Comparative antiradical activity and molecular Docking/Dynamics analysis of octopamine and norepinephrine: the role of OH groups

AbstractIn an attempt to find novel, potent α-glucosidase inhibitors, a library of poly-substituted 3-amino-2,4-diarylbenzo[4,5]imidazo[1,2-a]pyrimidines 3a–ag have been synthesized through heating a mixture of 2-aminobenzimidazoles 1 and α-azidochalcone 2 under the mild conditions. This efficient, facile protocol has been resulted into the desirable compounds with a wide substrate scope in good to excellent yields. Afterwards, their inhibitory activities against yeast α-glucosidase enzyme were investigated. Showing IC50 values ranging from 16.4 ± 0.36 µM to 297.0 ± 1.2 µM confirmed their excellent potency to inhibit α-glucosidase which encouraged us to perform further studies on α-glucosidase enzymes obtained from rat as a mammal source. Among various synthesized 3-amino-2,4-diarylbenzo[4,5]imidazo[1,2-a]pyrimidines, compound 3k exhibited the highest potency against both Saccharomyces cerevisiae α-glucosidase (IC50 = 16.4 ± 0.36 μM) and rat small intestine α-glucosidase (IC50 = 45.0 ± 8.2 μM). Moreover, the role of amine moiety on the observed activity was studied through substituting with chlorine and hydrogen resulted into a considerable deterioration on the inhibitory activity. Kinetic study and molecular docking study have confirmed the in-vitro results.

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Recent Advances in Fabrication of Non-Isocyanate Polyurethane-Based Composite Materials

Materials ◽

10.3390/ma14133497 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3497

Author(s):

Piotr Stachak ◽

Izabela Łukaszewska ◽

Edyta Hebda ◽

Krzysztof Pielichowski

Keyword(s):

Raw Materials ◽

Synthesis Method ◽

Polymeric Materials ◽

Original Research ◽

Significant Group ◽

Oh Groups ◽

New Class ◽

Hazardous Chemical ◽

Wide Range

Polyurethanes (PUs) are a significant group of polymeric materials that, due to their outstanding mechanical, chemical, and physical properties, are used in a wide range of applications. Conventionally, PUs are obtained in polyaddition reactions between diisocyanates and polyols. Due to the toxicity of isocyanate raw materials and their synthesis method utilizing phosgene, new cleaner synthetic routes for polyurethanes without using isocyanates have attracted increasing attention in recent years. Among different attempts to replace the conventional process, polyaddition of cyclic carbonates (CCs) and polyfunctional amines seems to be the most promising way to obtain non-isocyanate polyurethanes (NIPUs) or, more precisely, polyhydroxyurethanes (PHUs), while primary and secondary –OH groups are being formed alongside urethane linkages. Such an approach eliminates hazardous chemical compounds from the synthesis and leads to the fabrication of polymeric materials with unique and tunable properties. The main advantages include better chemical, mechanical, and thermal resistance, and the process itself is invulnerable to moisture, which is an essential technological feature. NIPUs can be modified via copolymerization or used as matrices to fabricate polymer composites with different additives, similar to their conventional counterparts. Hence, non-isocyanate polyurethanes are a new class of environmentally friendly polymeric materials. Many papers on the matter above have been published, including both original research and extensive reviews. However, they do not provide collected information on NIPU composites fabrication and processing. Hence, this review describes the latest progress in non-isocyanate polyurethane synthesis, modification, and finally processing. While focusing primarily on the carbonate/amine route, methods of obtaining NIPU are described, and their properties are presented. Ways of incorporating various compounds into NIPU matrices are characterized by the role of PHU materials in copolymeric materials or as an additive. Finally, diverse processing methods of non-isocyanate polyurethanes are presented, including electrospinning or 3D printing.

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Cyclodextrins tethered with oligolactides – green synthesis and structural assessment

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.13.77 ◽

2017 ◽

Vol 13 ◽

pp. 779-792 ◽

Cited By ~ 3

Author(s):

Cristian Peptu ◽

Mihaela Balan-Porcarasu ◽

Alena Šišková ◽

Ľudovít Škultéty ◽

Jaroslav Mosnáček

Keyword(s):

Ring Opening ◽

Laser Desorption Ionization ◽

Oh Groups ◽

Soft Ionization ◽

Light Scattering Detection ◽

Synthetic Procedure ◽

Evaporative Light Scattering ◽

Green Procedure ◽

Methylene Group

Biodegradable oligolactide derivatives based on α-, β- and γ-cyclodextrins (CDs) were synthesized by a green procedure in which CDs play the role of both the initiator and the catalyst. The synthetic procedure in which CDs and L-lactide (L-LA) are reacting in bulk at relatively high temperature of 110 °C was investigated considering the structural composition of the products. The obtained products were thoroughly characterized via mass spectrometry methods with soft ionization like matrix-assisted laser desorption ionization (MALDI) and electrospray ionization (ESI). Liquid chromatography (LC) separation with evaporative light scattering detection (ELSD) and NMR analysis were employed in order to elucidate the structural profiles of the obtained mixtures. The results clearly demonstrate that the cyclodextrins were tethered with more than one short oligolactate chain per CD molecule, predominantly at the methylene group, through ring opening of L-LA initiated by primary OH groups.

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The Role of Carboxyl and Hydroxyl Groups of Humic Acid in Removing AuCl4- from Aqueous Solution

Indonesian Journal of Chemistry ◽

10.22146/ijc.23620 ◽

2017 ◽

Vol 17 (1) ◽

pp. 95 ◽

Cited By ~ 5

Author(s):

Sri Sudiono ◽

Mustika Yuniarti ◽

Dwi Siswanta ◽

Eko Sri Kunarti ◽

Triyono Triyono ◽

...

Keyword(s):

Aqueous Solution ◽

Humic Acid ◽

Peat Soil ◽

Sharp Decrease ◽

Hydroxyl Groups ◽

Mixed Solution ◽

Oh Groups ◽

Characterization Result ◽

Ft Ir

Humic acid (HA) extracted from peat soil according to the recommended procedure of the International Humic Substances Society (IHSS) has been tested to remove AuCl4- from aqueous solution. The removal was optimum at pH 2.0 and it was mainly dictated by attachment through hydrogen bonding to unionized carboxyl (–COOH) groups and reduction by the action of the hydroxyl (–OH) groups to gold (Au) metal. The removal of AuCl4- improved after HA was purified through repeated immersion and shaking in a mixed solution containing 0.1 M HCl and 0.3 M HF. When the purification led to the sharp decrease in ash content from 39.34 to 0.85% (w/w) and significant increase in both the –COOH and –OH contents from 3240 to 3487 mmol/kg and from 4260 to 4620 mmol/kg, respectively; the removal of AuCl4- improved from 0.105 to 0.133 mmol/g. This improvement of AuCl4- removal by the purified HA was accompanied by higher ability in reduction to Au metal. The attached AuCl4- on –COOH groups of both crude and purified HAs was qualitatively observed by the characterization result of FT-IR spectroscopy, while the presence of Au metal on the surface of those HAs was verified by the characterization result of XRD.

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Moisture Induced Degradation of Porous Low-k Materials

MRS Proceedings ◽

10.1557/proc-0914-f02-06 ◽

2006 ◽

Vol 914 ◽

Cited By ~ 6

Author(s):

Mikhail Baklanov ◽

David O'Dwyer ◽

Adam M Urbanowicz ◽

Quoc Toan Le ◽

Steven Demuynck ◽

...

Keyword(s):

Water Film ◽

Internal Surface ◽

Hydrophobic Surface ◽

Adsorbed Water ◽

Bulk Water ◽

Oh Groups ◽

Film Bulk ◽

Low K

AbstractInteraction of moisture with porous low-k films is evaluated by using in situ ellipsometry setup. The adsorbed water amount is calculated from change of refractive index measured during the adsorption. Pristine low-k films reversibly adsorb 2 - 5% of water that reflects presence of constitutive hydrophilic centrums. Plasma and thermal treatments increase the number of hydrophilic centrums. Once the amount of these centrums has reached a certain critical value sufficient to form a continuous water film, bulk water condensation is observed. Change of properties during the water adsorption in the damaged films is not fully reversible. Each additional adsorption cycle increases the dielectric function of the film because of decreasing porosity, increasing skeleton density and shrinkage. The pressure corresponding to the bulk condensation allows us to calculate internal contact angle (internal surface energy) of low-k materials. The water molecules adsorbed on separate OH groups play the role of a catalyst that hydrolyses the siloxane bridges initially present on hydrophobic surface.

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Role of Molecular Docking in Computer-Aided Drug Design and Development

Advances in Medical Technologies and Clinical Practice - Applied Case Studies and Solutions in Molecular Docking-Based Drug Design ◽

10.4018/978-1-5225-0362-0.ch001 ◽

2016 ◽

pp. 1-28

Author(s):

Rahul Agarwal ◽

Ashutosh Singh ◽

Subhabrata Sen

Keyword(s):

Molecular Docking ◽

Drug Design ◽

Protein Binding ◽

Design And Development ◽

Advantages And Disadvantages ◽

Computer Aided ◽

Drug Designing ◽

Near Future

Molecular Docking is widely used in CADD (Computer-Aided Drug Designing), SBDD (Structure-Based Drug Designing) and LBDD (Ligand-Based Drug Designing). It is a method used to predict the binding orientation of one molecule with the other and used for any kind of molecule based on the interaction like, small drug molecule with its protein target, protein – protein binding or a DNA – protein binding. Docking is very much popular technique due to its reliable prediction properties. This book chapter will provide an overview of diverse docking methodologies present that are used in drug design and development. There will be discussion on several case studies, pertaining to each method, followed by advantages and disadvantages of the discussed methodology. It will typically aim professionals in the field of cheminformatics and bioinformatics, both in academia and in industry and aspiring scientists and students who want to take up this as a profession in the near future. We will conclude with our opinion on the effectiveness of this technology in the future of pharmaceutical industry.

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Study on Structure Activity Relationship of Natural Flavonoids against Thrombin by Molecular Docking Virtual Screening Combined with Activity Evaluation In Vitro

Molecules ◽

10.3390/molecules25020422 ◽

2020 ◽

Vol 25 (2) ◽

pp. 422

Author(s):

Xiaoyan Wang ◽

Zhen Yang ◽

Feifei Su ◽

Jin Li ◽

Evans Owusu Boadi ◽

...

Keyword(s):

Molecular Docking ◽

Virtual Screening ◽

Screening Method ◽

Thrombin Inhibitors ◽

Coagulation Cascade ◽

Oh Groups ◽

Structure Activity Relationships ◽

Thrombin Inhibition ◽

Structure Activity

Thrombin, a key enzyme of the serine protease superfamily, plays an integral role in the blood coagulation cascade and thrombotic diseases. In view of this, it is worthwhile to establish a method to screen thrombin inhibitors (such as natural flavonoid-type inhibitors) as well as investigate their structure activity relationships. Virtual screening using molecular docking technique was used to screen 103 flavonoids. Out of this number, 42 target compounds were selected, and their inhibitory effects on thrombin assayed by chromogenic substrate method. The results indicated that the carbon-carbon double bond group at the C2, C3 sites and the carbonyl group at the C4 sites of flavones were essential for thrombin inhibition, whereas the methoxy and O-glycosyl groups reduced thrombin inhibition. Noteworthy, introduction of OH groups at different positions on flavonoids either decreased or increased anti-thrombin potential. Myricetin exhibited the highest inhibitory potential against thrombin with an IC50 value of 56 μM. Purposively, the established molecular docking virtual screening method is not limited to exploring flavonoid structure activity relationships to anti-thrombin activity but also usefully discovering other natural active constituents.

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Synthesis of a Rationally Designed Multi-Component Photocatalyst Pt:SiO2:TiO2(P25) with Improved Activity for Dye Degradation by Atomic Layer Deposition

Nanomaterials ◽

10.3390/nano10081496 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1496 ◽

Cited By ~ 1

Author(s):

Dominik Benz ◽

Hao Van Bui ◽

Hubertus T. Hintzen ◽

Michiel T. Kreutzer ◽

J. Ruud van Ommen

Keyword(s):

Atomic Layer Deposition ◽

Dye Degradation ◽

Atomic Layer ◽

Oh Groups ◽

Practical Applications ◽

Beneficial Effects ◽

Layer Deposition ◽

The Individual ◽

Materials Behavior

Photocatalysts for water purification typically lack efficiency for practical applications. Here we present a multi-component (Pt:SiO2:TiO2(P25)) material that was designed using knowledge of reaction mechanisms of mono-modified catalysts (SiO2:TiO2, and Pt:TiO2) combined with the potential of atomic layer deposition (ALD). The deposition of ultrathin SiO2 layers on TiO2 nanoparticles, applying ALD in a fluidized bed reactor, demonstrated in earlier studies their beneficial effects for the photocatalytic degradation of organic pollutants due to more acidic surface Si–OH groups which benefit the generation of hydroxyl radicals. Furthermore, our investigation on the role of Pt on TiO2(P25), as an improved photocatalyst, demonstrated that suppression of charge recombination by oxygen adsorbed on the Pt particles, reacting with the separated electrons to superoxide radicals, acts as an important factor for the catalytic improvement. Combining both materials into the resulting Pt:SiO2:TiO2(P25) nanopowder exceeded the dye degradation performance of both the individual SiO2:TiO2(P25) (1.5 fold) and Pt:TiO2(P25) (4-fold) catalysts by 6-fold as compared to TiO2(P25). This approach thus shows that by understanding the individual materials’ behavior and using ALD as an appropriate deposition technique enabling control on the nano-scale, new materials can be designed and developed, further improving the photocatalytic activity. Our research demonstrates that ALD is an attractive technology to synthesize multicomponent catalysts in a precise and scalable way.

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Evidence for the role of high density lipoproteins in mediating the antioxidant effect of estrogens

Acta Endocrinologica ◽

10.1530/eje.0.1420079 ◽

2000 ◽

pp. 79-83 ◽

Cited By ~ 15

Author(s):

W Abplanalp ◽

MD Scheiber ◽

K Moon ◽

B Kessel ◽

JH Liu ◽

...

Keyword(s):

Density Lipoprotein ◽

Antioxidant Effect ◽

High Density ◽

In Vivo Studies ◽

Ldl Oxidation ◽

High Density Lipoproteins ◽

Oh Groups

Estrogens possess strong antioxidant effects in vitro, but in vivo studies in humans have yielded conflicting results. Little is known regarding factors that mediate the antioxidant effect of estrogens in vivo. In this study the potential role of high density lipoprotein (HDL) was examined. The antioxidant effect of estradiol-17beta (E2) added to low density lipoprotein (LDL) was lost after dialysis. In contrast, the antioxidant effect of E2 added to HDL was conserved after dialysis, suggesting that E2 was bound to HDL. Binding of E2 to LDL increased after esterification (especially to long chain fatty acids). In the presence of HDL, an increased amount of E2 was transferred to LDL. E2-17 ester was as potent as E2 in preventing LDL oxidation in vitro, but 3,17-diesters were not as effective (E2=E2-17 ester>E2-3 ester>E2-3,17 diester). This was also supported by experiments which showed that estrogens with masked 3-OH groups were not effective as antioxidants. These studies provide evidence that HDL could facilitate the antioxidant effect of E2 through initial association, esterification and eventual transfer of E2 esters to LDL. Therefore it is critical that HDL peroxidation parameters be evaluated in subjects receiving estrogen replacement therapy.

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