Growth inhibition of microorganisms have been screened for synthesised compounds of variable substitutions (R: electron withdrawing group and electron donating group) by zone of inhibition study on gram-positive and gram-negative microbes. Incubation for 6 hours the zone of electron donating groups becomes equal to the zone for electron withdrawing groups. The synthesized molecule has three units: Fused ring heterocyclic having three nitrogen + Fused ring nonheterocyclic + Fused ring heterocyclic having two nitrogen. All three units have fused pentacyclic ring in which nitrogen atom is bioisosteric with hydrocarbon which inhibits the bacterial growth from 500ìg/ml which is the MIC level. Experimental result for the individual unit: Benztriazole, Benzimidazole and Indanone acetic acid showed no inhibition for microbial growth but the combined units of these three by Schiff base with homologous ethylene chain showed a remarkable result in bacteriostatic action.