scholarly journals Insights into the Antioxidant Mechanism of Newly Synthesized Benzoxazinic Nitrones: In Vitro and In Silico Studies with DPPH Model Radical

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1224
Author(s):  
Stefania Marano ◽  
Cristina Minnelli ◽  
Lorenzo Ripani ◽  
Massimo Marcaccio ◽  
Emiliano Laudadio ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Epr Spectroscopy ◽  
Point Of View ◽  
Uv Spectrophotometry ◽  
Design And Synthesis ◽  
Antioxidant Mechanism ◽  
Primary Mechanism ◽  
In Silico Studies ◽  
Wide Range

Synthetic nitrone spin-traps are being explored as therapeutic agents for the treatment of a wide range of oxidative stress-related pathologies, including but not limited to stroke, cancer, cardiovascular, and neurodegenerative diseases. In this context, increasing efforts are currently being made to the design and synthesis of new nitrone-based compounds with enhanced efficacy. The most researched nitrones are surely the ones related to α-phenyl-tert-butylnitrone (PBN) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO) derivatives, which have shown to possess potent biological activity in many experimental animal models. However, more recently, nitrones with a benzoxazinic structure (3-aryl-2H-benzo[1,4]oxazin-N-oxides) have been demonstrated to have superior antioxidant activity compared to PBN. In this study, two new benzoxazinic nitrones bearing an electron-withdrawing methoxycarbonyl group on the benzo moiety (in para and meta positions respect to the nitronyl function) were synthesized. Their in vitro antioxidant activity was evaluated by two cellular-based assays (inhibition of AAPH-induced human erythrocyte hemolysis and cell death in human retinal pigmented epithelium (ARPE-19) cells) and a chemical approach by means of the α,α-diphenyl-β-picrylhydrazyl (DPPH) scavenging assay, using both electron paramagnetic resonance (EPR) spectroscopy and UV spectrophotometry. A computational approach was also used to investigate their potential primary mechanism of antioxidant action, as well as to rationalize the effect of functionalization on the nitrones reactivity toward DPPH, chosen as model radical in this study. Further insights were also gathered by exploring the nitrone electrochemical properties via cyclic voltammetry and by studying their kinetic behavior by means of EPR spectroscopy. Results showed that the introduction of an electron-withdrawing group in the phenyl moiety in the para position significantly increased the antioxidant capacity of benzoxazinic nitrones both in cell and cell-free systems. From the mechanistic point of view, the calculated results closely matched the experimental findings, strongly suggesting that the H-atom transfer (HAT) is likely to be the primary mechanism in the DPPH quenching.

Chalcones: As potent α-amylase enzyme inhibitors; synthesis, in vitro, and in silico studies

2020 ◽  
Vol 16 ◽  
Author(s):  
Mahboob Ali ◽  
Momin Khan ◽  
Khair Zaman ◽  
Abdul Wadood ◽  
Maryam Iqbal ◽  
...  
Keyword(s):  
In Silico ◽  
Enzyme Inhibitors ◽  
Biological Activities ◽  
Condensation Reaction ◽  
Type Ii Diabetes Mellitus ◽  
Spectroscopic Techniques ◽  
Chalcone Derivatives ◽  
In Silico Studies ◽  
Wide Range

: Background: The inhibition of α-amylase enzyme is one of the best therapeutic approach for the management of type II diabetes mellitus. Chalcone possesses a wide range of biological activities. Objective: In the current study chalcone derivatives (1-17) were synthesized and evaluated their inhibitory potential against α-amylase enzyme. Method: For that purpose, a library of substituted (E)-1-(naphthalene-2-yl)-3-phenylprop-2-en-1-ones was synthesized by ClaisenSchmidt condensation reaction of 2-acetonaphthanone and substituted aryl benzaldehyde in the presence of base and characterized via different spectroscopic techniques such as EI-MS, HREI-MS, 1H-, and 13C-NMR. Results: Sixteen synthetic chalcones were evaluated for in vitro porcine pancreatic α-amylase inhibition. All the chalcones demonstrated good inhibitory activities in the range of IC50 = 1.25 ± 1.05 to 2.40 ± 0.09 μM as compared to the standard commercial drug acarbose (IC50 = 1.34 ± 0.3 μM). Conclusion: Chalcone derivatives (1-17) were synthesized, characterized, and evaluated for their α-amylase inhibition. SAR revealed that electron donating groups in the phenyl ring have more influence on enzyme inhibition. However, to insight the participation of different substituents in the chalcones on the binding interactions with the α-amylase enzyme, in silico (computer simulation) molecular modeling analyses were carried out.

scholarly journals Isobornylchalcones as Scaffold for the Synthesis of Diarylpyrazolines with Antioxidant Activity

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3579
Author(s):  
Svetlana A. Popova ◽  
Evgenia V. Pavlova ◽  
Oksana G. Shevchenko ◽  
Irina Yu. Chukicheva ◽  
Aleksandr V. Kutchin
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Properties ◽  
Biological Properties ◽  
High Reactivity ◽  
Biologically Active ◽  
Brain Lipids ◽  
Wide Range ◽  
Privileged Structure ◽  
Vitro Model

The pyrazoline ring is defined as a “privileged structure” in medicinal chemistry. A variety of pharmacological properties of pyrazolines is associated with the nature and position of various substituents, which is especially evident in diarylpyrazolines. Compounds with a chalcone fragment show a wide range of biological properties as well as high reactivity which is primarily due to the presence of an α, β-unsaturated carbonyl system. At the same time, bicyclic monoterpenoids deserve special attention as a source of a key structural block or as one of the pharmacophore components of biologically active molecules. A series of new diarylpyrazoline derivatives based on isobornylchalcones with different substitutes (MeO, Hal, NO2, N(Me)2) was synthesized. Antioxidant properties of the obtained compounds were comparatively evaluated using in vitro model Fe2+/ascorbate-initiated lipid peroxidation in the substrate containing brain lipids of laboratory mice. It was demonstrated that the combination of the electron-donating group in the para-position of ring B and OH-group in the ring A in the structure of chalcone fragment provides significant antioxidant activity of synthesized diarylpyrazoline derivatives.

scholarly journals Revealing biophysical properties of KfrA-type proteins as a novel class of cytoskeletal, coiled-coil plasmid-encoded proteins

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
M. Adamczyk ◽  
E. Lewicka ◽  
R. Szatkowska ◽  
H. Nieznanska ◽  
J. Ludwiczak ◽  
...  
Keyword(s):  
Dna Binding ◽  
Host Range ◽  
Coiled Coil ◽  
Amino Acid Sequences ◽  
Broad Host Range ◽  
Biophysical Properties ◽  
Dna Binding Sites ◽  
In Silico Studies ◽  
Wide Range

Abstract Background DNA binding KfrA-type proteins of broad-host-range bacterial plasmids belonging to IncP-1 and IncU incompatibility groups are characterized by globular N-terminal head domains and long alpha-helical coiled-coil tails. They have been shown to act as transcriptional auto-regulators. Results This study was focused on two members of the growing family of KfrA-type proteins encoded by the broad-host-range plasmids, R751 of IncP-1β and RA3 of IncU groups. Comparative in vitro and in silico studies on KfrAR751 and KfrARA3 confirmed their similar biophysical properties despite low conservation of the amino acid sequences. They form a wide range of oligomeric forms in vitro and, in the presence of their cognate DNA binding sites, they polymerize into the higher order filaments visualized as “threads” by negative staining electron microscopy. The studies revealed also temperature-dependent changes in the coiled-coil segment of KfrA proteins that is involved in the stabilization of dimers required for DNA interactions. Conclusion KfrAR751 and KfrARA3 are structural homologues. We postulate that KfrA type proteins have moonlighting activity. They not only act as transcriptional auto-regulators but form cytoskeletal structures, which might facilitate plasmid DNA delivery and positioning in the cells before cell division, involving thermal energy.

In vitro and in silico studies of antioxidant activity of 2-thiazolylhydrazone derivatives

2019 ◽  
Vol 86 ◽  
pp. 106-112 ◽  
Author(s):  
Vinícius Gonçalves Maltarollo ◽  
Marina Ferrara de Resende ◽  
Thales Kronenberger ◽  
Cleudiomar Inácio Lino ◽  
Maria Clara Pinheiro Duarte Sampaio ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
In Silico ◽  
In Silico Studies

scholarly journals Modification of Hydroxypropyltrimethyl Ammonium Chitosan with Organic Acid: Synthesis, Characterization, and Antioxidant Activity

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2460
Author(s):  
Yingqi Mi ◽  
Wenqiang Tan ◽  
Jingjing Zhang ◽  
Zhanyong Guo
Keyword(s):  
Antioxidant Activity ◽  
Organic Acids ◽  
Organic Acid ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Scavenging Activity ◽  
Chitosan Derivatives ◽  
13C Nuclear Magnetic Resonance ◽  
Wide Range

A novel and green method for the preparation of chitosan derivatives bearing organic acids was reported in this paper. In order to improve the antioxidant activity of chitosan, eight different hydroxypropyltrimethyl ammonium chitosan derivatives were successfully designed and synthesized via introducing of organic acids onto chitosan by mild and non-toxic ion exchange. The data of Fourier Transform Infrared (FTIR), 13C Nuclear Magnetic Resonance (NMR), 1H NMR, and elemental analysis for chitosan derivatives indicated the successful conjugation of organic acid salt with hydroxypropyltrimethyl ammonium chloride chitosan (HACC). Meanwhile, the antioxidant activity of the chitosan derivatives was evaluated in vitro. The results indicated that the chitosan derivatives possessed dramatic enhancements in DPPH-radical scavenging activity, superoxide-radical scavenging activity, hydroxyl radical scavenging ability, and reducing power. Furthermore, the cytotoxicity of the synthesized compounds was investigated in vitro on L929 cells and showed low cytotoxicity. Thus, the enhanced antioxidant property of all novel chitosan products might be a great advantage, while applied in a wide range of applications in the form of antioxidant in biomedical, food, and cosmetic industry.

scholarly journals Aptamers in the Treatment of Bacterial Infections: Problems and Prospects

2016 ◽  
Vol 71 (5) ◽  
pp. 350-358
Author(s):  
N. A. Zeninskaya ◽  
A. V. Kolesnikov ◽  
A. K. Ryabko ◽  
I. G. Shemyakin ◽  
I. A. Dyatlov ◽  
...  
Keyword(s):  
Drug Discovery ◽  
High Throughput Screening ◽  
Bacterial Infections ◽  
Point Of View ◽  
Aptamer Selection ◽  
Wide Range ◽  
Therapeutic Molecules ◽  
Molecular Selection ◽  
The Stability

Aptamers are short single-stranded oligonucleotides which are selected via targeted chemical evolution in vitro to bind a molecular target of interest. The aptamer selection technology is designated as SELEX (Systematic evolution of ligands by exponential enrichment). SELEX enables isolation of oligonucleotide aptamers binding a wide range of targets of interest with little respect for their nature and molecular weight. A number of applications of aptamer selection were developed ranging from biosensor technologies to antitumor drug discovery. First aptamer-based pharmaceutical (Macugen) was approved by FDA for clinical use in 2004, and since then more than ten aptamer-based drugs undergo various phases of clinical trials. From the medicinal chemist’s point of view, aptamers represent a new class of molecules suitable for the development of new therapeutics. Due to the stability, relative synthesis simplicity, and development of advanced strategies of target specific molecular selection, aptamers attract increased attention of drug discovery community. Difficulties of the development of next-generation antibiotics basing on the conventional basis of combinatorial chemistry and high-throughput screening have also amplified the interest to aptamer-based therapeutic candidates. The present article reviews the investigations focused on the development of antibacterial aptamers and discusses the potential and current limitations of the use of this type of therapeutic molecules.

scholarly journals IN VITRO ANTIOXIDANT ACTIVITY AND WOUND HEALING ACTIVITY OF WHEATGRASS BY 1,1- DIPHENYL, 2 PICRYLHYDRAZYL METHOD

2018 ◽  
Vol 11 (12) ◽  
pp. 170
Author(s):  
Veermaneni Alekhya ◽  
Thiyagarajan Deepan ◽  
Magharla Dasaratha Dhanaraju
Keyword(s):  
Antioxidant Activity ◽  
Wound Healing ◽  
Skin Diseases ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Wheat Plant ◽  
Wide Range ◽  
Wound Healing Activity ◽  
In Vitro Antioxidant Activity

Objective: This study was designed to evaluate in vitro antioxidant activity and wound healing activity in Triticum aestivum (wheat grass).Methods: T. aestivum commonly known as Wheatgrass had a wide range of health benefits among the young grass of common wheat plant components includes chlorophyll, flavonoids, and Vitamins A, C, and E. Wheatgrass is used in Folklore medicine for treatment of skin diseases and wound healing. In our present study, petroleum ether, ethanol and aqueous extracts of T. aestivum have been evaluated for in vitro antioxidant activity and wound healing activity by 1,1- diphenyl, 2 Picrylhydrazyl radical scavenging activity, and Chick chorioallantoic method, respectively.Results: The results of both the assay showed that all the extracts of T. aestivum have significant antioxidant and wound healing activity on dose-dependent manner.Conclusion: The wheatgrass has antioxidant and wound healing activity.

Neuroprotection with Natural Antioxidants and Nutraceuticals in the Context of Brain Cell Degeneration: The Epigenetic Connection

2020 ◽  
Vol 19 (32) ◽  
pp. 2999-3011 ◽  
Author(s):  
Iván Carrera ◽  
Olaia Martínez ◽  
Ramón Cacabelos
Keyword(s):  
Antioxidant Activity ◽  
Biological Effects ◽  
Natural Antioxidants ◽  
Brain Cell ◽  
Point Of View ◽  
Cell Degeneration ◽  
Epigenetic Modifiers ◽  
Antioxidant Agents ◽  
Wide Range ◽  
The Brain

: Bioactive antioxidant agents present in selected plants are known to provide the first line of biological defense against oxidative stress. In particular, soluble vitamin C, E, carotenoids and phenolic compounds have demonstrated crucial biological effects in cells against oxidative damage, preventing prevalent chronic diseases, such as diabetes, cancer and cardiovascular disease. The reported wide range of effects that included anti-aging, anti-atherosclerosis, anti-inflammatory and anticancer activity were studied against degenerative pathologies of the brain. Vitamins and different phytochemicals are important epigenetic modifiers that prevent neurodegeneration. In order to explore the potential antioxidant sources in functional foods and nutraceuticals against neurodegeneration, the present paper aims to show a comprehensive assessment of antioxidant activity at chemical and cellular levels. The effects of the different bioactive compounds available and their antioxidant activity through an epigenetic point of view are also discussed.

Versatile and Valuable Utilization of Amidohydrolase L-glutaminase in Pharma and Food industries: A Review

2020 ◽  
Vol 21 (1) ◽  
pp. 11-24
Author(s):  
Chandrasai Potla Durthi ◽  
Madhuri Pola ◽  
Satish Babu Rajulapati ◽  
Anand Kishore Kola ◽  
Mohammad Amjad Kamal
Keyword(s):  
Enzyme Engineering ◽  
Soy Sauce ◽  
Acute Lymphocytic Leukaemia ◽  
Food Industries ◽  
In Silico Studies ◽  
Wide Range ◽  
Anti Cancer ◽  
Cancer Agent

L-glutaminase has versatile applications in pharma and food industries. In pharmaceutical industry, L-glutaminase can be used as anti-oxidant and anti-cancer agent to treat Acute Lymphocytic Leukaemia (ALL). Whereas, in the food industry, L-glutaminase is used for acrylamide degradation, theanine production, flavour enhancer, soy sauce and many. The other applications include nitrogen metabolism and its use as biosensor in hybridoma technology. Both intra-cellular and extra-cellular L-glutaminases from wide range of sources were identified. Because of its diverse applications, there is a need to improve the production of L-glutaminase by enzyme engineering technology. Effect of recombination on L-glutaminase production was also reported. Researchers also confirmed the antitumor properties of L-glutaminase by conducting in vitro, in vivo and in silico studies. Bacillus sps. and Aspergillus sps. are the commercial producers of L-glutaminase. In this review, the applications, different sources of Lglutaminase, anti-cancer properties were discussed.

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