- 5-Bromo- and 3,5-dibromo-2-hydroxy-N-phenylbenzamides - Inhibitors of photosynthesis
-
5-Bromo-(Br-PBA) and 3,5-dibromo-2-hydroxy-N-phenylbenzamides (Br 2-PBA) inhibited photosynthetic electron transport (PET) and their inhibitory efficiency depended on the compound lipophilicity as well as on the electronic properties of the R substituent in the N-phenyl moiety. Br-PBA showed higher PET inhibiting activity than Br2-PBA with the same R substituent. The most effective inhibitors in the tested series were the derivatives with R = 3-F (Br-PBA; IC50 = 4.3 μmol dm-3) and R = 3-Cl (Br2-PBA; IC50 = 8.6 μmol dm -3). Bilinear dependence of the PET inhibiting activity on the lipophilicity of the compounds as well as on the Hammett constant, σ, of the R substituent was observed for both investigated series. Using EPR spectroscopy it was found that the site of action of the tested compounds in the photosynthetic apparatus is situated on the donor side of PS 2, in D · or in the Z·/D· intermediates. Interaction of the studied compounds with chlorophyll a and aromatic amino acids present in the pigment-protein complexes mainly in photosystem 2 was documented by fluorescence spectroscopy.
- Kraaeova, Katarina,Sersen, Frantisek,Pesko, Matus,Waisser, Karel,Kubicova, Lenka
-
-
- 5-Bromo-and 3,5-dibromo-2-hydroxy-N-phenylbenzamides-inhibitors of photosynthesis
-
5-Bromo-(Br-PBA) and 3,5-dibromo-2-hydroxy-N-phenylbenzamides (Br2-PBA) inhibited photosynthetic electron transport (PET) and their inhibitory efficiency depended on the compound lipophilicity as well as on the electronic properties of the R substituent in the N-phenyl moiety. Br-PBA showed higher PET inhibiting activity than Br2-PBA with the same R substituent. The most effective inhibitors in the tested series were the derivatives with R = 3-F (Br-PBA; IC50 = 4.3 μmol dm-3) and R = 3-Cl (Br2-PBA; IC50 = 8.6 μmol dm-3). Bilinear dependence of the PET inhibiting activity on the lipophilicity of the compounds as well as on the Hammett constant, σ, of the R substituent was observed for both investigated series. Using EPR spectroscopy it was found that the site of action of the tested compounds in the photosynthetic apparatus is situated on the donor side of PS 2, in D· or in the Z·/D· intermediates. Interaction of the studied compounds with chlorophyll a and aromatic amino acids present in the pigment-protein complexes mainly in photosystem 2 was documented by fluorescence spectroscopy.
- Krlov, Katarna,ere, Frantiek,Peko, Mat,Waisser, Karel,Kubicov, Lenka
-
-
- Synthesis and antiproliferative activities against Hep-G2 of salicylanide derivatives: Potent inhibitors of the epidermal growth factor receptor (EGFR) tyrosine kinase
-
A series of salicylanilide derivatives (compounds 1-32) were synthesised by reacting substituted salicylic acids and anilines. The chemical structures of these compounds were determined by 1H-NMR, electrospray ionisation mass spectrometry (ESI-MS) and elemental analysis. The compounds were assayed for their antiproliferative activities against the Hep-G2 cell line by the 3-(4,5-dimethylthylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Among the compounds tested, 22 and 28 showed the most favouable antiproliferative activities with 50% inhibitory concentration (IC50) values of 1.7 and 1.3 μM, respectively, which were comparable to the positive control of 5-fluorouracil (IC50 = 1.8 μM). A solid-phase ELISA assay was also performed to evaluate the ability of compounds 1-32 to inhibit the autophosphorylation of the epidermal growth factor receptor tyrosine kinase (EGFR TK). Docking simulations of 22 and 28 were carried out to illustrate the binding mode of the molecule into the EGFR active site, and the result suggested that both compounds 22 and 28 could bind the EGFR kinase well.
- Zhu, Zhen-Wei,Shi, Lei,Ruan, Xiao-Ming,Yang, Ying,Li, Huan-Qiu,Xu, Suo-Ping,Zhu, Hai-Liang
-
experimental part
p. 37 - 45
(2011/10/30)
-
- Identification of halosalicylamide derivatives as a novel class of allosteric inhibitors of HCV NS5B polymerase
-
Halosalicylamide derivatives were identified from high-throughput screening as potent inhibitors of HCV NS5B polymerase. The subsequent structure and activity relationship revealed the absolute requirement of the salicylamide moiety for optimum activity. Methylation of either the hydroxyl group or the amide group of the salicylamide moiety abolished the activity while the substitutions on both phenyl rings are acceptable. The halosalicylamide derivatives were shown to be non-competitive with respect to elongation nucleotide and demonstrated broad genotype activity against genotype 1-3 HCV NS5B polymerases. Inhibitor competition studies indicated an additive binding mode to the initiation pocket that is occupied by the thiadiazine class of compounds and an additive binding mode to the elongation pocket that is occupied by diketoacids, but a mutually exclusive binding mode with respect to the allosteric thumb pocket that is occupied by the benzimidazole class of inhibitors. Therefore, halosalicylamides represent a novel class of allosteric inhibitors of HCV NS5B polymerase.
- Liu, Yaya,Donner, Pamela L.,Pratt, John K.,Jiang, Wen W.,Ng, Teresa,Gracias, Vijaya,Baumeister, Steve,Wiedeman, Paul E.,Traphagen, Linda,Warrior, Usha,Maring, Clarence,Kati, Warren M.,Djuric, Stevan W.,Molla, Akhteruzzaman
-
scheme or table
p. 3173 - 3177
(2009/04/11)
-
- Relationships between the chemical structure of antimycobacterial substances and their activity against atypical strains. Part 14: 3-Aryl-6,8-dihalogeno-2H-1,3-benzoxazine-2,4(3H)-diones)
-
A set of eight derivatives of 6,8-dichloro-3-phenyl-2H-benzoxazine-2,4(3H)-dione and nine derivatives of 6,8-dibromo-3-phenyl-2H-1,3-benzoxazine-2,4(3H)-dione, substituted on the phenyl ring, was prepared by the reaction of the corresponding salicylanilides with ethyl chloroformate. The compounds were evaluated in vitro for antimycobacterial activity against Mycobacterium tuberculosis, Mycobacterium kansasii, and Mycobacterium avium. Their activity increases with increasing hydrophobicity and electron-withdrawing ability of the substituents on the phenyl ring.
- Waisser, Karel,Hladuvkova, Jana,Gregor, Jiri,Rada, Tomas,Kubicova, Lenka,Klimesova, Vera,Kaustova, Jarmila
-
-
