scholarly journals Imidazole and Azo-Based Schiff Bases Ligands as Highly Active Antifungal and Antioxidant Components

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Siham Slassi ◽  
Adeline Fix-Tailler ◽  
Gérald Larcher ◽  
Amina Amine ◽  
Abdelkrim El-Ghayoury
Keyword(s):  
Radical Scavenging ◽  
Pathogenic Fungi ◽  
Imino Group ◽  
Absorption Bands ◽  
Visible Absorption ◽  
Full Characterization ◽  
Highly Active ◽  
Azobenzene Moiety ◽  
Base Fragment

We describe, herein, the synthesis, full characterization, and optical properties of four different ligandsL1-L4which associate an azo group, an imidazole unit, and a Schiff base fragment. The UV-visible absorption bands are characteristic ofπ→π⁎andn→π⁎transitions with an additional charge transfer between the azobenzene moiety and the imino group. Finally the determination of MIC80values against pathogenic fungi such asS. apiospermum,A. fumigatus,andC. albicansrevealed that these ligands have effective antifungal properties with highest activities (MIC80) onC. albicansfor the azole based ligandsL1-L3. DPPH radical scavenging of the studied ligands was also tested.

Polarographic and spectrophotometric behaviour of some N-p-phenyl substituted benzamidines

1991 ◽  
Vol 56 (12) ◽  
pp. 2791-2799 ◽  
Author(s):  
Juan A. Squella ◽  
Luis J. Nuñez-Vergara ◽  
Hernan Rodríguez ◽  
Amelia Márquez ◽  
Jose M. Rodríguez-Mellado ◽  
...  
Keyword(s):  
Spectrophotometric Study ◽  
Absorption Bands ◽  
Electrochemical Parameters ◽  
Wide Ph Range ◽  
Group A ◽  
Substituent Constants ◽  
Ph Range ◽  
The Waves

Five N-p-phenyl substituted benzamidines were studied by DC and DP polarography in a wide pH range. Coulometric results show that the overall processes are four-electron reductions. Logarithmic analysis of the waves indicate that the process are irreversible. The influence of the pH on the polarographic parameters was also studied. A UV spectrophotometric study was performed in the pH range 2-13. In basic media some variations in the absorption bands were observed due to the dissociation of the amidine group. A determination of the pK values was made by deconvolution of the spectra. Correlations of both the electrochemical parameters and spectrophotometric pK values with the Hammett substituent constants were obtained.

scholarly journals Investigation of antioxidant and anticancer activities of unsaturated oligo-galacturonic acids produced by pectinase of Streptomyces hydrogenans YAM1

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Afrouzossadat Hosseini Abari ◽  
Hamed Amini Rourani ◽  
Seyed Mahdi Ghasemi ◽  
Hyun Kim ◽  
Yun-Gon Kim
Keyword(s):  
Radical Scavenging Activity ◽  
Flow Cytometric Analysis ◽  
Radical Scavenging ◽  
Anticancer Activities ◽  
Pectin Degradation ◽  
New Approach ◽  
Flight Mass Spectrometry ◽  
Highly Active ◽  
Carbohydrate Polymer ◽  
Pectinase Activity

AbstractPectin, a diverse carbohydrate polymer in plants consists of a core of α-1,4-linked D-galacturonic acid units, includes a vast portion of fruit and agricultural wastes. Using the wastes to produce beneficial compounds is a new approach to control the negative environmental impacts of the accumulated wastes. In the present study, we report a pectinase producing bacterium Streptomyces hydrogenans YAM1 and evaluate antioxidative and anticancer effects of the oligosaccharides obtained from pectin degradation. The production of oligosaccharides due to pectinase activity was detected by thin layer chromatography (TLC) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Our results revealed that S. hydrogenans YAM1 can degrade pectin to unsaturated pectic oligo-galacturonic acids (POS) with approximately 93% radical scavenging activity in 20 mg/mL which it is more than 50% of the same concentration of pectin. Flow cytometric analysis revealed that MCF-7 cells viability decreased more than 32 and 92% following treatment with 6 and 20 mg/mL POS after 24 h, respectively. It is suggested that pectin degradation by S. hydrogenans YAM1 is not only a new approach to produce highly active compounds from fruit wastes, but also is an effective method to remove fibrous pollutants from different environments.

scholarly journals Screening of Phenolic Compounds in Australian Grown Berries by LC-ESI-QTOF-MS/MS and Determination of Their Antioxidant Potential

Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 26
Author(s):  
Vigasini Subbiah ◽  
Biming Zhong ◽  
Malik A. Nawaz ◽  
Colin J. Barrow ◽  
Frank R. Dunshea ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Phenolic Acid ◽  
Phenolic Content ◽  
Radical Scavenging ◽  
Vaccinium Corymbosum ◽  
Rubus Idaeus ◽  
Antioxidant Potential ◽  
Fresh Frozen ◽  
Flavonoid Quercetin

Berries are grown worldwide with the most consumed berries being blackberries (Rubus spp.), blueberries (Vaccinium corymbosum), red raspberries (Rubus idaeus) and strawberries (Fragaria spp.). Berries are either consumed fresh, frozen, or processed into wines, juices, and jams. In recent times, researchers have focused their attention on berries due to their abundance in phenolic compounds. The current study aimed to evaluate the phenolic content and their antioxidant potential followed by characterization and quantification using LC-ESI-QTOF-MS/MS and HPLC-PDA. Blueberries were highest in TPC (2.93 ± 0.07 mg GAE/gf.w.) and TFC (70.31 ± 1.21 µg QE/gf.w.), whereas the blackberries had the highest content in TTC (11.32 ± 0.13 mg CE/gf.w.). Blueberries had the highest radical scavenging capacities for the DPPH (1.69 ± 0.09 mg AAE/gf.w.), FRAP (367.43 ± 3.09 µg AAE/gf.w.), TAC (1.47 ± 0.20 mg AAE/gf.w.) and ABTS was highest in strawberries (3.67 ± 0.14 mg AAE/gf.w.). LC-ESI-QTOF-MS/MS study identified a total of 65 compounds including 42 compounds in strawberries, 30 compounds in raspberries, 28 compounds in blueberries and 21 compounds in blackberries. The HPLC-PDA quantification observed phenolic acid (p-hydroxybenzoic) and flavonoid (quercetin-3-rhamnoside) higher in blueberries compared to other berries. Our study showed the presence of phenolic acids and provides information to be utilized as an ingredient in food, pharmaceutical and nutraceutical industries.

scholarly journals KD determination from time-resolved experiments on live cells with LigandTracer and reconciliation with end-point flow cytometry measurements

2021 ◽  
Author(s):  
Diana Spiegelberg ◽  
Jonas Stenberg ◽  
Pascale Richalet ◽  
Marc Vanhove
Keyword(s):  
Flow Cytometry ◽  
Live Cells ◽  
Time Resolved ◽  
Surface Receptors ◽  
Full Characterization ◽  
End Point ◽  
Titration Curves ◽  
Kinetics Of

AbstractDesign of next-generation therapeutics comes with new challenges and emulates technology and methods to meet them. Characterizing the binding of either natural ligands or therapeutic proteins to cell-surface receptors, for which relevant recombinant versions may not exist, represents one of these challenges. Here we report the characterization of the interaction of five different antibody therapeutics (Trastuzumab, Rituximab, Panitumumab, Pertuzumab, and Cetuximab) with their cognate target receptors using LigandTracer. The method offers the advantage of being performed on live cells, alleviating the need for a recombinant source of the receptor. Furthermore, time-resolved measurements, in addition to allowing the determination of the affinity of the studied drug to its target, give access to the binding kinetics thereby providing a full characterization of the system. In this study, we also compared time-resolved LigandTracer data with end-point KD determination from flow cytometry experiments and hypothesize that discrepancies between these two approaches, when they exist, generally come from flow cytometry titration curves being acquired prior to full equilibration of the system. Our data, however, show that knowledge of the kinetics of the interaction allows to reconcile the data obtained by flow cytometry and LigandTracer and demonstrate the complementarity of these two methods.

scholarly journals The Importance of Motions that Accompany Those Occurring Along the Reaction Coordinate

2015 ◽  
Vol 68 (8) ◽  
pp. 1202 ◽  
Author(s):  
Jeffrey R. Reimers
Keyword(s):  
Reaction Coordinate ◽  
Spectral Measurements ◽  
Visible Absorption ◽  
Photochemical Process ◽  
New Approach ◽  
Energy Devices ◽  
Adiabatic Theory ◽  
Core Theory ◽  
Basic Ideas

The reaction coordinate is a well known quantity used to define the motions critical to chemical reactions, but many other motions always accompany it. These other motions are typically ignored but this is not always possible. Sometimes it is not even clear as to which motions comprise the reaction coordinate: spectral measurements that one may assume are dominated by the reaction coordinate could instead be dominated by the accompanying modes. Examples of different scenarios are considered. The assignment of the visible absorption spectrum of chlorophyll-a was debated for 50 years, with profound consequences for the understanding of how light energy is transported and harvested in natural and artificial solar-energy devices. We recently introduced a new, comprehensive, assignment, the centrepiece of which was determination of the reaction coordinate for an unrecognized photochemical process. The notion that spectroscopy and reactivity are so closely connected comes directly from Hush’s adiabatic theory of electron-transfer reactions. Its basic ideas are reviewed, similarities to traditional chemical theories drawn, key analytical results described, and the importance of the accompanying modes stressed. Also highlighted are recent advances that allow this theory to be applied to general transformations including isomerization processes, hybridization, aromaticity, hydrogen bonding, and understanding why the properties of first-row molecules such as NH3 (bond angle 108°) are so different to those of PH3–BiH3 (bond angles 90–93°). Historically, the question of what is the reaction coordinate and what is just an accompanying motion has not commonly been at the forefront of attention. In our new approach in which all chemical processes are described using the same core theory, this question becomes thrust forward as always being the most important qualitative feature to determine.

Solvent Extraction and GC-MS Analysis of Sesame Seeds for Determination of Bioactive Antioxidant Fatty Acid/Fatty Oil Components

Drug Research ◽  
2017 ◽  
Vol 68 (06) ◽  
pp. 344-348 ◽  
Author(s):  
Abdul Qadir ◽  
Athar Ali ◽  
Muhammad Arif ◽  
Abdulmohsen Al-Rohaimi ◽  
Satya Singh ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Palmitic Acid ◽  
Unsaturated Fatty Acids ◽  
Radical Scavenging ◽  
Ethanolic Extract ◽  
Gas Chromatography Mass Spectrometry ◽  
Sesame Seeds ◽  
Fatty Oil ◽  
Oleoyl Chloride

AbstractThe seed kernels of Sesamum indicum L. (family: Pedaliaceae) were extracted with ethanol and yield of components determined by Gas Chromatography/Mass Spectrometry (GC/MS). The free radical scavenging activities of ethanolic extract against1, 1-Diphenyl-2-picrylhydrazyl (DPPH) were determined by UV spectrophotometer at 517 nm. Phytochemical screening revealed the presence of numerous bioactive compounds including steroids, phenolic, terpenoids, fatty acids and different types of ester compounds. The ethanolic extract was purified and analyzed by GC MS.The prevailing compounds found in ethanolic extract were Carvacrol (0.04%),Sesamol (0.11%), 4-Allyl-2-methoxy-phenol(0.04%),Palmitic acid (1.08%), cis-9-Hexadecenal (85.40%), Lineoleoyl chloride (0.52%), Palmitic acid β-monoglyceride (0.40%), Dihydro-aplotaxene (0.61%), Oleoyl chloride (1.11%), (+)-Sesamin (4.73%), 1,3-Benzodioxole, 5-[4-(1,3-benzodioxol-5-yloxy)tetrahydro-1 H,3 H-furo [3,4-c]furan-1-yl], [1 S-(1,3,4,6α.), (2.01%)], 6-Nitrocholest-5-en-3-yl acetate (0.22%), Ergost-5-en-3β-ol (2.35%) and 24-Propylidenecholesterol (0.16%). The presence ofsaturated and unsaturated fatty acids in ethanolicextract justifies the use of this plant to treat many ailments in folk and traditional medicine. Ethanolic extract have shown significant antioxidant activity(IC50120.38±2.8 µg/ml). The presence of phenolic (Sesamol), lignin (Sesamin) compounds and unsaturated fatty acids are reported as possible contributor for antioxidantactivity of seed extract.

Meso-aryl-ß-pyrrolic positions interactions in meso-tetraarylporphyrins: Flat arylporphyrins and building blocks for oligoporphyrins

2004 ◽  
Vol 08 (02) ◽  
pp. 111-119 ◽  
Author(s):  
Henry J. Callot ◽  
Romain Ruppert ◽  
Christophe Jeandon ◽  
Sébastien Richeter
Keyword(s):  
Building Blocks ◽  
Absorption Bands ◽  
Visible Absorption ◽  
Aryl Ring ◽  
Porphyrin Macrocycle ◽  
Uv Visible

Aryl groups bound to the meso positions of porphyrins often react with neighboring groups, in particular ß-acyl groups to give highly diversified monomeric and dimeric new functionalized porphyrins. The products, whose meso-aryl ring approaches coplanarity with the porphyrin macrocycle, show large shifts of UV-visible absorption bands and various potentialities for building external chelating moieties and assembling oligoporphyrins.

scholarly journals Engineered unnatural ubiquitin for optimal detection of deubiquitinating enzymes

2020 ◽  
Author(s):  
Wioletta Rut ◽  
Mikołaj Żmudziński ◽  
Scott J. Snipas ◽  
Miklos Bekes ◽  
Tony T. Huang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Neurodegenerative Disorders ◽  
Unnatural Amino Acids ◽  
Biochemical Analysis ◽  
Deubiquitinating Enzymes ◽  
Fluorogenic Substrates ◽  
Protein Conjugates ◽  
Highly Active ◽  
Selective Chemical

AbstractDeubiquitinating enzymes (DUBs) are responsible for removing ubiquitin (Ub) from its protein conjugates. DUBs have been implicated as attractive therapeutic targets in the treatment of viral diseases, neurodegenerative disorders and cancer. The lack of selective chemical tools for the exploration of these enzymes significantly impairs the determination of their roles in both normal and pathological states. Commercially available fluorogenic substrates are based on the C-terminal Ub motif or contain Ub coupled to a fluorophore (Z-LRGG-AMC, Ub-AMC); therefore, these substrates suffer from lack of selectivity. By using a hybrid combinatorial substrate library (HyCoSuL) and a defined P2 library containing a wide variety of nonproteinogenic amino acids, we established a full substrate specificity profile for two DUBs—MERS PLpro and human UCH-L3. Based on these results, we designed and synthesized Ub-based substrates and activity-based probes (ABPs) containing selected unnatural amino acids located in the C-terminal Ub motif. Biochemical analysis and cell-based experiments confirmed the activity and selectivity of engineered Ub-based substrates and probes. Using this approach, we propose that for any protease that recognizes Ub and Ub-like substrates, a highly active and selective unnatural substrate or probe can be engineered.

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