Botryllamides K and L, new tyrosine derivatives from the Australian ascidian Aplidium altarium

Chemical investigation of the Australian ascidian Aplidium altarium led to the isolation of two new tyrosine derivatives, botryllamides K (1) and L (2), together with six known metabolites, botryllamides A–C (3–5), botryllamide G (6) and perspicamides A (7) and B (8). The structures of these compounds were elucidated by spectroscopic analysis. This is the first reported chemistry from this species. Compounds 1–8 were evaluated for their cytotoxicity towards the tumour cell lines, MCF-7 (breast), H460 (lung) and SF268 (central nervous system).