1. The molecule possesses a nitrogen atom capable of bearing a positive charge, preferably a quaternary ammonium salt 2. For maximum potency, the size of the alkyl groups substituted on the nitrogen should not exceed the size of methyl group 3. The molecule should have an oxygen atom preferably an ester-like oxygen, capable of participating in a hydrogen bond 4. There should be a two-carbon unit between the oxygen atom and the nitrogen atom Acyloxy group Quaternary ammonium o H3co+cH2—cH2N(cH3)c Ethylene group• 1. The molecule possesses a nitrogen atom capable of bearing a positive charge, preferably a quaternary ammonium salt. • 2. For maximum potency, the size of the alkyl groups substituted on the nitrogen should not exceed the size of methyl group. • 3. The molecule should have an oxygen atom, preferably an ester-like oxygen, capable of participating in a hydrogen bond. • 4. There should be a two-carbon unit between the oxygen atom and the nitrogen atom