Kittappa M. Mahadevan

Antioxidant, cytotoxic and genotoxic evaluation of alcoholic extract of Polyalthia cerasoides (Roxb.) Bedd.

Antioxidative potential of alcohol extract of Polyalthia cerasoides was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical, superoxide anion scavenging, and reducing power assays were performed. The extract showed significant reactive oxygen species (ROS) scavenging activity in all in vitro antioxidant assays and contained high level of total phenolic content. For in vivo genotoxic evaluation, Swiss albino mice were treated with alcohol extract at the concentration of 40mg/kg body weight. Frequency of aberration was compared with control. Both the sets did not showed genotoxic effect. Further the extract was subjected to cytotoxic study using 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphynyl tetrazolium bromide (MTT) assay, the extract confirmed to show moderate cytotoxicity against L929 cell line.

Synthesis and DNA cleavage studies of novel quinoline oxime esters

New 2-chloro-3-formyl quinoline oxime esters were synthesized by the reaction of 2-chloro-3-formyl quinoline oximes with various benzoyl chlorides in the presence of triethyl amine and dichloromethane at 0°C. The DNA photo cleavage studies of some new oxime esters were investigated by neutral agarose gel electrophoresis at different concentrations (40μM and 80μM). Analysis of the cleavage products in agarose gel indicated that few of quinoline oxime esters (3d-i) converted into supercoiled pUC19 plasmid DNA to its nicked or linear form.

An efficient microwave-assisted synthesis of thieno[2,3- b ]quinolines under solvent-free conditions

A novel and efficient method for the synthesis of substituted thieno[2,3-b]quinolines has been developed. A simple one-pot reaction of 3-formyl-2-mercaptoquinolines 2a–l with 1-chloroacetone, 2-chloroacetamide, ethyl chloroacetate and 2-chloro-1-phenylethanone in presence of catalytic amount of potassium carbonate under microwave irradiation and solvent-free conditions gave thieno[2,3-b]quinolin-2-ylethanone derivatives 3a–e, thieno[2,3-b]quinoline-2-carboxamide derivatives 4a–e, ethyl thieno[2,3-b]quinoline-2-carboxylate 5a–e and phenyl(thieno[2,3-b]quinolin-2-yl)methanone derivatives 6a–e compounds respectively. The structures of all the newly synthesised compounds were elucidated on the basis of elemental analysis, IR, 1H NMR and mass spectral data.

Antiproliferative, apoptotic and antimutagenic activity of isolated compounds from Polyalthia cerasoides seeds.

Phytochemical investigation of the petroleum ether extract fraction of Polyalthia cerasoides seeds led to the isolation of two phytosterols (alpha-spinasterol and spinasterol) and a clerodane di-terpenoid. The structures of these compounds were elucidated using IR, (1)H-NMR, (13)C-NMR and Mass spectral analysis. Further, these compounds were tested for antiproliferative action against CACO-2 cell line and apoptotic action was determined by nuclear staining and DNA fragmentation analysis. The results showed that the compounds exhibited antiproliferative action at various concentrations with an IC(50) value of 28.6+/-4.34nM/ml, 57.7+/-6.81nM/ml and 60.0+/-7.10nM/ml for clerodane diterpenoid, spinasterol and alpha-Spinasterol respectively. Furthermore, the isolated compounds were screened for antimutagenic effect against methylmethane sulfonate (MMS) induced mutation. Phytosterols showed protective effect, whereas clerodane diterpenoid was less effective to MMS induced chromosomal aberrations. Our research contributes to the characterization of phytochemical constituents and to understand the ability of these compounds to antiproliferative and antimutagenic responses from the seed extracts.

Efficient Synthesis of 2-Ethoxycarbonyl Indoles

Abstract An efficient one-pot procedure for the synthesis of 2-ethoxycarbonyl indoles from commercially available materials has been developed. The one-step procedure involves in situ formation of the hydrazones from phenylhydrazine hydrochloride and ethyl pyruvate in the presence of bismuth nitrate followed by Fischer cyclization in polyphosphoric acid and ethanol. This method is efficient and simple.

Synthesis of 1-(2-Methyl-1,2,3,4-tetrahydroquinolin-4-yl) pyrrolidin-2-ones from Anilines and N-Vinyl Pyrrolidin-2-one Through Imino Diels–Alder Reaction Using 4-Nitro Phthalic Acid as Catalyst

Abstract Aryl amines react smoothly and efficiently with N-vinyl pyrrolidin-2-one in the presence of 4-nitro phthalic acid in acetonitrile to afford the corresponding 1-(2-methyl-1,2,3,4-tetrahydroquinolin-4-yl)pyrrolidin-2-ones in good yields.

An Efficient Synthesis of 1,5-Thiadiazepines and 1,5-Benzodiazepines by Microwave-Assisted Heterocyclization

A novel and efficient method for the synthesis of substituted thiazepines and diazepines has been developed. A simple one-pot reaction of chalcones 1a–f with 1-amino-2-mercapto-5-phenyl-1,3,4-triazole and o-phenylenediamine in the presence of a catalytic amount of sodium acetate under microwave irradiation gave 2-(3,8-diphenyl-7,8-dihydro[1,2,4]triazolo[3,4-b][1,3,4]thiadiazepin-6-yl)phenoles 2a–f and 2-(2-phenyl-2,3-dihydro-1H-1,5-benzodiazepin-4-yl)phenoles 3a–f, respectively. The structure of all the synthesized compounds was elucidated on the basis of elemental analysis, IR, 1H and 13C NMR, and mass spectral data.

Microwave Assisted Synthesis of Some Novel Thiopyrano[2,3-b]quinolines as a New Class of Antimicrobial Agent

A series of novel substituted thiopyrano[2,3-b]quinolines 4a–e , 5a–e , and 6a–e were prepared from substituted 3-formyl-2-mercapto quinolines 2a–e , on reaction with ethyl acetoacetate, diethyl malonate, and ethyl cyanoacetate 3a–c by microwave irradiation in the presence of piperidine. Synthesized compounds were evaluated for antimicrobial activities. Among the compounds tested, 7-chloro-2-oxo-2H-thiopyrano[2,3-b]quinoline-3-carbonitrile 6d and 7-nitro-2-oxo-2H-thiopyrano[2,3-b]quinoline-3-carbonitrile 6e were highly active against S. aureus and M. roseus.

A Fast and Large-Scale Synthesis of 3-Formyl-2-mercaptoquinolines

A convenient, efficient, and inexpensive procedure for the synthesis of 3-formyl-2-mercaptoquinolines 2a–l has been developed by a simple one-pot reaction of 3-formyl-2-chloroquinolines 1a–l with sodium sulfide and hydrochloric acid in ethanol. The structures of all the synthesized compounds were elucidated on the basis of elemental analyses and IR, 1 H NMR, and mass spectral data.

Efficient InCl3/H2O-Catalyzed One-Pot Stereoselective Synthesis of cis-2-Methyl-4-amido-1,2,3,4-tetrahydroquinoline Derivatives

Abstract Various cis-2-methyl-4-amido-1,2,3,4-tetrahydroquinoline derivatives were synthesized efficiently by reacting aromatic amines and N-vinyl caprolactam or N-vinyl pyrrolidone in the presence of indium trichloride in an aqueous medium in good to excellent yields. These 2,4-disubstituted tetrahydrouinolines showed cis diastereoselectivity.