Structural and electronic effects induced by carboxylic acid substitution in isomeric 2,2′-bithiophenes and oligothiophenes: A computational study

Polymer ◽  
2005 ◽  
Vol 46 (22) ◽  
pp. 9452-9460 ◽  
Author(s):  
Jordi Casanovas ◽  
David Zanuy ◽  
Carlos Alemán
Keyword(s):  
Carboxylic Acid ◽  
Computational Study ◽  
Electronic Effects

scholarly journals Grafting TRAIL through Either Amino or Carboxylic Groups onto Maghemite Nanoparticles: Influence on Pro-Apoptotic Efficiency

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 502
Author(s):  
Hanene Belkahla ◽  
Andrei Alexandru Constantinescu ◽  
Tijani Gharbi ◽  
Florent Barbault ◽  
Alexandre Chevillot-Biraud ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Cancer Therapy ◽  
Computational Study ◽  
Carcinoma Cells ◽  
Maghemite Nanoparticles ◽  
Carboxylic Acid Groups ◽  
Lung Carcinoma Cells ◽  
Biological Studies ◽  
Apoptotic Effect ◽  
Carboxylic Groups

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF cytokine superfamily. TRAIL is able to induce apoptosis through engagement of its death receptors DR4 and DR5 in a wide variety of tumor cells while sparing vital normal cells. This makes it a promising agent for cancer therapy. Here, we present two different ways of covalently grafting TRAIL onto maghemite nanoparticles (NPs): (a) by using carboxylic acid groups of the protein to graft it onto maghemite NPs previously functionalized with amino groups, and (b) by using the amino functions of the protein to graft it onto NPs functionalized with carboxylic acid groups. The two resulting nanovectors, NH-TRAIL@NPs-CO and CO-TRAIL@NPs-NH, were thoroughly characterized. Biological studies performed on human breast and lung carcinoma cells (MDA-MB-231 and H1703 cell lines) established these nanovectors are potential agents for cancer therapy. The pro-apoptotic effect is somewhat greater for CO-TRAIL@NPs-NH than NH-TRAIL@NPs-CO, as evidenced by viability studies and apoptosis analysis. A computational study indicated that regardless of whether TRAIL is attached to NPs through an acid or an amino group, DR4 recognition is not affected in either case.

Vibrational spectroscopic, 1H NMR and quantum chemical computational study of 4-hydroxy-2-oxo-1,2-dihydroquinoline-8-carboxylic acid

2014 ◽  
Vol 121 ◽  
pp. 445-456 ◽  
Author(s):  
Rajeev T. Ulahannan ◽  
C. Yohannan Panicker ◽  
Hema Tresa Varghese ◽  
C. Van Alsenoy ◽  
Robert Musiol ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
1H Nmr ◽  
Quantum Chemical ◽  
Computational Study

A Solid-State NMR, X-ray Diffraction, and ab Initio Computational Study of Hydrogen-Bond Structure and Dynamics of Pyrazole-4-Carboxylic Acid Chains

2001 ◽  
Vol 123 (32) ◽  
pp. 7898-7906 ◽  
Author(s):  
Concepción Foces-Foces ◽  
Aurea Echevarría ◽  
Nadine Jagerovic ◽  
Ibon Alkorta ◽  
José Elguero ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Solid State ◽  
Carboxylic Acid ◽  
Ab Initio ◽  
Solid State Nmr ◽  
Computational Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Dynamics

A family of mixed-ligand oxidovanadium(v) complexes with aroylhydrazone ligands: a combined experimental and computational study on the electronic effects of para substituents of hydrazone ligands on the electronic properties, DNA binding and nuclease activities

RSC Advances ◽  
2015 ◽  
Vol 5 (112) ◽  
pp. 92456-92472 ◽  
Author(s):  
Debashis Patra ◽  
Nirmalendu Biswas ◽  
Bhavini Kumari ◽  
Prolay Das ◽  
Nayim Sepay ◽  
...  
Keyword(s):  
Dna Binding ◽  
Electronic Properties ◽  
Computational Study ◽  
Nuclease Activity ◽  
Mixed Ligand ◽  
Electronic Effects ◽  
Binding Ability ◽  
Marked Influence ◽  
Hydrazone Ligands

Substituents at 5-position in the acetophenone ring of the hydrazone ligands in a family of mixed-ligand oxidovanadium(v) complexes show marked influence on the electronic properties, DNA binding ability and nuclease activity.

scholarly journals Computational Study of Ortho-Substituent Effects on Antioxidant Activities of Phenolic Dendritic Antioxidants

Antioxidants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 189 ◽  
Author(s):  
Choon Young Lee ◽  
Ajit Sharma ◽  
Julius Semenya ◽  
Charles Anamoah ◽  
Kelli N. Chapman ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Electron Transfer ◽  
Antioxidant Activities ◽  
Computational Study ◽  
Radical Scavenging ◽  
Substituent Effects ◽  
Phenolic Antioxidants ◽  
Electronic Effects ◽  
Total Enthalpy ◽  
Structure Activity

Antioxidants are an important component of our ability to combat free radicals, an excess of which leads to oxidative stress that is related to aging and numerous human diseases. Oxidative damage also shortens the shelf-life of foods and other commodities. Understanding the structure–activity relationship of antioxidants and their mechanisms of action is important for designing more potent antioxidants for potential use as therapeutic agents as well as preservatives. We report the first computational study on the electronic effects of ortho-substituents in dendritic tri-phenolic antioxidants, comprising a common phenol moiety and two other phenol units with electron-donating or electron-withdrawing substituents. Among the three proposed antioxidant mechanisms, sequential proton loss electron transfer (SPLET) was found to be the preferred mechanism in methanol for the dendritic antioxidants based on calculations using Gaussian 16. We then computed the total enthalpy values by cumulatively running SPLET for all three rings to estimate electronic effects of substituents on overall antioxidant activity of each dendritic antioxidant and establish their structure–activity relationships. Our results show that the electron-donating o-OCH3 group has a beneficial effect while the electron-withdrawing o-NO2 group has a negative effect on the antioxidant activity of the dendritic antioxidant. The o-Br and o-Cl groups did not show any appreciable effects. These results indicate that electron-donating groups such as o-methoxy are useful for designing potent dendritic antioxidants while the nitro and halogens do not add value to the radical scavenging antioxidant activity. We also found that the half-maximal inhibitory concentration (IC50) values of 2,2-diphenyl-1-picrylhydrazyl (DPPH) better correlate with the second step (electron transfer enthalpy, ETE) than the first step (proton affinity, PA) of the SPLET mechanism, implying that ETE is the better measure for estimating overall radical scavenging antioxidant activities.

Sign in / Sign up

Export Citation Format

Share Document