Prakash Kumar

This research has focused on the incorporation of the thiadiazole moiety into versatile pyridine ring because of their biological properties. In order to explore the possibilities of some altered biological action author envisaged that by designing the Schiff base derivatives of 1, 3, 4-thiadiazole moiety may exhibit anticancer properties. These novel 1,3,4-thiadiazole Schiff base compounds have been synthesized by microwave-assisted synthesis and screened for their cytotoxicity on HeLa, HepG2 and MCF7 cancer cell lines.The key intermediate 2-(4-fluorophenyl)pyridine-3-carboxylic acid was obtained by hydrolysing the ester 3 in presence of KOH and methanol.Thus obtained compound 4 was treated with thiosemicarbazide and phosphorous oxychloride and cyclized in microwave inorder to get the intermediate 5-[2-(4-fluorophenyl) pyridin-3-yl]-1, 3, 4-thiadiazol-2-amine. The amine 5 was reacted with different aldehydes (a-h) in presence of catalytic amount of acetic acid and obtaineda series of novel Schiff base derivatives 6a-6h. These compounds were characterized by MS, 1H-NMR,IR and elemental analysis. Most of the compounds in this series have exhibited moderate cytotoxicity onall the three human cell lines at different concentrations, but two compounds 6f and 6h showed good inhibition towards liver carcinoma cell lines having IC50 of 23.8µMand 13.4µM respectively.

Extended spectrum -lactamases are plasmid mediated. These plasmids produce enzymes that hydrolyze broad spectrum cephalosporins and monobactams. They acquire resistance prevalently through plasmid encoded. Study determines plasmids and their correlation with drug resistance against many antibiotics that limits their therapeutic implications. Bacteriological analysis of 50 samples susceptible for ESBL was conducted. The samples subjected to susceptibility tests and detection of ESBL. Plasmid DNA isolation of all the ESBL positive strains of E. coli was done by alkali-lysis method. Finally the presence of plasmid was correlated with susceptibility to beta lactam drugs. ESBL was detected in 56% (28 out of 50 isolates). Maximum ESBL incidence recorded of E. coli (30 %) followed by Klebseilla pnemoniae (18%) and Pseudomonas aeruginosa (8 %). ESBL exhibited high-level resistance to beta lactam antimicrobial agents like  Amoxiclave (56%), Cefuroxime (54%), Cephotaxime (54%), Ceftriaxon (50%), Ceftazidime (46%) and Cefixime (36%). During plasmid profiling of eight isolates of ESBL E. coli showed one to four definite bands indicating the presence of different plasmids. ESBL’s constitute a growing class of plasmid-mediated -lactamases which confer resistance to broad spectrum β-lactam antibiotics. Incidence of ESBL is continuously increasing globally with limited treatment alternatives and formulates treatment policy. Moreover, restricted use of the third generation cephalosporins lead to withdrawal of selective pressure and use of lactam and -lactamase inhibitor combinations may exert reverse mutation on these enzymes. There is a strong correlation between the number of plasmids harbored by an isolate and drug resistance.