Erylusamines A-E (1-5) have been isolated from the marine sponge Eryfus placenta, as IL-6 receptor antagonists. Their gross structures were assigned by interpretation of 2D NMR and FABMS data as tetrasaccharides of long-chain dihydroxyketo-fatty acid amides formed with N,Wdimethyl- 1,5-pentanediamine. Stereochemistry of 2 was established by spectroscopic and chemical methods.