“…The thiosemicarbazone compounds used in clinical research include acetamidobenzaldehyde semicarbazide ( 1 ), N-methylisatin thiosemicarbazone ( 2 ), 5-hydroxy-2-methylcarbamate acylpyridine thiosemicarbazide ( 3 ), 3-aminopyridine-2-carbaldehyde thiosemicarbazide ( 4 ), COTI-2 ( 5 ), bis-2-pyridyl ketone 4-cyclohexyl-4-methyl-3-thiosemicarbazide ( 6 ) ( Scheme 1 ) ( Summers, 2019a ; Matesanz et al, 2021a ; Scarim and Chin, 2022a ). Triapine is the most prevalent anti-cancer agent and has been included in over 20 clinical trials for treating multiple cancers, including pancreatic cancer, non-small cell lung cancer (NSCLC), leukaemia and myeloproliferative diseases ( Scarim and Chin, 2022a ). However, some tumour types respond poorly to Triapine, developing serious side effects, such as hyperhemoglobinemia ( Yu et al, 2006 ; Yu et al, 2009 ).…”