Isolation and structure of convolutamydines B ∼ D from marine bryozoan Amathia convoluta

Abstract Convolutamydines B ∼ D (2 ∼ 4), three new alkaloids containing a dibromohydroxyoxindole moiety, were isolated from the Floridian bryozoan Amathia convoluta and the structures were elucidated on the basis of spectroscopic data. Convolutamydine B (2) has been found to exhibit a biological activity in the differention of HL-60 cells.