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Uracil DNA glycosylase (UDG or Ung) is a key enzyme involved in uracil excision from the DNA as a repair mechanism. Designing Ung inhibitors is thus a promising strategy to treat different cancers and infectious diseases. The uracil ring and its derivatives have been shown to inhibit Mycobacterium tuberculosis Ung (MtUng), resulting from specific and strong binding with the uracil-binding pocket (UBP). To design novel MtUng inhibitors, we screened several non-uracil ring fragments hypothesised to occupy MtUng UBP due to their high similarity to the uracil structural motif. These efforts have resulted in the discovery of novel MtUng ring inhibitors. Here we report the co-crystallised poses of these fragments, confirming their binding within the UBP, thus providing a robust structural framework for the design of novel lead compounds. We selected the barbituric acid (BA) ring as a case study for further derivatisation and SAR analysis. The modelling studies predicted the BA ring of the designed analogues to interact with the MtUng UBP much like the uracil ring. The synthesised compounds were screened in vitro using radioactivity and a fluorescence-based assay. These studies led to a novel BA-based MtUng inhibitor 18a (IC 50  = 300 μM) displaying ∼24-fold potency over the uracil ring., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Herein we report the synthesis and activity of a novel class of HDAC inhibitors based on 2, 3-diphenyl acrylic acid derivatives. The compounds in this series have shown to be potent HDAC inhibitors possessing significant antiproliferative activity. Further compounds in this series were subjected to metabolic stability in human liver microsomes (HLM), mouse liver microsomes (MLM), and exhibits promising stability in both. These efforts culminated with the identification of a developmental candidate (5a), which displayed desirable PK/PD relationships, significant efficacy in the xenograft models and attractive ADME profiles., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

A general method for the synthesis of a library of hitherto unreported amino-1,4-naphthoquinone-appended triazoles was accomplished via a sequential three-component reaction of substituted N-propargylaminonaphthoquinones with variously substituted alkyl bromides/2-bromonaphthalene-1,4-dione and sodium azide in the presence of Et3N/CuI in water. Aminonaphthoquinone-appended iminochromene-triazole hybrid heterocycles were also synthesized from the amino-1,4-naphthoquinone-appended-1,2,3-triazolylacetonitriles. All the triazole hybrids were screened for their in vitro activity against Mycobacterium tuberculosis H37Rv (MTB). Among the triazoles, 2-(((1-benzyl-1H-1,2,3-triazol-4-yl)methyl)(4-(trifluoromethyl)phenyl)amino)naphthalene-1,4-dione (7d) emerged as the most active one with IC50 = 1.87 μM, being more potent than the anti-TB drugs, cycloserine (6 times), pyrimethamine (20 times) and equipotent as the drug ethambutol (IC50 < 1.56 μM)., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

A series of 3-indolyl-3-hydroxy oxindole derivatives (n = 41) were synthesized by the green aminocatalytic method with excellent yields under mild reaction conditions. All the newly synthesized derivatives were subjected to evaluate their cytotoxic properties against different human cancer cell lines. Results indicated that about 73% of the derivatives exhibited significant anti-proliferative activities against leukemia (U937, THP-1), lung (A549) and breast cancer (MCF7) cell lines. Among them a few of the derivatives exhibited the most potent and effective cytotoxic activities on U937 (34, 36, 38 and 41) and MCF7 (12, 35, 40 and 41) cell lines, and their anti-proliferation activities are better than the positive control, Etoposide., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

A novel series of substituted (E)-3-(Benzo [d]thiazol-2-ylamino)phenylprop-2-en-1-onewere synthesized starting from 2-aminobenzothiazole and 1-aryl-3,3-bis- (methylsulfanyl)-2-propen-1-onesin the presence of a catalytic amount of sodium hydride in THF. The synthesised compounds' structures were confirmed by IR, Mass spectrometry, (1)H NMR, (13)C NMR and HRMS spectral data. These compounds were evaluated for their antidiabetic activity, and most of the derivatives of (E)-3-(Benzo [d]thiazol-2-ylamino)phenylprop-2-en-1-one displayed significant antidiabetic activity., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

A novel series of 11-p-substituted phenyl-12-phenyl-11a,12-dihydro-11H-indeno[2,1-c][1,5]benzothiazepines (3) has been synthesized and screened for their antimicrobial activity against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria and fungi (Aspergillus fumigates and Candida albicans). The antimicrobial evaluation data indicated that the compounds, 3d, 3g, 3h, 3k-3p exhibited very promising antibacterial activity and the derivatives 3k, 3l, 3o and 3p exhibited high antifungal activity. The QSAR studies carried out to find out the correlation between the antimicrobial activity and physicochemical properties of synthesized benzothiazepines (3) indicated the predominance of electronic parameters in describing their antimicrobial activity., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

A series of new 1,3-disubstituted-1H-naphtho[1,2-e][1,3]oxazines (3 and 7) was synthesized in good yields and the structure was determined with the help of NMR, 2D-NMR, HRMS studies and X-ray crystallography. These compounds were tested in vitro for their antibacterial activity against Gram-positive and Gram-negative bacteria and as well as for antifungal activity. The compounds 3c, 3e, 7a, 7d and 7k showed significant antibacterial activity and 7l showed moderate antifungal activity. The cytotoxicity of 1,3-disubstituted-1H-naphtho[1,2-e][1,3]oxazines showed that 3e and 7e are more effective against breast, lung and colon cell proliferation., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

A series of 10a-phenylbenzo[b]indeno[1,2-e][1,4]thiazin-11(10aH)-ones (3) has been synthesized and tested for their antimicrobial activity. The antimicrobial evaluation data indicated that compounds, 3b, 3d, 3k and 3m exhibited very promising antibacterial activity and the compounds 3b and 3k exhibited notable activity, almost comparable to penicillin for Staphylococcus aureus and Bacillus subtilis respectively. The derivatives 3g and 3l exhibited high antifungal activity. Moreover, antibacterial activities were more prolific than antifungal activity. The QSAR studies indicated the importance of topological parameters, Kiers second order molecular index (κα(2)) and molecular connectivity index (χ) in describing the antibacterial activity and electronic parameters, the energy of highest occupied molecular orbital (HOMO) and the dipole moment (μ) in describing the antifungal activity., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

A series of 6-methyl-4-[1-(2-substituted-phenylamino-acetyl)-1H-indol-3-yl]-2-oxo/thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylic acid ethyl esters (1-16) were synthesized and evaluated in vitro for their antimicrobial and anticancer potential. 6-Methyl-4-{1-[2-(4-nitro-phenylamino)-acetyl]-1H-indol-3-yl}-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylic acid ethyl ester (15, pMIC(ec) = 2.50 μM/mL) was found to be almost equipotent to the standard drug, norfloxacin (pMIC(ec) = 2.61 μM/mL) against Escherichia coli and emerged as most potent antimicrobial agent (pMIC(am) = 1.84 μM/mL). 4-{1-[2-(2-Chloro-4-nitro-phenylamino)-acetyl]-1H-indol-3-yl}-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylic acid ethyl ester (4, IC(50) = 5 μg/mL) was more potent than the standard drug 5-fluorouracil (IC(50) = 6 μg/mL) against HCT-116 a colon cancer cell line, and emerged as the most potent anticancer agent. The QSAR studies demonstrated the importance of topological parameter, Balaban index (J) followed by lipophillic parameter, log P in describing the antimicrobial activity of the synthesized compounds., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

A series of novel hexahydro-2H-pyrano[3,2-c]quinoline analogues derived from dibenzo[b,d]furan and 9-methyl-9H-carbazole has been synthesized in very good yields through SnCl(2)·2H(2)O catalyzed one-pot Povarov reaction (imino-Diels-Alder reaction). The imines generated in situ from dibenzo[b,d]furan-2-carbaldehyde or 9-methyl-9H-carbazole-3-carbaldehyde and aromatic amines, were reacted with 3,4-dihydro-2H-pyran in a diasteroselective manner in acetonitrile at RT. These synthesized isomeric pyranoquinoline analogues have been evaluated for their in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv (MTB) by agar dilution method. Among the 23 compounds screened, 5-(dibenzo[b,d]furan-2-yl)-9-fluoro-3,4,4a,5,6,10b-hexahydro-2H-pyrano[3,2-c]quinoline 4f, 5-(dibenzo[b,d]furan-2-yl)-9-fluoro-3,4,4a,5,6,10b-hexahydro-2H-pyrano[3,2-c]quinoline 5f and 9-fluoro-5-(9-methyl-9H-carbazol-3-yl)-3,4,4a,5,6,10b-hexa hydro-2H-pyrano[3,2-c]quinoline 7f (MIC 3.13 μg/mL) were resulted as most active antitubercular agents., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

A series of benzoic acid hydrazones and its nicotinyl derivatives (1-10) were prepared and evaluated for their antitubercular activity towards a strain of Mycobacterium tuberculosis (MTB). The structures of newly synthesized compounds were confirmed by infrared (IR) and 1H-nuclear magnetic resonance (NMR) spectral data and elemental analysis. The in vitro antitubercular activity of synthesized compounds against MTB was carried out in Middlebrook 7H11agar medium supplemented with OADC by agar dilution method. The antitubercular activity results indicated that nicotinic acid N-(3,5-dinitro-benzoyl)-N'-(4-methoxy-benzylidene)-hydrazide (1) is the most potent among the synthesized compounds with MIC of 3.5×10(-3) μM., (Copyright © 2010 Elsevier Masson SAS. All rights reserved.)

A series of 4-[1-(substituted aryl/alkyl carbonyl)-benzoimidazol-2-yl]-benzene sulphonic acids (1-20) was synthesized and evaluated, in vitro, for their antimicrobial activity and the results indicated that compounds 4-[1-(4-Nitrobenzoyl)-1H-benzoimidazol-2-yl]-benzenesulfonic acid (9) and 4-(1-octadec-9-enoyl-1H-benzoimidazol-2-yl)-benzenesulfonic acid (18) were found to be the most active ones. QSAR investigations indicated that the multi-target QSAR model was effective in describing the antimicrobial activity over the one-target QSAR models. Further the mt-QSAR model indicated the importance of the topological parameter, Balaban index (J) followed by the electronic parameter, LUMO and topological parameter, valence second order molecular connectivity index (2χv) in describing the antimicrobial activity of synthesized compounds (1-20)., (Copyright © 2010 Elsevier Masson SAS. All rights reserved.)

A series of novel dibenzo[b,d]furan mono-carboxylic acid derivatives were synthesized, characterized and evaluated for their ability to inhibit Protein Tyrosine Phosphatase 1B (PTP1B) in vitro in order to use them as potential anti-diabetic agents. Structure-activity relationship study led to the identification of potent compound 5 E which inhibited PTP1B with IC(50) value of 82+/-0.43 nM. Compound 5 E was screened in vivo as drug candidate for anti-diabetic activity using rosiglitazone maleate as the standard. Compound 5 E showed significant reduction in body weight, fed-state whole blood glucose (WBG), fasting WBG, plasma glucose and plasma cholesterol levels and non-significant reduction in fasting plasma triglyceride levels in ob/ob mice., (2010 Elsevier Masson SAS. All rights reserved.)

A series of benzylidene hydrazides (1-20) was synthesized and tested, in vitro, for antibacterial, antifungal and antiviral activities. The microbial screening results indicated that compounds having chloro and nitro substituents were the most active ones. The antiviral evaluation depicted that compounds 9 and 19 were active against Vesicular stomatitis virus (VSV) in HeLa cell cultures. QSAR investigations indicated that the multi-target QSAR model was effective in describing the antimicrobial (antibacterial and antifungal) activity over the one-target QSAR models. Further the mt-QSAR model indicated that the topological parameters, second order molecular connectivity index ((2)chi) and third order Kier's alpha shape index (kappaalpha(3)) are effective in describing the antimicrobial activity of synthesized hydrazides., (Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.)

A convenient, fast and high yielding method for the preparation of 7-methoxyisoflavanone and 2,3-diarylchromanones has been developed by the condensation of benzyl-2-hydroxy-4-alkoxyphenylketone with arylaldehyde/paraformaldehyde in presence of diethylamine, assisted by microwave activation. All the synthesized compounds were screened for anticancer as well as antioxidant activities. Among the nine compounds, 7-methoxyisoflavanone 7 and diarylchromanone 6c shows potential anticancer activity and diarylchromanone 6b has potential antioxidant activity. Compound 6h possesses anticancer and antioxidant activity at the same concentration., (Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.)

A series of novel isochroman mono-carboxylic acid derivatives were synthesized, characterized and evaluated for their ability to inhibit protein tyrosine phosphatase 1B (PTP1B) in vitro in order to use them as potential anti-diabetic agents. Analysis of structure-activity relationships led to the identification of potent compound 4n which inhibited PTP1B with IC(50) value of 51.63+/-0.91 nM. In general, high potency was associated with a dithiolane ring with a spacer of five carbons to the isochroman ring. Compound 4n has been selected for in vivo evaluation as drug candidate for anti-diabetic activity.

In the present study, we have synthesized 2-(substituted phenyl)-1H-imidazole (1-12) and (substituted phenyl)-[2-(substituted phenyl)-imidazol-1-yl]-methanone (13-26) analogues and screened them for their antimicrobial activity against gram positive, gram negative and fungal species. The results of antibacterial study indicated that compounds 15, 17 and 24 showed appreciable antibacterial activity and compound 26 emerged as the most potential antifungal agent. The results of SAR studies indicated that the presence of electron withdrawing groups is necessary for the antimicrobial activity of the synthesized compounds. The results of the present study indicated that compounds 15, 17 and 24 might be of interest for the identification of new antimicrobial molecules as their antibacterial activity is equivalent to the standard drug norfloxacin. Further, the antiviral screening of (substituted phenyl)-[2-(substituted phenyl)-imidazol-1-yl]-methanones (13-26) against a panel of viral strains indicated that compounds 16 and 19 can be selected as lead compounds for the development of novel antiviral agents.

A series of substituted hydrazide derivatives have been synthesized and screened for their in vitro antimicrobial activities against five representative microorganisms. The results of antimicrobial study indicated that the presence of electron withdrawing groups on the benzoic acid moiety improved antimicrobial activity. Further, the presence of heterocyclic ring furan does not improve the antimicrobial activity of substituted hydrazides. To understand the relationship between physicochemical parameters and antimicrobial activity of substituted hydrazide derivatives, QSAR investigation was performed by the development of one-target and multi-target models. The multi-target model was found to be effective in describing the antimicrobial activity of substituted hydrazides in comparison to the one-target models. Further, it indicated the importance of the topological parameter, valence third order molecular connectivity index ((3)chi(v)) and the electronic parameter, energy of highest occupied molecular orbital (HOMO) in describing the antimicrobial activity of substituted hydrazides.

A series of 2-(substituted phenyl)-1H-benzimidazole (1-10) and [2-(substituted phenyl)-benzimidazol-1-yl]-pyridin-3-yl-methanone (11-19) derivatives were synthesized and tested in vitro for their antimicrobial activity. The results of QSAR investigation indicated the importance of molecular descriptors, dipole moment (mu), log of octanol water partition coefficient (logP) and second order molecular connectivity index ((2)chi) in describing the antimicrobial activity of the synthesized compounds.

The synthesis, characterization and antimicrobial evaluation of a new series of veratric acid derivatives are presented. Preliminary in vitro antimicrobial activity of the title compounds was assessed against a panel of microorganisms including Gram-positive and Gram-negative bacteria and fungi. Some of the veratric acid derivatives exhibited significant in vitro antimicrobial activity. QSAR investigation applied to find a correlation between different physicochemical parameters of the veratric acid derivatives and their antimicrobial activity indicated the importance of topological parameters in describing the antimicrobial activity.

A series of esters (I(a-k)), substituted derivatives (II(a-d)) and amides (III(a-q)) of cinnamic acid were synthesized and evaluated as antibacterial and antifungal agents. All the derivatives belonging to the series I, II and III showed antimicrobial activity comparable to the standard. Compounds I(f) and II(c) proved to be the most effective compounds. Quantitative structure-activity relationship (QSAR) investigation with multiple linear regression analysis was applied to find a correlation between different calculated physicochemical parameters of the compounds and biological activity. The quantitative models relating the structural features of cinnamic acid derivatives I(a-k), II(a-d) and III(a-q) and their antimicrobial activity showed that Gram negative Escherichia coli and Candida albicans (fungus) were the most sensitive microorganisms.