Prepatellamide A, a new cyclic peptide from the ascidian Lissoclinum patella

A new cyclic peptide, prepatellamide A (1), along with three known cyclic peptides (2)(4), was isolated from the ascidian Lissoclinum patella. The structure of prepatellamide A was determined from one- and two-dimensional H-1 and C-13 NMR spectra. The known cyclic peptides were identified as patellamides A (2), B (3) and C (4).