Quantum chemical calculations using density functional theory and 6-311G (d) basis set have been applied to analyze the interactions of β -lactam compounds and the electronic structural properties including thermochemical parameters have been investigated. The present investigation is extended to calculate the HOMO?LUMO energy gap. The calculated HOMO?LUMO energy gap shows that the charge transfer occurs within the molecule. The frontier orbital and molecular electrostatic potential surface studies have been employed to understand the active structur. The results presented in this article will be helpful to improve existing model and will open up a whole new arena of study to understand the antimicrobial characteristic from natural products against the photosensitizing DNA damage induce by 6-aminopenicillanic acid extracts and enable amuch clearer understanding of how antimicrobial drugs mediate their effects on the specific spot.
HOMO, LUMO, DFT, 6-Aminopenicillanic acid