Theoretical Study of the Spectroscopic Properties of a Series of Makaluvamines in the Ultra-Violet Visible Range Using DFT (B3LYP) and TD-DFT Methods

This work was carried out with the aim of contributing to the treatment of cancer. Cancer is one of the most common causes of death. It constitutes a public health problem. Photodynamic therapy (PDT) is one treatment option. This study contributes to the search for photosensitizing molecules used in PDT. Makaluvamines have shown interesting properties in the treatment of several human cancer cell lines. The present study analyzes the ultraviolet and visible absorption spectroscopic properties of a few Makaluvamines. These have been listed in the literature and can be in neutral or charged states (protonated and methylated). The investigation is based on quantum chemical calculations. Molecular geometries and vibrational frequencies have been calculated at the B3LYP/6-311++G(d,p) level. Absorption properties in the visible and ultraviolet spectral range are measured on optimized structures using time-dependent density functional theory (TD-DFT). The absorption spectra are obtained using the “Chemissian” software. The results of our calculations have allowed us to determine the absorption zones of the molecules studied, the energy gaps of the frontier orbitals, the main transitions associated with the absorption process, and their lifetimes. They have also identified four Makaluvamines (E, G, M, and L) that absorb in the therapeutic domain and may have photosensitizer properties.