G. Pavithra

Synthesis of coumarin appended pyrazolyl-1,3,4-oxadiazoles and pyrazolyl-1,3,4-thiadiazoles: Evaluation of their in vitro antimicrobial and antioxidant activities and molecular docking studies

A series of semicarbazones, thiocarbazones, 1,3,4-oxadiazoles, and 1,3,4-thiadiazoles bearing coumarin and pyrazole moiety have been synthesized. The new synthesized compounds were screened in vitro for their antimicrobial and antioxidant activities. Preliminary studies showed that among the synthesized new compounds, chloro-substituted thiosemicarbazone showed excellent activities against all tested organisms; at the same time, methyl substituted thiosemicarbazone showed greater activity against E. coli. Chloro-substituted 1,3,4-oxadiazole and 1,3,4-thiadiazole demonstrated greater DPPH and hydroxyl radical scavenging abilities. Molecular docking studies indicate that 1,3,4-oxadiazoles and 1,3,4-thiadiazoles manifest better interaction with CAT (catalase) and GPx (glutathione peroxidase) than that with SOD (superoxide dismutase). Studies on the antimicrobial and antioxidant activities of the synthesized compounds compared with those of their starting compounds are discussed.

Evaluation of new tetra substituted pyrazolines for their antimicrobial and antioxidant activity; Structure-activity relationship

A series of synthesized new 8-(5-aryl-4-octyl-2-phenyl-3,4-dihydro-2H-pyrazol-3-yl)-octanoic acid ethyl esters 1 were evaluated in vitro for their antibacterial and antifungal activity against different organisms. The compounds were tested for their antioxidant activity and their reducing power ability. The structure-activity relationship of the compounds was described. I. Introduction The five membered heterocycles pyrazoles and their derivatives have flourished with considerable intensity because of their synthetic and biological applications. The literature review shows that pyrazoles have known to exhibit enormous biological activity such as antibacterial, antifungal, anti-inflammatory, anticonvulsant, hypoglycemic and anticancer activities. The pyrazoles possess antipyretic, antitumour, tranquilizing and herbicidal activities. Pyrazole derivatives are reported to exhibit antioxidant (1) and antimicrobial (2-4). A series of 3-substituted-5-hydroxy-5-trifluoro(chloro)methyl-1H-isonicotinoyl-4,5- dihydropyrazoles were synthesized and their in vitro antimicrobial activity was tested against INH susceptible mycobacterium tuberculosis H37Rv (5). Human body requires tats to function properly. Fatty acids serve as the components of more complex membrane lipids and as major components of stored fat in the body. Chemically, fatty acids and their esters are used in the synthesis of much class of compounds. 4,4-Dimethyl-2-oxazolines of fatty acids are useful derivatives for mass spectrometric analysis. The utility of these adducts for structural investigations of natural and artificial fatty acids is now well established (6). Recently Rai et al (7) reported the synthesis of 5-methyl-2- (5-methyl-1,3-diphenyl-1H-pyrazole-4-carbonyl)2,4-dihydro-pyrazol-3-ones and their antimicrobial and antioxidant activity. They also demonstrated the synthesis and antimicrobial activity of bis-heterocycles bearing pyrazoline and imidazole moieties (8). Pyrazolines obtained by the reaction of 4-acetyl thioanisole with aryl aldehydes through α,β-unsaturated ketones found to exhibit analgesic and anti-inflammatory activities (9). In view of the varied biological potency associated with pyrazole and their derivatives, a series of synthesized new tetra substituted pyrazolines (10) were considered for studying their biological activities. II. Materials And Methods The chemicals/reagents used were purchased from sigma-aldrich chemicals (India) and Merck Chemicals (India). In view of the biological potency associated with pyrazole derivatives, in the present investigation; the synthesized new 8-(5-aryl-4-octyl-2-phenyl-3,4-dihydro-2H-pyrazol-3-yl)-octanoic acid ethyl esters 1 (10) were considered for studying their antifungal, antibacterial, antioxidant activities and their reducing power ability.

Crystal structure of 3-(thio­phen-2-yl)-5-p-tolyl-4,5-di­hydro-1H-pyrazole-1-carbo­thio­amide

In the title compound, the central pyrazole ring adopts a twisted conformation on the –CH—CH2– bond and its mean plane makes dihedral angles of 7.19 (12) and 71.13 (11)° with the attached thiophene and toluene rings, respectively. In the crystal, molecules are linked by N—H⋯S hydrogen bonds, forming chains propagating along [010].