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Alar, a Pyridoxal 5′-phosphate (PLP)-dependent bacterial enzyme is responsible for the racemisation of L-alanine into D-alanine which is essential for the peptidoglycan biosynthesis in both...

Topoisomerase IV E (ParE) of Streptococcus pneumonia, a subunit of topoisomerase IV, ensures the regulation of DNA topology and demonstrated to be a bactericidal drug target. Availability of crystal structure of S. pneumonia ParE in complex with one of the thiazolo[5,4-b]pyridinones facilitated us to employ combined computational approach to explore the putative binding mode of selected inhibitors into the catalytic pocket of ParE. We developed a five-point pharmacophore model using 67 molecules having pIC50 ranging from 4.795 to 8.522. The generated model was validated using enrichment calculations. The three-dimensional quantitative structure–activity relationship (3D-QSAR) model showed a high correlation coefficient (R 2 = 0.892), cross-validation coefficient (Q 2 = 0.744), and F value (119) at three component partial least squares (PLS) factor. Using the crystallographic bound compound, the effectiveness of the flexible docking protocol was validated as evident from the low root mean square deviation (0.96 A). A 10-ns molecular dynamic simulation confirmed the stability of the 4MOT-ligand complex. Further, superposition of conformation of compound 45 after MD simulation and compound 45’s poses of XP-docking and 3D-QSAR model showed similar orientation. The molecular information obtained from docking and 3D-QSAR analysis was employed to propose new inhibitors. These findings provide insight for the design of molecules with better ParE inhibitory activity.

In an effort to face the multiple drug-resistant bacteria, various approaches have been discovered to design potent compounds and search new targets through computational design tools. With an aim to identify selective inhibitors against filamentous temperature-sensitive mutant Z (FtsZ), a library of Phase database compounds have been virtually screened. High-throughput virtual screening of compounds against Staphylococcal epidermidis FtsZ protein (4M8I) was performed using three sequential docking modes like high-throughput virtual screening, Glide standard precision, followed by Glide extra precision. Four top-ranked compounds were selected from molecular mechanics-generalized Born surface area (MM-GBSA) binding energy with better predicted free binding energies of - 89.309, - 54.382, - 53.667, and - 52.133 kcal/mol, respectively. It is also showed that the contribution of van der Waals and electrostatic solvation energy terms are playing a major part to make the hit molecule (T6288784) binding to S. epidermidis FtsZ protein. The result of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and energy gap analysis predicts the molecular reactivity and stability of hit molecules. Subsequently, Lipinski's rule of five and properties of absorption, distribution, metabolism, and excretion (ADME) were to calculate their bioavailability. The average binding energy - 9.67 kcal/mol of the best proposed hit molecule (T6288784) was found with half-maximal inhibitory concentration (IC50) value to be 75.53 nM. A 15-ns molecular dynamics simulation study revealed the stable conformation of hit molecule. On a wide-range research discipline, in silico studies of our proposed compound confirm promising results and can be successfully used towards the development of novel FtsZ inhibitor with better binding affinity. Graphical Abstract.

Infections due to resistant bacteria are the life-threatening and leading cause of mortality worldwide. The current therapy for bacterial infections includes treatment with various drugs and antibiotics. The misuse and over usage of these antibiotics leads to bacterial resistance. There are several mechanisms by which bacteria exhibit resistance to some antibiotics. These include drug inactivation or modification, elimination of antibiotics through efflux pumps, drug target alteration, and modification of metabolic pathway. However, it is difficult to treat infections caused by resistant bacteria by conventional existing therapy. In the present study binding affinities of some glitazones against ParE and MurE bacterial enzymes are investigated by in silico methods. As evident by extra-precision docking and binding free energy calculation (MM-GBSA) results, rivoglitazone exhibited higher binding affinity against both ParE and MurE enzymes compared to all other selected compounds. Further molecular dynamic (MD) simulations were performed to validate the stability of rivoglitazone/4MOT and rivoglitazone/4C13 complexes and to get insight into the binding mode of inhibitor. Thus, we hypothesize that structural modifications of the rivoglitazone scaffold can be useful for the development of an effective antibacterial agent.

Staphylococcus aureus MurE enzyme catalyzes the addition of l-lysine as third residue of the peptidoglycan peptide moiety. Due to the high substrate specificity and its ubiquitous nature among bacteria, MurE enzyme is considered as one of the potential target for the development of new therapeutic agents. In the present work, induced fit docking (IFD), binding free energy calculation, and molecular dynamics (MD) simulation were carried out to elucidate the inhibition potential of 2-thioxothiazolidin-4-one based inhibitor 1 against S. aureus MurE enzyme. The inhibitor 1 formed majority of hydrogen bonds with the central domain residues Asn151, Thr152, Ser180, Arg187, and Lys219. Binding free-energy calculation by MM-GBSA approach showed that van der Waals (ΔGvdW, −57.30 kcal/mol) and electrostatic solvation (ΔGsolv, −36.86 kcal/mol) energy terms are major contributors for the inhibitor binding. Further, 30-ns MD simulation was performed to validate the stability of ligand–protein complex and also to get structural insight into mode of binding. Based on the IFD and MD simulation results, we designed four new compounds D1–D4 with promising binding affinity for the S. aureus MurE enzyme. The designed compounds were subjected to the extra-precision docking and binding free energy was calculated for complexes. Further, a 30-ns MD simulation was performed for D1/4C13 complex.

Phosphodiesterases 4 enzyme is an attractive target for the design of anti-inflammatory and bronchodilator agents. In the present study, pharmacophore and atom-based 3D-QSAR studies were carried out for pyrazolopyridine and quinoline derivatives using Schrödinger suite 2014-3. A four-point pharmacophore model was developed using 74 molecules having pIC50 ranging from 10.1 to 4.5. The best four feature model consists of one hydrogen bond acceptor, two aromatic rings, and one hydrophobic group. The pharmacophore hypothesis yielded a statistically significant 3D-QSAR model, with a high correlation coefficient (R2 = .9949), cross validation coefficient (Q2 = .7291), and Pearson-r (.9107) at six component partial least square factor. The external validation indicated that our QSAR model possessed high predictive power with R2 value of .88. The generated model was further validated by enrichment studies using the decoy test. Molecular docking, free energy calculation, and molecular dynamics (MD) simulation studies have been performed to explore the putative binding modes of these ligands. A 10-ns MD simulation confirmed the docking results of both stability of the 1XMU–ligand complex and the presumed active conformation. Outcomes of the present study provide insight in designing novel molecules with better PDE4 inhibitory activity.

ATP dependent ParE enzyme is as an attractive target for the development of antibacterial agents. Atom based 3D-QSAR model AADHR.187 was developed based on the thirty eight Escherichia coli ParE inhibitors. The generated model showed statistically significant coefficient of determinations for the training (R2 = 0.985) and test (R2 = 0.86) sets. The cross-validated correlation coefficient (q2) was 0.976. The utility of the generated model was validated by the enrichment study. The model was also validated with structurally diverse external test set of ten compounds. Contour plot analysis of the generated model unveiled the chemical features necessary for the E. coli ParE enzyme inhibition. Extra-precision docking result revealed that hydrogen bonding and ionic interactions play a major role in ParE protein-ligand binding. Binding free energy was computed for the data set inhibitors to validate the binding affinity. A 30-ns molecular dynamics simulation showed high stability and effective binding of inhibitor 34 within the active site of ParE enzyme. Using the best fitted model AADHR.187, pharmacophore-based high-throughput virtual screening was performed to identify virtual hits. Based on the above studies three new molecules are proposed as E. coli ParE inhibitors with high binding affinity and favourable ADME properties.

GyrB and ParE are type IIA topoisomerases and found in most bacteria. Its function is vital for DNA replication, repair and decatenation. The highly conserved ATP-binding subunits of DNA GyrB and ParE are structurally related and have been recognized as prime candidates for the development of dual-targeting antibacterial agents with broad-spectrum potential. However, no natural product or small molecule inhibitors targeting ATPase catalytic domain of both GyrB and ParE enzymes have succeeded in the clinic. Moreover, no inhibitors of these enzymes with broad-spectrum antibacterial activity against Gram-negative pathogens have been reported. Availability of high resolution crystal structures of GyrB and ParE made it possible for the design of many different classes of inhibitors with dual mechanism of action. Among them benzimidazoles, benzothiazoles, thiazolopyridines, imidiazopyridazoles, pyridines, indazoles, pyrazoles, imidazopyridines, triazolopyridines, pyrrolopyrimidines, pyrimidoindoles as well as related structures are disclosed in literatures. Unfortunately most of these inhibitors are found to be active against Gram-positive pathogens. In the present review we discuss about studies on novel dual targeting ATPase inhibitors.

Alanine racemase is a fold type III PLP-dependent amino acid racemase enzyme catalysing the conversion of l-alanine to d-alanine utilised by bacterial cell wall for peptidoglycan synthesis. As there are no known homologs in humans, it is considered as an excellent antibacterial drug target. The standard inhibitors of this enzyme include O-carbamyl-d-serine, d-cycloserine, chlorovinyl glycine, alaphosphin, etc. d-Cycloserine is indicated for pulmonary and extra pulmonary tuberculosis but therapeutic use of drug is limited due to its severe toxic effects. Toxic effects due to off-target affinities of cycloserine and other substrate analogs have prompted new research efforts to identify alanine racemase inhibitors that are not substrate analogs. In this review, an updated status of known inhibitors of alanine racemase enzyme has been provided which will serve as a rich source of structural information and will be helpful in generating selective and potent inhibitor of alanine racemase.

Pro-inflammatory cytokines regulate the magnitude of allergic reactions during asthma. Tumor necrosis factor--alpha (TNF-α), interleukin-6 (IL-6) and interleukin-13 (IL-13) play a crucial role in aggravating the inflammatory conditions during allergic asthma. In addition, oxidative stress contributes to the pathogenesis of asthma by altering the physiological condition resulting in the development of status asthmaticus. Anti-inflammatory corticosteroids are being widely used for treating allergic asthma. In the present study 5-aminosalicylic acid (5-ASA), a salicylic acid derivative, was evaluated, in vivo for its potential to suppress TNF-α, IL-6 and IL-13 using ovalbumin (OVA) induced allergic asthma in Balb/C mice. Oral administration of 65, 130 and 195 mg/kg 5-ASA significantly reduced the OVA induced total and differential leucocyte count, TNF-α, IL-6, IL-13, nitrite, nitrate, MDA, MPO and TPL levels in the lung lavage samples. Collectively, these findings suggest that 5-ASA is a potent immunomodulator and suppresses key Th2 cytokines production and oxidative stress in OVA-induced asthma.

FtsZ is an appealing target for the design of antimicrobial agent that can be used to defeat the multidrug-resistant bacterial pathogens. Pharmacophore modelling, molecular docking and molecular dynamics (MD) simulation studies were performed on a series of three-substituted benzamide derivatives. In the present study a five-featured pharmacophore model with one hydrogen bond acceptors, one hydrogen bond donors, one hydrophobic and two aromatic rings was developed using 97 molecules having MIC values ranging from .07 to 957 μM. A statistically significant 3D-QSAR model was obtained using this pharmacophore hypothesis with a good correlation coefficient (R2 = .8319), cross validated coefficient (Q2 = .6213) and a high Fisher ratio (F = 103.9) with three component PLS factor. A good correlation between experimental and predicted activity of the training (R2 = .83) and test set (R2 = .67) molecules were displayed by ADHRR.1682 model. The generated model was further validated by enrichment studies using the decoy test and MAE-based criteria to measure the efficiency of the model. The docking studies of all selected inhibitors in the active site of FtsZ protein showed crucial hydrogen bond interactions with Val 207, Asn 263, Leu 209, Gly 205 and Asn-299 residues. The binding free energies of these inhibitors were calculated by the molecular mechanics/generalized born surface area VSGB 2.0 method. Finally, a 15 ns MD simulation was done to confirm the stability of the 4DXD–ligand complex. On a wider scope, the prospect of present work provides insight in designing molecules with better selective FtsZ inhibitory potential.

DNA gyrase subunit B (GyrB) is an attractive drug target for the development of antibacterial agents with therapeutic potential. In the present study, computational studies based on pharmacophore modelling, atom-based QSAR, molecular docking, free binding energy calculation and dynamics simulation were performed on a series of pyridine-3-carboxamide-6-yl-urea derivatives. A pharmacophore model using 49 molecules revealed structural and chemical features necessary for these molecules to inhibit GyrB. The best fitted model AADDR.13 was generated with a coefficient of determination (r²) of 0.918. This model was validated using test set molecules and had a good r² of 0.78. 3D contour maps generated by the 3D atom-based QSAR revealed the key structural features responsible for the GyrB inhibitory activity. Extra precision molecular docking showed hydrogen bond interactions with key amino acid residues of ATP-binding pocket, important for inhibitor binding. Further, binding free energy was calculated by the MM-GBSA rescoring approach to validate the binding affinity. A 10 ns MD simulation of inhibitor #47 showed the stability of the predicted binding conformations. We identified 10 virtual hits by in silico high-throughput screening. A few new molecules were also designed as potent GyrB inhibitors. The information obtained from these methodologies may be helpful to design novel inhibitors of GyrB.

The discovery of clinically relevant inhibitors against MurF enzyme has proven to be a challenging task. In order to get further insight into the structural features required for the MurF inhibitory activity, we performed pharmacophore and atom-based three-dimensional quantitative structure–activity relationship studies for novel thiophene-3-carbonitriles based MurF inhibitors. The five-feature pharmacophore model was generated using 48 inhibitors having IC50 values ranging from 0.18 to 663 μm. The best-fitted model showed a higher coefficient of determination (R2 = 0.978), cross-validation coefficient (Q2 = 0.8835) and Pearson coefficient (0.9406) at four component partial least-squares factor. The model was validated with external data set and enrichment study. The effectiveness of the docking protocol was validated by docking the co-crystallized ligand into the catalytic pocket of MurF enzyme. Further, binding free energy calculated by the molecular mechanics generalized Born surface area approach showed that van der Waals and non-polar solvation energy terms are the main contributors to ligand binding in the active site of MurF enzyme. A 10-ns molecular dynamic simulation was performed to confirm the stability of the 3ZM6-ligand complex. Four new molecules are also designed as potent MurF inhibitors. These results provide insights regarding the development of novel MurF inhibitors with better binding affinity.

The present study deals with the optimization of some novel heterocyclic compounds containing two biological scaffolds such as long alkyl/alkenyl side chain of fatty acids and five-membered azoles named as 1,3,4-oxadiazole, 1,2,4-triazole and 1,3,4-thiadiazoles as antidepressant agents. In-silico docking studies have been carried out for the tested compounds into the crystal structure of human mono amine oxidase-B using GLIDE integrated Maestro (9.3) version. Five analogues exhibited higher XP G-Scores than selegeline. Also, it was verified by in vivo antidepressant screening, where two of the compounds PA-2 and GLA-2 showed significant antidepressant activity. Drug likelinesss and comparative bioactive analysis for the analogues are done using Qik.Prop 3.4.

Phosphodiesterase 4B (PDE4B) is a member of the phosphodiesterase family of proteins that plays a critical role in regulating intracellular levels of cyclic adenosine monophosphate (cAMP) by controlling its rate of degradation. It has been demonstrated that this isoform is involved in the orchestra of events which includes inflammation, schizophrenia, cancers, chronic obstructive pulmonary disease, contractility of the myocardium, and psoriatic arthritis. Phosphodiesterase 4B has constituted an interesting target for drug development. In recent years, a number of PDE4B inhibitors have been developed for their use as therapeutic agents. In this review, an up-to-date status of the inhibitors investigated for the inhibition of PDE4B has been given so that this rich source of structural information of presently known PDE4B inhibitors could be helpful in generating a selective and potent inhibitor of PDE4B.

The binding modes of well known MurD inhibitors have been studied using molecular docking and molecular dynamics (MD) simulations. The docking results of inhibitors 1-30 revealed similar mode of interaction with Escherichia coli-MurD. Further, residues Thr36, Arg37, His183, Lys319, Lys348, Thr321, Ser415 and Phe422 are found to be important for inhibitors and E. coli-MurD interactions. Our docking procedure precisely predicted crystallographic bound inhibitor 7 as evident from root mean square deviation (0.96 A). In addition inhibitors 2 and 3 have been successfully cross-docked within the MurD active site, which was pre-organized for the inhibitor 7. Induced fit best docked poses of 2, 3, 7 and 15/2Y1O complexes were subjected to 10 ns MD simulations to determine the stability of the predicted binding conformations. Induce fit derived docked complexes were found to be in a state of near equilibrium as evident by the low root mean square deviations between the starting complex structure and the energy minimized final average MD complex structures. The results of molecular docking and MD simulations described in this study will be useful for the development of new MurD inhibitors with high potency.

2-Mercaptobenzothiazoles are an important class of bioactive and industrially important organic compounds. These compounds are reported for their antimicrobial and antifungal activities, and are subsequently highlighted as a potent mechanism-based inhibitor of several enzymes like acyl coenzyme A cholesterol acyltransferase, monoamine oxidase, heat shock protein 90, cathepsin D, and c-Jun N-terminal kinases. These derivatives are also known to possess antitubercular, anti-inflammatory, antitumor, amoebic, antiparkinsonian, anthelmintic, antihypertensive, antihyperlipidemic, antiulcer, chemoprotective, and selective CCR3 receptor antagonist activity. This present review article focuses on the pharmacological profile of 2-mercaptobenzothiazoles with their potential activities.

A number of substituted-a,β -unsaturated carbonyl compounds (1a-i) were prepared by Claisen-Schmidt condensation of substituted acetophenone with selected araldehydes, which on cycloaddition with thiourea furnished 4,6-disubstituted pyrimidine-2-thiols (2a-i). Reaction of (2a-i) with ethyl chloroacetate followed by condensation with hydrazine hydrate yielded 2-[(4,6-disubstituted pyrimidine-2-yl) thio] acetohydrazides (4a-c). Condensation of compounds (4a-c) with phenyl isothiocyanate gave 2-{[(4,6-disubstituted pyrimidine-2-yl) thio] acetyl}-N-phenylhydrazinecarbothioamides (5a-c) which on treatment with concentrated sulphuric acid afforded titled compounds 5-{(4,6-disubstituted pyrimidine-2-yl) thio] methyl}-N-phenyl-1,3,4-thiadiazole-2-amines (6a-c). These compounds have been characterized on the basis of elemental analysis, IR, 1 H NMR and MS. Compounds have been evaluated for their anticancer and antioxidant activities. Compounds 2b, 2c and 6b exhibited significant antitumor activity against human breast cancer MCF 7 cell line. However, moderate antioxidant activity was observed with compounds 2c, 2d, 2g and 6b.

The 3-amino-2-methylquinazoline/6-bromo-2-methylquinazoline-4(3H)-ones, 2a,b, on treatment with 2,3-indolinedione in the presence of traces of glacial acetic acid yielded 3-{(2'-oxo-1',2'-dihydroindole-3'-ylidene)amino} -2-methylquinazolin/6-bromo-2-methylquinazolin-4-(3H)-ones, 3a,b, which on condensation with various secondary amines and formaldehyde in ethanol afforded title compounds 3-{(1'-alkyl/arylaminomethyl-2'-oxo-1',2'-dihydroindole-3'-ylidene)amino} -2-methyl-6-quinazolin-4-(3H)-ones, 4a1-6 and 4b1-6. C, H, N analysis, infrared spectroscopy, ¹H NMR, and mass spectroscopy allowed the identification of the synthesized compounds, which were investigated for their antimicrobial, analgesic, anti-inflammatory and antihelmintic activities. The results of the biological activities revealed that the compounds 4a3, 4a4 and 4b6 exhibited significant analgesic and anti-inflammatory activities. Compounds 4b5 and 4b6 showed antihelmintic activity when tested against Pheretima posthuma. O tratamento de 3-amino-2-metilquinazolina/6-bromo-2-metilquinazolina-4(3H)-onas, 2a,b, com 2,3-indolinediona na presença de traços de ácido acético glacial forneceu 3-{(2'-oxo-1',2'-di-hidroindol-3'-ilideno)amino} -2-metilquinazolina/6-bromo-2-metilquinazolina-4-(3H)-onas, 3a,b, as quais foram condensadas com várias aminas secundárias e formaldeído em etanol para originar compostos do tipo 3-{(1'-alquil/arilaminometil-2'-oxo-1',2'-di-hidroindol-3'-ilideno)amino} -2-metil-6-quinazolin-4-(3H)-onas, 4a1-6 e 4b1-6.Os compostos sintetizados foram caracterizados por análise elementar, espectroscopia no infravermelho, RMN ¹H e espectrometria de massas. Adicionalmente, foram investigadas suas atividades antimicrobiana, analgésica, anti-inflamatória e anti-helmíntica. Os resultados das atividades biológicas revelaram que os compostos 4a3, 4a4 e 4b6 exibiram atividades analgésica e anti-inflamatória significativas. Os compostos 4b5 e 4b6 apresentaram atividade anti-helmíntica, quando testados frente a Pheretima posthuma.

In the present investigation a novel series of N-(phenyl) chalconyl anthranilic acids containing pyrazolines (4a–j), tetrahydropyrimidines (4k–o), tetrahydrothiopyrimidines (4p–t) and 2-phenylquinazolin-4(3H)-ones containing pyrazolines (8a–f), isoxazolines (8g–l), tetrahydropyrimidines (8m–r) and tetrahydrothiopyrimidines (8s–x) were synthesized and characterized by elemental analysis, FT-IR, 1H NMR and mass spectroscopy. The title compounds (4a–t) and (8a–x) were investigated for their analgesic, anti-inflammatory, antimicrobial and in vitro protein denaturation activities. Compounds 4j and 8x were identified as lead compounds with optimum analgesic, anti-inflammatory and antimicrobial activities.Keywords: Quinazolines, antimicrobial, analgesic, anti-inflammatory, protein denaturation

Phosphodiesterases 4 enzyme is an attractive target for the design of anti-inflammatory and bronchodilator agents. In the present study pharmacophore and atom based 3D-QSAR studies were carried out for pyrozolo[1,5-a]pyridine/4,4-dimethylpyrazolone analogues. A five point pharmacophore model was developed using 52 molecules having pIC50 values ranging from 9.959 to 3.939. The best predictive pharmacophoric hypothesis AHHRR.3 was characterized by survival score (2.944), cross validated (r(2) = 0.8147), regression coefficient (R(2) = 0.9545) and Fisher ratio (F =173) with 4 component PLS factor. Results explained that one hydrogen bond acceptor, two aromatic rings and two hydrophobic groups are crucial for the PDE4 inhibition. The docking studies of all selected inhibitors in the active site of PDE4 showed crucial hydrogen bond interactions with Asp392, Asn395 Tyr233, and Gln443 residues. The pharmacophoric features R15 and R16 exhibited π-π stacking with His234, Phe414, and Phe446 residues. The generated model was further validated by carrying out the decoy test. The binding free energies of these inhibitors in the catalytic domain of 1XMU were calculated by the molecular mechanics/generalized Born surface area VSGB 2.0 method. The results of molecular dynamics simulation confirmed the extra precision docking-predicted priority for binding sites, the accuracy of docking, and the reliability of active conformations. Pyrozolo[1,5-a]pyridine/4,4-dimethylpyrazolone analogues in this study showed lower binding affinity toward PDE3A in comparison to PDE4. Outcomes of the present study provide insight in designing novel molecules with better PDE4 inhibitory activity. Graphical Abstract Pyrozolo[1,5-a]pyridines/4,4-dimethylpyrazolones.

Several 2-mercaptobenzothiazole derivatives 5a-i containing 1,2,4-triazole moiety incorporating two additional substituents were synthesized. All the newly synthesized compounds were tested for in vitro activity against certain strains of bacteria such as Enterococcus faecalis, Bacillus coagulans, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. Compound 5a showed significant activity against the Gram-negative bacteria Escherichia coli. Compounds 5a-i were also screened for their antifungal activity against Candida albicans and compounds 5a, 5b, 5d and 5g displayed significant activity against this fungus. Some of these compounds were evaluated for their in vivo anti-inflammatory activity, acute toxicity and ulcerogenic actions. Tested compounds 5g and 5h showed significant anti-inflammatory activity and significant gastrointestinal protection compared to the standard drug diclofenac sodium. Molecular modeling studies of the synthesized compounds are presented.

In the present study, a series of benzothiazol derivatives 3a-l containing pyrazolo[3,4-d]pyrimidine moiety at the second position were synthesized and characterized by analytical and spectral data. The compounds were tested for their in vitro antimicrobial activity. Compounds 1-(1,3-benzothiazol-2- yl)-3-methyl-4-phenyl-1H-pyrazolo[3,4-d]pyrimidine (3a), 1- (1,3-benzothiazol-2-yl)-4-(4-chlorophenyl)-3-methyl-1H-pyrazolo[ 3,4-d]pyrimidine (3d) and 1-(1,3-benzothiazol-2-yl)- 3-methyl-4-substituted phenyl-1H-pyrazolo[3,4-d]pyrimidines (3h-j) showed significant inhibitory activity against P. aeruginosa whereas compounds 1-(1,3-benzothiazol-2-yl)-4- (2-chlorophenyl)-3-methyl-1H-pyrazolo[3,4-d]pyrimidine (3b), 2-[1-(1,3-benzothiazol-2-yl)-3-methyl-1H-pyrazolo[3,4-d]pyrimidin- 4-yl]phenol (3e), 1-(1,3-benzothiazol-2-yl)-4-(3,4-dimethoxyphenyl)- 3-methyl-1H-pyrazolo[3,4-d]pyrimidine (3h), 4-[1-(1,3-benzothiazol-2-yl)-3-methyl-1H-pyrazolo[3,4-d]pyri midin-4-yl]-N,N-dimethylaniline (3j) and 1-(1,3-benzothiazol- 2-yl)-3-methyl-4-[2-phenylvinyl]-1H-pyrazolo[3,4-d]pyrimidine (3k) were found to be active against C. albicans. Some of these synthesized compounds were evaluated for their in vivo acute toxicity, analgesic, anti-inflammatory, and ulcerogenic actions. The tested compound 4-[1-(1,3-benzothiazol- 2-yl)-3-methyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl]-N, N-dimethylaniline (3j) exhibited maximum analgesic and anti-inflammatory activities. Compounds 1-(1,3-benzothiazol- -2-yl)-3-methyl-4-(3-nitrophenyl)-1H-pyrazolo[3,4-d]pyrimidine (3i) and 3j showed a significant gastrointestinal protection compared to the standard drug diclofenac sodium.

university Department of Pharmaceutical Sciences, Department of Chemistry, Utkal University, Vanivihar, Bhubaneswar-751 005, Orissa, India E-mail : tutu_kh@yahoo.co.in Department of Pharmaceutical Chemistry, J.S.S., College of Pharmacy, Ootacamund-643 001, Tamilnadu, India Manuscript received 10 February 2009, revised 14 December 2009, accepted 29 December 2009 A new simple, sensitive, highly specific and economical UV spectrophotometric method has been developed for determination of cefepime hydrochloride in pure and pharmaceutical (parentral form) formulation using different solvents, 0.001 N HCI and phosphate buffer (pH 6.8), Cefepime hydrochloride exhibited maximum absorbance (λmax)at 261.6 nm and 258.4 nm for 0.001 N HCI and phosphate buffer (pH 6.8), respectively. Beer's law is obeyed over a concentration range of 5-60 µg/ml with correlation coefficient r > 0.998. The proposed method Is validated statistically for both the solvents. Recovery study confirmed the accuracy of the proposed method.

University Department of Pharmaceutical Sciences, Utkal University, Vanivihar, Bhubaneswar-751 005, Orissa, India E-mail : tutu_kh@yahoo.com Department of Pharmaceutical Chemistry, J. S. S., College of Pharmacy, Ootacamund-643 001, Tamilnadu, India Manuscript received 18 September 2007, revised 30 September 2008, accepted 12 November 2008 A new simple, precise, sensitive, highly specific and economical ultraviolet spectrophotometric method for the determination of celecoxib in bulk and its pharmaceutical formulation (dispersible tablets and capsules) has been developed. The absorbance maxima of celecoxib in a mixture of methanol and 0.01 N sodium hydroxide (1 : 1 v/v) were determined at 253.1 nm. Beer's law is obeyed over concentration range of 8-22 µg/ml with correlation coefficient r > 0.999. The results have been validated statistically and by recovery studies.

University Department of Pharmaceutical Sciences, Utkal University, Vani Vihar, Bhubaneswar-75 I 005, Orissa, India E-mail: tutu_kh@yahoo.com Department of Pharmaceutical Chemistry, 1. S. S. College of Pharmacy, Ootacamund-643 00 I, Tamilnadu, India Department of Chemistry, Berhampur University, Berhampur-760 00 I, Orissa, India Manuscript received 4 May 2006, revised 24 May 2007, accepted 20 July 2007 3-Phthalimidomethylbcnzoic acids 2 were prepared by treating N-hydroxymethylphthalimidc 1 with substituted benzoic acids. The corresponding acid chlorides 3were condensed with 4-aminoal·etophenone in the presence of anhydrous potassium carbonate to give 3-phthalimidomcthyl-4-acctyl substituted benzanilidcs 4. The substituted benzanilidc derivatives 4 were condensed with diverse aromatic aldehydes to afford the compounds 5. Compounds 5a1-d7 on treatment with hydroxylamine hydrochloride in the presence of sodium acetate and with hydrazine dihydrochloridc in the presence of sodium acetate afforded the title compounds 6a1-d7and 7a1-a9, respectively. Compounds 6a1-d1 and 7a1-a3 were screened for their antibacterial and antifungal activities and 6a1 and 7a1 for anthelmintic and hypoglycemic activitis. &nbsp

Starting chloropropane derivative (2) was prepared by the reaction of 2-methyl-8-hydroxyquinoline (1) with 1- bromo-3-chloropropane in presence of a base. Various new 1-(2-methyl-8-quinolyloxy)-3-propylamines (3a-3j) have been synthesized by the condensation of 1-(2-methyl-8-quinolyloxy)-3-chloropropane (2) with different amines. Compounds were screened for the possible central nervous system depressant activities. Some of them showed moderate central nervous system depressant activity.

Substituted aryl-N-chalconyl aminophenols 1a-f were synthesized by base catalysed condensation of equimolar mixture of N-(4-hydroxyphenyl)-acetamide and appropriate araldehydes. Treatment of compounds 1a-f with hydroxylamine hydrochloride in ethanol afforded a series of novel 4-(5′-substituted-aryl-4′,5′-dihydro-isoxazole-3′-yl-amino) phenols have been synthesized by treating substituted aryl-N-chalconyl aminophenol with hydroxylamine hydrochloride. Structures of newly synthesized compounds 2a-f were confirmed by IR, 1 H-NMR and elemental analysis data. The synthesized compounds were investigated for their analgesic and antimicrobial activities. Compounds 2e and 2f exhibited significant analgesic activity in comparison to the reference drug paracetamol. In in vitro anti-microbial screening, compounds 2c and 2f showed higher antibacterial and antifungal activity in comparison to the reference standard ciprofloxacin and clotrimazole, respectively. Compound 2f bearing 4-Cl phenyl substitution at 5 position of Ioxazoline ring was found to be the most potent compound of the series. Key words : Isoxazole, Analgesic, Antibacterial activity. doi: 10.3329/dujps.v7i2.2165 Dhaka Univ. J. Pharm. Sci. 7 (2): 113-118, 2008 (December)