Computational study on the Metabolism of Antibacterial Prontisil (PROTO1) and Salfalazine(SASP4)

The ab- initio / HF of(6-31) ( the basic sets parameters that make the molecule more stable) according to (Gaussian) program and density functional theory of polarization) and PM3 semiempericalmethod,showed that the net charge distributions for 4-aminobenzene sulfonamide (sulfanilamide)(SAM2) and Sulfa pyridine( SP) (the active drugs) were less than those of prodrugsProntisil (PROTO1) and Salfalazine (SASP4) which indicated the stabilities and easy of formation (or liberation) of these active drugs. In addition to that, the stabilities of these liberated drugs also proved by the steric energies which were less than those of the pro-drugs. The energy gaps between the HOMO and LUMO of the active drugs liberated in vivo( by metabolism) were very small which agreed with the previous two observations.