Axinelloside A was isolated from the lipophilic extract of the Japanease marine sponge Axinella infundibula as a strong human telomerase inhibitor (IC50 2.0 mu g/mL). It has the molecular weight of 4780.4 as the monoisotopic mass of the 19 sodium salt. The chemical structure was elucidated mainly by spectroscopic methods (2D NIVIR and IVIS). Axinelloside A consists of twelve sugars, e.g., a scyllo-inositol, a D-arabinose, 5 D-galactoses, and 5 L-fucoses, together with an (R)-3-hydroxy-octadecanoic acid, 3 (E)2-hexadecenoic acids, and 19 sulfates.