Fractionation of the stem bark of Enantia chlorantha Oliv yields three alkaloids Palmatine (1), Jatrorrhizine (2), Columbamine (3), and β-Sitosterol (4). In this investigation, density functional theory (DFT) calculations were carried out to evaluate the electronic structure and properties of 1-4 by DFT-B3LYP/6-31G level of theory using Gaussian 09 software. Quantum molecular descriptors of the title compounds: ionization potential (IP) and Electron Affinities (EA), Hardness (η), Softness (S), Electronegativity (μ), Electrophilic Index (ω), Electron Donating Power (ω-), Electron Accepting Power (ω+) and Energy Gap (Eg) have been calculated. The in vitro cytotoxicity of the compounds was investigated against MCF-7, HCT116 cancer cell lines using Wi-38 cells as control. The compounds inhibited the proliferation of the MCF-7 and HCT116 cell lines and induced apoptosis via up-regulation of caspase-3, Bax, PARP cleavage, and downregulation of Bcl-2. DFT analyses revealed that compounds 1 and 3 have smaller energy gaps, 0.072 and 0.071eV, respectively, with the highest dipole moments, hence, more chemically reactive and exhibited better modulation of caspase-3 enzyme and inhibitory activities of the MCF-3 and HCT116 cell lines. The antimicrobial and antiparasitic evaluation of 1 - 4 showed moderate efficacy against the bacterial strains and moderate antiparasitic activity against Cichlidogyrus tilapia.