Cytotoxic Compounds from Alcyoniidae: An Overview of the Last 30 Years

The octocoral family Alcyoniidae represents a rich source of bioactive substances with intriguing and unique structural features. This review aims to provide an updated overview of the compounds isolated from Alcyoniidae and displaying potential cytotoxic activity. In order to allow a better comparison among the bioactive compounds, we focused on molecules evaluated in vitro by using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide (MTT) assay, by far the most widely used method to analyze cell proliferation and viability. Specifically, we surveyed the  last  thirty  years  of  research,  finding  153  papers  reporting  on  344  compounds  with  proven  cytotoxicity. The data were organized in tables to provide a ranking of the most active compounds, to be exploited for the selection of the most promising candidates for further screening and pre‐clinical evaluation as anti‐cancer agents. Specifically, we found that (22S,24S)‐24‐methyl‐22,25‐epoxyfurost‐5‐ene‐3β,20β‐diol (16), 3β,11‐dihydroxy‐24‐methylene‐9,11‐secocholestan‐5‐en‐9‐one (23),  (24S)‐ergostane‐3β,5α,6β,25  tetraol  (146),  sinulerectadione  (227),  sinulerectol  C  (229),  and  cladieunicellin I (277) exhibited stronger cytotoxicity than their respective positive control and that their mechanism of action has not yet been further investigated