Participation of the β-hydroxyketone part for potent cytotoxicity of callystatin A, a spongean polyketide Original Research Article

The participation of the β-hydroxyketone part of callystatin A in the potent cytotoxicity was analyzed through the analogue-syntheses and the assessment of their biological potencies. The ketonic carbonyl, the 19-hydroxyl, and the three asymmetric methyl groups located in the β-hydroxyketone part of callystatin A were revealed to contribute to the cytotoxic potency, respectively. Moreover, the α,β-unsaturated δ-lactone portion was shown to serve as a conclusive functional group for the cytotoxic activity.