This thesis discusses the activity of febrifugine and febrifugine's 3-D similar structural compounds to prostate cancer cell lines. Cancer is one of the most common diseases in the world. With the development of medicine, various diseases can be cured, but cancer is still difficult to cure completely. One of the most common issues of anti-cancer treatment is multidrug resistance. To defend against this, a different approach is important such as alkaloid. The pipeline is one of the alkaloids, that came from natural products and is used as an anti-cancer treatment. As febrifugine is also alkaloid, came from hydrangea, and is potentially toxic in high doses, it is important to understand the dose-response effect on its own. Column chromatography and NMR are used to extract febrifugine from hydrangea. The result of Dragendorff was positive, which indicates that there were alkaloid compounds in the separated compounds. However, febrifugine was not isolated from hydrangea. Febrifugine's 3-D similar structural compounds are chosen by using Pubchem, SwissADME, and Toxnet. There were more than 200 similar compounds and three filters (lipophilicity, lead likeness, and drug-likeness) are used to choose the final three compounds. As a result, halofuginone, 3-[(2S)-2,5-dihydroxy-2-methylpentyl]-8-methoxyquinazolin-4-one, and 2-(2,4-dioxo-1,4-dihydroquinazolin-3(2H)-yl)-N-(1-hydroxy-3-phenylpropan-2-yl) acetamide were selected. Two cell lines are used in this study which are WPMY-1 (healthy prostate cell line) and PC-3 (prostate cancer cell line). Current prostate cancer treatment drugs are used as control which are doxorubicin and docetaxel. Resazurin assay is used to measure of cytotoxicity of tested compounds. Overall, all the compounds have activity on both cell lines, especially, febrifugine and halofuginone had strong activity compared to the other two compounds. In addition, febrifugine and halofuginone have similar dose-response curves to doxorubicin. As cancer still remains a predominant cause of morbidity and mortality, studying cancer treatment is important. This study examined the anti-cancer activity of febrifugine and its 3-D structural compounds. Unfortunately, these compounds did not exhibit selective toxicity on prostate cancer cell lines. However, it is plausible that the compounds may have selective toxicity in different cancer cell lines, warranting further comprehensive to elucidate the characteristics of the compounds. Furthermore, febrifugine, sourced from a flower, has applications as an anti-malaria drug. There are many natural compounds worldwide and many of them have not been fully investigated. Researching natural compounds has a significant role in drug development as many drugs are derived from natural products.