Manda Sarangapani

AlCl3/PCC-SiO2-Promoted Oxidation of Azaindoles and Indoles

Abstract A simple and efficient method is described for the oxidation of 7-azaindoles and indoles to 7-azaisatins and isatins using pyridinium chlorochromate–silica gel (PCC-SiO2) with the aid of Lewis acid catalyst aluminium chloride (AlCl3) in dichloroethane. Simplicity of the reaction conditions, easy workup procedure, and good yields are the key features of this protocol. GRAPHICAL ABSTRACT

Synthesis and antidepressant activity of di substituted-5-aryl-1,2,4-triazoles

A series of 5-aryl-1H-1,2,4-triazole-3-thiol (3) were synthesized. Alkylation of thiol group with N,N-dimethyl/diethyl/dicyclo hexyl-(2-chloro ethyl) amine gave compounds N,N-disubstituted-2-(5-aryl-1H-1,2,4-triazol-3-ylthio)ethanamine (4). These compounds were characterized on the basis of IR, 1H NMR, Mass spectral data, and elemental analysis. The newly synthesized compounds were screened for their antidepressant activity by using tail suspension test in mice.

Synthesis, characterization, and antimicrobial and antioxidant activities of novel bis-isatin carbohydrazone derivatives

In the present study, the synthesis of new bis-isatin carbohydrazone derivatives and their antimicrobial and antioxidant activities were investigated. The structures of new compounds were elucidated by Fourier transform infrared, 1H nuclear magnetic resonance and mass spectra. The antimicrobial activity of the compounds was determined by using the two-fold serial dilution technique against various bacterial and fungal species in comparison to standard drugs. All synthesized compounds displayed a broad spectrum of activities with minimum inhibitory concentration values ranging from 6.25 to 100 μg/ml against tested microorganisms. The in vitro antioxidant activity was evaluated using 1,1-diphenyl-2-picryl-hydrazyl and hydrogen peroxide (H2O2), and the total antioxidant capacity by a phosphomolybdenum assay and their ability to chelate ferrous iron. In general, the derivatives were found to exhibit antioxidant activity. Further, the compounds with electron-withdrawing groups at the C5 position demonstrated significant antimicrobial and antioxidant activities.

A facile route for the synthesis 1,4-disubstituted tetrazolone derivatives and evaluation of their antimicrobial activity

A facile route for the synthesis of 20 new 1,4-disubstituted tetrazolone derivatives from allyl bromides of Baylis–Hillman adducts and various 1-substituted tetrazolones is described. All the synthesized compounds were screened for in vitro antibacterial and antifungal activity. Out of 20 newly synthesized compounds 16 compounds showed very good activity against the Gram-positive bacteria Bacillus subtilis compare to the standard drug ciprofloxacin. The compounds 7b, 7n and 7o showed remarkable activity against both the Gram-positive bacteria B. subtilis and Staphylococcus aureus. Two compounds 7l and 7o showed very good activity against the Gram-negative bacteria Escherichia coli. The compounds, when tested for antifungal activity four compounds— 7b, 7l, 7o and 7s— showed very good activity against the strain Aspergillus niger, whereas seven compounds— 7e, 7g, 7h, 7l, 7o and 7s— display good activity against Candida albicans. Compounds 7b, 7e, 7g, 7l and 7o exhibited very good-to-high activity towards all the strains tested.

In vitro antioxidant and antibacterial activities of certain 3-{4-(5-mercapto-1,3,4-oxadiazole-2-yl)phenylimino}-indolin-2-one derivatives

A new series of 5- or 7-substituted 3-{4-(5-mercapto-1,3,4-oxadiazol-2-yl)phenylimino}-indolin-2-one derivatives were screened for in vitro antioxidant and antimicrobial activities. The results of this study revealed that all synthesized compounds were significantly scavenged DPPH free radicals in a concentration-dependant manner. The IC50 values of all test compounds were found to be between 18.34 and 50.54 µM. All compounds significantly inhibited growth of bacteria and most of the minimum inhibitory concentration values were between 20 and 100 mg mL−1 indicating potent to moderate antibacterial activity. In conclusion, 3-{4-(5-mercapto-1,3,4-oxadiazole-2-yl)phenylimino)-5 or 7-substituted indolin-2-ones derivatives exhibited moderate antioxidant and antimicrobial activities.

Synthesis and Screening of Biologically Significant 5-Hydroxy Isatin Derivatives for Antioxidant Activity

In the present work, some new 5-Hydroxyindole 3-thiosemicarbazone 2-ones and 5-[2(3)-dialkylaminoalkoxy] Indole 3-hydrazone 2-ones were prepared from 5-hydroxy isatin. The structures of the products were characterized by IR, NMR, and MASS Spectral studies. All the compounds were examined for antioxidant activity by using 1,1-diphenyl-2-picryl-hydrazyl and hydrogen peroxide (H2O2), and the total antioxidant capacity by a phosphomolybdenum assay. In general, the derivatives were found to exhibit antioxidant activity. Further, the compounds with dialkyl amino alkoxy at the C5 position demonstrated significant antioxidant activity.

Cardioprotective effect of N-(benzo[d]oxazol-2-yl)-2-(5-bromo-2-oxoindolin-3-ylidene)hydrazinecarboxamide against doxorubicin induced cardiotoxicity in rats

The present study was aimed to evaluate the cardioprotective activity of N-(benzo[d]oxazol-2-yl)-2-(5-bromo-2-oxoindolin-3-ylidene)hydrazinecarboxamide (coded as ARL) in rats. Doxorubicin (DOX) (15 mg kg−1, i.p, single dose) was used to induce cardiotoxicity in rats. Four groups of female Wistar albino rats were used. Group 1 was used as control (0.5% CMC, oral); the other groups were treated with DOX (single i.p. dosage of 15 mg kg−1) or DOX plus compound ARL (50 or 100 mg kg−1 day−1, p.o.), respectively. Animals were treated with ARL or CMC for 7 days. On 6th day, a single dose of DOX was administered to rats. Blood was collected on 7th day. Evaluation of cardioprotective activity was estimated using biochemical parameters including plasma aspartate aminotransferase, creatine kinase (CK-MB), lactate dehydrogenase (LDH), and triglycerides (TG) levels. Pretreatment with compound ARL significantly reduced the elevated levels of cardiotoxic biomarkers in plasma. DOX-induced depletion of glutathione levels in blood was significantly alleviated by pretreatment with compound ARL.

Synthesis and antiepileptic activity of schiff's bases of dialkylamino alkoxy isatin derivatives.

In the present work, some new 5-[2(3)-dialkylamino alkoxy] Indole 3-thiosemicarbazone 2-ones and 5-[2(3)-dialkylamino alkoxy] Indole 3-hydrazone 2-one were prepared from 5-hydroxy isatin. The structures of the products were characterized by IR, NMR, and MASS Spectral studies. All the compounds were examined for antiepileptic activity by maximal electroshock seizure (MES) and pentylenetetrazole (PTZ) induced convulsion method. These compounds were also evaluated for their neurotoxicity study by rotarod method. Some of these compounds showed good antiepileptic activity when compared with standard drug Phenytoin and all the compounds showed less neurotoxicity when compared with standard drug Diazepam.