scholarly journals The QSAR study for antibacterial activity of structurally diverse nitroaromatics

Chemija ◽  
2019 ◽  
Vol 30 (1) ◽  
Author(s):  
Jonas Šarlauskas ◽  
Evelina Polmickaitė-Smirnova ◽  
Narimantas Čėnas ◽  
Kastis Krikštopaitis ◽  
Žilvinas Anusevičius
Keyword(s):  
Antibacterial Activity ◽  
Energy Gap ◽  
Specific Interaction ◽  
Coli Strain ◽  
Log P ◽  
Chemical Hardness ◽  
Qsar Study ◽  
Van Der Waals Volume ◽  
Relationship Analysis

The antibacterial activity of a series of structurally diverse nitroaromatic compounds (NACs) (nitrobenzene and nitroheterocyclic derivatives) was estimated in terms of the minimum inhibitory concentrations (MICs) against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria strains in vitro. The resultant log of 1/MICs (pMICs) was subjected to a quantitative structure–activity relationship analysis (QSAR) using a set of molecular descriptors of the compounds assessed by means of quantum mechanical computation and other methods. The estimated pMIC values of NACs tentatively increased with an increase in their electrophilic potency (in terms of LUMO energy) along with the LUMO–HOMO energy gap (or chemical hardness) towards both bacteria strains. No reliable contribution of lipophilicity (octanol/water log P) of nitroaromatics was found to both bacteria strains. The activity of NACs towards S. aureus increased with an increase in their molecular weight and van der Waals volume, and it also tended to increase with an increase in their polar surface area (PSA) and in the number of hydrogen bond-acceptors (HBAs), whereas using these descriptors against E. coli strain, no satisfactory correlations were obtained. The activity of NACs towards both bacteria strains showed a parabolic type dependence upon the highest positive values of molecular electrostatic potentials (VS, max) that might partially be associated with the non-specific interaction of nitroaromatics with the surfaces of the negatively charged envelopes of bacteria at the initial stage of NACs’ action.

scholarly journals SalmonellaTyphimurium utilizes a T6SS-mediated antibacterial weapon to establish in the host gut

2016 ◽  
Vol 113 (34) ◽  
pp. E5044-E5051 ◽  
Author(s):  
Thibault G. Sana ◽  
Nicolas Flaugnatti ◽  
Kyler A. Lugo ◽  
Lilian H. Lam ◽  
Amanda Jacobson ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Klebsiella Oxytoca ◽  
Specific Interaction ◽  
Commensal Bacteria ◽  
Cell Contact ◽  
Target Cells ◽  
Dependent Manner ◽  
Type Vi Secretion System ◽  
Pathogen Invasion

The mammalian gastrointestinal tract is colonized by a high-density polymicrobial community where bacteria compete for niches and resources. One key competition strategy includes cell contact-dependent mechanisms of interbacterial antagonism, such as the type VI secretion system (T6SS), a multiprotein needle-like apparatus that injects effector proteins into prokaryotic and/or eukaryotic target cells. However, the contribution of T6SS antibacterial activity during pathogen invasion of the gut has not been demonstrated. We report that successful establishment in the gut by the enteropathogenic bacteriumSalmonella entericaserovar Typhimurium requires a T6SS encoded withinSalmonellapathogenicity island-6 (SPI-6). In an in vitro setting, we demonstrate that bile salts increase SPI-6 antibacterial activity and thatS. Typhimurium kills commensal bacteria in a T6SS-dependent manner. Furthermore, we provide evidence that one of the two T6SS nanotube subunits, Hcp1, is required for killingKlebsiella oxytocain vitro and that this activity is mediated by the specific interaction of Hcp1 with the antibacterial amidase Tae4. Finally, we show thatK. oxytocais killed in the host gut in an Hcp1-dependent manner and that the T6SS antibacterial activity is essential forSalmonellato establish infection within the host gut. Our findings provide an example of pathogen T6SS-dependent killing of commensal bacteria as a mechanism to successfully colonize the host gut.

scholarly journals Application of QSAR models in analysis of antibacterial activity of some benzimidazole derivatives against Sarcina lutea

2013 ◽  
Vol 67 (1) ◽  
pp. 27-33
Author(s):  
Sanja Podunavac-Kuzmanovic ◽  
Dragoljub Cvetkovic ◽  
Lidija Jevric ◽  
Natasa Uzelac
Keyword(s):  
Antibacterial Activity ◽  
Inhibitory Activity ◽  
Antibacterial Activities ◽  
Quantitative Structure Activity Relationship ◽  
Benzimidazole Derivatives ◽  
Log P ◽  
Statistical Parameters ◽  
Qsar Analysis ◽  
Qsar Models

In the present paper, a quantitative structure activity relationship (QSAR) has been carried out on a series of 2-methyl and 2-aminobenzimidazole derivatives to identify the lipophilicity requirements for their inhibitory activity against bacteria Sarcina lutea. The tested compounds displayed in vitro antibacterial activity and minimum inhibitory concentration (MIC) was determined for all compounds. The partition coefficients of the studied compounds were measured by the shake flask method (log P) and by theoretical calculation (Clog P). The relationships between lipophilicity descriptors and antibacterial activities were investigated and the mathematical models have been developed as a calibration models for predicting the inhibitory activity of this class of compounds. The models were validated by leave-one-out (LOO) technique as well as by the calculation of statistical parameters for the established models. Therefore, QSAR analysis reveals that lipophilicity descriptor govern the inhibitory activity of benzimidazoles studied against Sarcina lutea.

Phytochemical Analysis and In Vitro Antibacterial Activity of Soymida febrifuga (Roxb.) Juss. and Hemidesmus indicus (L.)

2011 ◽  
Vol 3 (12) ◽  
pp. 57-59 ◽  
Author(s):  
K. Riazunnisa K. Riazunnisa ◽  
◽  
U. Adilakshmamma U. Adilakshmamma ◽  
C. Habeeb khadri
Keyword(s):  
Antibacterial Activity ◽  
Phytochemical Analysis ◽  
Hemidesmus Indicus ◽  
In Vitro Antibacterial Activity

A comparative study of the antibacterial activity of Quercus robur (Ethanolic extract) and Zinc oxide nanoparticles on Salmonella (In vitro)

2018 ◽  
Vol 9 (SPL1) ◽  
Author(s):  
Hams H. H. Alfattli ◽  
Ghufran Zuhair Jiber ◽  
Ghaidaa Gatea Abbass
Keyword(s):  
Zinc Oxide ◽  
Antibacterial Activity ◽  
Zinc Oxide Nanoparticles ◽  
Quercus Robur ◽  
Ethanolic Extract ◽  
Inhibitory Effect ◽  
Significant Inhibition ◽  
Oxide Nanoparticles ◽  
Inhibition Zones

This study which designed to evaluate the inhibitory effect of Ethanolic extract of (Quercusrobur) and Zinc oxide nanoparticles on the growth of one genus of enterobacteriacae (Salmonella). In vitro. For this purpose graduate concentrates for plant extract (50, 100, 200, 400 )mg/ml which prepared and compared with Zinc oxide nanoparticles of different concentration (2, 1, 0.5, 0.25) μg/ml,and examined. The result showed that the studied medicinal plant has antibacterial activity against this bacteria which used. The result showed that the plant has good activity in decrease the growth of this bacteria. The results of the study also showed that the nano-ZnO has very effective antibacterial action against the studied bacteria which was Salmonella,nanoparticles concentrations lead to increasing in the inhibition zones of tested bacterial growth. We also study the effect of three antibiotics Lomefloxacin (LOM), Ciprofloxacin (SIP) and Rifampin (RA) and the result showed,in a comparison within the tested bacteria,Salmonella had a significant inhibition increase in Lomefloxacin ; the ciprofloxacin showed effect on tested bacteria. However,Rifampin does not show any effect on tested bacteria.

Quantitative Structure-activity Relationship Analysis for Predicting Lipophilicity of Aniline Derivatives (Including some Pharmaceutical Compounds)

2019 ◽  
Vol 22 (5) ◽  
pp. 333-345
Author(s):  
Morteza Rezaei ◽  
Esmat Mohammadinasab ◽  
Tahere Momeni Esfahani
Keyword(s):  
Density Functional ◽  
Pharmaceutical Compounds ◽  
Partial Least Square ◽  
Least Square ◽  
Basis Set ◽  
Van Der Waals Volume ◽  
Relationship Analysis ◽  
Aniline Derivatives ◽  
Aqueous Solvent ◽  
Qsar Models

Background: In this study, we used a hierarchical approach to develop quantitative structureactivity relationship (QSAR) models for modeling lipophilicity of a set of 81 aniline derivatives containing some pharmaceutical compounds. Objective: The multiple linear regression (MLR), principal component regression (PCR) and partial least square regression (PLSR) methods were utilized to construct QSAR models. Materials & Methods: Quantum mechanical calculations at the density functional theory level and 6- 311++G** basis set were carried out to obtain the optimized geometry and then, the comprehensive set of molecular descriptors was computed by using the Dragon software. Genetic algorithm (GA) was applied to select suitable descriptors which have the most correlation with lipophilicity of the studied compounds. Results: It was identified that such descriptors as Barysz matrix (SEigZ), hydrophilicity factor (Hy), Moriguchi octanol-water partition coefficient (MLOGP), electrophilicity (ω/eV) van der Waals volume (vWV) and lethal concentration (LC50/molkg-1) are the best descriptors for QSAR modeling. The high correlation coefficients and the low prediction errors for MLR, PCR and PLSR methods confirmed good predictability of the three models. Conclusion: In present study, the high correlation between experimental and predicted logP values of aniline derivatives indicated the validation and the good quality of the resulting three regression methods, but MLR regression procedure was a little better than the PCR and PLSR methods. It was concluded that the studied aniline derivatives are not hydrophilic compounds and this means these compounds hardly dissolve in water or an aqueous solvent.

Correlation between in vitro and in vivo Data of Radiolabeled Peptide for Tumor Targeting

2019 ◽  
Vol 19 (12) ◽  
pp. 950-960
Author(s):  
Soghra Farzipour ◽  
Seyed Jalal Hosseinimehr
Keyword(s):  
Tumor Targeting ◽  
Single Photon ◽  
Specific Binding ◽  
Specific Interaction ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Mixed Effect ◽  
Radiolabeled Peptides

Tumor-targeting peptides have been generally developed for the overexpression of tumor specific receptors in cancer cells. The use of specific radiolabeled peptide allows tumor visualization by single photon emission computed tomography (SPECT) and positron emission tomography (PET) tools. The high affinity and specific binding of radiolabeled peptide are focusing on tumoral receptors. The character of the peptide itself, in particular, its complex molecular structure and behaviors influence on its specific interaction with receptors which are overexpressed in tumor. This review summarizes various strategies which are applied for the expansion of radiolabeled peptides for tumor targeting based on in vitro and in vivo specific tumor data and then their data were compared to find any correlation between these experiments. With a careful look at previous studies, it can be found that in vitro unblock-block ratio was unable to correlate the tumor to muscle ratio and the success of radiolabeled peptide for in vivo tumor targeting. The introduction of modifiers’ approaches, nature of peptides, and type of chelators and co-ligands have mixed effect on the in vitro and in vivo specificity of radiolabeled peptides.

Synthesis and Evaluation of Aromatic Surfactants as Potential Antibacterial and Cytotoxic Agents

2019 ◽  
Vol 16 (6) ◽  
pp. 478-484
Author(s):  
Kenia Barrantes ◽  
Mary Fuentes ◽  
Luz Chacón ◽  
Rosario Achí ◽  
Jorge Granados-Zuñiga ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Hela Cells ◽  
Cytotoxic Agents ◽  
Cytotoxic Activities ◽  
Hydroxybenzoic Acid ◽  
Derivatives Of

Two ether and one ester derivatives of the 4-nitro-3-hydroxybenzoic acid were synthesized and characterized. The in vitro antimicrobial and cytotoxic activities of the three novel compounds were also evaluated. The aromatic derivatives showed antibacterial activity against one of the four microorganisms tested and two compounds (C8 and NOBA) had a lower IC50 in HeLa cells.

In Vitro Evaluation of the Antibacterial Activity and Antibiotic- Modulatory Effect of Gracilaria cervicornis (Tuner) J. Agardh

2018 ◽  
Vol 15 (3) ◽  
Author(s):  
Israeliane F. Cordeiro ◽  
Henrique D. M. Coutinho ◽  
Joao V. A. Ferreira ◽  
Lucindo J. Quintans Junior ◽  
Irwin R. A. Menezes ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
In Vitro Evaluation

Synthesis, Molecular Modelling and Antibacterial Activity Against Helicobacter pylori of Novel Diflunisal Derivatives as Urease Enzyme Inhibitors

2019 ◽  
Vol 16 (4) ◽  
pp. 392-400 ◽  
Author(s):  
Göknil Pelin Coşkun ◽  
Teodora Djikic ◽  
Sadık Kalaycı ◽  
Kemal Yelekçi ◽  
Fikrettin Şahin ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Antibacterial Activity ◽  
Enzyme Inhibitors ◽  
Binding Modes ◽  
Bacterial Strains ◽  
Urease Enzyme ◽  
H Pylori ◽  
Ulcer Treatment ◽  
Main Factor

Background:The main factor for the prolongation of the ulcer treatment in the gastrointestinal system would be Helicobacter pylori infection, which can possibly lead to gastrointestinal cancer. Triple therapy is the treatment of choice by today's standards. However, observed resistance among the bacterial strains can make the situation even worse. Therefore, there is a need to discover new targeted antibacterial therapy in order to make success in the eradication of H. pylori infections.Methods:The targeted therapy rule is to identify the related macromolecules that are responsible for the survival of the bacteria. Thus, 2-[(2',4'-difluoro-4-hydroxybiphenyl-3-yl)carbonyl]-N- (substituted)hydrazinocarbothioamide (3-13) and 5-(2',4'-difluoro-4-hydroxybiphenyl-3-yl)-4- (substituted)-2,4-dihydro-3H-1,2,4-triazole-3-thiones (14-17) were synthesized and evaluated for antibacterial activity in vitro against H. pylori.Results:All of the tested compounds showed remarkable antibacterial activity compared to the standard drugs (Ornidazole, Metronidazole, Nitrimidazin and Clarithromycin). Compounds 4 and 13 showed activity as 2µg/ml MIC value.Conclusion:In addition, we have investigated binding modes and energy of the compounds 4 and 13 on urease enzyme active by using the molecular docking tools.

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