scholarly journals Synthesis and Biological Evaluation of a Novel C8-Pyrrolobenzodiazepine (PBD) Adenosine Conjugate. A Study on the Role of the PBD Ring in the Biological Activity of PBD-Conjugates

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1243
Author(s):  
Lindsay Ferguson ◽  
Sanjib Bhakta ◽  
Keith R. Fox ◽  
Geoff Wells ◽  
Federico Brucoli
Keyword(s):  
Biological Activity ◽  
Dna Sequences ◽  
Covalent Binding ◽  
Biological Evaluation ◽  
Binding Motif ◽  
Dna Minor Groove ◽  
Dnase I Footprinting ◽  
Convergent Approach ◽  
Dynamics Simulations ◽  
Mycobacterium Aurum

Here we sought to evaluate the contribution of the PBD unit to the biological activity of PBD-conjugates and, to this end, an adenosine nucleoside was attached to the PBD A-ring C8 position. A convergent approach was successfully adopted for the synthesis of a novel C8-linked pyrrolo(2,1-c)(1,4)benzodiazepine(PBD)-adenosine(ADN) hybrid. The PBD and adenosine (ADN) moieties were synthesized separately and then linked through a pentynyl linker. To our knowledge, this is the first report of a PBD connected to a nucleoside. Surprisingly, the compound showed no cytotoxicity against murine cells and was inactive against Mycobacterium aurum and M. bovis strains and did not bind to guanine-containing DNA sequences, as shown by DNase I footprinting experiments. Molecular dynamics simulations revealed that the PBD–ADN conjugate was poorly accommodated in the DNA minor groove of two DNA sequences containing the AGA-PBD binding motif, with the adenosine moiety of the ligand preventing the covalent binding of the PBD unit to the guanine amino group of the DNA duplex. These interesting findings shed further light on the ability of the substituents attached at the C8 position of PBDs to affect and modulate the biological and biophysical properties of PBD hybrids.

Synthesis and Biological Evaluation of Various New Substituted 1,3,4-oxadiazole-2-thiols

2008 ◽  
Vol 59 (4) ◽  
Author(s):  
Gabriela Laura Almajan ◽  
Stefania Felicia Barbuceanu ◽  
Ioana Saramet ◽  
Mihaela Dinu ◽  
Cristian Vasile Doicin ◽  
...  
Keyword(s):  
Biological Activity ◽  
Plant Growth ◽  
1H Nmr ◽  
Elemental Analysis ◽  
13C Nmr ◽  
Biological Evaluation ◽  
Ethyl Chloroacetate ◽  
Low Concentrations ◽  
Synthesis And Biological Evaluation

5-[4-(4X-phenylsulfonyl)phenyl]-1,3,4-oxadiazole-2-thiols, X=H, Cl, Br, reacted with ethyl chloroacetate to give S-alkylated compounds. Aminomethylation of the thione form of oxadiazoles yielded N(3)-derivatives. All the products have been characterized by elemental analysis, IR, 1H-NMR and 13C-NMR. The plant-growth regulating effects of the title compounds were examined. From the biological activity results, we found that most compounds showed weak stimulatory activities at low concentrations.

scholarly journals Tracing Potential Covalent Inhibitors of an E3 Ubiquitin Ligase through Target-Focused Modelling

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3125 ◽  
Author(s):  
Imane Bjij ◽  
Pritika Ramharack ◽  
Shama Khan ◽  
Driss Cherqaoui ◽  
Mahmoud E. S. Soliman
Keyword(s):  
Ubiquitin Ligase ◽  
Covalent Binding ◽  
Protein A ◽  
E3 Ubiquitin Ligase ◽  
Pharmacophore Model ◽  
Biological Evaluation ◽  
Pharmacokinetic Analysis ◽  
Unsaturated Ester ◽  
Dynamic Simulations ◽  
Covalent Inhibitors

The Nedd4-1 E3 Ubiquitin ligase has been implicated in multiple disease conditions due its overexpression. Although the enzyme may be targeted both covalently and non-covalently, minimal studies provide effective inhibitors against it. Recently, research has focused on covalent inhibitors based on their characteristic, highly-selective warheads and ability to prevent drug resistance. This prompted us to screen for new covalent inhibitors of Nedd4-1 using a combination of computational approaches. However, this task proved challenging due to the limited number of electrophilic moieties available in virtual libraries. Therefore, we opted to divide an existing covalent Nedd4-1 inhibitor into two parts: a non-covalent binding group and a pre-selected α, β-unsaturated ester that forms the covalent linkage with the protein. A non-covalent pharmacophore model was built based on molecular interactions at the binding site. The pharmacophore was then subjected to virtual screening to identify structurally similar hit compounds. Multiple filtrations were implemented prior to selecting four hits, which were validated with a covalent conjugation and later assessed by molecular dynamic simulations. The results showed that, of the four hit molecules, Zinc00937975 exhibited advantageous molecular groups, allowing for favourable interactions with one of the characteristic cysteine residues. Predictive pharmacokinetic analysis further justified the compound as a potential lead molecule, prompting its recommendation for confirmatory biological evaluation. Our inhouse, refined, pharmacophore model approach serves as a robust method that will encourage screening for novel covalent inhibitors in drug discovery.

scholarly journals Synthesis, characterization and biological activity of organometallic derivatives of the antimalarial drug mefloquine as new antischistosomal drug candidates

MedChemComm ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 1905-1909 ◽  
Author(s):  
Faustine d'Orchymont ◽  
Jeannine Hess ◽  
Gordana Panic ◽  
Marta Jakubaszek ◽  
Lea Gemperle ◽  
...  
Keyword(s):  
Biological Activity ◽  
Antimalarial Drug ◽  
Biological Evaluation ◽  
Design Synthesis ◽  
Drug Candidates ◽  
Derivatives Of

The design, synthesis, characterization and biological evaluation of new ferrocenyl and ruthenocenyl derivatives of the antimalarial mefloquine is described.

scholarly journals Chicken beta B1-crystallin gene expression: presence of conserved functional polyomavirus enhancer-like and octamer binding-like promoter elements found in non-lens genes.

1991 ◽  
Vol 11 (3) ◽  
pp. 1488-1499 ◽  
Author(s):  
H J Roth ◽  
G C Das ◽  
J Piatigorsky
Keyword(s):  
Transcription Factors ◽  
Hela Cell ◽  
Dna Sequences ◽  
Nuclear Extract ◽  
Regulatory Elements ◽  
Dnase I ◽  
Flanking Sequence ◽  
Mobility Shift ◽  
Promoter Elements ◽  
Dnase I Footprinting

Expression of the chicken beta B1-crystallin gene was examined. Northern (RNA) blot and primer extension analyses showed that while abundant in the lens, the beta B1 mRNA is absent from the liver, brain, heart, skeletal muscle, and fibroblasts of the chicken embryo, suggesting lens specificity. Promoter fragments ranging from 434 to 126 bp of 5'-flanking sequence (plus 30 bp of exon 1) of the beta B1 gene fused to the bacterial chloramphenicol acetyltransferase gene functioned much more efficiently in transfected embryonic chicken lens epithelial cells than in transfected primary muscle fibroblasts or HeLa cells. Transient expression of recombinant plasmids in cultured lens cells, DNase I footprinting, in vitro transcription in a HeLa cell extract, and gel mobility shift assays were used to identify putative functional promoter elements of the beta B1-crystallin gene. Sequence analysis revealed a number of potential regulatory elements between positions -126 and -53 of the beta B1 promoter, including two Sp1 sites, two octamer binding sequence-like sites (OL-1 and OL-2), and two polyomavirus enhancer-like sites (PL-1 and PL-2). Deletion and site-specific mutation experiments established the functional importance of PL-1 (-116 to -102), PL-2 (-90 to -76), and OL-2 (-75 to -68). DNase I footprinting using a lens or a HeLa cell nuclear extract and gel mobility shifts using a lens nuclear extract indicated the presence of putative lens transcription factors binding to these DNA sequences. Competition experiments provided evidence that PL-1 and PL-2 recognize the same or very similar factors, while OL-2 recognizes a different factor. Our data suggest that the same or closely related transcription factors found in many tissues are used for expression of the chicken beta B1-crystallin gene in the lens.

Molecular dynamics simulations and binding free energy analysis of DNA minor groove complexes of curcumin

2011 ◽  
Vol 17 (11) ◽  
pp. 2805-2816 ◽  
Author(s):  
Mathew Varghese Koonammackal ◽  
Unnikrishnan Viswambharan Nair Nellipparambil ◽  
Chellappanpillai Sudarsanakumar
Keyword(s):  
Molecular Dynamics ◽  
Free Energy ◽  
Molecular Dynamics Simulations ◽  
Energy Analysis ◽  
Binding Free Energy ◽  
Minor Groove ◽  
Dna Minor Groove ◽  
Dynamics Simulations ◽  
Free Energy Analysis

scholarly journals Amino Alcohols from Eugenol as Potential Semisynthetic Insecticides: Chemical, Biological, and Computational Insights

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6616
Author(s):  
Renato B. Pereira ◽  
Nuno F. S. Pinto ◽  
Maria José G. Fernandes ◽  
Tatiana F. Vieira ◽  
Ana Rita O. Rodrigues ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Biological Activity ◽  
Virtual Screening ◽  
Serine Proteases ◽  
Insect Cells ◽  
Amino Alcohols ◽  
Odorant Binding Proteins ◽  
Synthetic Pesticide ◽  
Dynamics Simulations ◽  
Odorant Binding

A series of β-amino alcohols were prepared by the reaction of eugenol epoxide with aliphatic and aromatic amine nucleophiles. The synthesized compounds were fully characterized and evaluated as potential insecticides through the assessment of their biological activity against Sf9 insect cells, compared with a commercial synthetic pesticide (chlorpyrifos, CHPY). Three derivatives bearing a terminal benzene ring, either substituted or unsubstituted, were identified as the most potent molecules, two of them displaying higher toxicity to insect cells than CHPY. In addition, the most promising molecules were able to increase the activity of serine proteases (caspases) pivotal to apoptosis and were more toxic to insect cells than human cells. Structure-based inverted virtual screening and molecular dynamics simulations demonstrate that these molecules likely target acetylcholinesterase and/or the insect odorant-binding proteins and are able to form stable complexes with these proteins. Encapsulation assays in liposomes of DMPG and DPPC/DMPG (1:1) were performed for the most active compound, and high encapsulation efficiencies were obtained. A thermosensitive formulation was achieved with the compound release being more efficient at higher temperatures.

scholarly journals Synthesis of Signals for De Novo DNA Methylation in Neurospora crassa

2003 ◽  
Vol 23 (7) ◽  
pp. 2379-2394 ◽  
Author(s):  
Hisashi Tamaru ◽  
Eric U. Selker
Keyword(s):  
Dna Methylation ◽  
Neurospora Crassa ◽  
Point Mutation ◽  
Dna Sequences ◽  
De Novo ◽  
Test Site ◽  
Minor Groove ◽  
Binding Motif ◽  
Repeat Induced Point Mutation

ABSTRACT Most 5-methylcytosine in Neurospora crassa occurs in A:T-rich sequences high in TpA dinucleotides, hallmarks of repeat-induced point mutation. To investigate how such sequences induce methylation, we developed a sensitive in vivo system. Tests of various 25- to 100-bp synthetic DNA sequences revealed that both T and A residues were required on a given strand to induce appreciable methylation. Segments composed of (TAAA) n or (TTAA) n were the most potent signals; 25-mers induced robust methylation at the special test site, and a 75-mer induced methylation elsewhere. G:C base pairs inhibited methylation, and cytosines 5′ of ApT dinucleotides were particularly inhibitory. Weak signals could be strengthened by extending their lengths. A:T tracts as short as two were found to cooperate to induce methylation. Distamycin, which, like the AT-hook DNA binding motif found in proteins such as mammalian HMG-I, binds to the minor groove of A:T-rich sequences, suppressed DNA methylation and gene silencing. We also found a correlation between the strength of methylation signals and their binding to an AT-hook protein (HMG-I) and to activities in a Neurospora extract. We propose that de novo DNA methylation in Neurospora cells is triggered by cooperative recognition of the minor groove of multiple short A:T tracts. Similarities between sequences subjected to repeat-induced point mutation in Neurospora crassa and A:T-rich repeated sequences in heterochromatin in other organisms suggest that related mechanisms control silent chromatin in fungi, plants, and animals.

Design, Synthesis, and Biological Activity of Hybrid Compounds between Uramustine and DNA Minor Groove Binder Distamycin A

2002 ◽  
Vol 45 (17) ◽  
pp. 3630-3638 ◽  
Author(s):  
Pier Giovanni Baraldi ◽  
Romeo Romagnoli ◽  
Antonio Entrena Guadix ◽  
Maria Josè Pineda de las Infantas ◽  
Miguel Angel Gallo ◽  
...  
Keyword(s):  
Biological Activity ◽  
Minor Groove ◽  
Minor Groove Binder ◽  
Design Synthesis ◽  
Distamycin A ◽  
Dna Minor Groove ◽  
Hybrid Compounds ◽  
Dna Minor Groove Binder

The Synthesis and Biological Evaluation of Anithiactin A/Thiasporine C and Analogues

2015 ◽  
Vol 68 (12) ◽  
pp. 1829 ◽  
Author(s):  
Richard A. Lamb ◽  
Michael P. Badart ◽  
Brooke E. Swaney ◽  
Sinan Gai ◽  
Sarah K. Baird ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Biological Activity ◽  
Cell Lines ◽  
Breast Cancer Cell ◽  
Phenyl Group ◽  
Biological Evaluation ◽  
Breast Cancer Cell Lines ◽  
High Concentration ◽  
Structural Requirements ◽  
Synthesis And Biological Evaluation

The synthesis of anithiactin A has been achieved in four steps. Several closely related analogues were synthesised and their biological activity against colon and breast cancer cell lines evaluated. Anithiactin A was found not to be cytotoxic even at a high concentration (100 μM); however, two 4-substituted phenyl thiazoles were found to be moderately cytotoxic at 10 μM. Based on these results, 4-substitution on the phenyl group appears to be critical for cytotoxicity. However, the exact electronic and structural requirements are unclear.

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