Synthesis and cytotoxicity evaluation of some novel chromone annulated phosphorus heterocycles

Novel chromono[2,3-e][1,2,4,3]triazaphosphepines 3−7, chromono[2,3-d][1,3,2]diazaphosphinine 8, chro-monyl α-hydrazinophosphonic acid 10, chromono[3,2-d][1,2]azaphosphole 11 and diethyl N-chromony-lphosphonoacetamide 12 were synthesized from treatment of 2-amino-3-[(2-phenylhydrazinylidene)methyl]chromone (2) with some phosphorus reagents such as phosphorus halides, phosphorus sulfides, and phosphonic acid and its diesters, in dry dioxane. The cytotoxic effects of the synthesized compounds were evaluated in vitro in relation to hepatocellular Hep-G2, breast MCF-7 and colon HCT-116 human cancer cell lines, using a crystal violet viability assay. Compounds 6, 7, 8, and 10 had significant cytotoxic effects against the three cancer cell lines. Their IC₅₀ values ranged between 1.56 and 12.4 µg/mL in comparison to doxorubicin (IC₅₀ = 0.426-0.469 µg/mL).