ChemInform Abstract: Acetyl Group and a Tetrazolium Salt: Combination of a Direct and Indirect Protection in the Synthesis of Mono- and Diaminoformazans.

ChemInform ◽  
2010 ◽  
Vol 24 (42) ◽  
pp. no-no
Author(s):  
S. A. BELYAKOV
2019 ◽  
Vol 15 (2) ◽  
pp. 120-130
Author(s):  
Mohammad Ghanbari ◽  
Reza Safaralizadeh ◽  
Kiyanoush Mohammadi

At the present time, cancer is one of the most lethal diseases worldwide. There are various factors involved in the development of cancer, including genetic factors, lifestyle, nutrition, and so on. Recent studies have shown that epigenetic factors have a critical role in the initiation and development of tumors. The histone post-translational modifications (PTMs) such as acetylation, methylation, phosphorylation, and other PTMs are important mechanisms that regulate the status of chromatin structure and this regulation leads to the control of gene expression. The histone acetylation is conducted by histone acetyltransferase enzymes (HATs), which are involved in transferring an acetyl group to conserved lysine amino acids of histones and consequently increase gene expression. On the basis of similarity in catalytic domains of HATs, these enzymes are divided into different groups such as families of GNAT, MYST, P300/CBP, SRC/P160, and so on. These enzymes have effective roles in apoptosis, signaling pathways, metastasis, cell cycle, DNA repair and other related mechanisms deregulated in cancer. Abnormal activation of HATs leads to uncontrolled amplification of cells and incidence of malignancy signs. This indicates that HAT might be an important target for effective cancer treatments, and hence there would be a need for further studies and designing of therapeutic drugs on this basis. In this study, we have reviewed the important roles of HATs in different human malignancies.


2003 ◽  
Vol 47 (4) ◽  
pp. 1200-1206 ◽  
Author(s):  
Robert S. Liao ◽  
Robert P. Rennie ◽  
James A. Talbot

ABSTRACT Amphotericin B treatment was previously shown to inhibit Candida albicans reproduction and reduce the fluorescence of vitality-specific dyes without causing a corresponding increase in the fluorescence of the mortality-specific dyes bis-(1,3-dibutylbarbituric acid)trimethine oxonol and SYBR Green Ι. In the present study, we have confirmed these results and have shown that the numbers of CFU are reduced by 99.9% by treatment with 0.5 μg of amphotericin B per ml for 10 h at 35°C. This reduction was not due to fungal cell death. First, the level of reduction of the tetrazolium salt 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide increased in the presence of concentrations of amphotericin B that caused greater than 90% reductions in the numbers of CFU. Second, fungal cells treated with amphotericin B at a concentration of 0.5 μg/ml were resuscitated by further incubation at 22°C for 15 h in the continued presence of amphotericin B. Third, recovery of the ability to replicate was prevented by sequential treatment with 20 μg of miconazole per ml, which also increased the fluorescence of mortality-specific dyes to near the maximal levels achieved with 0.9 μg of amphotericin B per ml. Sequential treatment with fluconazole and flucytosine did not increase the levels of staining with the mortality-specific dyes. Itraconazole was less effective than ketoconazole, which was less effective than miconazole. The practice of equating the loss of the capacity of C. albicans to form colonies with fungal cell death may give incorrect results in assays with amphotericin B, and the results of assays with caution with other antifungal agents that are lipophilic or that possess significant postantifungal effects may need to be interpreted.


1991 ◽  
Vol 19 (3) ◽  
pp. 352-360
Author(s):  
Kazuhiko Otoguro ◽  
Kanki Komiyama ◽  
Satoshi Ωmura ◽  
Charles A. Tyson

Isolated hepatocytes from male Sprague-Dawley rats suspended in culture medium supplemented with either 0.2 or 2% bovine serum albumin (BSA) were allowed to attach to collagen coated 96-well dishes. Ten test chemicals from the MEIC list and salicylic acid were added individually to the dishes, and at the end of 24 and 48 hours, cytotoxicity was determined by measuring MTT (tetrazolium salt) reduction (mitochondrial integrity) and total cellular protein using Coomassie blue dye (reflecting cell number). Total cellular lactate dehydrogenase activity was also determined in some experiments, as an indicator of plasma membrane integrity. The relative toxicities of the test chemicals were quantified by the estimation of EC10, EC20 and EC50 values for each parameter. Except for one chemical, digoxin, in the MTT assay, cytotoxic potency increased with incubation time. The hepatocytes tended to be more sensitive to the chemicals in medium containing 0.2% BSA than in medium containing 2% BSA. Simple linear regression analyses of the log transformed data from the MTT assay versus log oral LD50 in rats for the test chemicals gave the best results using EC10 at 24 hours (r2 = 0.86). With protein as the cytotoxic indicator, the best results were obtained with EC values in the medium containing 2% BSA, again at 24 hours (r2 = 0.83). These results suggest that the MTT and Coomassie blue dye assays could be useful indicators for testing the cytotoxic potential of chemicals in rat hepatocyte cultures.


ChemBioChem ◽  
2021 ◽  
Author(s):  
Robert Lassfolk ◽  
Sara Bertuzzi ◽  
Ana Ardá ◽  
Johan Wärnå ◽  
Jesús Jiménez‐Barbero ◽  
...  

Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 678
Author(s):  
Carlo Diaferia ◽  
Elisabetta Rosa ◽  
Enrico Gallo ◽  
Giovanni Smaldone ◽  
Mariano Stornaiuolo ◽  
...  

Peptide-based hydrogels (PHGs) are biocompatible materials suitable for biological, biomedical, and biotechnological applications, such as drug delivery and diagnostic tools for imaging. Recently, a novel class of synthetic hydrogel-forming amphiphilic cationic peptides (referred to as series K), containing an aliphatic region and a Lys residue, was proposed as a scaffold for bioprinting applications. Here, we report the synthesis of six analogues of the series K, in which the acetyl group at the N-terminus is replaced by aromatic portions, such as the Fmoc protecting group or the Fmoc-FF hydrogelator. The tendency of all peptides to self-assemble and to gel in aqueous solution was investigated using a set of biophysical techniques. The structural characterization pointed out that only the Fmoc-derivatives of series K keep their capability to gel. Among them, Fmoc-K3 hydrogel, which is the more rigid one (G’ = 2526 Pa), acts as potential material for tissue engineering, fully supporting cell adhesion, survival, and duplication. These results describe a gelification process, allowed only by the correct balancing among aggregation forces within the peptide sequences (e.g., van der Waals, hydrogen bonding, and π–π stacking).


1995 ◽  
Vol 48 (7) ◽  
pp. 1379 ◽  
Author(s):  
TW Badran ◽  
CLL Chai ◽  
CJ Easton ◽  
JB Harper ◽  
DM Page

From intermolecular and intramolecular competition experiments, it has been established that, by comparison with an N-methyl substituent, an N-acetyl group deactivates glycine residues in piperazine-2,5-diones towards free-radical bromination. Combined with the ease of introduction and removal of N-acetyl substituents, the deactivating effect provides a method for regiocontrolled functionalization of these compounds.


2007 ◽  
Vol 63 (11) ◽  
pp. o4278-o4278
Author(s):  
Alexandra M. Z. Slawin ◽  
William T. A. Harrison

In the title compound, C9H13N2O+·I−, the dihedral angle between the aromatic ring and the N-acetyl group is 73.93 (8)°. In the crystal structure, the cation and anion interact by way of an N—H...I hydrogen bond.


1995 ◽  
Vol 73 (1) ◽  
pp. 16-21 ◽  
Author(s):  
Raul G. Enriquez ◽  
Juan M. Fernandez-G ◽  
Ismael Leon ◽  
William F. Reynolds ◽  
Ji.-Ping Yang ◽  
...  

The Schiff base condensation reaction of 1,2-diaminoethane with a series of 2-acetylcycloalkanones (from cyclopentanone to cyclooctanone) has been investigated and the products characterized by two-dimensional nuclear magnetic resonance. The site of attack of the amino groups, i.e., ring ketone or acetyl ketone, is determined primarily by ring size. 2-Acetylcyclohexanone yields two products in ca. 9:1 ratio, the major product where the two amino groups attack at the ring ketones of two different cyclohexanone molecules, and the minor product where one amino group attacks one ring carbonyl of one cyclohexanone while the second amino group attacks the acetyl group of another. 2-Acetylcyclopentanone yields all three possible products with the major product involving attack at the acetyl groups of two different cyclopentanones. The corresponding reactions for 2-acetylcycloheptanone and 2-acetylcyclooctanone each give a single product corresponding to attack at the acetyl groups of two different cycloalkanones. Similar product distributions are observed for the reactions of the different 2-acetylcycloalkanones with 1,4-diaminobutane. Keywords: Schiff base reactions, diketones, 2D NMR.


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