Computational Study of an Antimalarial Quinone Methide Pentacyclic Triterpenoid Derivative Isolated from Salacia leptoclada Tul (Celastraceae)Author(s): Issofa Patouossa, Gloria Kabuo Sifa, Jason Thambwe Kilembe, Bienfait Kabuyaya Isamura, Koto-te-Nyiwa Ngbolua, Virima Mudogo, Jules Tshishimbi Muya
DFT calculations and polarizable continuum model are employed to elucidate the structure and reactivity of a naturally occurring quinone methide pentacyclic triterpenoid derivative isolated from Salacia Leptoclada Tul (Celastraceae). Our computational results reveal that the lowest stereoisomer is more stabilized in less polar solvents. The interaction energies between the stereoisomer with water and adenine at B97D3/6-31++G(d,p) amount to -9 kcal/mol and -17 kcal/mol. Furthermore, theoretical spectra of the lowest stereoisomer are first reported for experimental characterization. Molecular docking calculations indicate that the molecule binds in the groove of double-helical DNAs to guanosine and adenosine bases owing to hydrogen interaction.