Dilemmaones A-C, unusual indole alkaloids from a mixed collection of south african sponges

Three indole alkaloids, dilemmaones A-C (1-3), were isolated from a mixture of sponges that was collected near Cape Town, South Africa. The structures of dilemmaones A-C (1-3) were elucidated by interpretation of spectroscopic data. The dilemma caused by faulty differentiation of similar specimens in the field is discussed in detail.