CTSB and neoplasm: The surugamides and their derivatives have been shown to possess a number of bioactivities, with the surugamides A–E and the surugamides G–J being shown to possess anticancer activity by inhibiting bovine cathepsin B, a cysteine protease reported to be involved in the invasion of metastatic tumour cells [14,16]; while another derivative, namely acyl-surugamide A, has been shown to possess anti-fungal activity [16].