Novel sixteen chalcones and thirteen 1,3,5-triphenyl-2-pyrazolines were synthesized and characterized using FT-IR, HR-Mass, NMR (1H-NMR, 13C-NMR, 135 DEPT, 1H-1H CoSY and 1H and 13C CoSY) and XRD. These compounds were evaluated for their antibacterial activity against six micro-organisms, namely Bacillus subtilis NCIM 2718, Staphylococcus aureus NCIM 5021, Salmonella typhi NCIM 2501, Enterobacter aerogenes NCIM 5139, Pseudomonas aeruginosa NCIM 5029, and Proteus vulgaris NCIM 2813 by twofold dilution method using resazurin as the indicator dye. In the case of chalcones, compounds with hydroxyl and bromo substitutions in the B-ring favor activity and benzyloxy substitution irrespective of its position in the A-ring. In the case of 1,3,5-triphenyl-2-pyrazolines, chloro substitution in the A-ring favors activity. Hydrophilic/lipophilic balance of the compounds plays a major role in their antibacterial activity. © 2010 John Wiley &amp; Sons A/S.

Mukesh Doble

Department Of Biotechnology

Ponnurengan Malliappan Sivakumar

ampicillin

antiinfective agent

chalcone derivative

hydroxyl group

PYRAZOLINE DERIVATIVE

resazurin

Tetracycline

Antibacterial activity

article

Bacillus Subtilis

carbon nuclear magnetic resonance

dilution

drug synthesis

ENTEROBACTER AEROGENES

fourier transformation

Hydrophilicity

Lipophilicity

microorganism

nonhuman

nuclear magnetic resonance

priority journal

proton nuclear magnetic resonance

Pseudomonas

Salmonella typhi

Spectroscopy

Staphylococcus aureus

substitution reaction

X ray diffraction

Anti-Bacterial Agents

Chalcones

Magnetic Resonance Spectroscopy

Microbial Sensitivity Tests

Pyrazoles

Spectroscopy, Fourier Transform Infrared

Structure-Activity Relationship

PROTEUS VULGARIS

Pseudomonas aeruginosa

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Chemical Biology and Drug Design

A series of norephedrine-based Schiff bases (1a-6a and 1b-6b) were synthesized by reacting substituted salicylaldehydes with d-norephedrine or l-norephedrine. The structure of these compounds was confirmed by elemental analyses and spectroscopic techniques. The molecular structures of 5a and 6a have been determined by X-ray crystallography, which revealed that the compounds are in the oxoamino form, with bent intramolecular N-H···O (N···O≈2.58Å) hydrogen bonds and that they are associated in dimers bridged by linear intermolecular O-H···O (O···O≈2.69Å) hydrogen bonds. The density functional theory calculations on 5a confirmed that the oxoamino form is more stable than the phenolimino form by 12.2kcal/mol. All the compounds were evaluated for their antibacterial activity using resazurin dye as indicator by twofold dilution method against four bacteria namely, Bacillus subtilis (NCIM2718), Staphylococcus aureus (NCIM5021), Escherichia coli (NCIM2931), and Proteus vulgaris (NCIM2813). © 2011 John Wiley & Sons A/S.

Antibacterial Activities of 4-Substituted-2-[(E)-{(1S,2R)/(1R,2S)-1-Hydroxy-1-Phenylpropan-2-Ylimino}Methyl]Phenol

2-Acetyl naphthalene reacts with various methoxy substituted benzaldehyde in the presence of 10&nbsp;% sodium hydroxide solution giving functionalized chalcones. The synthesized chalcones when further reacted with hydrazine hydrate in the presence of acetic acid afforded N-acetyl pyrazolines. All the synthesized products were confirmed by various spectral data such as FTIR, 1H NMR, 13C NMR, and HRMS studies. All the synthesized compounds were screened for cytotoxicity against various cell lines.

Research on Chemical Intermediates

Synthesis and cytotoxicity study of pyrazoline derivatives of methoxy substituted naphthyl chalcones

In this paper, the synthesis of 48 chalcones and their in vitro antifungal activity against Aspergillus flavus NCIM 594, Fusarium proliferatum NCIM1105, Aspergillus niger NCIM 596 and Candida tropicalis NCIM 3556 are reported. Predominantly, the active compounds (6, 9, 14, 27, and 47) against all four fungi have found to have electron withdrawing substitutions in their para substitution in B-ring. Quantitative structure-activity relationship indicated that the antifungal activities are correlated with absorption distribution metabolism and excretion, electrophilicity, spatial and topological descriptors. The statistical measures such as r2 (0.68-0.71), r2-adj (0.62-0.66), q2 (0.60-0.61) and F-ratio (12-17) are reasonable. The data is divided into training and a test set, the former is used to develop the models, and the later is used to test their predictive capability. The predictions are found to be within the 99% confidence level except for two of the cases. SEM (scanning electron microscopy) and BacLight Live/Dead assay indicate that the chalcones act by disrupting the fungal cell wall. © 2009 John Wiley and Sons A/S.

Antifungal activity, mechanism and QSAR studies on chalcones

Forty-eight chalcone analogs were synthesized and their in vitro antibacterial activity against Staphylococcus aureus NCIM 5021, Bacillus subtilis NCIM 2718, Phaseolus vulgaris NCIM 2813, Escherichia coli NCIM 2931, Salmonella typhi 2501 and Enterobacter aerogenes NCIM 5139 were evaluated by microdilution broth assay. Quantitative structure-activity relationships were developed for all the cases (r2 = 0.68-0.79; = 0.58-0.78; q 2 = 0.51-0.68; F = 13.02-61.51). Size, polarizability, electron-donating/withdrawing and hydrophilic nature of the molecule determine the activity against these Gram-positive and Gram-negative bacteria. Staphylococcus aureus was the most and S. typhi was the least hydrophobic of these organisms. These chalcones act better against more hydrophobic organisms. The more active chalcones have log P between 1.5 and 3. Compound 24, one of the most active compounds, was found to act by damaging the cell wall of S. aureus. Slimicidal activity of five of the most active compounds (24, 31, 32, 34 and 37) was found to be in the range of 48-60% against S. aureus and 40-54% against E. coli. A correlation was observed among the hydrophobicity of the compounds, hydrophobicity of the bacterial cell surface and the antibacterial activity of the compound. © 2009 Blackwell Munksgaard.

Synthesis, biological evaluation, mechanism of action and quantitative structure-activity relationship studies of chalcones as antibacterial agents

In order to develop relatively small molecules as antimycobacterial agents, twenty-five chalcones were synthesized, their activity was evaluated, and quantitative structure-activity relationship (QSAR) was developed. The synthesis was based on the Claisen-Schimdt scheme and the resultant compounds were tested for antitubercular activity by luciferase reporter phage (LRP) assay. Compound C24 was found to be the most active (∼99%) in this series based on the percentage reduction in Relative Light Units at both 50 and 100 μg/ml levels, followed by compound C21. Four compounds at the 50 μg/ml and eight compounds at the 100 μg/ml showed activity above 90% level. QSAR model was developed between activity and spatial, topological, and ADME descriptors for the 50 μg/ml data. The statistical measures such as r, r2, q2, and F values obtained for the training set were in acceptable range and hence this relationship was used for the test set. The predictive ability of the model is satisfactory (q2 = 0.56) and it can be used for designing similar group of compounds. © 2007 Elsevier Ltd. All rights reserved.

Bioorganic and Medicinal Chemistry Letters

Synthesis, antimycobacterial activity evaluation, and QSAR studies of chalcone derivatives

Arkivoc

Microwave assisted synthesis, antibacterial activity against Bordetella bronchiseptica of a library of 3΄-hydroxyaryl and heteroaryl chalcones and molecular descriptors-based SAR

Chemical Papers

QSAR analysis of 1,3-diaryl-2-propen-1-ones and their indole analogs for designing potent antibacterial agents

Novel chalcones and 1,3,5-triphenyl-2-pyrazoline derivatives as antibacterial agents

Journal	Chemical Biology and Drug Design
ISSN	17470277
Open Access	No