[GRAPHICS]
The novel alkaloids 1 and 4 were isolated from an Australian non-verongid s
ponge, Oceanapia sp, Compound 1 contains an unprecedented imidazolyl-quinol
inone substructure attached to a bromotyrosine-derived spiro isoxazoline. T
hree other known alkaloids were isolated in addition to 1 and 4 and togethe
r represent the first examples of inhibitors of a new mycobacterial enzyme
mycothiol S-conjugate amidase (MCA).