Kottamides A−D:  Novel Bioactive Imidazolone-Containing Alkaloids from the New Zealand Ascidian Pycnoclavella kottae

Kottamides A−D (14), novel 2,2,5-trisubstituted imidazolone-containing alkaloids, were isolated from the New Zealand endemic ascidian Pycnoclavella kottae and structurally characterized using 15N natural abundance 2-D NMR in addition to standard spectroscopic methods. The kottamides exhibited anti-inflammatory and anti-metabolic activity as well as cytotoxicity toward tumor cell lines.