Synthesis and applications of functionalized silsesquioxane polymers attached to organic and inorganic matrices

Organofunctionalized silsesquioxane polymers obtained in a water-soluble form can be used to coat various substrates such as SiO2, SiO2/Al2O3, Al2O3, cellulose/Al2O3, and graphite or, when obtained in a water-insoluble form, can be used directly. These organofunctionalized silsesquioxanes can also be attached to poly(dimethylsiloxane) (PDMS) polymers. The functional groups constituted by neutral amine groups or cationic groups (pyridinium, 3- and 4-picolinium, or 1,4-diazabicyclo[2.2.2]octane (DABCO), mono- or -dicationic) have relatively high affinity for metal ion in ethanol solutions, as shown by their stability constants. Materials containing attached cationic functional groups have also been efficiently used to immobilize various electroactive species and to construct electrochemical sensors for analytical applications. This work discusses the preparation of silsesquioxane derivatives, their characterization as prepared and when dispersed on several substrates, and comments on some applications of these materials, with an emphasis on the metal adsorption process and manufacture of electrochemical sensors.

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Characterization of an Insoluble and Soluble Form of Melanin Produced by Streptomyces cavourensis SV 21, a Sea Cucumber Associated Bacterium

Marine Drugs ◽

10.3390/md20010054 ◽

2022 ◽

Vol 20 (1) ◽

pp. 54

Author(s):

Joko Tri Wibowo ◽

Matthias Y. Kellermann ◽

Lars-Erik Petersen ◽

Yustian R. Alfiansah ◽

Colleen Lattyak ◽

...

Keyword(s):

Biological Properties ◽

Water Soluble ◽

Soluble Form ◽

Wide Range ◽

Biological Form ◽

Insoluble Form ◽

New Perspective ◽

Living Organisms ◽

Purification Protocol

Melanin is a widely distributed and striking dark-colored pigment produced by countless living organisms. Although a wide range of bioactivities have been recognized, there are still major constraints in using melanin for biotechnological applications such as its fragmentary known chemical structure and its insolubility in inorganic and organic solvents. In this study, a bacterial culture of Streptomyces cavourensis SV 21 produced two distinct forms of melanin: (1) a particulate, insoluble form as well as (2) a rarely observed water-soluble form. The here presented novel, acid-free purification protocol of purified particulate melanin (PPM) and purified dissolved melanin (PDM) represents the basis for an in-depth comparison of their physicochemical and biological properties, which were compared to the traditional acid-based precipitation of melanin (AM) and to a synthetic melanin standard (SM). Our data show that the differences in solubility between PDM and PPM in aqueous solutions may be a result of different adjoining cation species, since the soluble PDM polymer is largely composed of Mg2+ ions and the insoluble PPM is dominated by Ca2+ ions. Furthermore, AM shared most properties with SM, which is likely attributed to a similar, acid-based production protocol. The here presented gentler approach of purifying melanin facilitates a new perspective of an intact form of soluble and insoluble melanin that is less chemical altered and thus closer to its original biological form.

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Adsorption of Pb(II) and Cd(II) by SquidOmmastrephes bartramiMelanin

Bioinorganic Chemistry and Applications ◽

10.1155/2009/901563 ◽

2009 ◽

Vol 2009 ◽

pp. 1-7 ◽

Cited By ~ 17

Author(s):

Shiguo Chen ◽

Changhu Xue ◽

Jingfeng Wang ◽

Hui Feng ◽

Yuming Wang ◽

...

Keyword(s):

Functional Groups ◽

Metal Binding ◽

Metal Ion ◽

Ion Concentration ◽

Obvious Effect ◽

Removal Of Heavy Metals ◽

New Material ◽

Amine Groups ◽

Ir Analysis ◽

Ph Range

The adsorption of Cd(II) and Pb(II) by squid melanin was investigated. At a metal ion concentration of 2 mM/L, the biosorption efficiency of melanin reached 95% for Cd(II) and Pb(II). The maximum content of bound Cd(II) and Pb(II) was 0.93 mM/g and 0.65 mM/g, respectively. Temperature had no obvious effect on the adsorption of the metals, and in a pH range of 4.0–7.0, the adsorption yield was high and stable. Macrosalts such as NaCl,MgCl2, andCaCl2had no obvious effect on the binding of Pb(II) but greatly diminished the adsorption of Cd(II), which indicated that different functional groups in squid melanin are responsible for their adsorption. IR analysis of metal ion-enriched squid melanin demonstrated that the possible functional groups responsible for metal binding were phenolic hydroxyl (OH), carboxyl (COOH), and amine groups (NH). This study reports a new material for the removal of heavy metals from low-strength wastewater.

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The Ability of Edible Fungi Residue to Remove Lead in Wastewater

Frontiers in Environmental Science ◽

10.3389/fenvs.2021.723087 ◽

2021 ◽

Vol 9 ◽

Author(s):

Yanyan Jing ◽

Zongyu Li ◽

Yameng Li ◽

Gao Lei ◽

Liangliang Li ◽

...

Keyword(s):

Functional Groups ◽

Metal Ion ◽

Adsorption Process ◽

Agricultural Waste ◽

Common Source ◽

Edible Fungi ◽

Solution Ph ◽

Adsorption Sites ◽

Before And After ◽

Factor Design

Lead (Pb)-contaminated wastewater is the most common source of heavy metal ion pollution. In this study, agricultural waste edible fungi residue (EFR) was used to adsorb Pb(II) ions in wastewater as a strategy to reduce environmental pollution and minimize poisoning by Pb. The influence of Pb(II) concentration, solution pH, and EFR concentration on the removal efficiency (R) of Pb(II) was investigated with single factor design and response surface analysis. The maximum predicted R for Pb(II) was 76.34% under optimal conditions of Pb(II) concentration of 483.83 mg/L, EFR concentration of 4.99 g/L, and pH of 5.89. The actual experimental value of R reached 76.97% under these conditions. The competition of Pb(II) ions for the available adsorption sites on EFR limited the maximum R. A comparison of Fourier transform infrared spectroscopy before and after the adsorption of Pb(II), indicated that the functional groups of EFR significantly affected the effect of adsorption of heavy metals, and that the adsorption process was primarily affected by functional groups in the range of wavenumbers from 500 to 2,000 cm−1.

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MODIFICATION OF HUMIC SUBSTANCES FOR DEVELOPMENT OF MATERIALS FOR ENVIRONMENTAL TECHNOLOGIES

Environment Technology Resources Proceedings of the International Scientific and Practical Conference ◽

10.17770/etr2019vol1.4123 ◽

2019 ◽

Vol 1 ◽

pp. 101

Author(s):

Maris Klavins

Keyword(s):

Molecular Weight ◽

Metal Ions ◽

Humic Substances ◽

Functional Groups ◽

Metal Ion ◽

Spectral Characteristics ◽

Water Soluble ◽

13C Nuclear Magnetic Resonance ◽

Mobility Behaviour ◽

Derivatives Of

Humic substances are high molecular weight refractory polycationites formed during decay of living organic matter and through biosynthesis of low molecular weight organic substances (metabolites or decay products of living organisms). Presence of many functional groups in the structure of humic substances determines their ability to interact with metal ions forming stable complexes and influencing metal ion speciation in the environment and mobility, behaviour and speciation forms in the environment. Presently humic substances are a product of industrial scale and quantities in amounts of hundreds of tons are produced. The aim of this study is to analyse derivatization possibilities of humic substances. To achieve this aim derivatization of humic substances using acylation (at first introduction of acetylgroups, but also changing length acyl chains are considered) are used. Also alkylation is used. Mild oxidation can help to obtain modified products with reduced molecular weight. Another approach includes introduction of new functional groups and structures. To achieve this aim, conjugates with short peptides, amines and sugar derivatives using coupling with water-soluble carbodiimides are obtained. As basic characteristics elemental analysis as well as functional analysis have been used, supported with Fourier transform infrared (FTIR), 13C nuclear magnetic resonance spectrometry and other methods. Derivatives of humic substances containing sulpho, amino, and hydroxylgroups and thiolgroups were synthesized and their properties were analyzed in respect to their their elemental composition; functional group content changes in spectral characteristics. The derivatives of humic substances showed significant differences in the number and in ability to interact with the metal ions, which were reflected in their complexation properties towards metal ions. FTIR spectra gave evidence of the presence of metal ions, strongly bound and protected in inner sphere complexes. The obtained derivatives of humic substances can be used for remediation of environment contaminated with heavy metal ions.

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Biosorpsi Ion Logam Kadmium (Cd2+) Pada Biosorben Rumput Laut Coklat (Padina australis) Asal Pantai Liti Pulau Kisar

Indo J Chem Res ◽

10.30598//ijcr.2018.6-cath ◽

2018 ◽

Vol 6 (1) ◽

pp. 51-58

Author(s):

Catherina M. Bijang ◽

Helna Tehubijuluw ◽

Terence Ghereds Kaihatu

Keyword(s):

Atomic Absorption ◽

Functional Groups ◽

Contact Time ◽

Metal Ion ◽

Adsorption Process ◽

Brown Seaweed ◽

Atomic Absorption Spectrophotometer ◽

Optimum Ph

The research about biosorption of Cadmium (Cd2+) metal ion in brown seaweed biosorben (Paladina australis) from Liti beach, Kisar island has been done. Analysis of decreasing Cd2+ content using Atomic Absorption Spectrophotometer (SSA) and also use FTIR to know functional groups contained in alginate compounds. A total of 0.5 g of brown seaweed powder was introduced into 25 mL of Cd2+ 50 ppm solution with variations of pH 1-7 and shaker for five hours. After the optimum pH was obtained, the adsorption process was applied on pH 5 solution with variation of contact time 1, 3, and 5 hours, after which it was filtered. The result of analysis and calculation showed that Cd2+ ion was optimum at pH 5 of 99.64% and 3 hours contact time was 74.54%.

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Photophysical Characterisation, Metal Ion Binding and Enantiomeric Recognition of Chiral Ligands Containing Phenazine Fluorophore

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20040885 ◽

2004 ◽

Vol 69 (4) ◽

pp. 885-896 ◽

Cited By ~ 8

Author(s):

Luisa Stella Dolci ◽

Péter Huszthy ◽

Erika Samu ◽

Marco Montalti ◽

Luca Prodi ◽

...

Keyword(s):

Metal Ion ◽

Photophysical Properties ◽

Ion Binding ◽

Metal Ion Binding ◽

Ammonium Ions ◽

Enantiomerically Pure ◽

Binding Process ◽

High Affinity ◽

Enantiomeric Recognition ◽

Chiral Species

Enantiomerically pure dimethyl- and diisobutyl-substituted phenazino-18-crown-6 ligands bind metal and ammonium ions and also primary aralkylammonium perchlorates in acetonitrile with high affinity, causing pronounced changes in their luminescence properties. In addition, they show enantioselectivity towards chiral primary aralkylammonium perchlorates. The possibility to monitor the binding process by photoluminescence spectroscopy can gain ground for the design of very efficient enantioselective chemosensors for chiral species. The observed changes in the photophysical properties are also an important tool for understanding the interactions present in the adduct.

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Identification and functional analysis of cadmium-binding protein in the visceral mass of Crassostrea gigas

Scientific Reports ◽

10.1038/s41598-021-90882-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Zehua Zheng ◽

Kazuhiro Kawakami ◽

Dingkun Zhang ◽

Lumi Negishi ◽

Mohamed Abomosallam ◽

...

Keyword(s):

Crassostrea Gigas ◽

Metal Ion ◽

Defense Mechanisms ◽

Three Dimensional ◽

Tryptophan Fluorescence ◽

Water Soluble ◽

Titration Calorimetry ◽

Visceral Mass ◽

The Pacific ◽

Liquid Chromatography Tandem Mass

AbstractThe Pacific oyster, Crassostrea gigas, is a traditional food worldwide. The soft body of the oyster can easily accumulate heavy metals such as cadmium (Cd). To clarify the molecular mechanism of Cd accumulation in the viscera of C. gigas, we identified Cd-binding proteins. 5,10,15,20-Tetraphenyl-21H,23H-porphinetetrasulfonic acid, disulfuric acid, tetrahydrate, and Cd-binding competition experiments using immobilized metal ion affinity chromatography revealed the binding of water-soluble high molecular weight proteins to Cd, including C. gigas protein disulfide isomerase (cgPDI). Liquid chromatography–tandem mass spectrometry (LC–MS/MS) analyses revealed two CGHC motifs in cgPDI. The binding between Cd and rcgPDI was confirmed through a Cd-binding experiment using the TPPS method. Isothermal titration calorimetry (ITC) revealed the binding of two Cd ions to one molecule of rcgPDI. Circular dichroism (CD) spectrum and tryptophan fluorescence analyses demonstrated that the rcgPDI bound to Cd. The binding markedly changed the two-dimensional or three-dimensional structures. The activity of rcgPDI measured by a PDI Activity Assay Kit was more affected by the addition of Cd than by human PDI. Immunological analyses indicated that C. gigas contained cgPDI at a concentration of 1.0 nmol/g (viscera wet weight). The combination of ITC and quantification results revealed that Cd-binding to cgPDI accounted for 20% of the total bound Cd in the visceral mass. The findings provide new insights into the defense mechanisms of invertebrates against Cd.

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Analyzing the Carotenoid Composition of Melilot (Melilotus officinalis (L.) Pall.) Extracts and the Effects of Isolated (All-E)-lutein-5,6-epoxide on Primary Sensory Neurons and Macrophages

Molecules ◽

10.3390/molecules26020503 ◽

2021 ◽

Vol 26 (2) ◽

pp. 503

Author(s):

Györgyi Horváth ◽

Eszter Csikós ◽

Eichertné Violetta Andres ◽

Tímea Bencsik ◽

Anikó Takátsy ◽

...

Keyword(s):

Liquid Chromatography ◽

Sensory Neurons ◽

Biological Activities ◽

Water Soluble ◽

Soluble Form ◽

Primary Sensory Neurons ◽

Isolation And Identification ◽

Melilotus Officinalis ◽

Carotenoid Composition ◽

Anti Inflammatory

Melilotus officinalis is known to contain several types of secondary metabolites. In contrast, the carotenoid composition of this medicinal plant has not been investigated, although it may also contribute to the biological activities of the drug, such as anti-inflammatory effects. Therefore, this study focuses on the isolation and identification of carotenoids from Meliloti herba and on the effect of isolated (all-E)-lutein 5,6-epoxide on primary sensory neurons and macrophages involved in nociception, as well as neurogenic and non-neurogenic inflammatory processes. The composition of the plant extracts was analyzed by high performance liquid chromatography (HPLC). The main carotenoid was isolated by column liquid chromatography (CLC) and identified by MS and NMR. The effect of water-soluble lutein 5,6-epoxide-RAMEB (randomly methylated-β-cyclodextrin) was investigated on Ca2+-influx in rat primary sensory neurons induced by the activation of the transient receptor potential ankyrin 1 receptor agonist to mustard-oil and on endotoxin-induced IL-1β release from isolated mouse peritoneal macrophages. (all-E)-Lutein 5,6-epoxide significantly decreased the percent of responsive primary sensory neurons compared to the vehicle-treated stimulated control. Furthermore, endotoxin-evoked IL-1β release from macrophages was significantly decreased by 100 µM lutein 5,6-epoxide compared to the vehicle-treated control. The water-soluble form of lutein 5,6-epoxide-RAMEB decreases the activation of primary sensory neurons and macrophages, which opens perspectives for its analgesic and anti-inflammatory applications.

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Human Lanosterol 14-Alpha Demethylase (CYP51A1) Is a Putative Target for Natural Flavonoid Luteolin 7,3′-Disulfate

Molecules ◽

10.3390/molecules26082237 ◽

2021 ◽

Vol 26 (8) ◽

pp. 2237

Author(s):

Leonid Kaluzhskiy ◽

Pavel Ershov ◽

Evgeniy Yablokov ◽

Tatsiana Shkel ◽

Irina Grabovec ◽

...

Keyword(s):

Cholesterol Metabolism ◽

Cholesterol Biosynthesis ◽

Clinical Importance ◽

Optical Biosensor ◽

Water Soluble ◽

Soluble Form ◽

Redox Partner ◽

Access Channel ◽

Kd Values ◽

Key Steps

Widespread pathologies such as atherosclerosis, metabolic syndrome and cancer are associated with dysregulation of sterol biosynthesis and metabolism. Cholesterol modulates the signaling pathways of neoplastic transformation and tumor progression. Lanosterol 14-alpha demethylase (cytochrome P450(51), CYP51A1) catalyzes one of the key steps in cholesterol biosynthesis. The fairly low somatic mutation frequency of CYP51A1, its druggability, as well as the possibility of interfering with cholesterol metabolism in cancer cells collectively suggest the clinical importance of CYP51A1. Here, we show that the natural flavonoid, luteolin 7,3′-disulfate, inhibits CYP51A1 activity. We also screened baicalein and luteolin, known to have antitumor activities and low toxicity, for their ability to interact with CYP51A1. The Kd values were estimated using both a surface plasmon resonance optical biosensor and spectral titration assays. Unexpectedly, in the enzymatic activity assays, only the water-soluble form of luteolin—luteolin 7,3′-disulfate—showed the ability to potently inhibit CYP51A1. Based on molecular docking, luteolin 7,3′-disulfate binding suggests blocking of the substrate access channel. However, an alternative site on the proximal surface where the redox partner binds cannot be excluded. Overall, flavonoids have the potential to inhibit the activity of human CYP51A1 and should be further explored for their cholesterol-lowering and anti-cancer activity.

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Mediation of interleukin-11-dependent biological responses by a soluble form of the interleukin-11 receptor

Biochemical Journal ◽

10.1042/bj3180489 ◽

1996 ◽

Vol 318 (2) ◽

pp. 489-495 ◽

Cited By ~ 35

Author(s):

Julia KAROW ◽

Keith R. HUDSON ◽

Mark A. HALL ◽

Ann B. VERNALLIS ◽

Jacky A. TAYLOR ◽

...

Keyword(s):

Biological Effects ◽

Biological Response ◽

Cytoplasmic Domain ◽

Soluble Form ◽

High Affinity ◽

Biological Responses ◽

Interleukin 11 ◽

Biological Actions ◽

In Cells

Interleukin-11 (IL-11) is a polyfunctional cytokine whose biological actions require a specific IL-11 receptor (IL-11R) and the transmembrane transducer gp130. Here we report the production of a soluble form of the murine IL-11R and demonstrate that it interacts with IL-11 ligand with high affinity. The affinity of IL-11 alone for gp130 is below the level of detection, but a complex of IL-11 and soluble IL-11R interacts with gp130 with high affinity. The addition of soluble IL-11R potentiates the effects of exogenous IL-11 in cells that are normally responsive to IL-11. A biological response to IL-11 can be reconstituted in BAF cells transfected with gp130 by addition of IL-11 and soluble IL-11R. These findings show that the cytoplasmic domain of the IL-11R is not required for the biological effects of IL-11 and that a complex of IL-11 and IL-11R mediates signalling by association with gp130.

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