital tract, as well as HSV infection, emphasizing its potential as a microbicide. Structure-activity relationships (SAR) showed that pharmacophoric groups of piceatannol are strictly required to inhibit HIV-1 entry. By a ligand-based in silico study, we speculated that piceatannol and norartocarpetin may have a very similar mechanism of action and efficacy because of the highly comparable pharmacophoric and 3D space, while guibourtinidol-(4α®8)-epiafzelechin and cassiabrevone may display a different mechanism. We finally show that cassiabrevone plays a major role of the crude extract of CA by blocking the binding activity of HIV-1 gp120 and CD4.

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Structure-properties relationship for energy storage redox polymers: a review

Journal of Polymer Engineering ◽

10.1515/polyeng-2019-0395 ◽

2020 ◽

Vol 40 (5) ◽

pp. 373-393 ◽

Cited By ~ 1

Author(s):

Narendra Singh Chundawat ◽

Nishigandh Pande ◽

Ghasem Sargazi ◽

Mazaher Gholipourmalekabadi ◽

Narendra Pal Singh Chauhan

Keyword(s):

Energy Storage ◽

Cost Efficiency ◽

Energy Storage Materials ◽

High Scale ◽

Chemical Structures ◽

Redox Active ◽

Potential Applications ◽

Intelligent Clothing ◽

The Relationship ◽

Structure Properties

AbstractRedox-active polymers among the energy storage materials (ESMs) are very attractive due to their exceptional advantages such as high stability and processability as well as their simple manufacturing. Their applications are found to useful in electric vehicle, ultraright computers, intelligent electric gadgets, mobile sensor systems, and portable intelligent clothing. They are found to be more efficient and advantageous in terms of superior processing capacity, quick loading unloading, stronger security, lengthy life cycle, versatility, adjustment to various scales, excellent fabrication process capabilities, light weight, flexible, most significantly cost efficiency, and non-toxicity in order to satisfy the requirement for the usage of these potential applications. The redox-active polymers are produced through organic synthesis, which allows the design and free modification of chemical constructions, which allow for the structure of organic compounds. The redox-active polymers can be finely tuned for the desired ESMs applications with their chemical structures and electrochemical properties. The redox-active polymers synthesis also offers the benefits of high-scale, relatively low reaction, and a low demand for energy. In this review we discussed the relationship between structural properties of different polymers for solar energy and their energy storage applications.

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Evidence for interaction between the triheme cytochrome PpcA from Geobacter sulfurreducens and anthrahydroquinone-2,6-disulfonate, an analog of the redox active components of humic substances

Biochimica et Biophysica Acta (BBA) - Bioenergetics ◽

10.1016/j.bbabio.2014.02.004 ◽

2014 ◽

Vol 1837 (6) ◽

pp. 750-760 ◽

Cited By ~ 19

Author(s):

Joana M. Dantas ◽

Leonor Morgado ◽

Teresa Catarino ◽

Oleksandr Kokhan ◽

P. Raj Pokkuluri ◽

...

Keyword(s):

Humic Substances ◽

Geobacter Sulfurreducens ◽

Active Components ◽

Redox Active

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Spin-Dependent Electron Transport through Bacterial Cell Surface Multiheme Electron Conduits

10.26434/chemrxiv.9748046.v1 ◽

2019 ◽

Author(s):

Suryakant Mishra ◽

Sahand Pirbadian ◽

Amit Kumar Mondal ◽

Moh El-Naggar ◽

Ron Naaman

Keyword(s):

Electron Transport ◽

Cell Surface ◽

Bacterial Cell ◽

Shewanella Oneidensis ◽

Extracellular Electron Transfer ◽

Long Distance ◽

Force Microscopy ◽

Bacterial Cell Surface ◽

Redox Active ◽

Gain Energy

Multiheme cytochromes, located on the bacterial cell surface, function as long-distance (> 10 nm) electron conduits linking intracellular reactions to external surfaces. This extracellular electron transfer process, which allows microorganisms to gain energy by respiring solid redox-active minerals, also facilitates the wiring of cells to electrodes. While recent studies suggested that a chiral induced spin selectivity effect is linked to efficient electron transmission through biomolecules, this phenomenon has not been investigated in the extracellular electron conduits. Using magnetic conductive probe atomic force microscopy, Hall voltage measurements, and spin-dependent electrochemistry of the decaheme cytochromes MtrF and OmcA from the metal-reducing bacterium <i>Shewanella oneidensis</i> MR-1, we show that electron transport through these extracellular conduits is spin-selective. Our study has implications for understanding how spin-dependent interactions and magnetic fields may control electron transport across biotic-abiotic interfaces in both natural and biotechnological systems.

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Synthesis and Control of the Shell Thickness of Polyaniline and Polypyrrole Half Hollow Spheres Using the Polystyrene Cores

Journal of Nanomaterials ◽

10.1155/2012/894539 ◽

2012 ◽

Vol 2012 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Su-Ryeon Yun ◽

Gyeong-Ok Kim ◽

Chan Woo Lee ◽

Nam-Ju Jo ◽

Yongku Kang ◽

...

Keyword(s):

Shell Thickness ◽

Hollow Spheres ◽

Core Shell ◽

Chemical Structures ◽

The Core ◽

Vis Spectroscopy ◽

Ft Ir ◽

Core Shell Structure ◽

And Control ◽

Ft Ir Spectroscopy

Polyaniline (Pani) and polypyrrole (Ppy) half hollow spheres with different shell thicknesses were successfully synthesized by three steps process using polystyrene (PS) as the core. The PS core was synthesized by emulsion polymerization. Aniline and pyrrole monomers were polymerized on the surface of the PS core. The shells of Pani and Ppy were fabricated by adding different amounts of aniline and pyrrole monomers. PS cores were dissolved and removed from the core shell structure by solvent extraction. The thicknesses of the Pani and Ppy half hollow spheres were observed by FE-SEM and FE-TEM. The chemical structures of the Pani and Ppy half hollow spheres were characterized by FT-IR spectroscopy and UV-Vis spectroscopy. The shell thicknesses of the Pani half hollow spheres were 30.2, 38.0, 42.2, 48.2, and 52.4 nm, while the shell thicknesses of the Ppy half hollow spheres were 16.0, 22.0, 27.0, and 34.0 nm. The shell thicknesses of Pani and Ppy half hollow spheres linearly increased as the amount of the monomer increased. Therefore, the shell thickness of the Pani and Ppy half hollow spheres can be controlled in these ranges.

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1,3,4-Thiadiazole-Containing Azo Dyes: Synthesis, Spectroscopic Properties and Molecular Structure

Molecules ◽

10.3390/molecules25122822 ◽

2020 ◽

Vol 25 (12) ◽

pp. 2822

Author(s):

Agnieszka Kudelko ◽

Monika Olesiejuk ◽

Marcin Luczynski ◽

Marcin Swiatkowski ◽

Tomasz Sieranski ◽

...

Keyword(s):

Azo Dyes ◽

Density Functional ◽

Density Functional Theory Calculations ◽

Spectroscopic Properties ◽

Radiation Absorption ◽

Functional Theory ◽

Chemical Structures ◽

Vis Spectroscopy ◽

High Yields

Three series of azo dyes derived from 2-amino-5-aryl-1,3,4-thiadiazoles and aniline, N,N-dimethylaniline and phenol were synthesized in high yields by a conventional diazotization-coupling sequence. The chemical structures of the prepared compounds were confirmed by 1H-NMR, 13C-NMR, IR, UV-Vis spectroscopy, mass spectrometry and elemental analysis. In addition, the X-ray single crystal structure of a representative azo dye was presented. For explicit determination of the influence of a substituent on radiation absorption in UV-Vis range, time-dependent density functional theory calculations were performed.

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UV–Vis Absorption Properties of New Aromatic Imines and Their Compositions with Poly({4,8-bis[(2-Ethylhexyl)oxy]Benzo[1,2-b:4,5-b′]Dithiophene-2,6-diyl}{3-Fluoro-2-[(2-Ethylhexyl)Carbonyl]Thieno[3,4-b]Thiophenediyl})

Materials ◽

10.3390/ma12244191 ◽

2019 ◽

Vol 12 (24) ◽

pp. 4191 ◽

Cited By ~ 3

Author(s):

Agnieszka Gonciarz ◽

Robert Pich ◽

Krzysztof Artur Bogdanowicz ◽

Beata Jewloszewicz ◽

Wojciech Przybył ◽

...

Keyword(s):

Absorption Spectra ◽

Organic Solar Cells ◽

Density Functional ◽

Bulk Heterojunction ◽

Theoretical Calculations ◽

Dft Methods ◽

Functional Theory ◽

Chemical Structures ◽

Vis Spectroscopy ◽

Aromatic Imines

In this paper, four new aromatic imines containing at least one thiazole-based heterocycle were analyzed in detail by UV–Vis spectroscopy, taking into consideration their chemical structures and interactions with PTB7, a known polymeric electron donor widely used in bulk heterojunction organic solar cells. It is demonstrated that the absorption spectra of the investigated active compositions can be modified not only by changing the chemical structure of imine, but also via formulations with PTB7. For all investigated imines and PTB7:imine compositions, calibration curves were obtained in order to find the optimum concentration in the composition with PTB7 for expansion and optimization of absorption spectra. All imines and PTB7:imine compositions were investigated in 1,2-dichlorobenzene by UV–Vis spectroscopy in various concentrations, monitoring the changes in the π–π* and n–π* transitions. With increasing imine concentrations, we did not observe changes in absorption maxima, while with increasing imine concentrations, a hypochromic effect was observed. Finally, we could conclude that all investigated compositions exhibited wide absorptions of up to 800 nm and isosbestic points in the range of 440–540 nm, confirming changes in the macromolecular organization of the tested compounds. The theoretical calculations of their vibration spectra (FTIR) and LUMO–HOMO levels by Density Functional Theory (DFT) methods are also provided. Finally, IR thermal images were measured for organic devices based on imines and the imine:PTB7 composite.

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