Two novel pyrroloquinoline ribosides, N-1-b-D-ribofuranosyldamirone C (1), and N-1-b-D-ribofuranosylmakaluvamine I (2) were isolated from a new species of South African latrunculid sponge, Strongylodesma aliwaliensis. Standard spectroscopic techniques were used to determine the structures of 1 and 2. Molecular modeling studies and NOESY data of 1 and 2, in combination with chiral GC analysis of their derivatized acid hydrolysis products, established the b-D-configuration of the ribofuranose moieties.