Isodiplamine, cystodytin K and lissoclinidine: novel bioactive alkaloids from the New Zealand ascidian Lissoclinum notti

A study of the bioactive crude extract of the New Zealand ascidian Lissoclinum notti led to the isolation of the new pyridoacridine alkaloids isodiplamine (4), cystodytin K (5) and lissoclinidine (6), as well as the known pyridoacridine alkaloids diplamine (7) and cystodytin J (8) and the benzopentathiepin varacin (3) and related trithiane varacin A. The new alkaloids were characterised using standard spectroscopic techniques, including 2D 1H–15N NMR experiments. Pyridoacridine alkaloids 4–8 were assayed for a range of biological activities including antitumour and antibiotic properties. [Copyright &y& Elsevier]