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A novel silica supported palladium catalyst has been prepared and investigated for the Suzuki cross-coupling reaction between aryl bromides and benzeneboronic acid in the presence of K 2 CO 3 as base and o-xylene as solvent. The key features of the catalyst include rapid reactions with 100% conversion of aryl bromides, excellent catalyst recyclability and total stability under the reaction conditions (passes hot filtration test successfully). No change in the catalyst structure has been observed on the basis of surface analysis and simultaneous thermal analysis even after the 7 th use. The catalyst can be used for consecutive Suzuki reactions in a single step and hence successfully applied to the synthesis of polyaryls.

The MAR indexes of hospital isolates of Pseudomonas aeruginosa were determined with reference to nine different cephalosporins. The values for all the strains were higher than 0·2 suggesting their origin from a high risk source of contamination where antibiotics are often used. Emergence of MAR pathogenic strains of Ps. aeruginosa indicated possible nosocomial infection in the hospital environment. β‐Lactamases produced by these organisms were tested and their inhibition by clavulanic acid was studied. β‐Lactamase produced by one of these strains (Ps‐1) could not be inhibited by clavulanic acid whereas β‐lactamases of three other strains (Ps‐2, Ps‐3 and Ps‐4) could be inhibited by clavulanic acid in the presence of cephalosporins, suggesting a possible use of clavulanic acid in combination with cephalosporins, to combat β‐lactamase induced resistance in Ps. aeruginosa.