“…20 Owing to the signicant role of heterocyclic ring systems in drug discovery and development, many studies have been undertaken to develop biologically active heterocyclic compounds. [21][22][23][24][25][26][27][28][29] Podophyllotoxin, an important plant-derived natural product, has several semisynthetic derivatives such as etoposide, teniposide and etophos, which have been employed in chemotherapy for various cancer types. 30 Although podophyllotoxin and its derivatives have been known as tubulin polymerization or DNA topoisomerase II inhibitors, they are too toxic for therapeutic use and causes some side effects.…”