This study revealed that the Papaver lacerum extract strongly inhibited HeLa cell proliferation, resulting in 13% cell viability. As a result of phytochemical studies, one known compound, Tyrosol-1-O-beta-xylopyranosyl-(1 -> 6)-O-beta-glucopyranoside) (I), and one new compound, 5-O-(6-O-alpha-rhamnopyronosyl-beta-glucopyronosyl) mevalonic acid (II), were isolated. Compounds I and II were found to possess a moderate cytotoxic effect with an IC50 of 66.4 mu M (p < 0.0001) and 54 mu M (p < 0.0001), respectively. The ligand-based virtual screening technique was used to reveal the possible molecular target of compounds I and II. The molecular target was identified as protein-tyrosine kinase Syk for compound I, and aldo-keto reductase family-1 for compound II. Molecular docking was used to assess the binding affinity of the compounds with the targets obtained from ligand-based virtual screening.