Synthesis of phenanthridine spiropyrans and studies of their effects on G-quadruplex DNA

2017 ◽  
Vol 15 (15) ◽  
pp. 3265-3275 ◽  
Author(s):  
M. Livendahl ◽  
J. Jamroskovic ◽  
M. Hedenström ◽  
T. Görlich ◽  
N. Sabouri ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
Quadruplex Dna ◽  
Quadruplex Structure ◽  
G Quadruplex

Low molecular weight spirocycles efficiently stabilize G-quadruplex DNA without changing its structure by binding the top of the G-quadruplex structure.

scholarly journals Effect of Ionic Strength on Porphyrin Drugs Interaction with Quadruplex DNA Formed by the Promoter Region of C-myc and Bcl2 Oncogenes

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Narayana Nagesh ◽  
Varun K. Sharma ◽  
A. Ganesh Kumar ◽  
Edwin A. Lewis
Keyword(s):  
Ionic Strength ◽  
Fluorescence Spectroscopy ◽  
Drug Interactions ◽  
Promoter Region ◽  
Promoter Regions ◽  
Quadruplex Dna ◽  
Quadruplex Structure ◽  
G Quadruplex ◽  
Drugs Interaction ◽  
Dna Complex

C-myc and Bcl2 are well characterized oncogenes that are capable of forming G-quadruplex structures. Promoter regions of C-myc and Bcl2 forming G-quadruplex structures are chemically synthesized and G-quadruplex structure is formed in presence of 100 mM potassium ion. Three different porphyrin drugs, namely TMPyP2, TMPyP3, and TMPyP4 are allowed to interact with quadruplex DNA complex and the site and nature of interaction are studied. Drug interactions with quadruplex DNA were carried out in different potassium ionic strengths using fluorescence spectroscopy. It is found that fluorescence hypochromicity decreases with an increase in ionic strength in the case of TMPyP4, TMPyP3, and TMPyP2. Fluorescence titration studies and Job plots indicate that four molecules of TMPyP4, two molecules of TMPyP3 and TMPyP2 are interacting with one molecule of quadruplex DNA.

scholarly journals Arylboronate esters mediated self-healable and biocompatible dynamic G-quadruplex hydrogels as promising 3D-bioinks

2018 ◽  
Vol 54 (14) ◽  
pp. 1778-1781 ◽  
Author(s):  
Ankan Biswas ◽  
Sara Malferrari ◽  
Deepak M. Kalaskar ◽  
Apurba K. Das
Keyword(s):  
Molecular Weight ◽  
Cell Viability ◽  
Low Molecular Weight ◽  
Cell Distribution ◽  
High Cell ◽  
G Quadruplex ◽  
Homogeneous Cell

High cell viability and homogeneous cell distribution within extrudable low molecular weight self-healable G-quadruplex hydrogel make it as suitable 3D bioink.

scholarly journals Interaction of TMPyP4, TMPyP3, and TMPyP2 with Intramolecular G-Quadruplex Formed by Promoter Region of Bcl2 and KRAS NHPPE

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Narayana Nagesh ◽  
Arumugam Ganesh Kumar
Keyword(s):  
Promoter Region ◽  
Dna Interaction ◽  
Predominant Role ◽  
Promoter Regions ◽  
Ligand Interaction ◽  
Quadruplex Dna ◽  
Molecular Binding ◽  
Quadruplex Structure ◽  
G Quadruplex ◽  
Structure Environment

Oncogenes are rich in guanine and capable of forming quadruplex structure. Promoter regions oncogenes such as Bcl2 and KRAS NHPPE are rich in guanine content and they can form quadruplex structures. Alterations in the mode and nature of molecular binding to DNA, certainly has effect on the posttranscriptional activities. Recent experiments indicate that structure of quadruplex complex and ligand has predominant role on ligand-quadruplex DNA interaction. In order to understand the nature of each ligand interaction with quadruplex DNA, Bcl2, KRAS NHPPE quadruplex DNA interaction with three porphyrin was studied using spectroscopy, microcalorimetry and mass spectrometry. Our studies, indicate that mode of ligand interaction varies with structure, environment and concentration of ligand. Fluorescence quenching experiments show that TMPyP4 interaction is ligand concentration dependent. Job plots and ITC experiments demonstrate that four molecules of TMPyP4 and two molecules of TMPyP3, TMPyP2 interact with each quadruplex complex. Through ITC titrations, ligand binding constant are higher for TMPyP4 (≈107 M−1) compared to TMPyP3, TMPyP2 (≈105 M−1). ESI-MS experiments confirm the stoichiometry of TMPyP4 : 39Bcl2 is 4 : 1 at saturation and it is 2 : 1 in case of KRAS NHPPE quadruplex.

Selective alkylation of parallel G-quadruplex structure

2021 ◽  
Vol 19 (13) ◽  
pp. 2891-2894
Author(s):  
Kazumitsu Onizuka ◽  
Erchissaran Ganbold ◽  
Yue Ma ◽  
Shogo Sasaki ◽  
Madoka E. Hazemi ◽  
...  
Keyword(s):  
Quadruplex Dna ◽  
Quadruplex Structure ◽  
G Quadruplex ◽  
Selective Alkylation

We achieve selective alkylation of parallel G-quadruplex DNA using a conjugate of a macrocyclic hexaoxazole and a sulfoxide precursor to a vinyl-quinazolinone.

scholarly journals Discovery of new G-quadruplex binding chemotypes

2014 ◽  
Vol 50 (8) ◽  
pp. 960-963 ◽  
Author(s):  
Stephan A. Ohnmacht ◽  
Ehsan Varavipour ◽  
Rupesh Nanjunda ◽  
Ingrida Pazitna ◽  
Gloria Di Vita ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Proliferative Activity ◽  
Low Molecular Weight ◽  
G Quadruplex

We report a novel furan-based low molecular weight chemotype with high G-quadruplex affinity and potent anti-proliferative activity.

Anticancer Activity of Platinum (II) Complex as G-Quadruplex DNA Binders

2013 ◽  
Vol 781-784 ◽  
pp. 1130-1133
Author(s):  
Qi Pin Qin ◽  
Yu Lan Li ◽  
Yan Cheng Liu ◽  
Xu Jian Luo
Keyword(s):  
Cell Lines ◽  
Cancer Cell ◽  
Normal Cell ◽  
Cancer Cell Lines ◽  
Cytotoxic Activities ◽  
Binding Properties ◽  
Quadruplex Dna ◽  
Quadruplex Structure ◽  
G Quadruplex ◽  
Dna Binders

A platinum (II) complex has been synthesized and characterized. The complex binding properties with G-quadruplex DNA and ds26 were examined by FID and CD spectroscopic methods. The results revealed that the platinum (II) complex can induce the antiparallel G-quadruplex structure of HTG21 conformation in the absence of added K+ with selectivity over other G-quadruplex DNA and duplex DNA. The cytotoxicity of the platinum (II) was screened against four cancer cell lines and normal cells of HL-7702 in comparison to cisplatin and it showed a higher activity than cisplatin, with inhibition rates ranging from (40.06±1.65)% to (89.47±1.14)%. Furthermore, the platinum (II) complex displayed lower cytotoxic activities to HL-7702 (normal cell) compared with the cancer cell lines.

Alkylating probes for the G-quadruplex structure and evaluation of the properties of the alkylated G-quadruplex DNA

2018 ◽  
Vol 16 (9) ◽  
pp. 1436-1441 ◽  
Author(s):  
Norihiro Sato ◽  
Shuntaro Takahashi ◽  
Hisae Tateishi-Karimata ◽  
Madoka E. Hazemi ◽  
Tomoko Chikuni ◽  
...  
Keyword(s):  
Quadruplex Dna ◽  
Quadruplex Structure ◽  
G Quadruplex

In this paper, we report the development of a new G-4 alkylating molecule and the evaluation of the properties of the alkylated G-4 DNA.

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

Low-molecular-weight heparin in the prevention and treatment of thromboembolic disorders

1998 ◽  
Vol 1 (5) ◽  
pp. 166-174 ◽  
Author(s):  
Evelyn R Hermes De Santis ◽  
Betsy S Laumeister ◽  
Vidhu Bansal ◽  
Vandana Kataria ◽  
Preeti Loomba ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Low Molecular Weight ◽  
Prevention And Treatment
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