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Coumarins are the family of benzopyrones, in which benzene ring amalgamated with the pyrone ring. Their versatile oxygen-containing heterocyclic structure and physicochemical characteristics are responsible to attract great attention from medicinal chemists and pharmacologists and for being a privileged scaffold in medicinal chemistry. In this study, 1, 3, 4 -oxadiazole incorporated a series of new coumarin derivatives have been synthesized. Structures of the newly synthesized compounds were established on the basis of FT-IR, 1H NMR spectroscopic techniques and elemental analysis. The synthesized compounds were screened for their in vitro antifungal activity against five pathogenic fungal strains: Aspergillus niger, Penicillium notatum, Saccharomyces cerevisiae, Penicillium chrysogenum and Neurospora crassa by disk-diffusion method. All the compounds were found to have significant antifungal activity against all the fungal strains.

To establish a comparative account within the taxa by assessing its anti-oxidative property and mapping it with the morphometric characters. The methanolic leaf extracts of 12 Cassia L. species were screened for their antioxidant activity using 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging assay and reducing power capability with reference to standard Ascorbic acid. Chamaecrista kleinii exhibited strong antioxidant activity with IC50 2.17 µg mL-1, followed with Senna auriculata (IC50 11.51 µg mL-1) and Senna polyphylla (15.17 µg mL-1). Highest reducing ability was observed in Senna auriculata extract with 0.676 nm absorbance. The correlation observed between the reducing power and DPPH radical scavenging assay supports the contribution of the phytoconstitutents like phenolics and flavonoids towards managing oxidative stress. The present study reveals the beneficiary effects of the selected plants by virtue of their antioxidant activity that can be harnessed in drug formulations. Keywords: Antioxidant, 1, 1-diphenyl-2-picryl hydrazyl, reducing power, Cassia.

Synthesis of certain new fused 1,4-diazepine derivatives, namely, cyclopentathienodiazepinones and their benzothieno analogues IV to produce new compounds of possible CNS depressant activity. Eleven compounds IV 1, 5, 6, 7, 12, 13, 15, 19, 20, 21 & 26 were selected and submitted to pharmacological evaluation for anxiolytic and tranquilizing activity in the open field test.

A series of substituted 1, 2, 4-triazole derivatives have been synthesized, using chloroform mediated phenylimino dichloromethane. It was added to a chloroform suspension of N'-(arylidene) ethanehydrazonohydrazide and the mixture was refluxed over water bath for 3 hours. The evolution of hydrogen chloride gas was noticed. The structures of synthesized compounds are confirmed on spectral analysis like IR; 1H NMR and 13C NMR data. All newly synthesized compounds were screened for their antimicrobial activity towards Gram-positive and Gram-negative bacterial strains and antifungal activity including  B. subtilis, E. coli, S. aureus, S. ablong, Candida and A. niger. Results showed that most of compounds have measurable antibacterial and antifungal activity.

In the undertaken research, 5-(5-H/Br benzofuran-2-yl)-N'-((-2-(p-tolyloxy) substituted quinolin-3-yl)methylene)-1-phenyl-1H-pyrazole-3-carbohydrazide (3a-h)  on treatment with acetic anhydride afforded novel 1-(5-(5-(5-H/Br benzofuran-2-yl)-1-phenyl-1H-pyrazol-3-yl)-2-(-2-(p-tolyloxy)substitutedquinolin-3-yl)-1,3,4-oxadiazol-3(2H)-yl)ethanone derivatives (4a-h). 5-fused heteryl pyrazole-3-carbohydrazone (3a-h) needed  for the synthesis of  4a-h were synthesized by reaction of 2-(p-tolyloxy) substituted quinoline-3-carbaldehyde (2a-h) with 5-(5-H/Br benzofuran-2-yl)-1-phenyl-1H-pyrazole-3-carbohydrazides (1a-b) in ethanol as solvent. The structures of the newly synthesized compounds were identified on the basis of elemental analysis and spectral studies like IR, 1H NMR and Mass spectra. The in-vitro antibacterial screening of these synthesized compounds against E. coli, S. aureus, E. areogenes and B. thurengienesis relative to the reference standard Chloramphenicol have been found to possesses good to moderate inhibitory activity.

The present communication deals with the synthesis of some N´-alkylidene/arylidene-2-(4-substituted-5-phenyl-1,3,4-oxadiazol-2-ylthio) aceto/arylhydrazides, their characterization and antimicrobial activity against medically important microbes. The final compounds were synthesized by reaction of 2-(4-substituted-5-phenyl-1,3,4-oxadiazol-2-ylthio) acetohydrazide with various aliphatic and aromatic aldehydes in presence of glacial acetic acid in ethanol. The structures of the synthesized compounds were established by IR, NMR and Mass spectral studies. The antimicrobial activity was studied against Staphylococcus aureus (MTCC 87), Bacillus subtilis (MTCC 121), Pseudomonas aeruginosa (MTCC 424), Escherichia coli (MTCC 40), Candida albicans (MTCC 183), Fusarium solani (MTCC 2935) using agar well diffusion method. Some of the tested compounds exhibited activity against all the microorganisms.  In particular, compounds 12, 19 and 22 were found to be active against all the tested bacterial strains and fungal strain Candida albicans. It was concluded that number and position of electron withdrawing substituents affects the activity.

A simple and efficient protocol for the synthesis of 1,4-dihydropyridines has been developed. In this one-pot multicomponent condensation methodology, all the reactants aldehydes, β-ketoester, ammonium acetate and catalyst were subjected to react at acetonitrile reflux to afford the corresponding products in very good yields. In all reactions, the catalyst Zn(OTf)2 was used in catalytic amount only and all the products were characterized by their spectroscopy analysis.  

Simple, sensitive and specific spectrophotometric method was developed and validated for quantification of nebivolol (NBV) in tablet dosage form. Studies were carried out to investigate the reaction between NBV and 1, 2-naphthoquinone-4-sulphonate (NQS) reagent. In alkaline medium (pH 9), a red-colored product exhibiting maximum absorption peak (λmax) at 521 nm was produced. The stoichiometry of the reaction was investigated and the reaction mechanism was postulated. Under the optimized reaction conditions, Beer's law correlating the absorbance with NBV concentration was obeyed in the range of 2 - 55μg/ml with good correlation coefficient 0.9996. The molar absorptivity was 0.124 × 104l/mol.cm. The limits of detection and quantification were 0.539 and 1.634μg/ml, respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 2%. No interference was observed from the excipients that are present in the tablets. The proposed method was applied successfully for the determination of NBV in its pharmaceutical tablets with good accuracy and precisions. The results were compared favorably with those of a reference pre-validated method. The method is practical and valuable in terms of its routine application in quality control laboratories.

A series of 1-(2, 6-difluorobenzyl)-1H-1, 2, 3-triazole (5a-d and 7a-d) were synthesized and evaluated for CNS depressant  and anticonvulsant activities by photoactometer, rotarod and pentylene tetrazole induced convulsion method respectively in Swiss albino mice. Diazepam was used as a standard drug. Out of the 8 compounds tested, compounds (5b, 7a and 7b) were showed the CNS depressant activity comparable to that of diazepam at a dose of 5 mg/kg. The active members of the series (5b, 7a and 7b) were selected for anticonvulsant activity study.

Angiotensin I-converting enzyme (ACE) is a key therapeutic target for combating hypertension and related cardiovascular diseases. ACE inhibitory novel designed substituted 1, 4-benzothiazine derivatives offer the prospect of enhanced potency, high specificity, and no or low side effect. Novel 1,4-benzothiazine derivatives were designed keeping in view the structural requirement of pharmacophore and Quantitatively structure Activity Relationship (QSAR).In the docking study, the most active compounds of the series were, AR 1, AR 2 and AR 3 exhibited good binding properties. Result reveals that the protein-ligand interaction energy of derivatives AR 1, AR 2 and AR 3 were -7.51 kcal/mol, -8.80 kcal/mol and -7.63 kcal/mol, which is slightly greater than the marketed antihypertensive Losartan drug as -5.51 kcal/mol, so that the derivatives have satisfactory affinity with established hypertensive receptor namely Angiotensin converted enzyme II. A computational study was also carried out including prediction of pharmacokinetic properties, toxicity and bioactivity studies. The percentage of absorption (%ABS) was calculated and observed that all titled compounds exhibited a better %ABS %ABS ranging 90.54, 91.42 and 90.55 respectively and compared than standard Losartan drug as %ABS 77.06.Although other pharmacological parameters were better than the standard drug. The above observation suggested that these compounds would serve as better lead compound for antihypertensive screening for future drug design perspective.