International Journal of Medicinal Chemistry The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Design and Synthesis of Novel Antileishmanial Compounds Wed, 21 Jan 2015 08:40:23 +0000 According to the WHO, infectious diseases, and in particular neglected tropical diseases in poor developing countries, still play a significant role in a vast number of deaths reported worldwide. Among them, leishmaniasis occurs as a complex and clinically diverse illness caused by protozoan Leishmania species which are transmitted through the bite of sandflies. They develop through a complex life cycle, from promastigotes in sandflies to amastigotes in humans. The severity of disease is determined by the type of infecting Leishmania species and also depends strongly on whether the parasite infection leads to a systemic involvement or not. Since the sensitivity towards diverse medicaments highly differs among the Leishmania species, it is advantageous to treat leishmaniasis with species-specific drugs. Towards this goal we report a synthetic methodology and characterization of novel small molecular agents active against both forms of L. major. This synthetic approach allows for rapid access to new active antileishmanial drug templates and their first derivatives in moderate to very good yields. Although the compounds reported here are bioactive, the detailed biological results are part of a more comprehensive study and will be reported separately by our collaborators. Melanie Loedige Copyright © 2015 Melanie Loedige. All rights reserved. Synthesis and Structural Activity Relationship Study of Antitubercular Carboxamides Tue, 30 Dec 2014 06:06:26 +0000 The unusual structure and chemical composition of the mycobacterial cell wall, the tedious duration of therapy, and resistance developed by the microorganism have made the recurrence of the disease multidrug resistance and extensive or extreme drug resistance. The prevalence of tuberculosis in synergy with HIV/AIDS epidemic augments the risk of developing the disease by 100-fold. The need to synthesize new drugs that will shorten the total duration of effective treatment and/or significantly reduce the dosage taken under DOTS supervision, improve on the treatment of multidrug-resistant tuberculosis which defies the treatment with isoniazid and rifampicin, and provide effective treatment for latent TB infections which is essential for eliminating tuberculosis prompted this review. In this review, we considered the synthesis and structure activity relationship study of carboxamide derivatives with antitubercular potential. D. I. Ugwu, B. E. Ezema, F. U. Eze, and D. I. Ugwuja Copyright © 2014 D. I. Ugwu et al. All rights reserved. Synthetic Antimicrobial Peptides Exhibit Two Different Binding Mechanisms to the Lipopolysaccharides Isolated from Pseudomonas aeruginosa and Klebsiella pneumoniae Sun, 28 Dec 2014 09:19:42 +0000 Circular dichroism and 1H NMR were used to investigate the interactions of a series of synthetic antimicrobial peptides (AMPs) with lipopolysaccharides (LPS) isolated from Pseudomonas aeruginosa and Klebsiella pneumoniae. Previous CD studies with AMPs containing only three Tic-Oic dipeptide units do not exhibit helical characteristics upon interacting with small unilamellar vesicles (SUVs) consisting of LPS. Increasing the number of Tic-Oic dipeptide units to six resulted in five analogues with CD spectra that exhibited helical characteristics on binding to LPS SUVs. Spectroscopic and in vitro inhibitory data suggest that there are two possible helical conformations resulting from two different AMP-LPS binding mechanisms. Mechanism one involves a helical binding conformation where the AMP binds LPS very strongly and is not efficiently transported across the LPS bilayer resulting in the loss of inhibitory activity. Mechanism two involves a helical binding conformation where the AMP binds LPS very loosely and is efficiently transported across the LPS bilayer resulting in an increase in inhibitory activity. Mechanism three involves a nonhelical binding conformation where the AMP binds LPS very loosely and is efficiently transported across the LPS bilayer resulting in an increase in inhibitory activity. Hanbo Chai, William E. Allen, and Rickey P. Hicks Copyright © 2014 Hanbo Chai et al. All rights reserved. Evaluation of 11 Scoring Functions Performance on Matrix Metalloproteinases Thu, 25 Dec 2014 07:24:34 +0000 Matrix metalloproteinases (MMPs) have distinctive roles in various physiological and pathological processes such as inflammatory diseases and cancer. This study explored the performance of eleven scoring functions (D-Score, G-Score, ChemScore, F-Score, PMF-Score, PoseScore, RankScore, DSX, and X-Score and scoring functions of AutoDock4.1 and AutoDockVina). Their performance was judged by calculation of their correlations to experimental binding affinities of 3D ligand-enzyme complexes of MMP family. Furthermore, they were evaluated for their ability in reranking virtual screening study results performed on a member of MMP family (MMP-12). Enrichment factor at different levels and receiver operating characteristics (ROC) curves were used to assess their performance. Finally, we have developed a PCA model from the best functions. Of the scoring functions evaluated, F-Score, DSX, and ChemScore were the best overall performers in prediction of MMPs-inhibitors binding affinities while ChemScore, Autodock, and DSX had the best discriminative power in virtual screening against the MMP-12 target. Consensus scorings did not show statistically significant superiority over the other scorings methods in correlation study while PCA model which consists of ChemScore, Autodock, and DSX improved overall enrichment. Outcome of this study could be useful for the setting up of a suitable scoring protocol, resulting in enrichment of MMPs inhibitors. Jamal Shamsara Copyright © 2014 Jamal Shamsara. All rights reserved. Molecular Modeling Studies of Thiophenyl C-Aryl Glucoside SGLT2 Inhibitors as Potential Antidiabetic Agents Wed, 10 Dec 2014 00:10:11 +0000 A QSAR study on thiophenyl derivatives as SGLT2 inhibitors as potential antidiabetic agents was performed with thirty-three compounds. Comparison of the obtained results indicated the superiority of the genetic algorithm over the simulated annealing and stepwise forward-backward variable method for feature selection. The best 2D QSAR model showed satisfactory statistical parameters for the data set (, , and pred_) with four descriptors describing the nature of substituent groups and the environment of the substitution site. Evaluation of the model implied that electron-rich substitution position improves the inhibitory activity. The good predictive 3D-QSAR models by k-nearest neighbor (kNN) method for molecular field analysis (MFA) have cross-validated coefficient value of 0.7663 and predicted value of 0.7386. The results have showed that thiophenyl groups are necessary for activity and halogen, bulky, and less bulky groups in thiophenyl nucleus enhanced the biological activity. These studies are promising for the development of novel SGLT2 inhibitor, which may have potent antidiabetic activity. Mukesh C. Sharma and Smita Sharma Copyright © 2014 Mukesh C. Sharma and Smita Sharma. All rights reserved. A Predictive HQSAR Model for a Series of Tricycle Core Containing MMP-12 Inhibitors with Dibenzofuran Ring Sun, 07 Dec 2014 08:08:04 +0000 MMP-12 is a member of matrix metalloproteinases (MMPs) family involved in pathogenesis of some inflammatory based diseases. Design of selective matrix MMPs inhibitors is still challenging because of binding pocket similarities among MMPs family. We tried to generate a HQSAR (hologram quantitative structure activity relationship) model for a series of MMP-12 inhibitors. Compounds in the series of inhibitors with reported biological activity against MMP-12 were used to construct a predictive HQSAR model for their inhibitory activity against MMP-12. The HQSAR model had statistically excellent properties and possessed good predictive ability for test set compounds. The HQSAR model was obtained for the 26 training set compounds showing cross-validated value of 0.697 and conventional value of 0.986. The model was then externally validated using a test set of 9 compounds and the predicted values were in good agreement with the experimental results (). Then, the external validity of the model was confirmed by Golbraikh-Tropsha and metrics. The color code analysis based on the obtained HQSAR model provided useful insights into the structural features of the training set for their bioactivity against MMP-12 and was useful for the design of some new not yet synthesized MMP-12 inhibitors. Jamal Shamsara and Ahmad Shahir-Sadr Copyright © 2014 Jamal Shamsara and Ahmad Shahir-Sadr. All rights reserved. Synthesis Antimicrobial and Anticancer Evaluation of 1-Aryl-5-(o-methoxyphenyl)-2-S-benzyl Isothiobiurets Thu, 20 Nov 2014 13:46:53 +0000 A series of S-benzyl aryl thiourea were condensed with o-Methoxy phenyl isocyanate to yield respective isothiobiuret derivatives. The newly synthesized compounds were characterized by 1H-NMR, IR, and Mass Spectral studies and tested for biological activities. Mohammed M. Ansari, Shirish P. Deshmukh, Rizwan Khan, and Mohammed Musaddiq Copyright © 2014 Mohammed M. Ansari et al. All rights reserved. Synthesis, Physicochemical Properties, and Antimicrobial Studies of Iron (III) Complexes of Ciprofloxacin, Cloxacillin, and Amoxicillin Wed, 19 Nov 2014 10:30:22 +0000 Iron (III) complexes of ciprofloxacin, amoxicillin, and cloxacillin were synthesized and their aqueous solubility profiles, relative stabilities, and antimicrobial properties were evaluated. The complexes showed improved aqueous solubility when compared to the corresponding ligands. Relative thermal and acid stabilities were determined spectrophotometrically and the results showed that the complexes have enhanced thermal and acid stabilities when compared to the pure ligands. Antimicrobial studies showed that the complexes have decreased activities against most of the tested microorganisms. Ciprofloxacin complex, however, showed almost the same activity as the corresponding ligand. Job’s method of continuous variation suggested 1 : 2 metals to ligand stoichiometry for ciprofloxacin complex but 1 : 1 for cloxacillin complex. Fabian I. Eze, Uzoechi Ajali, and Pius O. Ukoha Copyright © 2014 Fabian I. Eze et al. All rights reserved. Chemical Characteristics, Synthetic Methods, and Biological Potential of Quinazoline and Quinazolinone Derivatives Thu, 13 Nov 2014 00:00:00 +0000 The heterocyclic fused rings quinazoline and quinazolinone have drawn a huge consideration owing to their expanded applications in the field of pharmaceutical chemistry. Quinazoline and quinazolinone are reported for their diversified biological activities and compounds with different substitutions bring together to knowledge of a target with understanding of the molecule types that might interact with the target receptors. Quinazolines and quinazolinones are considered as an important chemical for the synthesis of various physiological significance and pharmacological utilized molecules. Quinazolines and quinazolinone are a large class of biologically active compounds that exhibited broad spectrum of biological activities such as anti-HIV, anticancer, antifungal, antibacterial, antimutagenic, anticoccidial, anticonvulsant, anti-inflammatory, antidepressant, antimalarial, antioxidant, antileukemic, and antileishmanial activities and other activities. Being considered as advantaged scaffold, the alteration is made with different substituent. Mohammad Asif Copyright © 2014 Mohammad Asif. All rights reserved. Mannich Bases: An Important Pharmacophore in Present Scenario Wed, 12 Nov 2014 08:44:10 +0000 Mannich bases are the end products of Mannich reaction and are known as beta-amino ketone carrying compounds. Mannich reaction is a carbon-carbon bond forming nucleophilic addition reaction and is a key step in synthesis of a wide variety of natural products, pharmaceuticals, and so forth. Mannich reaction is important for the construction of nitrogen containing compounds. There is a number of aminoalkyl chain bearing Mannich bases like fluoxetine, atropine, ethacrynic acid, trihexyphenidyl, and so forth with high curative value. The literature studies enlighten the fact that Mannich bases are very reactive and recognized to possess potent diverse activities like anti-inflammatory, anticancer, antifilarial, antibacterial, antifungal, anticonvulsant, anthelmintic, antitubercular, analgesic, anti-HIV, antimalarial, antipsychotic, antiviral activities and so forth. The biological activity of Mannich bases is mainly attributed to α, β-unsaturated ketone which can be generated by deamination of hydrogen atom of the amine group. Suman Bala, Neha Sharma, Anu Kajal, Sunil Kamboj, and Vipin Saini Copyright © 2014 Suman Bala et al. All rights reserved. Protective Effect of Selected Medicinal Plants against Hydrogen Peroxide Induced Oxidative Damage on Biological Substrates Wed, 12 Nov 2014 00:00:00 +0000 Oxidative stress is developed due to susceptibility of biological substrates to oxidation by generation of free radicals. In degenerative diseases, oxidative stress level can be reduced by antioxidants which neutralize free radicals. Primary objective of this work was to screen four medicinal plants, namely, Andrographis paniculata, Costus speciosus, Canthium parviflorum, and Abrus precatorius, for their antioxidant property using two biological substrates—RBC and microsomes. The antioxidative ability of three solvent extracts, methanol (100% and 80%) and aqueous leaf extracts, was studied at different concentrations by thiobarbituric acid reactive substances method using Fenton’s reagent to induce oxidation in the substrates. The polyphenol and flavonoid content were analyzed to relate with the observed antioxidant effect of the extracts. The phytochemical screening indicated the presence of flavonoids, polyphenols, tannins, and β-carotene in the samples. In microsomes, 80% methanol extract of Canthium and Costus and, in RBC, 80% methanol extract of Costus showed highest inhibition of oxidation and correlated well with the polyphenol and flavonoid content. From the results it can be concluded that antioxidants from medicinal plants are capable of inhibiting oxidation in biological systems, suggesting scope for their use as nutraceuticals. Namratha Pai Kotebagilu, Vanitha Reddy Palvai, and Asna Urooj Copyright © 2014 Namratha Pai Kotebagilu et al. All rights reserved. Development of Small Molecular Proteasome Inhibitors Using a Caenorhabditis elegans Screen Tue, 11 Nov 2014 08:25:29 +0000 We have developed a screening protocol to identify compounds with characteristics of small molecule proteasome inhibitors using the real-time analysis of the Caenorhabditis elegans germ line. This screen is able to identify compounds that induce germ line phenotypes characteristic of a reduction in proteasome function such as changes in polarity, aberrant nuclear morphology, and stimulation of apoptosis. This basic protocol is amenable to a high throughput (96-well) format and has been used successfully to identify multiple compounds for further analysis based on structural elements from the naturally occurring compounds lactacystin and the β-lactone homologs omuralide and salinosporamide A. The further development of this assay system should allow for the generation of novel small molecule proteasome inhibitors in a genetically tractable whole animal amenable to biochemical analysis. Sudhir Nayak, Michela Fiaschi, Dana King, Erica R. Tabakin, Lyndsay Wood, and David A. Hunt Copyright © 2014 Sudhir Nayak et al. All rights reserved. Nitro Derivatives of Naturally Occurring β-Asarone and Their Anticancer Activity Wed, 01 Oct 2014 00:00:00 +0000 β-Asarone (2, 4, 5-trimethoxy-(Z)-1-propenylbenzene) was obtained from Acorus calamus. Nitration of β-asarone with AgNO2/I2 in ether yielded 1-(2, 4, 5-trimethoxy phenyl)-2-nitropropene (1) but with NaNO2/I2 in ethylene glycol obtained 1-(2, 4, 5-trimethoxy phenyl)-1-nitropropene (2). Compound 2 was prepared for the first time and characterized using IR, 1H-NMR, 13C-NMR, and GC-MS spectra and it was converted into 1-(2, 4, 5-trimethoxy) phenyl-1-propanone (3) using modified Nef reaction. Based on 1D NOESY experiments, compounds 1 and 2 have been assigned E configuration. Compounds 1 and 2 were subjected to cytotoxic activity using five human cancer cell lines, namely, MCF-7, SW-982, HeLa, PC-3, and IMR-32 by MTT assay. Except in breast cancer line (MCF-7) compound 2 exhibited five- to tenfold increase in activity compared to β-asarone and twofold increase over compound 1. Suvarna Shenvi, Latha Diwakar, and G. Chandrasekara Reddy Copyright © 2014 Suvarna Shenvi et al. All rights reserved. Synthesis and Biological Evaluation of Aminonaphthols Incorporated Indole Derivatives Wed, 10 Sep 2014 00:00:00 +0000 An efficient one pot condensation of naphthols (1), 2,5-disubstituted indole-3-carboxaldehydes (2), and secondary amines (3) has been achieved using dichloromethane as a solvent, stirring at room temperature. Some of the new [(disubstituted amino)(5-substituted 2-phenyl-1H-indol-3-yl)methyl]naphthalene-ols (4) derivatives were prepared in good yields. The significant features of this method are simple work-up procedure, inexpensive nontoxic solvent, shorter reaction times, and excellent product yields. The structures of newly synthesized compounds (4a–r) are confirmed by their elemental analysis, FTIR, 1H and 13C NMR, and mass spectral data. These compounds were screened for their in vitro antioxidant, antimicrobial, antitubercular, and anticancer activities. Among the synthesized compounds (4a–r), the compound 4e exhibited highest activity for radical scavenging and ferric ions reducing antioxidant power activities; compounds 4b, 4h, and 4k showed good metal chelating activity. Compounds 4n and 4q showed excellent antimicrobial activities with MIC value 08 µg/mL against tested strains. Compounds 4h, 4k, 4n, and 4q exhibited promising antitubercular activity with MIC value 12.5 µg/mL. Compounds 4k and 4q exhibited 100% cell lysis at concentration 10 µg/mL against MDA-MB-231 (human adenocarcinoma mammary gland) cell lines. Saundane Anand Raghunath and Kirankumar Nandibeoor Mathada Copyright © 2014 Saundane Anand Raghunath and Kirankumar Nandibeoor Mathada. All rights reserved. Docking Studies and Biological Activity of Fosinopril Analogs Sun, 06 Jul 2014 06:48:37 +0000 The purpose of the present study was to determine the angiotensin-I converting enzyme inhibitory activity of few novel Fosinopril derivatives which were predicted to possess better ACE inhibitory activity and lesser side effects than the existing drug molecule. In vitro study was carried out to determine ACE inhibitory activity of six different Fosinopril analogs by spectrophotometric assay procedure. Analog A2 showed the highest activity compared to other analogs and as well as Fosinopril itself. Docking studies of the compounds were done with the help of VLife MDS 3.0 software using GRIP batch docking method to find out which derivative had a better docking with ACE. The compounds which showed the highest negative score in docking have also exhibited good ACE inhibitory activity. Jayant Choudary, Suvarna G. Kini, Sreedhara Ranganath Pai Karkala, and Muhammad Mubeen Copyright © 2014 Jayant Choudary et al. All rights reserved. Target Based Designing of Anthracenone Derivatives as Tubulin Polymerization Inhibiting Agents: 3D QSAR and Docking Approach Thu, 17 Apr 2014 10:54:08 +0000 Novel anthracenone derivatives were designed through in silico studies including 3D QSAR, pharmacophore mapping, and molecular docking approaches. Tubulin protein was explored for the residues imperative for activity by analyzing the binding pattern of colchicine and selected compounds of anthracenone derivatives in the active domain. The docking methodology applied in the study was first validated by comparative evaluation of the predicted and experimental inhibitory activity. Furthermore, the essential features responsible for the activity were established by carrying out pharmacophore mapping studies. 3D QSAR studies were carried out for a series of 1,5- and 1,8-disubstituted10-benzylidene-10H-anthracen-9-ones and 10-(2-oxo-2-phenylethylidene)-10H-anthracen-9-one derivatives for their antiproliferation activity. Based on the pattern recognition studies obtained from QSAR results, ten novel compounds were designed and docked in the active domain of tubulin protein. One of the novel designed compounds “N1” exhibited binding energy −9.69 kcal/mol and predicted Ki 78.32 nM which was found to be better than colchicine. Abdul Samad, Moawiah M. Naffaa, Mohammed Afroz Bakht, Manav Malhotra, and Majid A. Ganaie Copyright © 2014 Abdul Samad et al. All rights reserved. Significance and Biological Importance of Pyrimidine in the Microbial World Sun, 23 Mar 2014 12:34:34 +0000 Microbes are unique creatures that adapt to varying lifestyles and environment resistance in extreme or adverse conditions. The genetic architecture of microbe may bear a significant signature not only in the sequences position, but also in the lifestyle to which it is adapted. It becomes a challenge for the society to find new chemical entities which can treat microbial infections. The present review aims to focus on account of important chemical moiety, that is, pyrimidine and its various derivatives as antimicrobial agents. In the current studies we represent more than 200 pyrimidines as antimicrobial agents with different mono-, di-, tri-, and tetrasubstituted classes along with in vitro antimicrobial activities of pyrimidines derivatives which can facilitate the development of more potent and effective antimicrobial agents. Vinita Sharma, Nitin Chitranshi, and Ajay Kumar Agarwal Copyright © 2014 Vinita Sharma et al. All rights reserved. A Novel Inhibitor of Mammalian Triosephosphate Isomerase Found by an In Silico Approach Sun, 23 Mar 2014 09:34:20 +0000 Triosephosphate isomerase (TIM) is an essential, highly conserved component of glycolysis. Tumors are often dependent on glycolysis for energy and metabolite production (the Warburg effect). Glycolysis inhibitors thus show promise as cancer treatments. TIM inhibition, unlike inhibition of other glycolysis enzymes, also produces toxic methylglyoxal targeted to regions of high glycolysis, an effect that might also be therapeutically useful. Thus TIM is an attractive drug target. A total of 338,562 lead-like molecules were analyzed computationally to find TIM inhibitors by an efficient “double screen” approach. The first fragment-sized compounds were studied using structure-based virtual screening to identify binding motifs for mammalian TIM. Subsequently, larger compounds, filtered to meet the binding criteria developed in the first analysis, were ranked using a second round of structure-based virtual screening. A compound was found that inhibited mammalian TIM in vitro in the micromolar range. Docking and molecular dynamics (MD) suggested that the inhibitor made hydrogen bond contacts with TIM catalytic residues. In addition, hydrophobic contacts were made throughout the binding site. All predicted inhibitor-TIM interactions involved TIM residues that were highly conserved. The discovered compound may provide a scaffold for elaboration of other inhibitors. Lorraine Marsh and Kaushal Shah Copyright © 2014 Lorraine Marsh and Kaushal Shah. All rights reserved. Experimental Design-Based Response Surface Methodology Optimization for Synthesis of β-Mercapto Carbonyl Derivatives as Antimycobacterial Drugs Catalyzed by Calcium Pyrophosphate Thu, 06 Mar 2014 11:09:10 +0000 A simple protocol for the efficient preparation of β-mercapto carbonyl derivatives as antimycobacterial drugs has been achieved via Thia-Michael reaction between chalcones derivatives and thiols in the presence of calcium pyrophosphate as a heterogeneous catalyst under mild reaction conditions. The central composite design was used to design an experimental program to provide data to model the effects of various factors on reaction yield . The variables chosen were catalyst weight , reaction time , and solvent volume . The mathematical relationship of reaction yield on the three significant independent variables can be approximated by a nonlinear polynomial model. Predicted values were found to be in good agreement with experimental values. The optimum reaction conditions for reaction model (chalcone and thiophenol) obtained by response surface were applied to other substrates. This procedure provides several advantages such as high yield, clean product formation, and short reaction time. Younes Abrouki, Abdelkader Anouzla, Hayat Loukili, Jamal Bennazha, Rabiaâ Lotfi, Ahmed Rayadh, My Abdellah Bahlaoui, Saïd Sebti, Driss Zakarya, and Mohamed Zahouily Copyright © 2014 Younes Abrouki et al. All rights reserved. Therapeutic Potential of Hydrazones as Anti-Inflammatory Agents Tue, 04 Mar 2014 09:06:24 +0000 Hydrazones are a special class of organic compounds in the Schiff base family. Hydrazones constitute a versatile compound of organic class having basic structure (R1R2C=NNR3R4). The active centers of hydrazone, that is, carbon and nitrogen, are mainly responsible for the physical and chemical properties of the hydrazones and, due to the reactivity toward electrophiles and nucleophiles, hydrazones are used for the synthesis of organic compound such as heterocyclic compounds with a variety of biological activities. Hydrazones and their derivatives are known to exhibit a wide range of interesting biological activities like antioxidant, anti-inflammatory, anticonvulsant, analgesic, antimicrobial, anticancer, antiprotozoal, antioxidant, antiparasitic, antiplatelet, cardioprotective, anthelmintic, antidiabetic, antitubercular, trypanocidal, anti-HIV, and so forth. The present review summarizes the efficiency of hydrazones as potent anti-inflammatory agents. Anu Kajal, Suman Bala, Neha Sharma, Sunil Kamboj, and Vipin Saini Copyright © 2014 Anu Kajal et al. All rights reserved. Clicked Cinnamic/Caffeic Esters and Amides as Radical Scavengers and 5-Lipoxygenase Inhibitors Tue, 18 Feb 2014 10:29:38 +0000 5-Lipoxygenase (5-LO) is the key enzyme responsible for the conversion of arachidonic acid to leukotrienes, a class of lipid mediators implicated in inflammatory disorders. In this paper, we describe the design, synthesis, and preliminary activity studies of novel clicked caffeic esters and amides as radical scavengers and 5-LO inhibitors. From known 5-LO inhibitor 3 as a lead, cinnamic esters 8a–h and amides 9a–h as well as caffeic esters 15a–h and amides 16a–h were synthesized by Cu(I)-catalyzed [1,3]-dipolar cycloaddition with the appropriate azide precursors and terminal alkynes. All caffeic analogs are proved to be good radical scavengers (IC50: 10–20 μM). Esters 15g and 15f possessed excellent 5-LO inhibition activity in HEK293 cells and were equipotent with the known 5-LO inhibitor CAPE and more potent than Zileuton. Several synthesized esters possess activities rivaling Zileuton in stimulated human polymorphonuclear leukocytes. Jérémie A. Doiron, Benoît Métayer, Ryan R. Richard, Dany Desjardins, Luc H. Boudreau, Natalie A. Levesque, Jacques Jean-François, Samuel J. Poirier, Marc E. Surette, and Mohamed Touaibia Copyright © 2014 Jérémie A. Doiron et al. All rights reserved. Abrus precatorius Leaves: Antioxidant Activity in Food and Biological Systems, pH, and Temperature Stability Thu, 30 Jan 2014 00:00:00 +0000 Natural antioxidants present in foods and other biological materials have attracted considerable interest because of their presumed safety and potential nutritional and therapeutic effects. Antioxidant constituents of plant materials act as radical scavengers and convert the radicals to less reactive species. Abrus precatorius (AP) was analyzed for its proximate and phytochemical composition. The leaves were extracted with methanol (ME) and analyzed for antioxidant activity by radical scavenging method, reducing power, ferric reducing capacity, and in vitro inhibition of Fenton’s reagent-induced oxidation in oil emulsion and microsomes. In addition, the effect of temperature (, 15, and 30 min) and pH (4.5, 7, and 9) C on the antioxidant activity of ME was investigated. The leaves were rich in total polyphenols, flavonoids, β-carotene, glutathione, α-tocopherol, and ascorbic acid. The ME exhibited varying degree of antioxidant activity in a dose-dependent manner. The AP exhibited more inhibition of oxidation in microsomes (73%) than compared to oil emulsion (21%). Heat treatment resulted in an increase of radical scavenging activity of extract (28% to 43%). At pH 4.5 the extract exhibited more antioxidant activity and stability compared to pH 7 and 9. Data indicates that potential exists for the utilization of Abrus precatorius as a natural antioxidant. Vanitha Reddy Palvai, Sowmya Mahalingu, and Asna Urooj Copyright © 2014 Vanitha Reddy Palvai et al. All rights reserved. Estimation of Anti-HIV Activity of HEPT Analogues Using MLR, ANN, and SVM Techniques Mon, 30 Dec 2013 08:57:17 +0000 The present study deals with the estimation of the anti-HIV activity of a large set of 107 HEPT analogues using molecular descriptors which are responsible for the anti-HIV activity. The study has been undertaken by three techniques MLR, ANN, and SVM. The MLR model fits the train set with while in ANN and SVM with higher values of , respectively. SVM model shows improvement to estimate the anti-HIV activity of trained data, while in test set ANN have higher value than those of MLR and SVM techniques. metrics and ridge regression analysis indicated that the proposed four-variable model MATS5e, RDF080u, T(O⋯O), and MATS5m as correlating descriptors is the best for estimating the anti-HIV activity (log 1/C) present set of compounds. Basheerulla Shaik, Tabassum Zafar, and Vijay K. Agrawal Copyright © 2013 Basheerulla Shaik et al. All rights reserved. Synthesis of N-(6-(4-(Piperazin-1-yl)phenoxy)pyridin-3-yl)benzenesulfonamide Derivatives for the Treatment of Metabolic Syndrome Mon, 23 Dec 2013 10:40:04 +0000 Metabolic syndrome is a widely prevalent multifactorial disorder associated with an increased risk of cardiovascular disease and type 2 diabetes mellitus. High plasma levels of insulin and glucose due to insulin resistance are a major component of the metabolic disorder. Thiazolidinediones (TZDs) are potent PPARγ ligand and used as insulin sensitizers in the treatment of type 2 diabetes mellitus. They are potent insulin-sensitizing agents but due to adverse effects like hepatotoxicity, a safer alternative of TZDs is highly demanded. Here we report synthesis of N-(6-(4-(piperazin-1-yl)phenoxy)pyridin-3-yl)benzenesulfonamide derivatives as an alternate remedy for insulin resistance. Nabajyoti Deka, Swapnil Bajare, Jessy Anthony, Amrutha Nair, Anagha Damre, Dharmeshkumar Patel, Chandrika B-Rao, H. Sivaramakrishnan, Shivaprakash Jagalur Mutt, Chandan Wilankar, and Rosalind Marita Copyright © 2013 Nabajyoti Deka et al. All rights reserved. HLA-Modeler: Automated Homology Modeling of Human Leukocyte Antigens Wed, 27 Nov 2013 10:35:30 +0000 The three-dimensional (3D) structures of human leukocyte antigen (HLA) molecules are indispensable for the studies on the functions at molecular level. We have developed a homology modeling system named HLA-modeler specialized in the HLA molecules. Segment matching algorithm is employed for modeling and the optimization of the model is carried out by use of the PFROSST force field considering the implicit solvent model. In order to efficiently construct the homology models, HLA-modeler uses a local database of the 3D structures of HLA molecules. The structure of the antigenic peptide-binding site is important for the function and the 3D structure is highly conserved between various alleles. HLA-modeler optimizes the use of this structural motif. The leave-one-out cross-validation using the crystal structures of class I and class II HLA molecules has demonstrated that the rmsds of nonhydrogen atoms of the sites between homology models and crystal structures are less than 1.0 Å in most cases. The results have indicated that the 3D structures of the antigenic peptide-binding sites can be reproduced by HLA-modeler at the level almost corresponding to the crystal structures. Shinji Amari, Ryoichi Kataoka, Takashi Ikegami, and Noriaki Hirayama Copyright © 2013 Shinji Amari et al. All rights reserved. Synthesis and Evaluation of Some Novel Chromone Based Dithiazoles as Antimicrobial Agents Wed, 27 Nov 2013 10:29:32 +0000 Novel substituted 1,2,4-dithiazolylchromones 3a–j were synthesized by the reaction of 3-formylchromones (1a–j) with two equivalents of p-chlorothiobenzamide (2) in dry xylene and characterized spectroscopically (IR, 1H and 13C NMR, mass) and elemental analysis. All synthesized compounds were screened for in vitro antimicrobial activity against various pathogenic bacterial and fungal strains and were found to possess good to moderate inhibitory potential against all tested strains. Antimicrobial results reveal that compounds bearing lipophilic electron withdrawing groups such as chloro and bromo displayed significant inhibitory potential against both bacterial and fungal strains. Particularly, compound 3c displayed significant inhibitory against bacterial strains and compound 3h exhibits significant inhibitory potential in comparison to standard drug fluconazole against fungal strain S. cerevisiae. Naureen Aggarwal, Vishal Sharma, Harpreet Kaur, and Mohan Paul Singh Ishar Copyright © 2013 Naureen Aggarwal et al. All rights reserved. Synthesis Characterization and Antibacterial, Antifungal Activity of N-(Benzyl Carbamoyl or Carbamothioyl)-2-hydroxy Substituted Benzamide and 2-Benzyl Amino-Substituted Benzoxazines Thu, 31 Oct 2013 13:28:05 +0000 New N-(benzyl carbamothioyl)-2-hydroxy substituted benzamides 13, 20, and 21 were synthesized using sodium bicarbonate and benzyl amine with 2-thioxo-substituted-1,3-benzoxazines 6, 10a, b, 11c, and 12a–n. The 2-thioxo-substituted-1,3-oxazines 6, 10a-b, 11d 12a–n, and 26 were converted to the corresponding 2-methylthio-substituted-1,3-oxazines 14a–l and 24 which were then converted to 2-benzyl amino-substituted-benzoxazines 15a–i by refluxing with benzylamine. Products 15a, b, e, f, and g were also synthesized by boiling the corresponding N-(benzyl carbamothioyl)-2-hydroxy substituted benzamides 13a, b, f, l, and m in acetic acid. 2-Oxo-substituted-1,3-benzoxazines 22 and 25 were prepared by treating the corresponding 2-methylthio-substituted-1,3-oxazines 14 and 24 with dilute HCl. The N-(benzyl carbamoyl)-2-hydroxy substituted benzamide 23 was synthesized from the reaction of 2-oxo-substituted-1,3-benzoxazine 22 with benzylamine. The new products were characterized using IR, 1H, and 13C NMR in addition to microanalysis. Selected compounds were tested in vitro for antibacterial and antifungi activity and the most active compounds were found to be the 4-(substituted-benzylamino)-2-hydroxy benzoic acids 9a and d (M. chlorophenolicum, MIC 50 and 25 µgm L−1, resp.), N1, N3-bis (benzyl carbamothioyl)-4,6-dihydroxy-substituted phthalamides 20a and 20c (B. subtilis MIC 12.5, 50 µgm L−1, resp.) and 21 (M. chlorophenolicum, MIC 50 µgm L−1). Tyson Belz, Saleh Ihmaid, Jasim Al-Rawi, and Steve Petrovski Copyright © 2013 Tyson Belz et al. All rights reserved. Novel Antimicrobial Agents: Fluorinated 2-(3-(Benzofuran-2-yl) pyrazol-1-yl)thiazoles Wed, 11 Sep 2013 11:06:21 +0000 A new series of 2-pyrazolin-1-ylthiazoles 8a–d and 13–16 was synthesized by cyclization of N-thiocarboxamide-2-pyrazoline with different haloketones and 2,3-dichloroquinoxaline. The structures of the new compounds were confirmed by elemental analyses as well as NMR, IR, and mass spectral data. The newly synthesized compounds were evaluated for their antimicrobial activities, and also their minimum inhibitory concentration (MIC) against most of test organisms was performed. Amongst the tested ones, compound 8c displayed excellent antimicrobial activity. Hanan A. Mohamed, Ehab Abdel-Latif, Bakr F. Abdel-Wahab, and Ghada E. A. Awad Copyright © 2013 Hanan A. Mohamed et al. All rights reserved. Computational Study of Estrogen Receptor-Alpha Antagonist with Three-Dimensional Quantitative Structure-Activity Relationship, Support Vector Regression, and Linear Regression Methods Tue, 14 May 2013 15:46:06 +0000 Human estrogen receptor (ER) isoforms, ERα and ERβ, have long been an important focus in the field of biology. To better understand the structural features associated with the binding of ERα ligands to ERα and modulate their function, several QSAR models, including CoMFA, CoMSIA, SVR, and LR methods, have been employed to predict the inhibitory activity of 68 raloxifene derivatives. In the SVR and LR modeling, 11 descriptors were selected through feature ranking and sequential feature addition/deletion to generate equations to predict the inhibitory activity toward ERα. Among four descriptors that constantly appear in various generated equations, two agree with CoMFA and CoMSIA steric fields and another two can be correlated to a calculated electrostatic potential of ERα. Ying-Hsin Chang, Jun-Yan Chen, Chiou-Yi Hor, Yu-Chung Chuang, Chang-Biau Yang, and Chia-Ning Yang Copyright © 2013 Ying-Hsin Chang et al. All rights reserved. Recent Pharmacological Developments on Rhodanines and 2,4-Thiazolidinediones Thu, 02 May 2013 09:07:53 +0000 Thiazolidines are five-member heterocyclic having sulfur, nitrogen, and oxygen atoms in their ring structure and exhibiting potent as well as wide range of pharmacological activities. In this minireview, recent updates on synthesis and pharmacological evaluations of molecules based on 2,4-thiazolidine and rhodanine are discussed. Ravinder Singh Bhatti, Sakshi Shah, Suresh, Pawan Krishan, and Jagir S. Sandhu Copyright © 2013 Ravinder Singh Bhatti et al. All rights reserved.